Ricochet

Summary

First major session on Ricochet — went from scratch to a playable bounce-and-shoot prototype with custom dot-halftone shader, dynamic resizable/rotating chamber, full combat loop, three-file split, and a private GitHub repo. Game was named "chamber" throughout the session and renamed to "Ricochet" at the end.

Visual design rules (design.md):

• Wrote a detailed Visual Design section based on five existing reference sheets (reference/01-05): overall direction (calm minimal abstract defense), neutral palette (paper #F6F4F0, ink #111111, charcoal #4A4A4A, light grey #DADADA), accent palette, typography (tall condensed sans + neutral sans/mono-like).
• User added typography specifics from sheet 03: primary "TALL CONDENSED SANS" for headings, secondary "NEUTRAL SANS / MONO-LIKE" for labels, with a 6-step size ladder (64/72 → 8/11).
• User refined hex values manually after my first-pass guesses.
• Later expanded with the dotted motif as a first-class visual language alongside line work, after user added new "(dotted)" reference sheet variants (01-06).
• Stroke weight hierarchy iterated multiple times: started as structure (2px) > actors (1.5px) > annotation (1px), eventually inverted to actors (1.5px / thin) being the loudest tier with structure also at hairline (1px), reasoning that the dot motif provides the visual mass once otherwise carried by chamber stroke.
• Mid grey #8A8A8A added later as a fifth neutral tier.

Phase 1 — scaffold + chamber:

• Set up main.lua with require('anchor')({width=1920, height=1080, scale=1, filter="smooth"}).
• Drew chamber as a square outline at screen center with charcoal corner brackets just outside each corner (CORNER_TICK_LEN=18, CORNER_TICK_GAP=10, 1px stroke).
• Sized at 240×240 (CHAMBER_HALF=120); user wanted slightly smaller after first version.

Phase 2 — ball physics:

• Added physics_init, registered tags 'ball'/'chamber', enabled collision pair.
• Built chamber as 4-wall static body with overlapping corners, restitution=1, friction=0 per shape.
• Ball: BALL_RADIUS=6, BALL_SPEED=800, dynamic circle, bullet=true for CCD, set_fixed_rotation.
• Per-frame velocity normalization to counter Box2D's energy bleed at restitution=1.
• Bounce angle jitter (±5° via BALL_BOUNCE_JITTER = math.pi/36) added so ball can't settle into repeating paths.
• Ball spring squash on wall hit (spring_pull(self.spring, 'hit', 0.3)).

Phase 3 — projectiles (heavy iteration):

• Sensor body, fires from wall-hit position, flies outward.
• Initial: 10×2 blue capsule at 850 px/sec. User: "shouldn't be blue, should be black, filled, like a v but more open and with shorter legs".
• Iterated to ink chevron: arms drawn with layer_line, opening angle 120° → 100° → 80° (math.rad(40) half-angle final).
• Stroke width: 2.5 → 3.5 → 1.5 → 2 → 2.5 across multiple iterations as user composed the visual.
• Speed reduced to 500 px/sec (user: projectiles "too fast" caused choppiness).
• Spawn position: initially at ball position, then offset by BALL_RADIUS + CORNER_TICK_GAP = 16 along wall normal (so the chevron emerges at the corner-tick ring distance regardless of bounce angle).
• Projectile angle rule (significant deliberation): initially math.angle_to_point(CHAMBER_X, CHAMBER_Y, ball.x, ball.y) (radial outward). User wanted midpoint of wall normal + ball's outgoing direction. First attempt averaged wall normal with post-bounce velocity → caused parallel-to-wall results because perpendicular hits gave (0,-1) + (0,1) = (0,0). Fixed by reflecting post-bounce velocity across wall normal first to recover pre-bounce (outward) direction, THEN averaging unit vectors via math.atan(sin(a)+sin(b), cos(a)+cos(b)).

Engine fix — render uncap + display selection:

• User reported choppiness when streaming Twitch on second monitor. Investigated anchor.c: physics steps at 120Hz, render is hard-capped at 60Hz with comment "for chunky pixel movement on high-refresh monitors".
• Found scripts/monitor_sim.c documenting the timing decision (Tyler Glaiel's "How to make your game run at 60fps"). The 60Hz cap is for pixel-art games; doesn't apply to smooth-filter games.
• Added engine flag render_uncapped (default false to preserve all existing pixel-art games), with engine_set_render_uncapped(bool) Lua binding. When true, render fires every main-loop iteration and vsync paces the rate.
• Added display init flag with engine_set_display(int) for opening on a specific monitor; clamps to display 0 if invalid.
• Bug fixed: display refresh rate query was hardcoded to SDL_GetCurrentDisplayMode(0, ...) regardless of which display the window opened on. Changed to SDL_GetWindowDisplayIndex(window) so vsync snap frequencies align with the actual monitor's refresh rate.
• Engine rebuilt; new anchor.exe and updated init.lua deployed to chamber project.

Phase 4 — enemies:

• Added 'enemy' physics tag with collision('enemy','chamber') and ('enemy','enemy').
• Initial: hollow ink circles with seek+separate steering toward chamber center.
• Speed 200-280 random, spawn rate 1/sec, ENEMY_STEER_FORCE=1200, damping 3.
• Originally bounced off chamber via push impulse; user changed to dying on chamber contact ("when they hit the box, they should be killed").
• Shape iteration: circle → diamond (4-vertex polygon, axis-aligned, no rotation since 4-fold symmetric) → directional arrowhead with notched base (4 vertices: tip, top-back, notch, bottom-back). User described shape as "a triangle but at the base it goes inside a little". Final: 24px length × 18px wide × 5px notch depth × 1.5px stroke.
• Re-enabled velocity-direction tracking for the directional arrowhead: self.r = math.lerp_angle_dt(0.99, 0.1, dt, self.r, math.atan(vy, vx)).
• Enemies spawn already facing the chamber to avoid first-frame snap.

Border zone + asymmetric layout:

• Originally 80px symmetric border on all sides for UI/cards.
• User changed to asymmetric: thick top/bottom (120/150px), no left/right border. Enemies spawn from left/right screen edges only.
• GAME_AREA_LEFT/RIGHT/TOP/BOTTOM constants; chamber center computed from gameplay-area center: (GAME_AREA_LEFT + GAME_AREA_RIGHT) / 2.
• draw_border_zone draws hairlines only at top and bottom (not a full rectangle).

Dot-grid reveal shader (major addition):

• Custom GLSL fragment shader loaded via shader_load_string with screen vertex shader.
• Architecture: dedicated mask_layer. Game code draws shapes (circles, polygons) into mask_layer; shader runs over it via layer_apply_shader(mask_layer, dot_shader) and outputs a dotted-grid pattern wherever mask alpha is non-zero.
• Shader logic: per-fragment, sample mask alpha; if > threshold, compute grid cell coords from frag_px / spacing, find dot center, distance to center, modulate dot radius via static value-noise.
• Final params: GRID_SPACING=5, GRID_BASE_RADIUS=1.2, GRID_NOISE_SCALE=0.05, GRID_NOISE_AMOUNT=0.7.
• Critical fix per user feedback ("rectangle in the middle is jarring with dot effect layered on top"): shader outputs mix(u_paper_color, u_dot_color, dot_alpha) in mask region (not transparent in gaps), with fragment alpha = mask_a. So fully opaque mask cleanly carves out a paper-and-dots patch over chamber lines; partially opaque blends.
• Static noise (no time uniform): same noise field every frame, but different per dot.

Hit FX redesign — dot motif as primary effect language:

• Replaced traditional particles entirely. User: "the way enemies spawn should be... they should fade into the world, modulated by the dot effect."
• hit_burst class: filled diamond (4 vertices: top/right/bottom/left), shrinks to 0 over duration, drawn into mask_layer.
• Initially circle, then changed to diamond after user request: "let's have the hit circle actually be a diamond, so a rotated square, to match the fact that enemies aren't circles."
• Three sizes: enemy death HIT_BURST_RADIUS=22 × 0.3s, ball wall hit BALL_HIT_BURST_RADIUS=14 × 0.18s, projectile death PROJECTILE_DEATH_BURST_RADIUS=14 × 0.18s.
• hit_line class (thick capsule line particles) was added then removed — user wanted ONLY hit_burst, no flying particles. Removed all HIT_LINE_* constants too.
• Enemy spawn fade-in: crossfade from dot silhouette to solid line over ENEMY_SPAWN_FADE_TIME=0.5. Mask alpha: lerp(t, 0.5, 0) (faint dot blob → 0). Solid alpha: t (0 → 1). User: "both should also be alpha'd so that their relative darkness is lower". Required shader change to multiply dot output by mask_a (not binary cutoff).
• Enemy death burst spawned at chamber wall contact point (ev.x, ev.y), not enemy center, for visual consistency with ball wall hits.

Combat loop — phase 5:

• Added physics_enable_sensor('projectile', 'enemy'). Sensor handler in main.lua: e:die(p.x, p.y); p:on_enemy_hit(e).
• Three modifier modes initially: homing, ricochet, spread. Each ball wall-hit randomly picked one via random_choice.
  • Homing: turns toward nearest enemy in HOMING_CONE_HALF=π/6 (60° total cone) at HOMING_TURN_RATE=8 rad/sec. pick_homing_target scans enemies. Used math.angle_to_point, angle_diff helper, math.sign(delta) * math.min(abs(delta), max_turn).
  • Ricochet (initially): on enemy kill, redirected to nearest un-hit enemy (1-5 redirects). Used hit_enemy_ids set on projectile.
  • Spread: 1-5 projectiles in a 60° fan, evenly distributed.
• User clarification: "For ricochet I meant against walls only, against enemies it would be called chain." Removed chain logic entirely (hit_enemy_ids, pick_ricochet_target). Reimplemented ricochet as wall bouncing: on border crossing, if ricochet_count > 0, reflect velocity off the crossed border, decrement count, emit small dot-burst.
• Eventually all projectiles got ricochet (user: "make ricochet for all of them, don't change inner workings").
• Final refactor — collapsed mode concept (user: "There should be no concept of a 'mode'. The projectile either has homing or ricochet, and both can happen at the same time"): removed self.mode, replaced with independent self.homing (bool, HOMING_CHANCE=0.5) and self.ricochet_count (int, random 1-MAX_RICOCHETS=5). Spread is purely caller-side (just spawn N projectiles instead of 1).

Projectile chamber ricochet:

• User: "Ricochet projectiles should also ricochet against the central chamber."
• First tried physics_enable_sensor('projectile', 'chamber'). Failed: Box2D 3 sensors don't have continuous collision detection (per types.h line 409: "Sensors do not have continuous collision"). Fast projectile (500 px/sec, ~4px per physics step) tunneled through 4px-thick chamber walls without firing sensor begin events.
• User asked: "Why not just make it physical collision versus projectiles?" — discussed extensively. Would require restructuring projectile↔enemy hit pipeline (sensor → collision events) and other changes. User then asked: "Can't we make the border zone a physical object? It should be one anyways, eventually I want to be able to both resize it and rotate it." Outlined full physics refactor.
• User redirected to simpler path: keep projectiles as sensor + manual checks. Implemented manual chamber-crossing check using was_inside_chamber state flag. Each frame: compute now_inside (axis-aligned point-in-bounds check); on false → true transition, call ricochet_chamber(). Track prev_x/prev_y to determine which axis was crossed, flip those velocity components.

File split:

• User asked: "do a general pass on the main.lua file and split it into relevant files."
• Split into 3 files:
  • main.lua (237 lines): config, palette, constants, physics setup, layers, camera, requires, entity collections, draw_border_zone helper, init, main loop.
  • entities.lua (411 lines): chamber, ball, projectile, hit_burst, enemy classes + spawn helpers + angle_diff helper.
  • dot_shader.lua (83 lines): GLSL source as Lua string + shader_load_string + immediate uniform setters.
• Order in main.lua: framework → palette → constants → physics → layers/camera → require('dot_shader') → collections → require('entities') → init → loop.
• Anchor 2 framework convention used: classes defined as globals, modules called for side effects.

Dynamic chamber (resize + rotate):

• User: "Eventually I'll want to both change the size of the chamber and rotate it. Can you support that feature now?"
• Restructured chamber class:
  • Added self.angle = 0 field.
  • Extracted chamber:_build_collider() for destroy+rebuild on resize.
  • Added methods: :resize(new_half), :set_angle(new_angle), :set_position(x, y).
  • Added helpers: :contains(px, py) (rotation-aware point-in-bounds), :wall_normal_for(px, py) (rotation-aware outward normal at a point).
  • Drawing uses layer_push(game_layer, self.x, self.y, self.angle, 1, 1) + local-coord drawing.
• All callers updated to use chamber instance methods instead of constants:
  • ball:on_wall_hit uses the_chamber:wall_normal_for.
  • projectile:update uses the_chamber:contains.
  • projectile:ricochet_chamber rotates prev position + velocity into chamber-local space, flips crossed components, rotates back.
  • enemy uses the_chamber.x/y for steering target.
• Continuous rotation: CHAMBER_ROTATION_RATE=0.3 rad/sec (positive = CCW math / CW screen). chamber:update advances angle.
• Resize keys: [ and ] bind to chamber_smaller/chamber_bigger. Step 15px, bounds 30 to 280.
• Bug fix — "Invalid body" error after multiple resizes: Error was physics.lua:31: Invalid body from body_to_entity calls inside collision_entities_begin('ball', 'chamber') after chamber:resize destroyed and rebuilt the body mid-update. The events from the physics step held references to the now-dead body. Fix: moved input-driven resize to the END of update(dt), after collision drains and process_destroy_queue, so this frame's events finish processing against the still-existing body before destruction.
• Defensive ball containment: ball:contain_in_chamber() runs every frame at end of ball:update. Clamps ball position to ±(half - radius - 1) in chamber-local space; if clamped, snaps position back via set_position and reflects outward velocity components. Catches resize-down, fast rotation, and CCD failures.

Final projectile shape iteration:

• User experimented with non-chevron shapes:
  • Filled rectangle (10×4)
  • Triangle (10×4 isoceles)
  • Equilateral triangle (PROJECTILE_SIZE=14, computed vertices using sqrt(3))
  • Reverted to chevron with 80° opening (40° half-angle), 2.5px stroke.

Game rename — chamber → Ricochet:

• User: "We need to rename this game. Chamber is very bad. I want an alien but cool name like Thalien Lune that matches the visuals of the game somewhat."
• First batch (alien names): Vellith Lune, Norien Aether, Caelin Halo, Sylven Glyph, Thavren Aria, Aerolith Veyl, Vellune, Aerolith, Carillun, Halicene.
• User: "How about more literal names like Slay the Spire or Mini Metro or Artifact and so on. It is a game about a ball bouncing inside a square, after all."
• Second batch (literal): Rebound, Ricochet, Trajectory, Square, Reverb, Hollow Square, Closed Loop, Inner Square, Tiny Chamber, Hold the Square, Defend the Box, Bounceback, Polyball, Bouncefield, Halftone, Schematic, Auto Bouncer, Square Defense, Wireframe, The Bounce.
• User picked Ricochet.
• Updated: window title (title = "Ricochet"), file headers in main.lua and entities.lua, design.md heading. Kept chamber class name and the_chamber global since they refer to the in-game object, not the project.

todo.md created:

• Listed for future sessions: fail state (chamber HP?), wave system, reset key, card/mana layer, HUD + typography phase, enemy families, pickups, FX polish, real MSAA, render interpolation between physics steps, pre-solve callback exposure.
• Included three suggested next-session groupings: (A) playable session loop, (B) HUD, (C) card layer.

Folder rename + private GitHub repo:

• User: "Rename the folder and create a private git repo for it."
• Folder rename via mv and PowerShell Move-Item blocked by file lock — likely the conversation's own filesystem handles. User performed the rename manually.
• Created .gitignore (OS junk + editor temp; engine binary + framework copy intentionally tracked).
• git init, switched to main branch, staged everything, made initial commit with detailed multi-paragraph message.
• gh repo create ricochet --private --source=. --remote=origin --push → github.com/a327ex/ricochet.
• run.bat updated chamber → ricochet references after folder rename.

Last session we started on a project named chamber at E:/a327ex/chamber, read the design.md document for a brief description. I additionally had ChatGPT generally the project's visual language, and those 5 images are present in reference/. Create a description of the game's visual design rules based on those images in the same design.md document, however be somewhat detailed, describing fonts, colors, general patterns, and so on. This doesn't need to be an extensive description, but it should be enough information that an instance can be guided on most decisions when we're actually drawing things in game without having to refer to the images all the time.

Opus 4.7

1    # chamber — design
2   
3   ## The game
4   
5   A square chamber sits at the center of the screen with a ball bouncing inside.
6   Every wall hit spawns a projectile that flies outward (radial from the chamber
7   center through the ball's position) and homes on the nearest enemy within a 60°
8   cone ahead of it. Enemies spawn from screen edges, seek the chamber, and
9   physically collide with the outer walls (pushed back on contact, Orblike-style).
10  Projectiles kill them.
11  
12  The chamber *is* the player — no separate avatar. The bounce-and-shoot engine
13  runs on autopilot. All active player agency lives one layer above it.
14  
15  ## Card / mana layer (Artifact-style)
16  
17  - **Deck drafting** before a run: build a deck from the available pool.
18  - **Each turn**: draw 2 cards, refresh a mana pool.
19  - **Spend mana** to play cards. Cards are the mod layer on top of the autopilot
20    engine: more mana, extra draw, add/modify a ball, change projectile behavior,
21    trigger burst attacks, buff/debuff, etc.
22  
23  Cards are the only active input during a run. Drafting + on-turn decisions are
24  where the game is actually played.
25  
26  ## v0 prototype
27  
28  Core loop is built and confirmed fun to watch (2026-04-23). Source archived at
29  `reference/main.lua`. A new instance will start a fresh main.lua using that as
30  a base.
... [12 more lines]

chamber\reference\main.lua
chamber\reference\01 - ART DIRECTION.png
chamber\reference\02 - GENERAL UI ELEMENTS .png
chamber\reference\03 - TYPOGRAPHY.png
chamber\reference\04 - COLOR.png
chamber\reference\05 - GAME OBJECTS.png

[
  {
    "type": "image",
    "note": "[image stored privately: vault/media/ricochet/001.png]"
  }
]

[
  {
    "type": "image",
    "note": "[image stored privately: vault/media/ricochet/002.png]"
  }
]

[
  {
    "type": "image",
    "note": "[image stored privately: vault/media/ricochet/003.png]"
  }
]

[
  {
    "type": "image",
    "note": "[image stored privately: vault/media/ricochet/004.png]"
  }
]

[
  {
    "type": "image",
    "note": "[image stored privately: vault/media/ricochet/005.png]"
  }
]

I have a good read on the five reference sheets. Now I'll append a detailed visual section to design.md.

The file E:\a327ex\chamber\design.md has been updated successfully. (file state is current in your context — no need to Read it back)

Added a detailed visual design section to design.md covering palette (with hex values), typography, line weights, composition, shape language, per-object rules (chamber/ball/projectiles/enemies/pickups/cards), UI element conventions, and motion — enough for in-game drawing decisions without re-opening the reference sheets.

A couple of honest caveats worth flagging:

• Hex values are my best-guess reads from the accent palette swatches, not sampled. The thumbnails I received are fairly small, so the exact warmth of the paper color and the saturation of the accents may drift from what ChatGPT actually produced. Worth sampling the real images with a color picker and correcting the six or seven hexes once you're actually implementing, rather than trusting me.
• Typography is described by analogue (Bebas/Oswald, Inter/IBM Plex) because I can't read the specific face names on sheet 03 at this resolution. If the reference specifies a particular font, override my suggestions.
• I opted for prescriptive rules (e.g. "~5% accent pixels", "2 px chamber stroke") rather than vague principles, because you said you wanted something that could guide decisions. If any of those numbers feel wrong against the images, they're easy knobs to turn.

The sheet names on sheet 03 say:

PRIMARY TYPE STYLE: TALL CONDENSED SANS, For major headings and high-impact information. SECONDARY TYPE STYLE: NEUTRAL SANS / MONO-LIKE, For labels UI text, stats, and supporting information

Sizes: DISPLAY, 64/72 SECTION TITLE 28/32, SUBHEADING 16/20, Body Note 12/18, Caption 10/14, UI Label 8/11.

MONO-LIKE for numbers/code

I also fixed the hex values for the colors in the file already.

The file E:\a327ex\chamber\design.md has been updated successfully. (file state is current in your context — no need to Read it back)

Updated the Typography section with the exact hierarchy from sheet 03: primary condensed sans for headings/high-impact, secondary neutral-sans/mono-like for labels-UI-stats, and the full six-step size ladder (64/72 → 8/11). Noted the mono-like variant is the go-to for numerals so timers and scoreboards don't jitter.

Let's get started on the actual project then. reference/main.lua contains a simple prototype we tried yesterday to verify the game is fun, it is so we'll build it, just using the current design rules instead of what it used. Try to match what's happening there. Our game will be using 'smooth' filter, default resolution of 1920x1080 (scaled down for smaller monitors using MSAA, I think the engine supports that, if it doesn't then we'll add it later). However, don't do it all at once, let's do it step by step, because I want to ensure that each element looks correct, since you said you couldn't see the images too well. Breakdown everything you'll have to do into phases, don't need to be super detailed or tell them to me, just make sure that at the end of each phase I can verify that a visual element looks and behaves as expected.

Before I plan phases, let me read the prototype and the relevant framework bits so the phases map to real work.

1    --[[
2     chamber — Anchor 2 physics-ball survivor prototype.
3   
4     A ball bounces inside a circular chamber; every wall-hit spawns a projectile
5     that briefly homes on the nearest enemy before switching to straight flight
6     (stops homing either when aligned within HOMING_ALIGN_RAD, or when
7     HOMING_DURATION elapses — whichever comes first). Enemies spawn at screen
8     edges and seek the chamber.
9   
10    Physics tags / collisions:
11      ball      ↔ chamber    bounce (only ball collides with wall; enemies pass through)
12      enemy     ↔ enemy      separation steering
13      projectile → enemy     sensor event (projectiles are sensors — pass through
14                             walls / ball, only detect enemies)
15  
16    Reset: R.
17  ]]
18  
19  require('anchor')({
20    width  = 480,
21    height = 270,
22    title  = "chamber",
23    scale  = 3,
24    filter = "rough",
25  })
26  
27  -- -----------------------------------------------------------------------------
28  -- palette + constants
29  -- -----------------------------------------------------------------------------
30  bg_color            = color(16, 16, 24)
... [530 more lines]

Read both. A heads-up before I list phases: the prototype uses the older procedural Anchor API (physics_init(), layer_new(), collider(self, tag, ...)) and the current framework is method-style on an (an:physics_init(), an:layer(), collider(tag, body_type, ...)). So this isn't a straight port — I'll rewrite against the current API as I go. Behavior stays identical; only the call sites change.

Also flagging two decisions that will come up early and I'd like your call on when they hit:

• Chamber size at 1920×1080. The prototype's 50×50 chamber on 480×270 is ~10% of screen width. Straight 4× scale = 200×200, but the design sheets suggest the chamber should feel more central and roomy — I'll probably want to re-proportion (maybe ~320–400 px). We can eyeball it in phase 1.
• MSAA support. I don't know off-hand whether Anchor's smooth filter already bundles MSAA or if it's linear-filter-only. I'll check when I get to scaffold; if it's missing we defer and flag it.

Phases

1. Scaffold + chamber — project boots at 1920×1080 with smooth filter, paper background, chamber square drawn centered with the medium ink stroke and optional corner ticks. Verify: resolution, colors, chamber framing all look right.

2. Ball — ball spawns in the chamber, bounces at constant speed, spring squash on wall-hit. Ink disc with optional dotted trail. Verify: physics feel identical to prototype, visual matches style.

3. Projectiles (no homing, no enemies) — wall-hits spawn radial-outward projectiles in accent blue. Verify: projectile shape, size, speed, color all read correctly.

4. Enemies — spawn from screen edges, seek chamber center, bounce off outer walls (push-back). Hollow ink shapes using the shape-family alphabet (circle / square / triangle). Verify: enemy look, motion, separation feel right.

5. Homing + combat — projectiles home on nearest enemy inside the 60° cone; sensor collisions damage/kill. Hit flash (stroke color swap to pink-red). Verify: combat feel matches the prototype.

6. Hit / death FX — redesign of hit_circle and hit_particle for the schematic aesthetic: expanding ring outlines + radiating short line-bursts instead of rounded rectangles. Verify: kill feedback feels punchy but quiet and on-style.

7. HUD — top-of-screen readouts using the real type hierarchy (condensed caps labels + mono-like numerals, small-caps micro-labels). Verify: typography reads correctly.

8. Reset + tuning pass — R to reset. Re-tune speeds, sizes, stroke weights now that everything's at 1920×1080 and the style is consistent. Verify: whole thing holds together.

Ready to start on phase 1 whenever you give the go-ahead.

I think you may be mistaken. The prototype uses Anchor2, and we'll use Anchor2 as well. Maybe your context files are pointing you to Anchor1 by mistake, but we have rewritten it anew. Your plan sounds good, let's get started if you have no more questions.

Good catch — let me find the Anchor2 API docs before starting.

app/
arena/
docs/
engine/
framework/
reference/
scripts/

ENGINE_API.md
ENGINE_API_QUICK.md
FRAMEWORK_API.md
FRAMEWORK_API_QUICK.md

1    # Framework API Quick Reference
2   
3   Function signatures for the Anchor 2 Lua framework. See `FRAMEWORK_API.md` for
4   detailed documentation with examples.
5   
6   **Architecture.** Anchor 2 is mostly procedural: most modules are plain functions that
7   take state as the first argument (e.g. `timer_update(self.timer, dt)`). The only
8   framework classes are `collider` (body+shape bundling and steering behaviors) and
9   thin wrappers around resource handles (`font`, `spritesheet`, `image`). Game
10  entities are your own classes created with `class()`.
11  
12  **No `an` god-object. No object tree. No action phases.** The game owns its
13  main loop; update and draw are top-level globals the engine calls directly.
14  
15  ---
16  
17  ## Initialization
18  
19  ```lua
20  require('anchor')({
21    width = 480,        -- game resolution width (default: 480)
22    height = 270,       -- game resolution height (default: 270)
23    title = "My Game",  -- window title (default: "Anchor")
24    scale = 3,          -- initial window scale (default: 3)
25    vsync = true,       -- vertical sync (default: true)
26    fullscreen = false, -- start fullscreen (default: false)
27    resizable = true,   -- window resizable (default: true)
28    filter = "rough",   -- "rough" or "smooth" (default: "rough")
29  })
30  ```
... [705 more lines]

You're right — my confusion came from the top-level CLAUDE.md pointing to Anchor/ (v1). The prototype is already in the current Anchor 2 API. Style carries over verbatim.

Quick check before I write phase 1: confirming how the engine handles scale for a 1920×1080 game and whether MSAA exists.

No files found

ARENA_PROGRESS.md
anchor/
anchor.exe*
assets/
main.lua
run.bat

Good — confirmed smooth filter is just GL_LINEAR sampling (no real MSAA). Lines at 1920×1080 native will rasterize crisply; if the window gets downscaled on smaller monitors, linear filtering will soften the shrink. We'll revisit real MSAA only if it ends up looking bad.

Let me check what's already in the chamber project folder vs what I need to set up.

total 4109
drwxr-xr-x 1 adn 197121       0 Apr 24 11:08 ./
drwxr-xr-x 1 adn 197121       0 Apr 23 23:25 ../
drwxr-xr-x 1 adn 197121       0 Apr 23 23:25 anchor/
-rwxr-xr-x 1 adn 197121 4177408 Apr 23 23:25 anchor.exe*
drwxr-xr-x 1 adn 197121       0 Apr 23 23:25 assets/
-rw-r--r-- 1 adn 197121    8849 Apr 24 11:08 design.md
drwxr-xr-x 1 adn 197121       0 Apr 24 10:02 reference/
-rw-r--r-- 1 adn 197121     141 Apr 23 23:29 run.bat

@echo off
REM Run chamber prototype. CWD must be repo root; engine receives the game folder name.

cd /d "%~dp0.."
"%~dp0anchor.exe" chamber
---
LanaPixel.ttf

Project folder's already scaffolded (anchor.exe, anchor/ framework, assets/, run.bat) — I just need to create main.lua. LanaPixel (the prototype's font) is a pixel font that'd clash with the new style; I won't load any fonts in phase 1 (no text yet) and we'll pick condensed/neutral sans fonts together when we reach phase 7.

Phase 1 — scaffold + chamber.

File created successfully at: E:\a327ex\chamber\main.lua (file state is current in your context — no need to Read it back)

Phase 1 done. When you run ./run.bat, you should see:

• A 1920×1080 window with a warm off-white paper background (#F6F4F0).
• A 320×320 chamber dead-center, drawn as a 2 px ink outline (#111111).
• Four charcoal-colored corner brackets (L-ticks) sitting 10 px outside the chamber corners, with 18 px arms and a 1 px stroke — schematic/blueprint flavor.
• Nothing else — no ball, no HUD, no motion.

Things to evaluate and call out:

1. Chamber size. 320×320 is ~30% of screen height — roomier than the prototype's ~19%. Too big, too small, about right?
2. Line weights. 2 px chamber stroke + 1 px corner ticks. At 1080p native these should read as "medium" and "thin" respectively; confirm they don't feel anemic on your monitor.
3. Corner tick styling. 18 px arms with a 10 px gap outside the chamber. Right proportions, or do you want them tighter/longer/closer/further?
4. Paper color warmth. #F6F4F0 is only lightly warm. Want it more cream, or pure whitish?
5. Window fit. If your monitor is 1920×1080, scale=1 will likely fill the screen and get cropped by window chrome. Tell me if it comes up off-screen or clipped and we'll pick a different default.

Once you've eyeballed those, say "good" or give tweaks and we'll move to phase 2 (ball).

Looks good. The box is a bit too big, should be smaller.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Shrunk to 240×240 (half = 120, ~22% of screen height — close to the prototype's ratio). The corner ticks keep their 10 px gap so they'll scale along with it visually.

Still too big, still too small, or about right? If fine-tuning, give me a rough direction (e.g. "a touch smaller still" or a specific number) and I'll dial in before we move to phase 2.

This is about right, you can move on.

Phase 2 — ball. Moving on.

A few sizing decisions I'm baking in (easy to tune after you see it):

• Ball radius: 7 px (14 px diameter). Design doc says "4–6 px" but that was written before we settled on 1920×1080; 14 px diameter reads as small-but-visible in a 240 px chamber without overpowering the 2 px chamber stroke.
• Ball speed: 800 px/sec. Scales the prototype's bounce cadence to the new chamber size (crosses the chamber in ~0.3 sec).
• Wall thickness: 4 px (physics only, not drawn). Thin, and bullet=true on the ball prevents tunneling.
• Dotted trail: skipping for now. Design says "optional"; easier to add later than to tear out if it looks busy.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now add physics walls to chamber and the ball class:

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now update the main loop to tick the ball and drain wall-hit events:

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Phase 2 done. When you run it you should see:

• Everything from phase 1, plus a small ink-colored ball bouncing inside the chamber at constant speed.
• A visible squash-and-recover pulse on every wall hit (spring pull = 0.3).
• No energy bleed — the ball never slows down.

Things to evaluate:

1. Ball size. 7 px radius / 14 px diameter. Too small, too big, about right?
2. Ball speed. 800 px/sec. Bounce cadence — right tempo, or too frantic / too lazy?
3. Squash strength. 0.3 pull. The squash should be subtle but noticeable on each hit. If it's too jarring or too invisible, we can dial it.
4. Chamber stroke vs ball. The ball is ink and the chamber is ink — do they compete visually, or does the hierarchy read fine because of size/shape?
5. No tunneling. Watch for a few seconds and make sure the ball never escapes through a corner.

Say "good" or give tweaks, and we'll move to phase 3 (projectiles flying outward on wall-hits, no homing/enemies yet).

Whenever the ball hits a wall its bounce angle should be randomized a bit so we don't have movement that's permanently the same. Let's try 6px ball radius too.

Two tweaks.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Changes:

• Ball radius → 6 px (12 px diameter).
• Bounce jitter: ±5° applied after each wall reflection. Small enough to still feel like a "real" bounce, large enough that any repeating orbit breaks within a couple of hits.

When you run it, watch for maybe 20 seconds and confirm the ball genuinely wanders rather than locking into a pattern. If ±5° feels too subtle (still finds near-loops) or too noisy (bounces look visibly "wrong"), tell me and I'll dial BALL_BOUNCE_JITTER.

OK, what's next?

Phase 3 — projectiles flying outward. No homing, no enemies yet — just confirm wall-hits spawn radial projectiles in the right direction with the right look.

Sizing decisions:

• Speed: 850 px/sec (slightly faster than the ball, matches the prototype's 190/180 ratio).
• Shape: 10×2 capsule in accent_blue, rotated along its travel direction. Reads as a small streak rather than a dot.
• Lifetime: 3 sec — long enough for projectiles to leave the screen, short enough that they don't accumulate.
• Sensor, so projectiles pass straight through the chamber wall on their way out.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now the ball spawns a projectile on hit, and the projectile class itself:

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Wire projectiles into update/draw:

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Phase 3 done. When you run it:

• Every wall-hit fires a small blue capsule projectile flying straight outward through the wall and off-screen.
• The projectile rotates to face its travel direction, briefly squashes on spawn (main spring pull = 0.5), then flies cleanly.
• Projectiles pass through the chamber walls and the ball (sensor body).
• They self-destruct after 3 seconds, so off-screen ones don't pile up.

Things to evaluate:

1. Color. #4A88FF accent blue against the paper background. Reads clearly without screaming, or too saturated/muddy?
2. Size. 10×2 capsule. Does it look like a "small" projectile relative to the 12 px ball, or too thin/too thick?
3. Speed. 850 px/sec. Feels right relative to ball, or want a bigger differential (slower = trails longer / faster = more punchy)?
4. Spawn position. Projectiles spawn at the ball's position when it hits the wall, then fly outward. Does the spawn point look correct (right at the wall, not inside the chamber)?
5. Capsule vs alternatives. Design also lists "disc, chevron, or short line segment". If the capsule streak doesn't feel right, we can try a small ink-outlined disc or a chevron arrow.

Say "good" or give tweaks, and we'll move to phase 4 (enemies).

These are too small and too fast, also they shouldn't be blue. Black, filled, and let's try them as an arrow of sorts, like a v but more open and with shorter legs. They're also too fast, but that's another problem. When objects are fast, the way they update can look quite choppy, we did quite a bit of work with the engine internals when making it to try to make sure that wouldn't happen, but it's still happening, so we either need a new solution or another solution on top, like say a shader that makes things look more blurry and thus smooth over time, but that's for after we fix the projectile.

Three changes for the projectile (color, shape, speed) and a quick note on the deeper choppiness problem at the end.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done. Summary of the projectile changes:

• Color: ink (#111111), not blue.
• Shape: open chevron — two 12 px arms angled 60° each side of centerline (120° opening), 2.5 px stroke. Total span ~21 px wide × 6 px deep, tip pointing along travel direction.
• Speed: 500 px/sec (was 850). Should feel much more readable.
• Collider: swapped to a small circle (radius 6) sensor — a box collider that matched the chevron bounding box would be 60% empty space.

Run it and see how the chevron reads. Likely tuning knobs: leg length, stroke thickness, opening angle, speed.

On the choppiness problem. Worth thinking through before we commit to a shader fix, because the right answer depends on what you're actually seeing:

1. Strobing / stuttering — the projectile looks sharp at each frame but seems to teleport between positions. Caused by frame-rate aliasing: at 60 fps, 500 px/sec = ~8 px between frames; at 800 px/sec it was ~13 px. Solutions:

   • Render-side interpolation between physics steps. If the engine fixed-steps physics at 1/120 and renders at the monitor refresh, interleaving with (1 - alpha)*prev + alpha*curr smooths jumps. Worth checking whether anchor.c already does this; if it doesn't, that's the most fundamental fix.
   • Slow the projectile (already partway there).

2. Choppy despite high frame rate — the projectile genuinely looks pixelated/jagged frame-to-frame. That's a rasterization issue, not a movement one. Less likely to be the case here.

3. Visual streaking that's missing — the eye expects fast objects to leave a motion-blur trail; without one they read as discontinuous. Solutions:

   • Multi-sample trail: render the chevron 2–4 times per frame at sub-step positions with falling alpha. Cheap, schematic-friendly, no shader needed.
   • Velocity-aligned blur shader: directional gaussian. More expensive, harder to keep on-style.
   • Persistence trail: draw a faint dotted streak from previous frame's position to current. Very on-style for our blueprint look.

My guess from the symptom you described ("choppy when fast"): it's #1 if the engine doesn't already interpolate between physics steps, or #3 if it does. Worth checking the engine before reaching for a shader. Want me to look into how Anchor 2 currently handles physics-vs-render timing before we commit to a solution?

Angle for projectiles is a bit too wide, I think they also should be a bit thicker.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Tightened opening to 100° (half-angle 50° from centerline), stroke up to 3.5 px. Should read as a more recognizable arrowhead now while staying open. Tell me if it wants another nudge in either direction.

OK, now the overall projectile should be a bit smaller. And then each projectile should spawn from a distance away from the edge of the box that's the same as the distance each of the corners is from the box.

Two tweaks. The spawn-offset is BALL_RADIUS + CORNER_TICK_GAP along the radial direction — that puts the projectile tip at the corner-bracket distance when the ball hits perpendicular (and approximately so for off-axis hits).

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done:

• Chevron size: legs 12 → 10. Total span ~13 px wide × 6 px deep, kept the 3.5 px stroke and 100° opening.
• Spawn offset: projectile now emerges at BALL_RADIUS + CORNER_TICK_GAP = 16 px outward from the ball — i.e. at the corner-bracket "ring" — instead of right at the wall. Visually they'll appear outside the chamber outline rather than overlapping it.

Tell me if the size is right and the spawn ring reads as intended.

[Pasted image/png]

It's possible the projectiles look a bit too thick when composing with the whole screen. The guidelines say something about this or not? We should decide on a rule I think that applies to most gameplay elements maybe?

You're right that the chevrons at 3.5 px now visually outweigh the 2 px chamber, which inverts the hierarchy — the moving thing should be subordinate to the container, not louder than it.

The existing design.md has stroke tiers but only addresses them by example (chamber → medium, ticks → hairline). It doesn't say where gameplay actors (projectiles, enemies) fit. So yes, we need to lock that rule down.

Proposed rule — three tiers, strict hierarchy:

• Annotation (1 px / hairline) — corner ticks, grid, leader lines. Reads as documentation around the game.
• Actors (1.5 px / thin) — projectile arms, enemy outlines, card borders, UI frames. Drawn-and-stroked things smaller than the chamber.
• Structure (2 px / medium) — chamber walls, major panel borders. The visual anchor; nothing in the world layer is heavier.
• Emphasis (3 px+ / heavy) — rare. Reserved for selected/hover, hit-flash on stroked things, key-art beats.

Filled shapes (ball, hit-flash discs, mana pips) sit outside this — they read by area + color, not by stroke.

The clean read: when the chamber gets a sibling, the chamber stays the loudest line. A projectile that's heavier than the chamber means the chamber stops feeling like a container.

Let me write that into the design doc and drop the projectile to 1.5 px.

The file E:\a327ex\chamber\design.md has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done.

• Design doc updated with the three-tier rule and explicit assignment for actors.
• Projectile stroke dropped to 1.5 px (thin / actor tier). It's now visibly lighter than the chamber's 2 px — chamber wins the hierarchy.

When we get to enemies in phase 4, their outlines should be 1.5 px too by the same rule. Run it, see if the hierarchy reads right now, and tell me if 1.5 looks too anemic at a small chevron — if so we can either bump arm length or live with a slightly heavier "actor" tier (closer to 1.75–2).

Did you change the wall? It looked better before.

I didn't touch the wall — CHAMBER_STROKE is still 2 px, same as it was last screenshot. Only PROJECTILE_STROKE went from 3.5 → 1.5.

What you're probably seeing is a relative change: with the projectiles at 3.5 the chamber looked thinner by comparison; with the projectiles dropped to 1.5 the chamber is now the heaviest line in view, which is the hierarchy I was going for — but it can read as "the wall got thinner" because there's nothing competing with it anymore.

Two ways forward:

1. Keep 2 px wall, accept the new look. This matches the rule we just locked in — chamber is structure, everything else is subordinate. Once we have enemies / HUD on screen the chamber will sit naturally inside a denser composition.

2. Bump the chamber to a slightly heavier weight (say 2.5 or 3 px) so it visually anchors more strongly without anything else on screen. We'd need to update the design doc's "structure = 2 px" rule too — probably retitle it "structure = 2–3 px" with chamber specifically using the upper end.

Which do you actually want? If you tell me "the wall in the previous screenshot looked right and now it looks too thin", I'd lean (2). If you say "I just thought you'd changed it but it's fine", we leave it.

Let's try projectile at 2

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Bumped to 2 px. This puts projectiles at the same weight as the chamber wall — actors and structure as equal peers rather than the strict hierarchy I proposed. See how it reads. If 2 ends up being the keeper, we'll loosen the design doc rule to allow active actors to match structure weight.

What's the rule currently for projectile angle? Seems kinda random. Should probably be the middle between the normal for wall hit and the angle of the ball when it hit (outwards).

Good catch. Current rule is just radial from chamber center through ball position — which works fine for perpendicular hits but ignores how the ball was actually moving, so glancing hits feel disconnected from the bounce.

The midpoint rule you're proposing:

• Wall normal: outward direction perpendicular to the wall just hit (axis-aligned: (0, π/2, π, -π/2) depending on which wall).
• Ball direction: ball's post-bounce velocity angle (already reflected by the time on_wall_hit fires).
• Projectile angle: average of the two as unit vectors, then atan — the wrap-safe way to take a midpoint of angles.

For the spawn offset, I'll switch from "along radial direction" to "along wall normal" while we're in there — that means the spawn point sits exactly BALL_RADIUS + CORNER_TICK_GAP perpendicular to the wall regardless of the projectile's own angle, which matches the literal reading of "distance from the box edge".

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done. New behavior:

• Projectile angle is the midpoint between the wall's outward normal and the ball's outgoing velocity. Perpendicular hits → projectile fires straight out. Glancing hits → projectile leans toward the ball's exit direction.
• Spawn point moved to be along the wall normal (not along projectile angle), so distance-from-wall stays consistent at BALL_RADIUS + CORNER_TICK_GAP = 16 px no matter how angled the projectile fires.

You should see projectiles now visibly "lean" with the ball's bounce direction — sharper bounces produce projectiles that fan out diagonally, near-perpendicular bounces produce projectiles flying nearly straight out.

Edge case worth eyeballing: when the ball hits very close to a corner, the wall-normal axis-detection might pick the "wrong" wall (the one the ball is more lined up with rather than the one it actually contacted). For typical mid-wall hits it's solid.

Angles are very wrong. Perpendicular hits are spawn projectiles at angle parallel to the wall.

You're right — the bug is that the ball's post-bounce velocity points back into the chamber (inward), so the "midpoint" with the outward wall normal is averaging two near-opposite vectors. For a perfect perpendicular hit they're exactly opposite and atan2(0,0) collapses to 0 — i.e. parallel to the wall.

The fix: reflect the ball's post-bounce velocity across the wall normal to recover the pre-bounce / outward direction first, then take the midpoint with the wall normal.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Behavior should now be:

• Perpendicular hit (ball straight into wall): wall normal and outward ball direction coincide → midpoint is just the wall normal → projectile fires straight perpendicular outward. ✓
• Glancing hit (ball at 45° into top wall, say up-and-right): wall normal is straight up, outward ball direction is up-right → midpoint is up-and-slightly-right at about 67.5° from horizontal → projectile leans toward where the ball was heading.

The visual effect: at near-perpendicular hits the projectile fires perpendicular; the more glancing the bounce, the more the projectile fans toward the ball's outgoing direction.

Perfect. Seems correct now. The framerate issue was happening if I had the other monitor open on Twitch. Still, I'd like to try to fix it even then. What would your preferred solution entail?

Let me check what the engine already does for the physics-vs-render timing before I recommend anything — your "we did work to try to prevent it" comment suggests there's already interpolation, in which case the right fix is different than if there isn't.

140:#define MAX_UPDATES 10              // Cap on fixed steps per frame (prevents spiral of death)
3842:// This handles rotation correctly because UV interpolation implicitly
9455:    "    // This handles rotation correctly because UV interpolation\n"
9487:    "        // time based on per-layer / per-font filter) does proper bilinear interpolation.\n"
9561:    "        alpha = 1.0 - smoothstep(-u_aa_width, u_aa_width, d);\n"
9563:    "        alpha = 1.0 - step(0.0, d);\n"

9920     if (dt_history_filled) {
9921            // Full buffer: average all values
9922            averaged_dt = 0;
9923            for (int i = 0; i < DT_HISTORY_COUNT; i++) {
9924                averaged_dt += dt_history[i];
9925            }
9926            averaged_dt /= DT_HISTORY_COUNT;
9927        } else {
9928            // Buffer not full yet: average only filled entries
9929            averaged_dt = 0;
9930            for (int i = 0; i < dt_history_index; i++) {
9931                averaged_dt += dt_history[i];
9932            }
9933            averaged_dt /= dt_history_index > 0 ? dt_history_index : 1;
9934        }
9935        dt = averaged_dt;
9936    
9937        // Accumulate physics lag, capped to prevent spiral of death
9938        physics_lag += dt;
9939        if (physics_lag > PHYSICS_RATE * MAX_UPDATES) {
9940            physics_lag = PHYSICS_RATE * MAX_UPDATES;
9941        }
9942    
9943        // Accumulate render lag, capped to prevent unbounded growth
9944        render_lag += dt;
9945        if (render_lag > RENDER_RATE * 2) {
9946            render_lag = RENDER_RATE * 2;
9947        }
9948    
9949        // Poll global hotkeys BEFORE SDL events (grab WM_HOTKEY thread messages first)
... [40 more lines]

9990             #endif
9991            }
9992            if (event.type == SDL_KEYUP) {
9993                SDL_Scancode sc = event.key.keysym.scancode;
9994                if (sc < SDL_NUM_SCANCODES) {
9995                    keys_current[sc] = false;
9996                }
9997            }
9998            // Track mouse motion
9999            if (event.type == SDL_MOUSEMOTION) {
10000               last_input_type = INPUT_TYPE_MOUSE;
10001               mouse_x = event.motion.x;
10002               mouse_y = event.motion.y;
10003               mouse_dx += event.motion.xrel;
10004               mouse_dy += event.motion.yrel;
10005           }
10006           // Track mouse buttons
10007           if (event.type == SDL_MOUSEBUTTONDOWN) {
10008               last_input_type = INPUT_TYPE_MOUSE;
10009               #ifdef __EMSCRIPTEN__
10010               audio_try_unlock();
10011               #endif
10012               int btn = event.button.button - 1;  // SDL buttons are 1-indexed
10013               if (btn >= 0 && btn < MAX_MOUSE_BUTTONS) {
10014                   mouse_buttons_current[btn] = true;
10015               }
10016               // Capture mode: capture the mouse button
10017               if (capture_mode && captured_control[0] == '\0') {
10018                   snprintf(captured_control, sizeof(captured_control), "mouse:%d", event.button.button);
10019               }
... [70 more lines]

10089                b2World_Step(physics_world, (float)(PHYSICS_RATE * time_scale), 4);  // 4 sub-steps recommended
10090               physics_process_events();  // Buffer events for Lua queries
10091           }
10092   
10093           // Call Lua update (skip if in error state)
10094           if (!error_state) {
10095               lua_pushcfunction(L, traceback);
10096               int err_handler = lua_gettop(L);
10097               lua_getglobal(L, "update");
10098               if (lua_isfunction(L, -1)) {
10099                   lua_pushnumber(L, PHYSICS_RATE);
10100                   if (lua_pcall(L, 1, 0, err_handler) != LUA_OK) {
10101                       snprintf(error_message, sizeof(error_message), "%s", lua_tostring(L, -1));
10102                       fprintf(stderr, "ERROR: %s\n", error_message);
10103                       lua_pop(L, 2);  // error + traceback
10104                       error_state = true;
10105                   } else {
10106                       lua_pop(L, 1);  // traceback
10107                   }
10108               } else {
10109                   lua_pop(L, 2);  // nil + traceback
10110               }
10111           }
10112   
10113           step++;
10114           game_time += PHYSICS_RATE;
10115           physics_lag -= PHYSICS_RATE;
10116   
10117           // Copy current input state to previous for next frame's edge detection
10118           input_post_update();
... [50 more lines]

Found the relevant engine code. Here's the timing model and what I'd recommend.

What the engine currently does (anchor.c:9294-10125):

• Physics + update() runs at fixed 120 Hz with a physics_lag accumulator. Spiral-of-death cap at 10 steps. Includes dt_history smoothing and timing_resync on focus gain — that's the "work to prevent it" you mentioned.
• draw() runs at fixed 60 Hz with its own render_lag accumulator. The render-time comment literally says "for chunky pixel movement on high-refresh monitors" — designed for pixel art.
• No interpolation between physics frames at render time. Render just shows the latest state.

So the judder has two contributing causes:

1. No subframe interpolation. Physics steps in 8.33 ms increments, render samples every 16.67 ms, and renders pick whatever the latest physics state is. At 500 px/sec that's ~8 px between render frames; if a frame drops it's ~16 px in one go. Visible as small but persistent stutter that gets nasty under load.
2. Render is hard-capped at 60 Hz even on 144/165 Hz monitors. A higher refresh would naturally smooth small motions.

My preferred solution: engine-level render interpolation.

The foundational fix. Conceptually small, pays off across every game built on this engine.

What it entails:

1. Capture prev_position before each physics step for every dynamic Box2D body. Box2D bodies already expose b2Body_GetPosition; one extra call per body per step.
2. Expose render_alpha to Lua as a new global, computed as render_lag / PHYSICS_RATE clamped to [0, 1] — i.e. "how far into the next physics step are we right now".
3. Add collider:get_render_position() (or auto-fill self.render_x, self.render_y during sync()) that returns lerp(prev, curr, render_alpha). Game :draw uses those instead of self.x, self.y.
4. Optionally: also interpolate angle, especially for the projectile chevron.

Cost: small engine change (~50 lines), small per-game ergonomics tax (self.render_x instead of self.x in draw). Result: motion stays smooth even when render frames are missed entirely, because we sample between known physics states rather than always landing on them.

While I'm in there I'd also uncap the render rate — let it run at the monitor's refresh, vsync-limited. With interpolation, higher-refresh-rate monitors get genuinely smoother motion for free. The "chunky pixel" comment doesn't apply to your smooth-filter use case; you'd still want it on for pixel-art games, so this should be a per-game flag (render_rate = "vsync" vs "60hz" in the init params).

Complementary aesthetic addition: motion echo trails.

Independent of the engineering fix, fast objects in our schematic style would benefit from a short echo trail anyway — it reads as motion blur in the visual language of technical drawings (a faint dotted streak rather than a gaussian smear). Implementation: each fast actor stores its last 3–4 positions and draws faded copies. ~10 lines per actor.

This is the "aesthetic motion blur" without breaking the line-art style. Would also serve as a fallback if the engine fix takes longer.

What I'd avoid: velocity-aligned blur shader.

Real motion blur shaders produce soft gaussian smears. That fights the design's hard-line schematic aesthetic — a blurred chevron stops looking like a technical drawing and starts looking like generic VFX. Save that tool for a different project.

If you want to do the engine fix, I'd estimate it's a half-day of focused work — small enough to prototype before committing. Want me to sketch the actual changes (so you can review before we touch engine code), or would you rather keep the engine alone for now and just add motion trails on the game side?

Why is the render hard-capped at 60Hz? I remember we decided on that for a reason but I don't remember why.

Let me dig for the actual rationale rather than guess from the comment.

E:\a327ex\Anchor2\scripts\monitor_sim.c:485:    printf("  %s -m 144 -t 60                # 144Hz monitor, 60Hz updates\n", prog);
E:\a327ex\Anchor2\arena\ARENA_PROGRESS.md:59:- User tests by running `./arena/anchor.exe arena` in a real window (should see a black 1440×810 window)
E:\a327ex\Anchor2\reference\progress.md:107:- Window opens at 480x270 (3x scale → 1440x810)
E:\a327ex\Anchor2\app\design.md:152:- **Primary target:** 1440 × 900 desktop window, single monitor,
E:\a327ex\Anchor2\app\design.md:1276:  1440×900).
E:\a327ex\Anchor2\reference\Anchor_v1\main.lua:652:orange = color(244, 144, 12)
E:\a327ex\Anchor2\app\main.lua:16:  width = 1440,
E:\a327ex\Anchor2\app\plan.md:47:- `Anchor2/app/` scaffolded with a smooth-vs-rough demo (`main.lua`). Runs at 1440×900 / scale=1 / smooth. Demonstrates the engine fixes; not the Phase 1 app itself.
E:\a327ex\Anchor2\app\plan.md:58:- Target hardware: single 1440×900 window initially; multi-monitor eventually.
E:\a327ex\Anchor2\engine\include\glad\gl.h:2078:#define GL_MAX_DEBUG_LOGGED_MESSAGES 0x9144
E:\a327ex\Anchor2\engine\include\glad\gl.h:2079:#define GL_MAX_DEBUG_LOGGED_MESSAGES_AMD 0x9144
E:\a327ex\Anchor2\engine\include\glad\gl.h:2080:#define GL_MAX_DEBUG_LOGGED_MESSAGES_ARB 0x9144
E:\a327ex\Anchor2\engine\include\glad\gl.h:2882:#define GL_PIXEL_TILE_GRID_DEPTH_SGIX 0x8144
E:\a327ex\Anchor2\engine\include\stb_vorbis.c:1951:  2.2670913e-07f, 2.4144197e-07f, 2.5713223e-07f, 2.7384213e-07f,
E:\a327ex\Anchor2\engine\include\stb_vorbis.c:1957:  1.0273513e-06f, 1.0941144e-06f, 1.1652161e-06f, 1.2409384e-06f,
E:\a327ex\Anchor2\engine\include\stb_vorbis.c:1961:  2.8133190e-06f, 2.9961443e-06f, 3.1908506e-06f, 3.3982101e-06f,
E:\a327ex\Anchor2\engine\include\stb_vorbis.c:1962:  3.6190449e-06f, 3.8542308e-06f, 4.1047004e-06f, 4.3714470e-06f,
E:\a327ex\Anchor2\engine\include\stb_vorbis.c:1994:  0.011444421f,   0.012188144f,   0.012980198f,   0.013823725f,
E:\a327ex\Anchor2\engine\include\stb\stb_perlin.h:108:   132, 48, 119, 144, 180, 138, 134, 193, 82, 182, 120, 121, 86, 220, 209, 3,
E:\a327ex\Anchor2\engine\include\stb\stb_perlin.h:126:   132, 48, 119, 144, 180, 138, 134, 193, 82, 182, 120, 121, 86, 220, 209, 3,
E:\a327ex\Anchor2\engine\src\anchor.c:139:#define RENDER_RATE  (1.0 / 60.0)   // 60 Hz render cap (for chunky pixel movement)
E:\a327ex\Anchor2\engine\src\anchor.c:10122:    // Render at 60Hz (for chunky pixel movement on high-refresh monitors)
E:\a327ex\Anchor2\engine\include\stb\stb_image_write.h:885:#define stbiw__zlib_huff2(n)  stbiw__zlib_huffa(0x190 + (n)-144, 9)
E:\a327ex\Anchor2\engine\include\freetype\ttnameid.h:417:#define TT_MAC_LANGID_SCOTTISH_GAELIC             144
E:\a327ex\Anchor2\engine\include\miniaudio.h:83206:    0xF0C4, 0xF144, 0xF1C4, 0xF244, 0xF2C4, 0xF344, 0xF3C4, 0xF444, 0xF4C4, 0xF544, 0xF5C4, 0xF644, 0xF6C4, 0xF744, 0xF7C4, 0xF844,
E:\a327ex\Anchor2\engine\include\miniaudio.h:83217:    0x0174, 0x0164, 0x0154, 0x0144, 0x0134, 0x0124, 0x0114, 0x0104, 0x00F4, 0x00E4, 0x00D4, 0x00C4, 0x00B4, 0x00A4, 0x0094, 0x0084,
E:\a327ex\Anchor2\engine\include\miniaudio.h:92731:        { { 0,16,20,24,28,32,40,48,56,64,80,96,112,128,160 }, { 0,16,24,28,32,40,48,56,64,80,96,112,128,160,192 }, { 0,16,32,48,64,80,96,112,128,144,160,176,192,208,224 } },
E:\a327ex\Anchor2\engine\include\miniaudio.h:93173:[Omitted long matching line]
E:\a327ex\Anchor2\engine\include\miniaudio.h:93174:[Omitted long matching line]
E:\a327ex\Anchor2\engine\include\miniaudio.h:93175:[Omitted long matching line]
... [12 more lines]

E:\a327ex\Anchor2\scripts\monitor_sim.c:354:// Algorithm 3: Anchor Final (120Hz physics, 60Hz render cap, vsync snapping)
E:\a327ex\Anchor2\scripts\monitor_sim.c:360:    double render_rate = 1.0 / 60.0;
E:\a327ex\Anchor2\scripts\monitor_sim.c:412:        if (render_lag > render_rate * 2) {
E:\a327ex\Anchor2\scripts\monitor_sim.c:413:            render_lag = render_rate * 2;
E:\a327ex\Anchor2\scripts\monitor_sim.c:425:        // Render at 60Hz cap
E:\a327ex\Anchor2\scripts\monitor_sim.c:427:        if (render_lag >= render_rate) {
E:\a327ex\Anchor2\scripts\monitor_sim.c:428:            render_lag -= render_rate;
E:\a327ex\Anchor2\scripts\monitor_sim.c:482:    printf("  3 = Anchor final     120Hz physics, 60Hz render cap, snapping\n\n");
E:\a327ex\Anchor2\scripts\monitor_sim.c:485:    printf("  %s -m 144 -t 60                # 144Hz monitor, 60Hz updates\n", prog);
E:\a327ex\Anchor2\engine\src\anchor.c:139:#define RENDER_RATE  (1.0 / 60.0)   // 60 Hz render cap (for chunky pixel movement)
E:\a327ex\Anchor2\engine\src\anchor.c:9945:    if (render_lag > RENDER_RATE * 2) {
E:\a327ex\Anchor2\engine\src\anchor.c:9946:        render_lag = RENDER_RATE * 2;
E:\a327ex\Anchor2\engine\src\anchor.c:10122:    // Render at 60Hz (for chunky pixel movement on high-refresh monitors)
E:\a327ex\Anchor2\engine\src\anchor.c:10123:    if (render_lag >= RENDER_RATE) {
E:\a327ex\Anchor2\engine\src\anchor.c:10124:        render_lag -= RENDER_RATE;
E:\a327ex\Anchor2\engine\src\anchor.c:10511:            // 2 physics steps per render frame (120Hz physics / 60Hz render)
E:\a327ex\Anchor2\engine\include\box2d\box2d.h:1019:/// runs at 60Hz then the joint stiffness should be 15Hz or less.

There's a scripts/monitor_sim.c simulation script that's clearly a record of the decision. Let me read it.

1    /*
2    * Monitor Simulator - Frame Timing Test Tool
3    *
4    * Tests frame timing algorithms against simulated monitor configurations.
5    * Based on Tyler Glaiel's approach from "How to make your game run at 60fps"
6    *
7    * Build: gcc -O2 -o monitor_sim monitor_sim.c -lm
8    * Usage: ./monitor_sim [algorithm] [monitor_hz] [num_frames]
9    *
10   * Algorithms:
11   *   0 = Anchor current (naive accumulator)
12   *   1 = Glaiel (vsync snapping + averaging)
13   *   2 = Anchor fixed (proposed improvements)
14   */
15  
16  #include <stdio.h>
17  #include <stdlib.h>
18  #include <stdint.h>
19  #include <stdbool.h>
20  #include <string.h>
21  #include <math.h>
22  #include <time.h>
23  
24  // Simulation clock (1MHz = microsecond precision)
25  #define SIM_FREQ 1000000
26  static int64_t sim_time = 0;
27  static int64_t next_vsync = 0;
28  
29  // Configuration
30  static struct {
... [70 more lines]

340              stats.update_counts[updates_this_frame]++;
341         }
342         if (updates_this_frame == 0) stats.zero_updates++;
343         if (updates_this_frame >= 2) stats.double_updates++;
344         if (updates_this_frame >= 3) stats.triple_updates++;
345 
346         if (frame < 200) {
347             printf("%d", updates_this_frame > 9 ? 9 : updates_this_frame);
348         }
349     }
350     printf(config.num_frames <= 200 ? "\n" : "...\n");
351 }
352 
353 // ============================================================================
354 // Algorithm 3: Anchor Final (120Hz physics, 60Hz render cap, vsync snapping)
355 // ============================================================================
356 
357 static void algo_anchor_final(void) {
358     // Configuration matching anchor.c
359     double physics_rate = 1.0 / 120.0;
360     double render_rate = 1.0 / 60.0;
361     int64_t vsync_maxerror = (int64_t)(SIM_FREQ * 0.0002);
362     int max_updates = 10;
363 
364     // Snap frequencies based on monitor refresh rate
365     int64_t snap_frequencies[8];
366     int64_t base_snap = sec_to_ticks(1.0 / config.monitor_hz);
367     for (int i = 0; i < 8; i++) {
368         snap_frequencies[i] = base_snap * (i + 1);
369     }
... [130 more lines]

No matches found

E:\a327ex\Anchor2\docs\ENGINE_API_QUICK.md:95:timing_resync()
E:\a327ex\Anchor2\docs\ENGINE_API_QUICK.md:324:engine_set_vsync(enabled)
E:\a327ex\Anchor2\docs\FRAMEWORK_API_QUICK.md:25:  vsync = true,       -- vertical sync (default: true)
E:\a327ex\Anchor2\docs\FRAMEWORK_API_QUICK.md:625:math.snap(value, grid) -> number
E:\a327ex\Anchor2\docs\ENGINE_API.md:726:### timing_resync
E:\a327ex\Anchor2\docs\ENGINE_API.md:728:`timing_resync()`
E:\a327ex\Anchor2\docs\ENGINE_API.md:730:Resets timing accumulators. Call after pausing or scene transitions to prevent catch-up updates.
E:\a327ex\Anchor2\docs\ENGINE_API.md:733:timing_resync()
E:\a327ex\Anchor2\docs\ENGINE_API.md:2297:### engine_set_vsync
E:\a327ex\Anchor2\docs\ENGINE_API.md:2299:`engine_set_vsync(enabled)`
E:\a327ex\Anchor2\docs\ENGINE_API.md:2304:engine_set_vsync(true)   -- VSync on
E:\a327ex\Anchor2\docs\ENGINE_API.md:2305:engine_set_vsync(false)  -- VSync off
E:\a327ex\Anchor2\docs\ENGINE_API.md:2520:## Performance Timing
E:\a327ex\Anchor2\docs\ENGINE_API.md:2559:Returns whether render mode is active (deterministic timing, vsync disabled). Set via `--render-mode` CLI flag.
E:\a327ex\Anchor2\docs\FRAMEWORK_API.md:119:  vsync = true,
E:\a327ex\Anchor2\docs\FRAMEWORK_API.md:134:| `vsync` | bool | true | Enable vertical sync |
E:\a327ex\Anchor2\docs\FRAMEWORK_API.md:1737:math.lerp_dt(p, time, dt, a, b) -> number     -- framerate-independent lerp
E:\a327ex\Anchor2\docs\FRAMEWORK_API.md:1745:interpolation is `p` complete after `time` seconds regardless of framerate.
E:\a327ex\Anchor2\docs\FRAMEWORK_API.md:1746:This is the framerate-independent version of `lerp` and is what you want for
E:\a327ex\Anchor2\docs\FRAMEWORK_API.md:1756:math.snap(value, grid) -> number               -- round to nearest grid multiple
E:\a327ex\Anchor2\app\design.md:165:All chrome and content snap to a **4 px subgrid**. The effective layout grid
E:\a327ex\Anchor2\app\design.md:1561:- Drag element → move (snaps to 4 px subgrid unless `⌥` held).

README.md
build.bat
find-recent-session.py*
jsonl-to-markdown.py*
monitor_sim.c
new-game.sh*
package.bat
package.sh*
patch-claude-code.sh*

Found the decision. It's recorded in scripts/monitor_sim.c — a frame-timing simulator the engine work was driven by. The header credits Tyler Glaiel's "How to make your game run at 60fps" article, and the chosen algorithm is the last one tested: "Anchor Final: 120Hz physics, 60Hz render cap, vsync snapping".

The reasoning, reconstructed from the comment in anchor.c (// 60 Hz render cap (for chunky pixel movement on high-refresh monitors)) plus the algorithm structure:

1. Pixel-art aesthetic preservation. At 60 Hz, motion shows in visible discrete steps — each pixel-grid jump is its own frame. On a 144 Hz monitor without the cap, the same pixel-art game would render the same chunky physics state across multiple monitor refreshes anyway, but if you uncapped and rendered every refresh, you'd be drawing identical frames 2.4× — and any inter-frame interpolation would defeat the point of pixel art looking pixel-art-y. The cap makes the engine commit to one frame per physics-aligned interval.
2. 120 Hz physics / 60 Hz render = 2 steps per frame, exactly. Clean integer ratio, no fractional alignment problems, no interpolation needed because the math always lines up. This is why --rate-mode decisions usually pick integer divisors of the physics rate.
3. Vsync snapping handles monitors that aren't exactly 60 Hz (59.94, 144, 165, etc.). The simulator confirms the algorithm doesn't drift on weird refresh rates.
4. CPU/GPU savings, especially on laptops — render half as many frames as a 144 Hz monitor would otherwise demand.

So the cap was specifically for pixel-art games on high-refresh-rate monitors, where rendering at the monitor's full rate would waste power without buying smoother motion (because the underlying art doesn't have sub-frame information to interpolate anyway).

The relevance to chamber: that reasoning doesn't apply to us. We're using the smooth filter at native 1920×1080 — not pixel art. The chunky 60 Hz cap is the cause of the judder you're seeing, not a feature. We're paying the cost (visible frame steps when motion is fast) without getting the benefit (preserved pixel-grid integrity).

The fix is two changes that should probably go together:

1. Uncap render (let it run at the monitor's vsync rate), opt-in via init flag — so existing pixel-art games keep the cap by default.
2. Add render interpolation between physics states, so even at higher render rates we sample between known good positions instead of just showing whichever physics step happens to be most recent.

For chamber specifically, just (1) might be enough on a 120/144/165 Hz monitor (because the gap between physics steps is shorter than your monitor's refresh interval — every refresh shows a fresh state). But (2) is the correct foundational fix and pays off for all high-speed objects regardless of monitor rate.

Want me to make this a per-game init flag (render_rate = "vsync" vs "60hz", defaulting to "60hz" so we don't break existing pixel-art games), and add interpolation in the same engine pass?

Let's just do 1 via a flag, seems to make sense. I remember the decision now too and it was in fact specific to pixel games, which doesn't apply here.

Good. Let me find the init parsing and the render gate before writing.

E:\a327ex\Anchor2\framework\anchor\collider.lua:125:function collider:set_filter_group(group, shape) physics_shape_set_filter_group(shape or self.shape, group) end
E:\a327ex\Anchor2\framework\anchor\font.lua:14:--- `filter` is optional: 'smooth' (grayscale atlas + linear sampling) or
E:\a327ex\Anchor2\framework\anchor\font.lua:16:--- current global filter mode. The filter is baked into the atlas at load time
E:\a327ex\Anchor2\framework\anchor\font.lua:18:function font:new(name, path, size, filter)
E:\a327ex\Anchor2\framework\anchor\font.lua:21:  self.filter = filter
E:\a327ex\Anchor2\framework\anchor\font.lua:22:  font_load(name, path, size, filter)
E:\a327ex\Anchor2\framework\anchor\font.lua:39:function font_register(name, path, size, filter)
E:\a327ex\Anchor2\framework\anchor\font.lua:40:  local f = font(name, path, size, filter)
E:\a327ex\Anchor2\framework\anchor\input.lua:8:  (The engine registers its functions during engine_init(), which runs
E:\a327ex\Anchor2\framework\anchor\init.lua:15:      vsync = true,
E:\a327ex\Anchor2\framework\anchor\init.lua:16:      filter = "rough",
E:\a327ex\Anchor2\framework\anchor\init.lua:125:  -- Apply engine configuration before engine_init
E:\a327ex\Anchor2\framework\anchor\init.lua:131:  if config.vsync ~= nil then engine_set_vsync(config.vsync) end
E:\a327ex\Anchor2\framework\anchor\init.lua:134:  if config.filter then set_filter_mode(config.filter) end
E:\a327ex\Anchor2\framework\anchor\init.lua:137:  engine_init()
E:\a327ex\Anchor2\framework\anchor\layer.lua:28:  After require('anchor.layer'), direct engine-style calls like
E:\a327ex\Anchor2\framework\anchor\layer.lua:91:--- `filter` is optional: 'smooth' (antialiased edges, linear sampling) or
E:\a327ex\Anchor2\framework\anchor\layer.lua:93:--- global filter mode, which is 'rough' unless changed via set_filter_mode.
E:\a327ex\Anchor2\framework\anchor\layer.lua:94:function layer_new(name, filter)
E:\a327ex\Anchor2\framework\anchor\layer.lua:97:    handle = eng.create(name, filter),
E:\a327ex\Anchor2\framework\anchor\layer.lua:98:    filter = filter,

animation.lua
array.lua
camera.lua
class.lua
collider.lua
color.lua
font.lua
helpers.lua
image.lua
init.lua
input.lua
layer.lua
math.lua
memory.lua
object.lua
physics.lua
shake.lua
spring.lua
spritesheet.lua
timer.lua

1    --[[
2     Anchor 2 — framework initialization.
3   
4     Loads all framework modules in dependency order, then returns a function
5     that takes config and initializes the engine + global state. The game's
6     main.lua is expected to define `update(dt)` and `draw()` as globals; the
7     C engine calls these directly each frame.
8   
9     Usage (from a game's main.lua):
10      require('anchor')({
11        width = 480,
12        height = 270,
13        title = "My Game",
14        scale = 3,
15        vsync = true,
16        filter = "rough",
17      })
18  
19      function update(dt)
20        sync_engine_globals()          -- refresh time/frame/etc. mirrors
21        -- your game update (physics is stepped by the engine automatically
22        -- before update() is called; you just consume collision events here)
23        process_destroy_queue()        -- drain deferred destruction
24      end
25  
26      function draw()
27        -- ... your game draw
28      end
29  
30    Framework modules are loaded in this order (dependency-driven):
... [135 more lines]

8425:static int l_engine_set_title(lua_State* L) {
8436:static int l_engine_set_scale(lua_State* L) {
8438:        return luaL_error(L, "engine_set_scale must be called before engine_init");
8444:static int l_engine_set_vsync(lua_State* L) {
9258:    lua_register(L, "engine_set_title", l_engine_set_title);
9259:    lua_register(L, "engine_set_scale", l_engine_set_scale);
9260:    lua_register(L, "engine_set_vsync", l_engine_set_vsync);

8420     game_width = luaL_checkinteger(L, 1);
8421        game_height = luaL_checkinteger(L, 2);
8422        return 0;
8423    }
8424    
8425    static int l_engine_set_title(lua_State* L) {
8426        const char* title = luaL_checkstring(L, 1);
8427        strncpy(window_title, title, sizeof(window_title) - 1);
8428        window_title[sizeof(window_title) - 1] = '\0';
8429        // If window already exists, update title immediately
8430        if (window) {
8431            SDL_SetWindowTitle(window, window_title);
8432        }
8433        return 0;
8434    }
8435    
8436    static int l_engine_set_scale(lua_State* L) {
8437        if (engine_initialized) {
8438            return luaL_error(L, "engine_set_scale must be called before engine_init");
8439        }
8440        initial_scale = (float)luaL_checknumber(L, 1);
8441        return 0;
8442    }
8443    
8444    static int l_engine_set_vsync(lua_State* L) {
8445        vsync_enabled = lua_toboolean(L, 1);
8446        // If window already exists, apply immediately
8447        if (window) {
8448            SDL_GL_SetSwapInterval(vsync_enabled ? 1 : 0);
8449        }
... [60 more lines]

Plan locked in. Going to:

1. Engine (anchor.c): new render_uncapped bool, defaults false (so all existing pixel-art games keep the cap). Add l_engine_set_render_uncapped Lua binding. Modify the render gate to skip the rate-cap when uncapped.
2. Framework (init.lua): forward config.render_uncapped → engine_set_render_uncapped.
3. Docs: add the param to API docs.
4. Build engine, copy artifacts to chamber/, set the flag in chamber's init.

Let me find the relevant globals and loop site.

84:static bool vsync_enabled = true;
85:static bool start_fullscreen = false;
86:static bool window_resizable = true;

9245:    lua_register(L, "engine_set_time_scale", l_engine_set_time_scale);
9257:    lua_register(L, "engine_set_game_size", l_engine_set_game_size);
9258:    lua_register(L, "engine_set_title", l_engine_set_title);
9259:    lua_register(L, "engine_set_scale", l_engine_set_scale);
9260:    lua_register(L, "engine_set_vsync", l_engine_set_vsync);
9261:    lua_register(L, "engine_set_fullscreen", l_engine_set_fullscreen);
9262:    lua_register(L, "engine_set_resizable", l_engine_set_resizable);
9263:    lua_register(L, "engine_set_headless", l_engine_set_headless);

Good. Now the engine changes.

The file E:\a327ex\Anchor2\engine\src\anchor.c has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\Anchor2\engine\src\anchor.c has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\Anchor2\engine\src\anchor.c has been updated successfully. (file state is current in your context — no need to Read it back)

Now modify the render gate in the main loop:

The file E:\a327ex\Anchor2\engine\src\anchor.c has been updated successfully. (file state is current in your context — no need to Read it back)

Now the framework init.lua:

The file E:\a327ex\Anchor2\framework\anchor\init.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\Anchor2\framework\anchor\init.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Update the docs:

The file E:\a327ex\Anchor2\docs\FRAMEWORK_API_QUICK.md has been updated successfully. (file state is current in your context — no need to Read it back)

110  
111 The framework is loaded by requiring it with a config table:
112 
113 ```lua
114 require('anchor')({
115   width = 480,
116   height = 270,
117   title = "My Game",
118   scale = 3,
119   vsync = true,
120   fullscreen = false,
121   resizable = true,
122   filter = "rough",
123 })
124 ```
125 
126 ### Configuration options
127 
128 | Option | Type | Default | Description |
129 |---|---|---|---|
130 | `width` | int | 480 | Game resolution width in virtual pixels |
131 | `height` | int | 270 | Game resolution height |
132 | `title` | string | "Anchor" | Window title |
133 | `scale` | int | 3 | Initial integer window scale multiplier |
134 | `vsync` | bool | true | Enable vertical sync |
135 | `fullscreen` | bool | false | Start in fullscreen |
136 | `resizable` | bool | true | Window is resizable |
137 | `filter` | string | "rough" | `"rough"` (pixel-perfect) or `"smooth"` (bilinear) |
138 
139 All options are optional. `require('anchor')({})` uses defaults.
... [20 more lines]

The file E:\a327ex\Anchor2\docs\FRAMEWORK_API.md has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\Anchor2\docs\FRAMEWORK_API.md has been updated successfully. (file state is current in your context — no need to Read it back)

Now build the engine, then copy the new binary + framework changes into chamber, then set the flag.

src/anchor.c(3234): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(3344): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(3353): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(3447): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(3449): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(4686): warning C4996: 'strdup': The POSIX name for this item is deprecated. Instead, use the ISO C and C++ conformant name: _strdup. See online help for details.

src/anchor.c(5766): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(6651): warning C4244: 'initializing': conversion from 'lua_Number' to 'float', possible loss of data

src/anchor.c(6652): warning C4244: 'initializing': conversion from 'lua_Number' to 'float', possible loss of data

src/anchor.c(8425): warning C4244: '=': conversion from 'lua_Integer' to 'int', possible loss of data

src/anchor.c(8426): warning C4244: '=': conversion from 'lua_Integer' to 'int', possible loss of data

src/anchor.c(8432): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(8479): error C2065: 'render_lag': undeclared identifier

src/anchor.c(8479): warning C4244: '=': conversion from 'double' to 'int', possible loss of data

src/anchor.c(8504): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(9772): warning C4996: 'strcpy': This function or variable may be unsafe. Consider using strcpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(9776): warning C4996: 'strcat': This function or variable may be unsafe. Consider using strcat_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(9781): warning C4996: 'strcpy': This function or variable may be unsafe. Consider using strcpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(9785): warning C4996: 'strcat': This function or variable may be unsafe. Consider using strcat_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(9791): warning C4996: 'strcpy': This function or variable may be unsafe. Consider using strcpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(9795): warning C4996: 'strcat': This function or variable may be unsafe. Consider using strcat_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(9801): warning C4996: 'strcpy': This function or variable may be unsafe. Consider using strcpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(9805): warning C4996: 'strcat': This function or variable may be unsafe. Consider using strcat_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(10327): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(10329): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(10332): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(10335): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

gl.c

Generating Code...

Build failed!

The setter references render_lag which is declared further down the file. Easiest fix is to drop the reset — the render block already clears render_lag to 0 when uncapped, so the first uncapped iteration self-recovers anyway.

The file E:\a327ex\Anchor2\engine\src\anchor.c has been updated successfully. (file state is current in your context — no need to Read it back)

src/anchor.c(10324): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(10326): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(10329): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

src/anchor.c(10332): warning C4996: 'strncpy': This function or variable may be unsafe. Consider using strncpy_s instead. To disable deprecation, use _CRT_SECURE_NO_WARNINGS. See online help for details.

gl.c

Generating Code...

LINK : warning LNK4098: defaultlib 'MSVCRT' conflicts with use of other libs; use /NODEFAULTLIB:library

Build successful: build/anchor.exe

Build succeeded. Now copy the new anchor.exe and the updated init.lua into chamber, then set the flag.

OK

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done. Summary:

• Engine: added render_uncapped flag (default false → preserves all existing pixel-art games' behavior). When true, the render block fires every main-loop iteration and render_lag is cleared each pass; vsync paces the actual frame rate.
• Framework: init.lua forwards config.render_uncapped to the engine setter.
• Docs: FRAMEWORK_API.md and FRAMEWORK_API_QUICK.md updated with the new param.
• Chamber: new anchor.exe and init.lua copied in; main.lua sets render_uncapped = true.

When you run, the ball and projectiles should look noticeably smoother — especially under load. On a high-refresh monitor (120/144/165 Hz) you'll get the full benefit; on a 60 Hz monitor the change should still help under contention because we're no longer flooring renders to RENDER_RATE.

If it still judders with Twitch on the second monitor, that means the render thread is genuinely missing vsync intervals, and the next escalation is interpolation between physics states — but I'd test the simple uncap first since it's the cheaper fix and might be sufficient.

udio engine initialized ERROR: anchor/init.lua:75: module 'anchor.memory' not found: no field package.preload['anchor.memory'] no file 'E:\a327ex\chamber\lua\anchor\memory.lua' no file 'E:\a327ex\chamber\lua\anchor\memory\init.lua' no file 'E:\a327ex\chamber\anchor\memory.lua' no file 'E:\a327ex\chamber\anchor\memory\init.lua' no file 'E:\a327ex\chamber..\share\lua\5.4\anchor\memory.lua' no file 'E:\a327ex\chamber..\share\lua\5.4\anchor\memory\init.lua' no file '.\anchor\memory.lua' no file '.\anchor\memory\init.lua' no file 'E:\a327ex\chamber\anchor\memory.dll' no file 'E:\a327ex\chamber..\lib\lua\5.4\anchor\memory.dll' no file 'E:\a327ex\chamber\loadall.dll' no file '.\anchor\memory.dll' no file 'E:\a327ex\chamber\anchor.dll' no file 'E:\a327ex\chamber..\lib\lua\5.4\anchor.dll' no file 'E:\a327ex\chamber\loadall.dll' no file '.\anchor.dll' stack traceback: [C]: in function 'require' anchor/init.lua:75: in main chunk [C]: in function 'require' main.lua:11: in main chunk Initialization complete. Press ESC to exit, F11 for fullscreen. Display refresh rate: 60Hz

The chamber's local anchor/ folder is missing memory.lua (it must've been added to the framework after chamber was scaffolded). Let me check what else might be out of sync and copy missing files.

14d13
< memory.lua

Only memory.lua missing. Copy it across.

OK

Fixed. Try running again. (Side observation from the error trace: the engine logged Display refresh rate: 60Hz on startup — so on this monitor the uncapped change shouldn't visibly change motion smoothness much, since vsync caps you at 60 anyway. The benefit will mostly show up on higher-refresh monitors and under load when frames would otherwise drop below the 60 Hz cap.)

Start the game on the other monitor.

Let me find the window creation call so I can add a display init param.

8752:    window = SDL_CreateWindow(
8754:        SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
8759:        return luaL_error(L, "SDL_CreateWindow failed: %s", SDL_GetError());

8730 static int l_engine_init(lua_State* L) {
8731        if (engine_initialized) {
8732            return luaL_error(L, "engine_init can only be called once");
8733        }
8734    
8735        if (headless_mode) {
8736            // Headless: skip all graphics initialization
8737            printf("Headless mode: skipping window and graphics initialization\n");
8738            engine_initialized = true;
8739            printf("Engine initialized (headless): %dx%d\n", game_width, game_height);
8740            return 0;
8741        }
8742    
8743        // Build window flags
8744        Uint32 window_flags = SDL_WINDOW_OPENGL;
8745        if (window_resizable) {
8746            window_flags |= SDL_WINDOW_RESIZABLE;
8747        }
8748        if (start_fullscreen) {
8749            window_flags |= SDL_WINDOW_FULLSCREEN_DESKTOP;
8750        }
8751    
8752        window = SDL_CreateWindow(
8753            window_title,
8754            SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
8755            (int)(game_width * initial_scale), (int)(game_height * initial_scale),
8756            window_flags
8757        );
8758        if (!window) {
8759            return luaL_error(L, "SDL_CreateWindow failed: %s", SDL_GetError());
... [5 more lines]

Adding a display init param. It indexes monitors 0, 1, 2, …; default 0 = primary.

The file E:\a327ex\Anchor2\engine\src\anchor.c has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\Anchor2\engine\src\anchor.c has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\Anchor2\engine\src\anchor.c has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\Anchor2\engine\src\anchor.c has been updated successfully. (file state is current in your context — no need to Read it back)

Now framework + docs + chamber:

The file E:\a327ex\Anchor2\framework\anchor\init.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\Anchor2\docs\FRAMEWORK_API_QUICK.md has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\Anchor2\docs\FRAMEWORK_API.md has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\Anchor2\docs\FRAMEWORK_API.md has been updated successfully. (file state is current in your context — no need to Read it back)

Build, copy, set the flag in chamber:

Generating Code...

LINK : warning LNK4098: defaultlib 'MSVCRT' conflicts with use of other libs; use /NODEFAULTLIB:library

Build successful: build/anchor.exe

OK

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done.

• Engine: new display init param (with engine_set_display() Lua binding). Out-of-range indices fall back to display 0 with a console warning.
• Framework: init.lua forwards it through.
• Docs updated.
• Chamber: display = 1 (secondary monitor).

If your high-refresh monitor isn't display 1 specifically, change the number — the engine prints a fallback message if the index doesn't exist, and on first launch you should see something like Display refresh rate: 144Hz instead of 60Hz if it landed correctly.

It shows Display refresh rate: 60Hz, even though display 1 is 143Hz

Let me find the refresh-rate query — it's probably hard-coded to display 0.

10486:        if (SDL_GetCurrentDisplayMode(0, &mode) == 0 && mode.refresh_rate > 0) {
10487:            display_hz = mode.refresh_rate;
10489:        printf("Display refresh rate: %dHz\n", display_hz);

10475    
10476       printf("Initialization complete. Press ESC to exit, F11 for fullscreen.\n");
10477   
10478       // Initialize timing state (not needed in headless but harmless)
10479       perf_freq = SDL_GetPerformanceFrequency();
10480       last_time = SDL_GetPerformanceCounter();
10481   
10482       if (!headless_mode) {
10483           // Initialize vsync snap frequencies based on display refresh rate
10484           int display_hz = 60;  // Default fallback
10485           SDL_DisplayMode mode;
10486           if (SDL_GetCurrentDisplayMode(0, &mode) == 0 && mode.refresh_rate > 0) {
10487               display_hz = mode.refresh_rate;
10488           }
10489           printf("Display refresh rate: %dHz\n", display_hz);
10490   
10491           // Compute snap frequencies for this refresh rate and its multiples
10492           // (handles 1x, 2x, 3x... of the base frame time for missed frames)
10493           double base_frametime = 1.0 / (double)display_hz;
10494           snap_frequency_count = 0;
10495           for (int i = 1; i <= 8 && snap_frequency_count < 8; i++) {
10496               snap_frequencies[snap_frequency_count++] = base_frametime * i;
10497           }
10498       }
10499   

Two bugs in one. The refresh-rate query is hardcoded to display 0, and worse — the vsync snap frequencies (used by the timing algorithm) are also computed from the wrong display, so the timing is misaligned with the actual monitor. Fix is to query the display the window actually landed on, via SDL_GetWindowDisplayIndex(window).

The file E:\a327ex\Anchor2\engine\src\anchor.c has been updated successfully. (file state is current in your context — no need to Read it back)

Generating Code...

LINK : warning LNK4098: defaultlib 'MSVCRT' conflicts with use of other libs; use /NODEFAULTLIB:library

Build successful: build/anchor.exe

Copied

Run it again. You should see Display refresh rate: 143Hz (display 1) — and the actual frame rate should now match. The vsync-snap fix is the more important one of the two: previously timing was being snapped to 16.67 ms (60 Hz) intervals while the real monitor was running at ~7 ms, which would cause persistent micro-stuttering even when nothing else was wrong.

If you're tracking down why it judders less now vs. before, it's almost certainly that snap-frequency mismatch rather than the render uncap by itself.

Great, now move the game to the main monitor again.,

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Back on display 0.

Perfect, it all works. Let's continue, what's next?

Phase 4 — enemies. Spawning from screen edges, seeking the chamber, bouncing off the outer walls (Orblike-style pushback). No combat yet — that's phase 5.

Sizing decisions for this phase:

• Shape: hollow circles. Single enemy family for now; we'll add square/triangle/hex families when we introduce types.
• Radius: 8 px (16 px diameter, slightly bigger than the 12 px ball — reads as "the thing the ball is killing").
• Stroke: 1.5 px (actor tier per the design rule).
• Speed: 200–280 px/sec random. Roughly 1/3 ball speed, matching the prototype's ratio.
• Spawn rate: 1.0/sec.
• Spawn margin from screen edge: 16 px.
• Push impulse: 100 on chamber contact, 0.5 sec push state, with 6→3 damping transition (matches prototype). Tunable.

Adding constants + physics tags:

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now insert the enemy class (and spawn helpers) after the projectile class, right before the init section.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Wire enemies into the spawn timer, update loop, and draw:

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Phase 4 done. When you run:

• A new enemy (hollow ink ring, 16 px diameter) spawns from a random screen edge every 1 second.
• Each spawns with a 0.15-sec solid-fill flash, then fades to its hollow outline.
• They steer toward the chamber center using seek + separate, so they fan out instead of clumping into a line.
• When they reach the chamber wall, the physics bounce plus a 100-impulse Orblike push knocks them back outward; they re-orient and re-approach.
• Projectiles still pass through them harmlessly (combat is phase 5).

Things to evaluate:

1. Enemy size. 16 px diameter relative to 12 px ball — does the hierarchy read right (ball as the anchor, enemy as a slightly larger but quieter hollow outline)?
2. Speed range. 200–280 px/sec. Should feel like a slow ominous encroachment, not a sprint.
3. Push strength. 100 is a guess; if enemies barely bounce or get launched off-screen, we'll dial it.
4. Steering force cap (1200). If enemies feel sluggish to redirect after the push wears off, we bump this. If they whip around too aggressively, drop it.
5. Spawn cadence. 1/sec is the prototype rate; on a much bigger 1080p screen they'll feel sparser. We can speed up later.

Once you've eyeballed it, "good" or tweaks → phase 5 (homing + actual combat).

Enemies should be diamonds instead of circles. When they hit the box, they should be killed.

Two changes. Let me first verify the polygon vertex format:

52:  polygon = layer_polygon,
53:  polygon_line = layer_polygon_line,
144:function layer_polygon(lyr, vertices, color)
148:function layer_polygon_line(lyr, vertices, color, line_width)
149:  eng.polygon_line(lyr_handle(lyr), vertices, color, line_width or 1)

No matches found

4881:static int l_layer_polygon(lua_State* L) {
4906:static int l_layer_polygon_line(lua_State* L) {
9073:    lua_register(L, "layer_polygon", l_layer_polygon);
9074:    lua_register(L, "layer_polygon_line", l_layer_polygon_line);

4881 static int l_layer_polygon(lua_State* L) {
4882        Layer* layer = (Layer*)lua_touserdata(L, 1);
4883        luaL_checktype(L, 2, LUA_TTABLE);
4884        uint32_t color = (uint32_t)luaL_checkinteger(L, 3);
4885    
4886        // Read vertices from table
4887        int table_len = (int)lua_rawlen(L, 2);
4888        int vertex_count = table_len / 2;
4889        if (vertex_count < 3) {
4890            return luaL_error(L, "Polygon requires at least 3 vertices");
4891        }
4892        if (vertex_count > 8) vertex_count = 8;
4893    
4894        float vertices[16];
4895        for (int i = 0; i < vertex_count * 2; i++) {
4896            lua_rawgeti(L, 2, i + 1);
4897            vertices[i] = (float)lua_tonumber(L, -1);
4898            lua_pop(L, 1);
4899        }
4900    
4901        layer_add_polygon(layer, vertices, vertex_count, 0.0f, color);
4902        return 0;
4903    }
4904    
4905    // layer_polygon_line(layer, vertices_table, color, line_width?) -- polygon outline
4906    static int l_layer_polygon_line(lua_State* L) {
4907        Layer* layer = (Layer*)lua_touserdata(L, 1);
4908        luaL_checktype(L, 2, LUA_TTABLE);
4909        uint32_t color = (uint32_t)luaL_checkinteger(L, 3);
4910        float line_width = (float)luaL_optnumber(L, 4, 1.0);
... [10 more lines]

Confirmed flat {x1, y1, x2, y2, ...} format. Making the changes:

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done. Changes:

• Diamond visual: 4-vertex polygon {0,-r, r,0, 0,r, -r,0} drawn with layer_polygon_line (hollow, 1.5 px stroke) for the normal state and layer_polygon (filled) for the spawn flash. Fixed orientation (no rotation applied), since a diamond has 4-fold symmetry.
• Death on chamber contact: e:kill() replaces the push impulse. Enemies vanish on touch.
• Cleaned up: removed the entire push() method, pushed/spin tracking, and the constants that supported them (CONTACT_PUSH_FORCE, PUSH_DURATION, ENEMY_DAMPING_PUSHED).

Note: the collider is still a circle (radius 8) — its hit area roughly matches the diamond's inscribed-to-circumscribed range. If precise diamond hit detection matters later (e.g. for tight projectile aim), we'd swap it for a polygon collider.

Worth flagging — this is a meaningful gameplay shift from the original prototype's "enemies bounce off the chamber" model. Now the chamber is a death zone for any enemy that touches it. Open question for later: does the chamber take damage from these contacts, or is touching it simply free for the player? Worth deciding when we get to the fail-state question.

[Pasted image/png]

Three things: the edges of the screen should have an area on all four sides that we'll use for cards, UI, as well as other gameplay objects. It should be thick enough to contain everything, maybe 1/3rd of the height of the central square or in width, for all sides. So, the entire screen is covered by that on the sides, like a border. Enemies will spawn from outside the border edge (inwards) instead of the pure edge of the screen itself. I also want to try a visual effect that will be used throughout the game. A shader that does the grid dots, except they're very close together and also warped by some noise, like perlin, or whatever, in terms of the size of each grid point. This effect takes most inspiration from the kinds of dots you see in manga pages or in anime-style videos, where they use these to give something to the backgrounds and so on. This grid is not visible generally. It's invisible, but when we draw certain shapes, that portion of the grid (that collides with the shape) is drawn as the grid itself. So if we spawn particles, or if we draw a shockwave, or whatever, it should look as though we can see the grid in the shape of that effect, the idea being that most effects will use this to add some juice to things, because spawning particles looks a bit distasteful in a game like this, so I wanna try something like that. And then last thing... I forgot. Ah, the enemies should be more like the shape in the image, directional so their movement direction is visible from a glance. Ask me any questions before doing all of this.

Good, holding off on implementation. A few clarifying questions before I touch anything — batched by topic:

Scope & order

1. I'd split this into three sub-phases:
   • (A) Border zone + spawn change (small, low-risk).
   • (B) Directional enemy shape (small).
   • (C) Grid-dots reveal shader (substantial — new layer, custom GLSL, mask API).

   We test (A), then (B), then (C). Do this, or you want all three landed together?

Border zone

1. Visualization. Three options:

   • (a) Invisible logical area — defined as constants only, nothing drawn.
   • (b) Faint hairline at the inner boundary — 1 px charcoal or light-grey marking "edge of gameplay zone".
   • (c) Fully drawn frame — panel fills, dividers, slots like the design sheet's UI mockups.

   I'd start at (b) — visible enough to read the layout while we build, easy to remove or upgrade later. OK?

2. Thickness. "1/3rd the height of the central square" → I'm reading this as 80 px (1/3 of 240) on all four sides. So the inner gameplay area becomes 1760 × 920 with the 240 × 240 chamber centered in it (lots of room around the chamber for now). Confirm?

Enemy shape

1. The image shows a hollow rightward-pointing triangle (▷). Two interpretations: a plain triangle (3 vertices, equilateral or isoceles), or an arrow with stem (head + tail). Which do you want? My read of the image is the plain triangle, but it's a thumbnail.

2. With a directional shape we go back to tracking velocity → facing. Lerping self.r toward atan(vy, vx) like the prototype did. Just confirming you want that re-enabled (we'd dropped it for the diamond's symmetry).

Grid-dots reveal shader

1. Mask mechanism. My proposal: a dedicated mask_layer that game code draws ordinary shapes into (layer_circle(mask_layer, ...) etc.). A second pass runs the dot-grid shader over the screen, sampling the mask layer's alpha — anywhere alpha > 0, the shader outputs the dotted grid; elsewhere it outputs nothing. Effects are then just "draw a circle/ring/etc. into the mask layer". Same authoring vocabulary as drawing a regular shape, but the result is the grid revealed within that shape. Sound right, or did you have a different mental model?

2. Noise: animated or static. Static = the noise field doesn't change over time, so the grid pattern is the same pattern every time it's revealed. Calmer, cheaper. Animated = the noise drifts very slowly, so revealed regions have a subtle live shimmer. More alive, slightly more GPU. Lean which way?

3. Color of revealed dots. Always ink (so the grid reads as "negative-space blueprint texture"), or per-effect tintable (pink dots for damage, ink for default, etc.)? I'd default to ink-only for design cohesion, and add per-effect color later if a specific moment demands it. OK?

Once I have answers I'll start with sub-phase (A).

1. One at a time.
2. Sure, b seems fine.
3. Sure, let's try it.
4. The image actually shows a triangle but at the base it goes inside a little, I don't know what that shape is called.
5. Sure.
6. Sure.
7. Let's try static first.
8. Always the same, black.

Sub-phase A — border zone + spawn change. Will hold off on directional enemy and the shader.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now add a draw helper for the border hairline and call it in draw():

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Sub-phase A done. When you run it:

• A faint light-grey 1 px rectangle is drawn at coords (80, 80) to (1840, 1000) — the inner edge of the 80 px border zone. Reads as a quiet "this is the gameplay area" boundary.
• Enemies now spawn at that inner boundary (not at the screen edge), so they emerge from the border zone heading inward.
• The chamber sits at screen center which also happens to be the gameplay-area center (gameplay area is symmetric around screen center).

Things to evaluate:

1. Hairline visibility. #DADADA against #F6F4F0 paper might be too faint. If you can't see it at all, I'll bump to charcoal (#4A4A4A). If it's too prominent and competes with the chamber, I'll go even lighter.
2. Layout proportions. Lots of empty space between the border and the chamber now. That's deliberate — UI/cards are going to fill the border zone, and gameplay objects (enemies passing through, projectiles flying out, eventually other things) will live in the gap. Tell me if it looks too cavernous.
3. Spawn position. Enemies appear at the inner edge — right where they cross from "off-limits border" to "in-play". Reads correctly?

Once eyeballed, sub-phase B (directional triangle-with-notched-base enemy) is next.

Looks good. Projectiles should also disappear on this border instead of screen edge.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

240    -- Enforce constant speed.
241   local vx, vy = self.collider:get_velocity()
242   local s = math.length(vx, vy)
243   if s > 0.01 then
244     local k = self.speed / s
245     self.collider:set_velocity(vx * k, vy * k)
246   end
247   self.collider:sync()
248 end
249 
250 function ball:draw()
251   local s = self.spring.hit.x
252   layer_push(game_layer, self.x, self.y, 0, s, s)
253   layer_circle(game_layer, 0, 0, self.radius, ink_color())
254   layer_pop(game_layer)
255 end
256 
257 function ball:destroy()
258   if self.collider then self.collider:destroy() end
259 end
260 
261 -- =============================================================================
262 -- projectile — sensor body, straight-line flight, dies after PROJECTILE_LIFETIME.
263 -- Homing logic and enemy hits arrive in phase 5.
264 -- =============================================================================
265 projectile = class()
266 
267 function projectile:new(x, y, angle)
268   self.x, self.y = x, y
269   self.r         = angle
... [5 more lines]

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now find and update projectile:update:

288:function projectile:update(dt)
289-  timer_update(self.timer, dt)
290-  spring_update(self.spring, dt)
291-  self.lifetime = self.lifetime - dt
292-  if self.lifetime <= 0 then self:kill(); return end
293-  self.collider:sync()
294-end
295-
296-function projectile:draw()
297-  -- Open chevron pointing along travel direction. Tip at origin; legs sweep
298-  -- back-up and back-down at PROJECTILE_HALF_ANGLE from the centerline.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done. Projectiles now die the frame after their center crosses any of the four GAME_AREA_* boundaries — i.e. the same hairline where enemies spawn. Removed the lifetime-based fallback since the border check is comprehensive (and per the no-redundant-fallback principle).

Side effect: projectile count will stabilize at a much smaller number now, since they die promptly instead of sitting offscreen for the rest of their 3-second lifetime. If you ever add card mechanics that need projectiles to bounce or persist past the border, we'll revisit.

Okay, what's the next step?

Sub-phase B — directional arrowhead-with-notched-base enemy.

Shape geometry: tip at the front, two back corners, and a fourth vertex notched inward from the base midpoint. Four vertices, drawn rotated to face the velocity direction.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

<tool_use_error>String to replace not found in file.
String: -- =============================================================================
-- enemy — diamond shape spawned at a screen edge that seeks the chamber and
-- dies on contact with the chamber wall. Steering combines `seek` (toward
-- chamber) with `separate` (avoid clumping). Diamonds have 4-fold symmetry,
-- so we don't track a facing angle — they sit in a fixed points-up
-- orientation regardless of velocity.
-- =============================================================================
enemy = class()

function enemy:new(x, y)
  self.x, self.y   = x, y
  self.radius      = ENEMY_RADIUS
  self.base_speed  = random_float(ENEMY_SPEED_MIN, ENEMY_SPEED_MAX)
  self.speed       = self.base_speed
  self.flashing    = false
  make_entity(self)
  self.timer  = timer_new()
  self.spring = spring_new()

  self.collider = collider(self, 'enemy', 'dynamic', 'circle', self.radius)
  self.collider:set_position(x, y)
  self.collider:set_gravity_scale(0)
  self.collider:set_fixed_rotation(true)
  self.collider:set_linear_damping(ENEMY_DAMPING)

  -- Spawn pulse: brief squash + fill flash.
  spring_pull(self.spring, 'main', 0.75, 3, 0.7)
  self.flashing = true
  timer_after(self.timer, 0.15, 'spawn_flash', function() self.flashing = false end)
... [32 more lines]

The user must've reformatted the enemy block. Let me re-read it.

330:-- enemy — diamond shape spawned at a screen edge that seeks the chamber and
336:enemy = class()

328  
329 -- =============================================================================
330 -- enemy — diamond shape spawned at a screen edge that seeks the chamber and
331 -- dies on contact with the chamber wall. Steering combines `seek` (toward
332 -- chamber) with `separate` (avoid clumping). Diamonds have 4-fold symmetry,
333 -- so we don't track a facing angle — they sit in a fixed points-up
334 -- orientation regardless of velocity.
335 -- =============================================================================
336 enemy = class()
337 
338 function enemy:new(x, y)
339   self.x, self.y   = x, y
340   self.radius      = ENEMY_RADIUS
341   self.base_speed  = random_float(ENEMY_SPEED_MIN, ENEMY_SPEED_MAX)
342   self.speed       = self.base_speed
343   self.flashing    = false
344   make_entity(self)
345   self.timer  = timer_new()
346   self.spring = spring_new()
347 
348   self.collider = collider(self, 'enemy', 'dynamic', 'circle', self.radius)
349   self.collider:set_position(x, y)
350   self.collider:set_gravity_scale(0)
351   self.collider:set_fixed_rotation(true)
352   self.collider:set_linear_damping(ENEMY_DAMPING)
353 
354   -- Spawn pulse: brief squash + fill flash.
355   spring_pull(self.spring, 'main', 0.75, 3, 0.7)
356   self.flashing = true
357   timer_after(self.timer, 0.15, 'spawn_flash', function() self.flashing = false end)
... [36 more lines]

The reformatted block — single-line steering_separate. Re-doing the edit against the actual content.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Sub-phase B done. Changes:

• Shape: 4-vertex arrowhead. 18 px long × 14 px wide, 4 px back-notch — gives the "triangle with the base indented inward toward the tip" look you described. Hollow ink outline at 1.5 px (actor tier), filled ink for the spawn flash.
• Re-enabled rotation tracking. self.r lerps toward atan(vy, vx) each frame so the arrowhead points along its velocity. Skipped when nearly stationary to avoid an atan2(0, 0) snap.
• Initial facing. Spawned enemies start oriented toward the chamber, so the first frame doesn't flicker from "facing right by default" to "facing inward".

Things to evaluate:

1. Notch depth. 4 px out of 18 length (~22%). "A little indented" was your phrasing — too subtle, too aggressive, or right?
2. Proportions. 18 × 14. Does the arrowhead read as recognizably directional, or does it feel chunky/elongated?
3. Rotation feel. The lerp constant 0.99 / 0.1 is a fast-but-smooth setting. If turns look snappy or laggy, we tune those.
4. Spawn-facing. First-frame orientation toward chamber center should mean no visible "rotate from 0° to seek angle" snap on spawn.

Once you've eyeballed it, sub-phase C — the grid-dots reveal shader — is next.

Make the enemies a bit bigger, then move to the next phase.

Bumping enemy size first.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Enemies are now 24×18 px (was 18×14), notch 5, collider radius 10. Now to sub-phase C — the grid-dots reveal shader. Need to research how Anchor 2 handles shaders before coding.

162:extern const char* fragment_shader_source;
467:    // Extra texture bindings for shaders (bound right before apply_shader draws)
3672:static void layer_apply_shader(Layer* layer, GLuint shader) {
3762:static void execute_apply_shader(Layer* layer, GLuint shader) {
4497:                    // Store for binding during execute_apply_shader
4517:            execute_apply_shader(layer, cmd->shader_id);
4520:            // (execute_apply_shader toggled textures_swapped, so current is now the destination)
4698:static GLuint effect_shader_load_file(const char* path);
4699:static GLuint effect_shader_load_string(const char* frag_source);
5430:static int l_shader_load_file(lua_State* L) {
5437:    GLuint shader = effect_shader_load_file(path);
5449:static int l_shader_load_string(lua_State* L) {
5455:    GLuint shader = effect_shader_load_string(source);
5467:static int l_shader_destroy(lua_State* L) {
5481:static int l_shader_set_float_immediate(lua_State* L) {
5491:static int l_shader_set_vec2_immediate(lua_State* L) {
5502:static int l_shader_set_vec4_immediate(lua_State* L) {
5515:static int l_shader_set_int_immediate(lua_State* L) {
5580:static int l_layer_apply_shader(lua_State* L) {
5584:    layer_apply_shader(layer, shader);
8811:    shader_program = create_shader_program(vertex_shader_source, fragment_shader_source);
9131:    lua_register(L, "shader_load_file", l_shader_load_file);
9132:    lua_register(L, "shader_load_string", l_shader_load_string);
9133:    lua_register(L, "shader_destroy", l_shader_destroy);
9134:    lua_register(L, "shader_set_float_immediate", l_shader_set_float_immediate);
9135:    lua_register(L, "shader_set_vec2_immediate", l_shader_set_vec2_immediate);
9136:    lua_register(L, "shader_set_vec4_immediate", l_shader_set_vec4_immediate);
9137:    lua_register(L, "shader_set_int_immediate", l_shader_set_int_immediate);
9143:    lua_register(L, "layer_apply_shader", l_layer_apply_shader);
9368:// GLSL source strings, compile/link utilities, effect shader loading
... [2 more lines]

No matches found

4698 static GLuint effect_shader_load_file(const char* path);
4699    static GLuint effect_shader_load_string(const char* frag_source);
4700    static void effect_shader_destroy(GLuint shader);
4701    // Forward declarations for custom draw shader
4702    static int l_set_draw_shader(lua_State* L);
4703    static int l_get_draw_shader(lua_State* L);
4704    
4705    // ============================================================================
4706    // LUA BINDINGS: RENDERING
4707    // Layer, texture, font, audio, shaders
4708    // ============================================================================
4709    
4710    // Lua bindings
4711    // layer_create(name [, filter]) — filter is 'smooth' or 'rough'; defaults to global filter_mode.
4712    static int l_layer_create(lua_State* L) {
4713        const char* name = luaL_checkstring(L, 1);
4714    
4715        int layer_filter = filter_mode;  // default: global
4716        if (lua_gettop(L) >= 2 && !lua_isnil(L, 2)) {
4717            const char* mode = luaL_checkstring(L, 2);
4718            if (strcmp(mode, "smooth") == 0) {
4719                layer_filter = FILTER_SMOOTH;
4720            } else if (strcmp(mode, "rough") == 0) {
4721                layer_filter = FILTER_ROUGH;
4722            } else {
4723                return luaL_error(L, "Invalid layer filter: %s (use 'smooth' or 'rough')", mode);
4724            }
4725        }
4726    
4727        Layer* layer = layer_get_or_create(name, layer_filter);
... [90 more lines]

3672 static void layer_apply_shader(Layer* layer, GLuint shader) {
3673        if (!shader) return;
3674        if (layer->command_count >= MAX_COMMAND_CAPACITY) return;
3675    
3676        DrawCommand* cmd = &layer->commands[layer->command_count++];
3677        memset(cmd, 0, sizeof(DrawCommand));
3678        cmd->type = COMMAND_APPLY_SHADER;
3679        cmd->shader_id = shader;
3680    }
3681    
3682    // Queue uniform setting commands (deferred - applied when processing commands)
3683    static void layer_shader_set_float(Layer* layer, GLuint shader, const char* name, float value) {
3684        if (!shader || layer->command_count >= MAX_COMMAND_CAPACITY) return;
3685    
3686        GLint loc = glGetUniformLocation(shader, name);
3687        if (loc == -1) return;  // Uniform not found
3688    
3689        DrawCommand* cmd = &layer->commands[layer->command_count++];
3690        memset(cmd, 0, sizeof(DrawCommand));
3691        cmd->type = COMMAND_SET_UNIFORM_FLOAT;
3692        cmd->shader_id = shader;
3693        cmd->uniform_location = (uint32_t)loc;
3694        cmd->params[0] = value;
3695    }
3696    
3697    static void layer_shader_set_vec2(Layer* layer, GLuint shader, const char* name, float x, float y) {
3698        if (!shader || layer->command_count >= MAX_COMMAND_CAPACITY) return;
3699    
3700        GLint loc = glGetUniformLocation(shader, name);
3701        if (loc == -1) return;
... [100 more lines]

162:extern const char* fragment_shader_source;
4699:static GLuint effect_shader_load_string(const char* frag_source);
5455:    GLuint shader = effect_shader_load_string(source);
8811:    shader_program = create_shader_program(vertex_shader_source, fragment_shader_source);
9420:const char* fragment_shader_source =
9713:static GLuint effect_shader_load_string(const char* frag_source) {
9749:    GLuint shader = effect_shader_load_string(source);

9713 static GLuint effect_shader_load_string(const char* frag_source) {
9714        return create_shader_program(screen_vertex_source, frag_source);
9715    }
9716    
9717    // Replace the default draw shader with a custom fragment shader (uses the same vertex shader).
9718    // The projection matrix and AA width are set every frame in the render loop, so they'll
9719    // automatically apply to the new shader.
9720    static GLuint custom_draw_shader = 0;
9721    static int l_set_draw_shader(lua_State* L) {
9722        if (headless_mode) return 0;
9723        const char* path = luaL_checkstring(L, 1);
9724        char* source = read_file_to_string(path);
9725        if (!source) return luaL_error(L, "Failed to read draw shader: %s", path);
9726        GLuint shader = create_shader_program(vertex_shader_source, source);
9727        free(source);
9728        if (!shader) return luaL_error(L, "Failed to compile draw shader: %s", path);
9729        if (custom_draw_shader) {
9730            glDeleteProgram(custom_draw_shader);
9731            mem_gl_program_count--;
9732        }
9733        custom_draw_shader = shader;
9734        shader_program = shader;
9735        printf("Custom draw shader loaded: %s\n", path);
9736        return 0;
9737    }
9738    
9739    // Get the current draw shader ID (so Lua can set uniforms on it via layer_shader_set_*)
9740    static int l_get_draw_shader(lua_State* L) {
9741        lua_pushinteger(L, (lua_Integer)shader_program);
9742        return 1;
... [70 more lines]

163:extern const char* screen_vertex_source;
8863:    screen_shader = create_shader_program(screen_vertex_source, screen_fragment_source);
9611:const char* screen_vertex_source =
9712:// Create an effect shader program from fragment source (uses screen_vertex_source)
9714:    return create_shader_program(screen_vertex_source, frag_source);

9611 const char* screen_vertex_source =
9612        "layout (location = 0) in vec2 aPos;\n"
9613        "layout (location = 1) in vec2 aTexCoord;\n"
9614        "uniform vec2 u_offset;\n"  // Offset in NDC (-1 to 1 range)
9615        "out vec2 TexCoord;\n"
9616        "void main() {\n"
9617        "    gl_Position = vec4(aPos + u_offset, 0.0, 1.0);\n"
9618        "    TexCoord = aTexCoord;\n"
9619        "}\n";
9620    
9621    const char* screen_fragment_source =
9622        "in vec2 TexCoord;\n"
9623        "out vec4 FragColor;\n"
9624        "uniform sampler2D screenTexture;\n"
9625        "void main() {\n"
9626        "    FragColor = texture(screenTexture, TexCoord);\n"
9627        "}\n";
9628    
9629    // Compile a shader and return its ID (0 on failure)
9630    // Automatically prepends platform-specific header
9631    static GLuint compile_shader(GLenum type, const char* source) {
9632        const char* header = (type == GL_VERTEX_SHADER) ? SHADER_HEADER_VERT : SHADER_HEADER_FRAG;
9633    
9634        // Concatenate header + source
9635        size_t header_len = strlen(header);
9636        size_t source_len = strlen(source);
9637        char* full_source = (char*)malloc(header_len + source_len + 1);
9638        memcpy(full_source, header, header_len);
9639        memcpy(full_source + header_len, source, source_len + 1);
9640    
... [70 more lines]

388:    COMMAND_SET_UNIFORM_FLOAT,  // Set float uniform on shader
3691:    cmd->type = COMMAND_SET_UNIFORM_FLOAT;
4473:        if (cmd->type == COMMAND_SET_UNIFORM_FLOAT ||
4484:                case COMMAND_SET_UNIFORM_FLOAT:
4487:                case COMMAND_SET_UNIFORM_VEC2:
4490:                case COMMAND_SET_UNIFORM_VEC4:
4493:                case COMMAND_SET_UNIFORM_INT:
4496:                case COMMAND_SET_UNIFORM_TEXTURE: {

4467 
4468        for (int i = 0; i < layer->command_count; i++) {
4469            const DrawCommand* cmd = &layer->commands[i];
4470    
4471            // Handle uniform setting commands
4472            // These need to temporarily switch programs, so flush batch first and restore after
4473            if (cmd->type == COMMAND_SET_UNIFORM_FLOAT ||
4474                cmd->type == COMMAND_SET_UNIFORM_VEC2 ||
4475                cmd->type == COMMAND_SET_UNIFORM_VEC4 ||
4476                cmd->type == COMMAND_SET_UNIFORM_INT ||
4477                cmd->type == COMMAND_SET_UNIFORM_TEXTURE) {
4478                // Flush any pending draws before switching programs
4479                batch_flush();
4480                current_batch_texture = 0;
4481    
4482                glUseProgram(cmd->shader_id);
4483                switch (cmd->type) {
4484                    case COMMAND_SET_UNIFORM_FLOAT:
4485                        glUniform1f((GLint)cmd->uniform_location, cmd->params[0]);
4486                        break;
4487                    case COMMAND_SET_UNIFORM_VEC2:
4488                        glUniform2f((GLint)cmd->uniform_location, cmd->params[0], cmd->params[1]);
4489                        break;
4490                    case COMMAND_SET_UNIFORM_VEC4:
4491                        glUniform4f((GLint)cmd->uniform_location, cmd->params[0], cmd->params[1], cmd->params[2], cmd->params[3]);
4492                        break;
4493                    case COMMAND_SET_UNIFORM_INT:
4494                        glUniform1i((GLint)cmd->uniform_location, (int)cmd->params[0]);
4495                        break;
4496                    case COMMAND_SET_UNIFORM_TEXTURE: {
... [30 more lines]

9373:    #define SHADER_HEADER_VERT "#version 300 es\n"
9374:    #define SHADER_HEADER_FRAG "#version 300 es\nprecision mediump float;\n"
9376:    #define SHADER_HEADER_VERT "#version 330 core\n"
9377:    #define SHADER_HEADER_FRAG "#version 330 core\n"
9632:    const char* header = (type == GL_VERTEX_SHADER) ? SHADER_HEADER_VERT : SHADER_HEADER_FRAG;

4453:static void layer_render(Layer* layer) {
5628:static int l_layer_render(lua_State* L) {
5646:    layer_render(layer);
9148:    lua_register(L, "layer_render", l_layer_render);

4453 static void layer_render(Layer* layer) {
4454        batch_vertex_count = 0;
4455        current_batch_texture = 0;
4456        uint8_t current_blend = BLEND_ALPHA;  // Start with default
4457        apply_blend_mode(current_blend);
4458    
4459        // Set u_aa_width for this layer's filter mode. The default draw shader is
4460        // shared across all layers, so we rebind the uniform each time a layer is
4461        // rendered so smooth and rough layers can coexist in the same frame.
4462        // Shape and sprite/glyph branches both branch on u_aa_width.
4463        glUseProgram(shader_program);
4464        GLint aa_loc = glGetUniformLocation(shader_program, "u_aa_width");
4465        float aa_width = (layer->filter_mode == FILTER_SMOOTH) ? 1.0f : 0.0f;
4466        glUniform1f(aa_loc, aa_width);
4467    
4468        for (int i = 0; i < layer->command_count; i++) {
4469            const DrawCommand* cmd = &layer->commands[i];
4470    
4471            // Handle uniform setting commands
4472            // These need to temporarily switch programs, so flush batch first and restore after

1923:static void layer_clear_commands(Layer* layer) {
3782:    glClear(GL_COLOR_BUFFER_BIT);
5611:static int l_layer_clear(lua_State* L) {
5621:    glClear(GL_COLOR_BUFFER_BIT);
5639:    glClear(GL_COLOR_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
8561:    glClear(GL_COLOR_BUFFER_BIT);
8674:    glClear(GL_COLOR_BUFFER_BIT);
9147:    lua_register(L, "layer_clear", l_layer_clear);
10117:            layer_clear_commands(layer_registry[i]);
10248:        glClear(GL_COLOR_BUFFER_BIT);
10569:                    layer_clear_commands(layer_registry[i]);
10640:                glClear(GL_COLOR_BUFFER_BIT);
10713:            glClear(GL_COLOR_BUFFER_BIT);

5628 static int l_layer_render(lua_State* L) {
5629        if (headless_mode) return 0;
5630        Layer* layer = (Layer*)lua_touserdata(L, 1);
5631    
5632        // Bind layer's FBO
5633        glBindFramebuffer(GL_FRAMEBUFFER, layer->fbo);
5634        glViewport(0, 0, layer->width, layer->height);
5635    
5636        // Clear color and stencil buffers
5637        glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
5638        glClearStencil(0);
5639        glClear(GL_COLOR_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
5640    
5641        // Ensure stencil starts disabled
5642        glDisable(GL_STENCIL_TEST);
5643        glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
5644    
5645        // Process all queued commands
5646        layer_render(layer);
5647    
5648        // Ensure stencil is disabled after rendering (in case commands left it enabled)
5649        glDisable(GL_STENCIL_TEST);
5650        glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
5651    
5652        // Clear command queue for next frame

I have what I need. The shader model is shader_load_string(source) → ping-pong apply via layer_apply_shader(mask_layer, dot_shader) over a layer's contents. The mask layer is the input texture; the shader outputs the dot pattern wherever the mask has alpha.

Plan for sub-phase C:

1. New mask_layer.
2. Define and load a fragment shader: reads mask alpha, computes grid cell + dot center + value-noise-modulated radius, outputs ink-colored dots wherever mask alpha > 0.5.
3. Set static uniforms once at init via the _immediate setters.
4. Draw a fixed test circle into mask_layer so you can visually inspect the dot pattern.
5. Composite mask_layer between game_layer and ui_layer in the draw flow.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now wire the mask layer + test shape into the draw flow:

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Sub-phase C done. When you run:

• A new mask_layer exists alongside game_layer and ui_layer.
• A custom GLSL fragment shader is loaded once at init and configured with the grid params.
• A static 80 px-radius test circle is drawn into mask_layer at (1500, 540) (right side of screen, vertically centered).
• The shader runs over the mask layer, producing a circle-shaped patch of small ink dots — spaced 5 px apart, with each dot's radius modulated by static value-noise (60–170% of base 1.2 px).
• The result composites between gameplay and UI.

Things to evaluate visually — these all matter because they control how this'll feel for every effect downstream:

1. Density. 5 px spacing → ~330×220 dots in a 1080p frame. Manga-y enough, or want tighter (3–4 px) / looser (6–8 px)?
2. Dot size + noise variation. Base 1.2 px, ±70% modulation. Want bigger/smaller average dots? More/less variation between adjacent dots?
3. Noise scale. 0.05 per cell unit means the noise field has ~20-cell (~100 px) period. Want softer big blobs of variation (lower scale) or chunkier small clumps (higher scale)?
4. Edge crispness. The mask shape's edge cuts off dots at half-alpha. Should be a clean circle outline filled with the dot pattern — confirm it doesn't look fuzzy.
5. Position/orientation. Confirm the patch appears on the right side of the screen (1500, 540). If the Y is flipped (TexCoord conventions can do that), let me know — easy fix.

If the visual lands well, we'll plumb it into actual effects next time we work on FX. If it needs major tuning, I'll iterate the params or shader logic.

Yes, that visual looks exactly like I was imagining. Can you draw a bigger circle so I can see more of the underlying variance in the dots?

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Bumped to 250 px radius (500 px diameter). At our u_noise_scale = 0.05 and u_spacing = 5, the noise field has roughly ~100 px period, so you'll see ~5 cycles of variation across the patch — enough to read whether the noise feels right (too repetitive, too chaotic, right amount of "warp"). Tell me if you want any of the params tuned now that you can see the field properly.

Great, now let's try various effects using this. You can be inspired by what's done in Orblike, I guess? Hit circles, particles, the works. Except the particles should be thick lines, they should never be small dots themselves I don't think, otherwise the dot effect won't be visible. Or maybe we should have "particles" at all, and just hit circle or something of that nature, I don't know yet. You can try some variations and some ideas of your own regarding effects whenever things happen. Ah, importantly, the way enemies spawn should be... they should fade into the world, modulated by the dot effect. So as they're coming out of the border edges they're mostly made up of the dots, and then as they move in they tween into their final form into of the dot form, if that makes sense.

Big batch but coherent. Plan:

1. Add hit_burst (filled circle that shrinks) and hit_line (capsule particle that flies, slows, and shrinks) — both draw into mask_layer.
2. Replace enemy's brief flash with a spawn fade: silhouette appears in mask_layer (showing as dots) for ~0.5 s, while the solid outline crossfades up over ~0.7 s in game_layer.
3. Wire effects: enemy death (burst + 4–6 lines), ball wall-hit (small burst). Skipping projectile death — its spawn cluster already has spring squash and adding effects to per-frame projectile deaths at the border would be visual noise.
4. Remove the test mask circle. Wire effects into update/draw, attach camera to mask_layer too so coordinates stay aligned.

Let me also quickly verify a couple of API details before writing.

E:\a327ex\Anchor2\framework\anchor\math.lua:222:function math.clamp(value, min, max)
E:\a327ex\Anchor2\framework\anchor\timer.lua:125:function timer_tween(t, duration, name_or_target, target_or_values, values_or_easing, easing_or_after, after_function)

OK writing now. Starting with constants + effects collection:

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Now insert the FX classes between projectile and enemy:

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Now update the enemy: remove flashing, add spawn_age, replace flash logic with crossfade, add die:

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Now hook the ball wall-hit into a small burst, swap collision drain to call e:die(), and wire effects into update/draw:

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Done. Summary of what's now happening in the game:

Enemy spawn fade. When an enemy appears at the border, for the first 0.5 s its silhouette is drawn into mask_layer (rendered as the dot pattern by the shader); meanwhile, its solid outline crossfades up in game_layer over 0.7 s. Net effect: enemies "compile" out of the dot field as they approach the chamber.

Enemy death (on chamber contact). Spawns:

• One hit_burst — 50 px filled circle that shrinks to 0 over 0.4 s with cubic-in-out easing, drawn into the mask layer (so it reads as a dot-pattern explosion).
• 4–6 hit_line particles — thick 6 px capsules of length 20–32 flying out at 180–350 px/sec, decelerating and shrinking over 0.3–0.5 s. Each one shows a streak of dots tapering off.

Ball wall hit. Small 14 px hit_burst at the contact point, 0.18 s — a quiet "blip" of dots co-located with the projectile spawn.

Things to evaluate:

1. Spawn fade timing. Mask 0.5 s, solid 0.7 s. Too fast / too slow / too crossfaded? Want to see more of the dot phase?
2. Death pop weight. 50 px burst + 4–6 lines. Too busy / not enough impact / right?
3. Ball-hit blip. Currently very subtle (14 px, 0.18 s). Easy to miss against the projectile. Should it be bigger so the wall-hit reads more, or stay quiet?
4. Particle line readability. 6 px thick — confirm that you can see the dot pattern within the line capsules (vs. them looking like solid bars).
5. General "effect density". Does the dot-fx on enemy deaths and ball hits feel like the right rhythm, or is the screen too busy when many enemies die in a short period?

Once you've eyeballed it, we can tune any of those — or roll into adding more effect triggers.

Spawn fade timing: both 1, both should also be alpha'd so that their relative darkness is lower, it should be a faint enemy at first that becomes more solid over time. Death pop: try 24px size, 50px is too big, try hit lines with higher variance across all axes. Ball hit: this is fine. Particle line: fine. General: add similar effect to ball hit when projectiles die. The real only problem with this effect is that it collides a bit with the rest of the game. For instance, when the effect happens over the rectangle in the middle, the solid nature of the rectangle is a bit jarring with the dot effect layered on top. But I'm not sure how to fix it or what to do about it...

Good batch. Let me work through each.

For the chamber collision issue — I have a concrete fix idea. Right now the shader outputs transparent in the gaps between dots (within a mask region), so the chamber line shows through those gaps and looks "stuck behind" the effect. If instead the shader outputs paper color in the gaps (with alpha controlled by mask intensity), the mask region effectively "carves out" a paper-and-dots patch over game_layer — when the mask is fully on it covers the chamber line entirely, when partly on it blends. That's a clean structural fix; let me roll it in.

Also: changing the shader from binary cutoff (mask_a < 0.5 ? discard) to alpha-modulated output, so the spawn fade can actually have faint dots at low mask alpha.

Updating shader first:

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Now constants — spawn duration to 1s, burst radius to 24, wider line variance, add thickness range:

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Update hit_line:new to randomize thickness too:

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Update enemy spawn fade to use both alphas with the new shader behavior:

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Add a projectile:die() method with a small burst at the death position, and call it from update:

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Done. Summary:

Spawn fade. Both timings consolidated to ENEMY_SPAWN_FADE_TIME = 1.0. Mask alpha tweens 0.5 → 0, solid alpha tweens 0 → 1. The combined visual at any moment is faint at start (just half-strength dot blob) and fully solid at end.

Death pop. Burst radius 50 → 24 (much tighter pop). Hit-line variance widened across all four axes:

• length 12–40 (was 20–32)
• thickness 5–10 (was a fixed 6, now randomized per particle)
• velocity 100–500 (was 180–350)
• duration 0.20–0.65 (was 0.30–0.50)

So a single death now produces 4–6 streaks of widely varying weight, length, speed, and lifespan — chaotic shower instead of uniform spray.

Projectile death. Same kind of small burst as ball-on-wall (14 px / 0.18 s). Each projectile that crosses the border now leaves a quiet dot-blip at its exit point.

Chamber-collision fix. This is the structural change you flagged. The shader now outputs paper color in the dot gaps (instead of transparent), with the fragment alpha controlled by mask_a. So when a mask is fully opaque it cleanly carves out a paper-and-dots patch over whatever's underneath in game_layer (chamber lines, border, etc.) — no more "solid line peeking through the dot gaps". When the mask is partly opaque (during the spawn fade's faint dots, for example), it blends — chamber line is partially visible underneath the half-strength dots, which is the right behavior for a faint effect.

If you see weird-looking edges or unexpected solid regions, it'll be from the new shader behavior — let me know and we can tune the alpha curves or the gap fill.

Yes, this looks much better. Let's remove the particles from enemy death and let's have the hit circle actually be a diamond, so a rotated square, to match the fact that enemies aren't circles. The same goes for the effect when projectiles die.

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Now change the burst shape from circle to diamond, and remove the hit_line class:

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Strip the line-particle spawning from enemy:die:

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Done. Summary:

• hit_burst shape: circle → diamond. Axis-aligned, points up/down/left/right, same radius semantics (half the point-to-point span). Affects all three users automatically: enemy death (24 px), ball wall hit (14 px), projectile death (14 px).
• Particles removed. No more hit_line flying outward on enemy death — just the single shrinking diamond. The class and all HIT_LINE_* constants deleted (dead code).
• enemy:die simplified to one line spawning the burst.

Visual hierarchy now: enemies are arrowheads (variant of the diamond family), and their hit/death FX are diamond bursts — same shape vocabulary throughout. The dot pattern inside the diamond gives the dispersion feel that the line particles previously did.

Enemy death effect should be a bit smaller, last a little less, and be spawned on top of the colliding wall, instead of on enemy position, for consistency.

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Done.

• Size: burst radius 24 → 18.
• Duration: 0.4 → 0.3.
• Position: spawns at the collision contact point (ev.x, ev.y) instead of the enemy's center. Same convention as ball:on_wall_hit, so wall impacts read consistently regardless of which actor caused them.

22 I think. After that, what's the next phase?

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Set to 22.

Where we are vs. the original phase plan:

• ✅ Phase 1 — scaffold + chamber
• ✅ Phase 2 — ball
• ✅ Phase 3 — projectiles
• ✅ Phase 4 — enemies (+ border zone, dot shader, spawn fade, hit FX — overflowed into other phases)
• ⬜ Phase 5 — homing + actual combat ← next
• 🟡 Phase 6 — hit/death FX (already partly done; spawn fade, hit_burst, projectile death blip — could revisit later for any gaps)
• ⬜ Phase 7 — HUD / typography
• ⬜ Phase 8 — reset key + tuning

Phase 5 — homing + combat. Currently projectiles fly outward in a straight line and just die at the border. They never interact with enemies. Phase 5 closes that loop:

1. Sensor pair: physics_enable_sensor('projectile', 'enemy') so contacts fire events.
2. Homing logic in projectile:update. Each frame, scan for the nearest enemy within a 60° cone ahead of the projectile's current facing; if found, turn toward it at a capped angular rate. If no target in cone, fly straight. (Direct port of the prototype.)
3. Enemy HP. Add ENEMY_HP (starting at 1 or 2 — 1 means one-shot kills, 2 means projectiles need two hits). I'd lean 1 for now since enemies already feel disposable, but it's an early gameplay knob.
4. Hit handling. On sensor begin: enemy takes damage, projectile dies. If enemy HP reaches 0, it dies via the existing :die() (which now spawns the diamond burst). Non-killing hits get a brief feedback — probably a quick mask flash (the enemy's silhouette appears in mask_layer for ~0.1 s, so it strobes through the dot pattern) plus a spring squash.
5. Projectile-on-enemy hit FX. The projectile's death already spawns a small burst (from phase 6 work) — for projectile-on-enemy that fires at the enemy's position, which feels right.

After phase 5 the game will have a proper combat loop: ball → projectiles → home → kill → enemies stop reaching the chamber. We can also consider a fail state at that point (chamber HP) but that's a design question for later.

Want me to start phase 5? And on the HP — start with 1 (one-shot kills) or 2?

Let's do projectile enemy hit + enemy death first.

Smaller scope first. Plan:

1. Enable the projectile/enemy sensor.
2. In the main update, drain sensor_entities_begin('projectile', 'enemy') — for each event, kill the projectile silently (the enemy's death burst is the visual; no need for a second projectile burst overlapping it) and call e:die(p.x, p.y) so the burst spawns at the actual impact point.

Skipping homing and HP for now per your "first" — projectiles still fly straight, but if they happen to hit something, that something dies.

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Now add the sensor drain to the main update. Let me find the right spot:

639:  for _, ev in ipairs(collision_entities_begin('enemy', 'chamber')) do
640-    local e = ev.a
641-    if e and not e._dead then e:die(ev.x or e.x, ev.y or e.y) end
642-  end
643-
644-  camera_update(main_camera, dt)

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Done. Two changes:

• Sensor pair enabled between projectile and enemy.
• Sensor handler in the main update — on overlap, the enemy dies at the projectile's position (so the burst sits where the impact actually happened), and the projectile is killed silently. No homing, no HP, no fancy non-killing-hit feedback yet.

Without homing, hits will be rare — projectiles fly straight outward through the wall and only kill enemies that happen to be in their flight path. Good enough for a first verification: spawn enough enemies, watch a few get caught by lucky shots.

If the hits land correctly, next step is homing (so projectiles actually seek targets within the cone), then deciding on HP/non-killing-hit feedback.

Draw various static circles, rectangles on the screen, I need to show the effect to someone.

655    process_destroy_queue()
656 end
657 
658 function draw()
659   layer_rectangle(game_layer, 0, 0, width, height, paper_color())
660 
661   camera_attach(main_camera, game_layer)
662   camera_attach(main_camera, mask_layer)
663   draw_border_zone()
664   the_chamber:draw()
665   for _, e in ipairs(enemies) do e:draw() end
666   for _, b in ipairs(balls) do b:draw() end
667   for _, p in ipairs(projectiles) do p:draw() end
668   for _, fx in ipairs(effects) do fx:draw() end
669   camera_detach(main_camera, mask_layer)
670   camera_detach(main_camera, game_layer)
671 
672   layer_apply_shader(mask_layer, dot_shader)
673 
674   layer_render(game_layer)
675   layer_render(mask_layer)
676   layer_render(ui_layer)
677   layer_draw(game_layer)
678   layer_draw(mask_layer)
679   layer_draw(ui_layer)
680 end
681 

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Done. Eight static shapes drawn into mask_layer each frame:

• Left side: four circles of varied sizes (45, 75, 95, 130 radius) at different vertical positions.
• Right side: three rectangles (wide-short, square-ish, wide-tall) plus one small circle for variety.

All ink-colored, fully opaque, so the shader renders them as the full-strength dotted pattern. They sit clear of the chamber so the gameplay's still readable.

When done with the demo, remove the block marked TEMP and the demo shapes go away.

You can remove them, let's try making the center square less thick. I want to see if it being slightly less visible makes things look better.

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Demo shapes removed. Chamber stroke 2 → 1.5.

Heads-up on the design implication: at 1.5 the chamber is now at the actor tier, the same weight as projectile arms and enemy outlines. This breaks the "structure ≥ actors" hierarchy I locked into design.md (where chamber was supposed to be the loudest line in the world). If 1.5 ends up being the keeper, we'll want to either:

• Update the design rule to "chamber and actors share the actor tier", or
• Drop the chamber to thinner than actors (1 px) so it reads as annotation while actors stand out, or
• Bring it back to 2.

See how it looks first; the rule can chase the visual taste.

Make it 1

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Set to 1. Now the chamber is a hairline — the quietest line in the scene. Actors (projectile chevrons, enemy outlines, both at 1.5) will read as the loudest game-world elements; the chamber recedes to "annotation that frames the action". Inverted hierarchy from where we started, but might work given the dot effect now does most of the heavy "structure" lifting visually.

If this lands, the design.md rule needs a rewrite — happy to do that whenever you confirm the look.

Sure, you may update design.md. I also asked Chat to update the design taking into account the dotted effect, which I want to use now as a visual motif for the entire project. You see the new images in reference/, they all have (dotted) in the title. The differences aren't huge but they're there, so you may also change design.md to that effect, introducing the dotted motif where it makes sense and making it's described as such.

Let me check the new reference images and then update the design doc.

01 - ART DIRECTION (DOTTED).png
02 - GENERAL UI ELEMENTS (dotted).png
03 - TYPOGRAPHY (dotted).png
04 - COLOR AND TEXTURE (dotted).png
05 - GAME OBJECTS (dotted).png
06 - TEMPLATES AND USAGE (dotted).png

[
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    "type": "image",
    "note": "[image stored privately: vault/media/ricochet/006.png]"
  }
]

[
  {
    "type": "image",
    "note": "[image stored privately: vault/media/ricochet/007.png]"
  }
]

[
  {
    "type": "image",
    "note": "[image stored privately: vault/media/ricochet/008.png]"
  }
]

[
  {
    "type": "image",
    "note": "[image stored privately: vault/media/ricochet/009.png]"
  }
]

[
  {
    "type": "image",
    "note": "[image stored privately: vault/media/ricochet/010.png]"
  }
]

[
  {
    "type": "image",
    "note": "[image stored privately: vault/media/ricochet/011.png]"
  }
]

Reading the current design.md to plan the rewrite:

1    # chamber — design
2   
3   ## The game
4   
5   A square chamber sits at the center of the screen with a ball bouncing inside.
6   Every wall hit spawns a projectile that flies outward (radial from the chamber
7   center through the ball's position) and homes on the nearest enemy within a 60°
8   cone ahead of it. Enemies spawn from screen edges, seek the chamber, and
9   physically collide with the outer walls (pushed back on contact, Orblike-style).
10  Projectiles kill them.
11  
12  The chamber *is* the player — no separate avatar. The bounce-and-shoot engine
13  runs on autopilot. All active player agency lives one layer above it.
14  
15  ## Card / mana layer (Artifact-style)
16  
17  - **Deck drafting** before a run: build a deck from the available pool.
18  - **Each turn**: draw 2 cards, refresh a mana pool.
19  - **Spend mana** to play cards. Cards are the mod layer on top of the autopilot
20    engine: more mana, extra draw, add/modify a ball, change projectile behavior,
21    trigger burst attacks, buff/debuff, etc.
22  
23  Cards are the only active input during a run. Drafting + on-turn decisions are
24  where the game is actually played.
25  
26  ## v0 prototype
27  
28  Core loop is built and confirmed fun to watch (2026-04-23). Source archived at
29  `reference/main.lua`. A new instance will start a fresh main.lua using that as
30  a base.
... [179 more lines]

Going to update design.md in several places: revise the visual-design intro to point at the new (dotted) sheets, add a new "Dotted motif" section as a first-class visual language element, invert the line-weight hierarchy now that the chamber is 1 px, refresh the game-objects descriptions to match the actual implementation, and rework motion & FX to describe dot-bursts instead of line-burst particles.

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Now invert the line-weight hierarchy:

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Now insert the new "Dotted motif" section after Shape language:

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Update Composition & layout to reflect 240×240 chamber and the border zone:

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Now update Game objects to match the actual implementation:

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Update Motion & feel to describe dot-bursts instead of line-burst particles:

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Finally, the do/don't list:

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Updated design.md. Summary of changes:

• Visual design intro — references all six sheets, calls out the (dotted) variants as canonical, names the dotted motif as the secondary visual language alongside line work.
• Line weight & geometry — collapsed to two everyday tiers (hairline 1 px / thin 1.5 px) plus heavy. Structure and annotation now share the hairline tier (differentiated by ink vs charcoal), and actors at 1.5 px are the loudest stroked layer. Added a paragraph explaining why the inversion makes sense given the dot motif.
• New section: Dotted motif — placed between Shape language and Game objects. Covers what it is, the implementation model (mask layer + shader), where to use it (FX, transitions, structural texture, state signaling), the always-ink color convention, and why it explains the rest of the design choices.
• Composition & layout — replaced the stale 50×50 chamber with the actual 240×240 chamber inside a 1760×920 gameplay area inside an 80 px border zone, and noted enemies spawn at the inner border edge.
• Game objects — rewrote each entry to match what's in the code: chamber at 1 px, ball at 6 px filled, projectile chevron with size/spawn details, enemy as directional arrowhead with the dot-fade-in spawn behavior, cards using the dot motif as well as the shape alphabet.
• Motion & feel — replaced "1–2 frame color inversion + line-burst particle" with the explicit dot-burst-at-impact recipe, and listed the four current impact recipes with their actual sizes/durations.
• Do/Don't — added "use the dotted motif for FX/transitions/atmosphere" to the do, and "flying point/dot particles" to the don't (because the motif replaces them).

Two things I did not touch but you might want to revisit later:

1. The Palette section's accent list still has 6 colors. The new sheet 04 ("Color and Texture") seemed to show ~9 accents — I didn't try to extract the new ones because the thumbnails are still small and color sampling matters. If you want me to add them, send me the precise hexes or a higher-res of sheet 04.
2. The v0 prototype section still references the old constants (50×50 chamber, BALL_SPEED=180, etc.). That's historical context for a phase we've moved past, so I left it alone — but if it's confusing, we could replace it with current constants or just delete the section.

I think the only new color you can add is mid gray which is 8A8A8A

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Added #8A8A8A mid grey to both design.md (in the neutral palette, between charcoal and light grey) and main.lua (mid_grey_color). Sits roughly midway in luminance between the two it's flanked by, so it slots into the "inactive / mid-tier divider" semantic gap.

[Pasted image/png]

Let's change the structure of the border around the screen to something more like this, and then have enemies only spawn from left/right instead of all four directions.

Two changes — border structure to asymmetric (thick top/bottom, thin left/right), and enemies only from left/right.

For sizing, I'll guess from the image proportions: top ~120 px, bottom ~150 px (taller because the image shows two rows of HUD chips down there), left/right ~50 px each. The chamber re-centers on the gameplay area's actual center (which now sits slightly above screen-center vertically because of the asymmetric top/bottom split).

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Update the design doc to match:

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Done.

• Border: asymmetric — top 120, bottom 150, left 50, right 50.
• Chamber position: computed from gameplay-area center, so it ends up at (960, 525) — 15 px above screen center. Stays consistent if border values change later.
• Enemy spawn: only LEFT or RIGHT inner edge now. Half chance each.
• Design doc updated to describe the asymmetric layout and side-only spawning.

Things you'll notice and might want to tune:

1. Border thicknesses are guesses — I scaled from the image's apparent proportions. If they feel too thick or too thin, tell me which sides to bump.
2. Chamber is slightly above screen center because of the asymmetric vertical split. If you'd rather keep it dead-center on the screen and let the chamber sit "low" in the gameplay area, change CHAMBER_Y back to 540.
3. Visual structure inside the bars (the dividers, label slots, chips visible in the image) isn't built yet — that's HUD work for the typography/HUD phase. The current border draw is still just the outer hairline rectangle.

Left/right should have no border at all.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now update draw_border_zone to only draw the top and bottom hairlines (no need for left/right edges since the border there is zero):

524    local rx, ry = self.collider:steering_separate(self.radius * 1.5, enemies, self.speed, ENEMY_STEER_FORCE)
525   local fx, fy = math.limit(sx + rx, sy + ry, ENEMY_STEER_FORCE)
526   self.collider:apply_force(fx, fy)
527   local vx, vy = self.collider:get_velocity()
528   vx, vy = math.limit(vx, vy, self.speed)
529   self.collider:set_velocity(vx, vy)
530   -- Lerp facing toward velocity direction. Skip when nearly stopped to
531   -- avoid atan2(0, 0) snapping the arrowhead to a default angle.
532   if math.length(vx, vy) > 1 then
533     self.r = math.lerp_angle_dt(0.99, 0.1, dt, self.r, math.atan(vy, vx))
534   end
535   self.collider:sync()
536 end
537 
538 function enemy:draw()

609:function draw_border_zone()
610-  layer_rectangle_line(game_layer,
611-    GAME_AREA_LEFT, GAME_AREA_TOP,
612-    GAME_AREA_RIGHT - GAME_AREA_LEFT,
613-    GAME_AREA_BOTTOM - GAME_AREA_TOP,
614-    light_grey_color(), BORDER_HAIRLINE)
615-end
616-
617--- -----------------------------------------------------------------------------
618--- init
619--- -----------------------------------------------------------------------------

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Update design.md to reflect:

The file E:\a327ex\chamber\design.md has been updated successfully. (file state is current in your context — no need to Read it back)

Done.

• BORDER_LEFT and BORDER_RIGHT set to 0 — gameplay area is now full screen width.
• draw_border_zone now draws only two horizontal hairlines (at the inner edges of the top and bottom HUD bars) instead of a four-sided rectangle.
• Enemies spawn at x = 0 or x = 1920 (right at the screen edges) and slide inward.
• Design doc updated.

OK, what's next?

Two reasonable directions, your call:

1. Finish the combat loop — homing. Currently projectiles fly straight and rarely catch enemies. Adding the homing-cone logic from the prototype (60° cone, capped angular turn rate) makes the core game actually play: projectiles seek targets, the chamber meaningfully defends itself. Plus the related decisions — enemy HP (one-shot or two-shot?) and feedback for non-killing hits if we go HP>1. This is the most impactful single thing left on the gameplay side.

2. Start filling in the HUD. The image you sent has wave/timer/score on top, HP/currency/chips/enemy-count on bottom. That's typography + layout work — picking the actual condensed-sans and neutral-sans fonts, drawing the bar dividers, getting placeholder text in. Builds on the border restructure we just did.

I'd lean homing first because the game still feels incomplete without projectiles actually hitting things, and the HUD is more rewarding to build once the gameplay it's reporting on is real (a wave timer feels meaningless if there are no waves yet, etc.).

Which way?

Let's do the combat loop. Let's do homing, ricochet, multiple projectiles. Before that, also do a general pass on the main.lua file and split it into relevant files, however you see fit. Don't over-split, just do what's necessary for the various components of the game.

Going to do the split first as a single step, then combat in a follow-up. Let me read the current file in full so I split cleanly.

686 E:/a327ex/chamber/main.lua

1    --[[
2     chamber — Anchor 2 physics-ball survivor.
3   
4     Being built phase-by-phase. See design.md for the visual rules.
5   
6     Phase 4 (current): scaffold + chamber + ball + projectiles + enemies +
7     border zone + dot-grid reveal shader. Enemies are directional arrowheads
8     that spawn from the inner edge of an 80 px reserved border zone, seek
9     the chamber, and die on contact. The dot-grid shader is the manga-style
10    reveal effect — anything drawn into mask_layer becomes a noise-warped
11    grid of dots on output. Currently driven by a single test circle for
12    visual verification; will be wired to real effects in phase 6.
13  ]]
14  
15  require('anchor')({
16    width            = 1920,
17    height           = 1080,
18    title            = "chamber",
19    scale            = 1,
20    filter           = "smooth",
21    render_uncapped  = true,         -- vsync-paced render; 60Hz cap is for pixel-art
22    display          = 0,            -- primary monitor
23  })
24  
25  -- -----------------------------------------------------------------------------
26  -- palette (see design.md § Visual design)
27  -- -----------------------------------------------------------------------------
28  paper_color      = color(246, 244, 240)   -- #F6F4F0
29  ink_color        = color(17, 17, 17)      -- #111111
30  charcoal_color   = color(74, 74, 74)      -- #4A4A4A
... [657 more lines]

Let me check how the engine sets up Lua package paths so my requires resolve correctly.

9779:static int zip_searcher(lua_State* L) {
9855:static void register_zip_searcher(lua_State* L) {
9867:    // Insert zip_searcher at position 1
9868:    lua_pushcfunction(L, zip_searcher);
10413:    register_zip_searcher(L);  // Enable require() from embedded zip

9855 static void register_zip_searcher(lua_State* L) {
9856        // Get package.searchers table
9857        lua_getglobal(L, "package");
9858        lua_getfield(L, -1, "searchers");
9859    
9860        // Shift existing searchers down (1->2, 2->3, etc.)
9861        int n = (int)lua_rawlen(L, -1);
9862        for (int i = n; i >= 1; i--) {
9863            lua_rawgeti(L, -1, i);
9864            lua_rawseti(L, -2, i + 1);
9865        }
9866    
9867        // Insert zip_searcher at position 1
9868        lua_pushcfunction(L, zip_searcher);
9869        lua_rawseti(L, -2, 1);
9870    
9871        lua_pop(L, 2);  // Pop searchers and package
9872    }
9873    
9874    static void engine_shutdown(void) {
9875        // Game rendering resources
9876        if (vbo) { glDeleteBuffers(1, &vbo); vbo = 0; }
9877        if (vao) { glDeleteVertexArrays(1, &vao); vao = 0; }
9878        if (shader_program) { glDeleteProgram(shader_program); shader_program = 0; mem_gl_program_count--; }
9879        // Layers
9880        for (int i = 0; i < layer_count; i++) {
9881            layer_destroy(layer_registry[i]);
9882            free(layer_names[i]);
9883            layer_registry[i] = NULL;
9884            layer_names[i] = NULL;
... [60 more lines]

26:#include <direct.h>  // _chdir
31:#include <unistd.h>  // chdir
10336:        const char* game_folder = NULL;
10362:            } else if (!game_folder && !zip_initialized) {
10363:                game_folder = argv[i];
10366:        if (game_folder) {
10368:            _chdir(game_folder);
10370:            chdir(game_folder);
10372:            printf("Game folder: %s\n", game_folder);

Engine chdirs into the game folder, so require('entities') resolves correctly. Going with three files:

• dot_shader.lua — GLSL source + load + uniforms
• entities.lua — chamber, ball, projectile, hit_burst, enemy (and their spawn helpers)
• main.lua — config, palette, constants, physics, layers, requires, init, main loop, border draw

Writing the new files first, then rewriting main.lua:

File created successfully at: E:\a327ex\chamber\dot_shader.lua (file state is current in your context — no need to Read it back)

File created successfully at: E:\a327ex\chamber\entities.lua (file state is current in your context — no need to Read it back)

Now rewrite main.lua as the slim orchestrator:

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

  237 E:/a327ex/chamber/main.lua
  411 E:/a327ex/chamber/entities.lua
   83 E:/a327ex/chamber/dot_shader.lua
  731 total

Split done. New layout:

• main.lua (237 lines) — config, palette, constants, physics, layers, camera, requires, entity collections, draw_border_zone, init, update, draw. Top-to-bottom orchestration of the game.
• entities.lua (411 lines) — every entity class (chamber, ball, projectile, hit_burst, enemy) with their spawn helpers (spawn_projectile, spawn_enemy, random_edge_position).
• dot_shader.lua (83 lines) — GLSL source as a Lua string + shader_load_string + the immediate uniform setters. Self-contained except for its declared dependencies on width/height/ink_color/paper_color/GRID_* globals.

Load order in main.lua: framework → palette → constants → physics → layers/camera → require('dot_shader') → collections → require('entities') → init → loop. Each require runs after its declared dependencies are set.

Behaviorally identical — verify the game still runs the same. Then say go and I'll start the combat features (homing, ricochet, multiple projectiles per wall-hit).

Great, now let's do the 3 projectile modifiers. Homing, ricochet, spread. Spread is N projectiles spawned in a fan, choose reasonable angles. Randomize between 1 of those for each projectile, randomize number of ricochets between 1, 5, randomize number of fan projectiles between 1, 5.

Going with this interpretation: each ball wall-hit randomly picks one of homing | ricochet | spread. Homing → 1 projectile that turns toward enemies in a 60° cone. Ricochet → 1 projectile with a random 1–5 ricochet budget; on enemy kill it redirects to the nearest other un-hit enemy (no cone restriction). Spread → 1–5 plain projectiles in a 60°-total fan. Spread projectiles don't get additional modifiers, otherwise the modes get tangled.

Adding constants, then the projectile-mode logic, then the wall-hit randomizer, then updating the sensor handler.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now in entities.lua: add the angle_diff helper at the top, then expand the projectile class with mode/ricochet tracking, homing logic, and the on_enemy_hit method. Also extend spawn_projectile to take args, and rewrite ball:on_wall_hit to randomize the mode.

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now expand the projectile class:

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Update spawn_projectile to forward args:

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now rewrite ball:on_wall_hit to randomize the modifier mode:

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Update the sensor handler in main.lua to call p:on_enemy_hit(e) instead of p:kill():

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done. Summary:

Per ball wall-hit, randomly picks one mode:

• Homing (1 projectile) — turns toward nearest enemy in a 60° forward cone at 8 rad/sec.
• Ricochet (1 projectile, 1–5 hits remaining) — on enemy kill, redirects to nearest un-hit enemy. Tracks hit_enemy_ids per projectile so it never re-targets a corpse.
• Spread (1–5 projectiles) — fan in a 60° total span centered on the base angle. Each projectile is plain (no homing or ricochet).

Implementation notes:

• Mode is stored on the projectile (self.mode); homing logic runs every frame in projectile:update, ricochet logic only fires in projectile:on_enemy_hit (called from main.lua's sensor drain).
• Enemy still dies from the caller side (e:die(p.x, p.y)); projectile decides its own fate via on_enemy_hit. If ricochet has budget AND a target is found, it redirects; otherwise :kill() (silent — no death burst on enemy hit, only on border exit).
• angle_diff added as a global helper at the top of entities.lua.
• HOMING_TURN_RATE = 8 (rather than the prototype's 14) — tuned for the larger scale; gives ~80 px turning radius which feels purposeful but not magnetic.

Things you'll notice and can tune:

1. Mode distribution. Currently 1/3 each, uniform. If one mode feels under- or over-represented, we can weight random_choice differently.
2. Spread fan angle. 60° total. Wider would feel more "shotgun-y", narrower more "rifle-burst".
3. Homing aggressiveness. 8 rad/sec + 60° cone. If projectiles miss too often → bump turn rate or widen cone. If they feel cheap → reduce.
4. Ricochet visual. When a projectile redirects to a far enemy, it'll snap its direction sharply. If that looks jarring, we could lerp the direction change instead of snapping.

For ricochet I meant against walls only, against enemies it would be called chain.

Got it. Renaming aside, I had the wrong behavior — ricochet should bounce off the border-zone walls (not redirect between enemies), and "chain" (the enemy-redirect behavior) is a separate concept I'll drop for now.

Updating: ricochet_count now means wall-bounce budget. On each border crossing, projectile reflects its velocity off whichever wall it hit (snapping its position back inside) and decrements the budget. When the budget is 0, it dies normally on the next border crossing. Ricochet projectiles also survive enemy kills — they keep flying through the map until they run out of bounces, killing whatever they touch along the way. Removing the hit_enemy_ids set, pick_ricochet_target, and the redirect logic.

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done. Summary:

• Ricochet now means wall bounces. Projectile reflects off whichever border (left/right/top/bottom) it's about to cross, snaps position back inside, decrements ricochet_count. Small dot-burst at each bounce point so it reads visibly.
• Ricochet projectiles survive enemy kills — they keep flying through the playfield, killing whatever they hit, until they exhaust their bounce budget on a border crossing. So a "5 ricochets" projectile can theoretically rack up many kills before dying.
• Chain (the enemy-redirect logic) is gone. Removed hit_enemy_ids, pick_ricochet_target, and the redirect block from on_enemy_hit. The method now just kills the projectile unless ricochet_count > 0.
• Mode rotation unchanged: homing | ricochet | spread, equal probability per wall hit. The randomizer in ball:on_wall_hit already passes mode = 'ricochet' with a ricochet_count = random_int(1, MAX_RICOCHETS).

Things to evaluate:

1. Ricochet feel. With 5 bounces and surviving kills, ricochet projectiles are quite powerful. If they feel too strong, lower MAX_RICOCHETS (or reduce frequency by weighting random_choice).
2. Bounce blip. Each bounce produces the same-size burst as projectile death (14 px). Might be too prominent if a projectile bounces 5 times — let me know if it gets noisy and we'll add a smaller RICOCHET_BUMP_RADIUS constant.
3. Bounce snap-back. When a projectile crosses the border, we snap it exactly to the boundary line. If you see projectiles "skip" a few px during the bounce, that's why; could lerp instead but the snap is cleaner physics.
4. Homing on ricochet projectile? Currently a ricochet projectile cannot also home (mutually exclusive modes). If a ricochet projectile that also homes feels good as a "rare" combo, that's a future card mechanic.

Ricochet projectiles should also ricochet against the central chamber.

Adding sensor pair projectile/chamber and a ricochet_chamber method. Same dominant-axis logic as the wall-normal computation in ball:on_wall_hit to figure out which chamber wall was hit, then reflect the perpendicular velocity component.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now add ricochet_chamber to the projectile class:

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done. Three changes:

• physics_enable_sensor('projectile', 'chamber') added to physics setup.
• New projectile:ricochet_chamber mirrors the border bounce: dominant-axis decides which chamber wall (horizontal vs vertical), reflect that velocity component, decrement budget, emit a small dot-burst.
• Sensor handler drains projectile/chamber events and calls ricochet_chamber only for projectiles with a budget. Non-ricochet projectiles still pass through the chamber unchanged.

Edge cases worth eyeballing:

1. Corner hits. If a projectile crosses near a chamber corner, two wall sensors might fire simultaneously. With both bouncing the same axis, they'd no-op each other; with both bouncing different axes, the projectile reverses direction. Not great, but rare. If it bothers you visually we'll add a per-frame guard.
2. No position snap. Unlike border ricochet, I don't snap the projectile to the wall edge — sensor begin fires when the projectile collider overlaps the wall (still slightly outside the chamber's drawn outline), so the bounce reads cleanly without a position correction. If you see a projectile briefly appearing inside the chamber outline before bouncing back out, that's the lag from the projectile's collider radius (6 px) extending into the wall area before the bounce.
3. Inside-the-chamber projectiles. A ricochet projectile that somehow ends up inside the chamber will bounce off the inside of the walls (same logic, dominant axis works either way), zooming around inside until budget exhausted. Currently no path to get inside the chamber, but if homing ever curves a ricochet projectile in there, this is what'll happen.

The projectiles are still going through the chamber.

Let me check how sensor enabling actually works at the engine level — there might be a filter that's blocking it.

5812:static int l_physics_enable_sensor(lua_State* L) {
9158:    lua_register(L, "physics_enable_sensor", l_physics_enable_sensor);

5812 static int l_physics_enable_sensor(lua_State* L) {
5813        const char* name_a = luaL_checkstring(L, 1);
5814        const char* name_b = luaL_checkstring(L, 2);
5815    
5816        PhysicsTag* tag_a = physics_tag_get_by_name(name_a);
5817        PhysicsTag* tag_b = physics_tag_get_by_name(name_b);
5818    
5819        if (!tag_a) return luaL_error(L, "Unknown physics tag: %s", name_a);
5820        if (!tag_b) return luaL_error(L, "Unknown physics tag: %s", name_b);
5821    
5822        // Enable sensor events both ways
5823        tag_a->sensor_mask |= tag_b->category_bit;
5824        tag_b->sensor_mask |= tag_a->category_bit;
5825        return 0;
5826    }
5827    
5828    static int l_physics_enable_hit(lua_State* L) {
5829        const char* name_a = luaL_checkstring(L, 1);
5830        const char* name_b = luaL_checkstring(L, 2);
5831    
5832        PhysicsTag* tag_a = physics_tag_get_by_name(name_a);
5833        PhysicsTag* tag_b = physics_tag_get_by_name(name_b);
5834    
5835        if (!tag_a) return luaL_error(L, "Unknown physics tag: %s", name_a);
5836        if (!tag_b) return luaL_error(L, "Unknown physics tag: %s", name_b);
5837    
5838        // Enable hit events both ways
5839        tag_a->hit_mask |= tag_b->category_bit;
5840        tag_b->hit_mask |= tag_a->category_bit;
5841        return 0;
... [20 more lines]

516:    uint64_t collision_mask;  // Which tags this collides with (physical response)
517:    uint64_t sensor_mask;     // Which tags trigger sensor events
689:static bool physics_custom_filter(b2ShapeId shapeIdA, b2ShapeId shapeIdB, void* context) {
5719:    b2World_SetCustomFilterCallback(physics_world, physics_custom_filter, NULL);
5772:    tag->collision_mask = 0;  // No collisions by default
5773:    tag->sensor_mask = 0;     // No sensor events by default
5791:    tag_a->collision_mask |= tag_b->category_bit;
5792:    tag_b->collision_mask |= tag_a->category_bit;
5807:    tag_a->collision_mask &= ~tag_b->category_bit;
5808:    tag_b->collision_mask &= ~tag_a->category_bit;
5823:    tag_a->sensor_mask |= tag_b->category_bit;
5824:    tag_b->sensor_mask |= tag_a->category_bit;
5857:    bool collides = (tag_a->collision_mask & tag_b->category_bit) != 0;
5958:    def->filter.maskBits = tag->collision_mask | tag->sensor_mask;  // Include both for filtering
5962:    def->enableSensorEvents = (tag->sensor_mask != 0);
5963:    def->enableContactEvents = (tag->collision_mask != 0);
6267:    chain_def.filter.maskBits = tag->collision_mask | tag->sensor_mask;
6268:    chain_def.enableSensorEvents = (tag->sensor_mask != 0);

689  static bool physics_custom_filter(b2ShapeId shapeIdA, b2ShapeId shapeIdB, void* context) {
690     ShapeUserData* ud_a = (ShapeUserData*)b2Shape_GetUserData(shapeIdA);
691     ShapeUserData* ud_b = (ShapeUserData*)b2Shape_GetUserData(shapeIdB);
692     if (!ud_a || !ud_b) return true;
693     if (ud_a->filter_group != 0 && ud_a->filter_group == ud_b->filter_group) return false;
694     return true;
695 }
696 
697 // Process physics events after b2World_Step
698 // Retrieves all events from Box2D and buffers them with tag info for Lua queries
699 static void physics_process_events(void) {
700     if (!physics_initialized) return;
701 
702     // Get contact events
703     b2ContactEvents contact_events = b2World_GetContactEvents(physics_world);
704 
705     // Process contact begin events
706     for (int i = 0; i < contact_events.beginCount && contact_begin_count < MAX_PHYSICS_EVENTS; i++) {
707         b2ContactBeginTouchEvent* e = &contact_events.beginEvents[i];
708         if (!b2Shape_IsValid(e->shapeIdA) || !b2Shape_IsValid(e->shapeIdB)) continue;
709 
710         int tag_a = physics_get_shape_tag(e->shapeIdA);
711         int tag_b = physics_get_shape_tag(e->shapeIdB);
712         if (tag_a < 0 || tag_b < 0) continue;
713 
714         PhysicsContactBeginEvent* ev = &contact_begin_events[contact_begin_count++];
715         ev->shape_a = e->shapeIdA;
716         ev->shape_b = e->shapeIdB;
717         ev->body_a = b2Shape_GetBody(e->shapeIdA);
718         ev->body_b = b2Shape_GetBody(e->shapeIdB);

630:static PhysicsSensorBeginEvent sensor_begin_events[MAX_PHYSICS_EVENTS];
631:static int sensor_begin_count = 0;
676:    sensor_begin_count = 0;
781:    b2SensorEvents sensor_events = b2World_GetSensorEvents(physics_world);
784:    for (int i = 0; i < sensor_events.beginCount && sensor_begin_count < MAX_PHYSICS_EVENTS; i++) {
792:        PhysicsSensorBeginEvent* ev = &sensor_begin_events[sensor_begin_count++];
6821:           sensor_begin_count, sensor_end_count);
7018:// physics_get_sensor_begin(tag_a, tag_b) -> array of {sensor_body, visitor_body, sensor_shape, visitor_shape, sensor_tag, visitor_tag}
7019:static int l_physics_get_sensor_begin(lua_State* L) {
7031:    for (int i = 0; i < sensor_begin_count; i++) {
7032:        PhysicsSensorBeginEvent* e = &sensor_begin_events[i];
9216:    lua_register(L, "physics_get_sensor_begin", l_physics_get_sensor_begin);

781      b2SensorEvents sensor_events = b2World_GetSensorEvents(physics_world);
782 
783     // Process sensor begin events
784     for (int i = 0; i < sensor_events.beginCount && sensor_begin_count < MAX_PHYSICS_EVENTS; i++) {
785         b2SensorBeginTouchEvent* e = &sensor_events.beginEvents[i];
786         if (!b2Shape_IsValid(e->sensorShapeId) || !b2Shape_IsValid(e->visitorShapeId)) continue;
787 
788         int sensor_tag = physics_get_shape_tag(e->sensorShapeId);
789         int visitor_tag = physics_get_shape_tag(e->visitorShapeId);
790         if (sensor_tag < 0 || visitor_tag < 0) continue;
791 
792         PhysicsSensorBeginEvent* ev = &sensor_begin_events[sensor_begin_count++];
793         ev->sensor_shape = e->sensorShapeId;
794         ev->visitor_shape = e->visitorShapeId;
795         ev->sensor_body = b2Shape_GetBody(e->sensorShapeId);
796         ev->visitor_body = b2Shape_GetBody(e->visitorShapeId);
797         ev->sensor_tag = sensor_tag;
798         ev->visitor_tag = visitor_tag;
799     }
800 
801     // Process sensor end events
802     for (int i = 0; i < sensor_events.endCount && sensor_end_count < MAX_PHYSICS_EVENTS; i++) {
803         b2SensorEndTouchEvent* e = &sensor_events.endEvents[i];
804         // Note: shapes may have been destroyed
805         int sensor_tag = b2Shape_IsValid(e->sensorShapeId) ? physics_get_shape_tag(e->sensorShapeId) : -1;
806         int visitor_tag = b2Shape_IsValid(e->visitorShapeId) ? physics_get_shape_tag(e->visitorShapeId) : -1;
807 
808         PhysicsSensorEndEvent* ev = &sensor_end_events[sensor_end_count++];
809         ev->sensor_shape = e->sensorShapeId;
810         ev->visitor_shape = e->visitorShapeId;
... [10 more lines]

5956:static void setup_shape_def_from_tag(b2ShapeDef* def, PhysicsTag* tag, bool is_sensor) {
5959:    def->isSensor = is_sensor;
5984:    bool is_sensor = false;
5988:        if (!lua_isnil(L, -1)) is_sensor = lua_toboolean(L, -1);
6002:    setup_shape_def_from_tag(&shape_def, tag, is_sensor);
6042:    bool is_sensor = false;
6047:        if (!lua_isnil(L, -1)) is_sensor = lua_toboolean(L, -1);
6065:    setup_shape_def_from_tag(&shape_def, tag, is_sensor);
6106:    bool is_sensor = false;
6110:        if (!lua_isnil(L, -1)) is_sensor = lua_toboolean(L, -1);
6124:    setup_shape_def_from_tag(&shape_def, tag, is_sensor);
6189:    bool is_sensor = false;
6192:        if (!lua_isnil(L, -1)) is_sensor = lua_toboolean(L, -1);
6198:    setup_shape_def_from_tag(&shape_def, tag, is_sensor);
6719:        bool is_sensor = b2Shape_IsSensor(shapes[i]);
6720:        lua_pushboolean(L, is_sensor);

5956 static void setup_shape_def_from_tag(b2ShapeDef* def, PhysicsTag* tag, bool is_sensor) {
5957        def->filter.categoryBits = tag->category_bit;
5958        def->filter.maskBits = tag->collision_mask | tag->sensor_mask;  // Include both for filtering
5959        def->isSensor = is_sensor;
5960    
5961        // Enable events based on tag configuration
5962        def->enableSensorEvents = (tag->sensor_mask != 0);
5963        def->enableContactEvents = (tag->collision_mask != 0);
5964        def->enableHitEvents = (tag->hit_mask != 0);
5965        def->enableCustomFiltering = true;
5966    }
5967    
5968    // physics_add_circle(body, tag, radius, [opts])
5969    static int l_physics_add_circle(lua_State* L) {
5970        if (!physics_initialized) {

100  ENEMY_SPEED_MAX       = 280
101 ENEMY_SPAWN_INTERVAL  = 1.0
102 ENEMY_STROKE          = 1.5              -- actor tier
103 ENEMY_STEER_FORCE     = 1200             -- max steering force (cap on seek+separate)
104 ENEMY_DAMPING         = 3
105 ENEMY_SPAWN_FADE_TIME = 0.5              -- spawn fade duration (mask 0.5→0, solid 0→1)
106 
107 -- Mask-layer FX (rendered as dots by the shader). All ink, all drawn into
108 -- mask_layer. Sizes/durations are tuned so dots are visible inside the shape.
109 HIT_BURST_RADIUS     = 22                -- default for enemy death
110 HIT_BURST_DURATION   = 0.3
111 
112 BALL_HIT_BURST_RADIUS         = 14       -- ball-on-wall pop
113 BALL_HIT_BURST_DURATION       = 0.18
114 PROJECTILE_DEATH_BURST_RADIUS = 14       -- projectile dying at the border
115 PROJECTILE_DEATH_DURATION     = 0.18
116 
117 -- Dot-grid reveal shader (see dot_shader.lua). Mask-layer is normally
118 -- invisible; effects draw shapes into it and the shader renders the dotted
119 -- manga-style grid wherever the mask has alpha. Static value-noise modulates

125  
126 -- -----------------------------------------------------------------------------
127 -- physics
128 -- -----------------------------------------------------------------------------
129 physics_init()
130 physics_set_gravity(0, 0)
131 physics_register_tag('ball')
132 physics_register_tag('chamber')
133 physics_register_tag('projectile')
134 physics_register_tag('enemy')
135 physics_enable_collision('ball', 'chamber')
136 physics_enable_collision('enemy', 'chamber')
137 physics_enable_collision('enemy', 'enemy')
138 physics_enable_sensor('projectile', 'enemy')
139 physics_enable_sensor('projectile', 'chamber')
140 
141 -- -----------------------------------------------------------------------------
142 -- layers / camera
143 -- -----------------------------------------------------------------------------
144 game_layer  = layer_new('game')
145 mask_layer  = layer_new('mask')   -- effect masks; shader turns this into dots
146 ui_layer    = layer_new('ui')
147 main_camera = camera_new(width, height)
148 
149 -- -----------------------------------------------------------------------------
150 -- shader (loads dot_shader, sets uniforms)
151 -- -----------------------------------------------------------------------------
152 require('dot_shader')
153 
154 -- -----------------------------------------------------------------------------
... [20 more lines]

184:the_chamber = chamber(CHAMBER_X, CHAMBER_Y, CHAMBER_HALF)

No matches found

408: /// A sensor shape generates overlap events but never generates a collision response.
413:    bool isSensor;
415:    /// Enable sensor events for this shape. This applies to sensors and non-sensors. False by default, even for sensors.
418:    /// Enable contact events for this shape. Only applies to kinematic and dynamic bodies. Ignored for sensors. False by default.
421:    /// Enable hit events for this shape. Only applies to kinematic and dynamic bodies. Ignored for sensors. False by default.
425:    /// and must be carefully handled due to multithreading. Ignored for sensors.
485:    /// Enable sensors to detect this chain. False by default.
516:    float sensorHits;
522:    float sensors;
928:/// A begin touch event is generated when a shape starts to overlap a sensor shape.
931:    /// The id of the sensor shape
932:    b2ShapeId sensorShapeId;
934:    /// The id of the shape that began touching the sensor shape
938:/// An end touch event is generated when a shape stops overlapping a sensor shape.
940:/// a filter. You will also get an end event if the sensor or visitor are destroyed.

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478  
479     /// Contact filtering data.
480     b2Filter filter;
481 
482     /// Indicates a closed chain formed by connecting the first and last points
483     bool isLoop;
484 
485     /// Enable sensors to detect this chain. False by default.
486     bool enableSensorEvents;
487 
488     /// Used internally to detect a valid definition. DO NOT SET.
489     int internalValue;
490 } b2ChainDef;
491 
492 /// Use this to initialize your chain definition

405      /// Enable custom filtering. Only one of the two shapes needs to enable custom filtering. See b2WorldDef.
406     bool enableCustomFiltering;
407 
408     /// A sensor shape generates overlap events but never generates a collision response.
409     /// Sensors do not have continuous collision. Instead, use a ray or shape cast for those scenarios.
410     /// Sensors still contribute to the body mass if they have non-zero density.
411     /// @note Sensor events are disabled by default.
412     /// @see enableSensorEvents
413     bool isSensor;
414 
415     /// Enable sensor events for this shape. This applies to sensors and non-sensors. False by default, even for sensors.
416     bool enableSensorEvents;
417 
418     /// Enable contact events for this shape. Only applies to kinematic and dynamic bodies. Ignored for sensors. False by default.
419     bool enableContactEvents;
420 
421     /// Enable hit events for this shape. Only applies to kinematic and dynamic bodies. Ignored for sensors. False by default.
422     bool enableHitEvents;
423 
424     /// Enable pre-solve contact events for this shape. Only applies to dynamic bodies. These are expensive
425     /// and must be carefully handled due to multithreading. Ignored for sensors.
426     bool enablePreSolveEvents;
427 
428     /// When shapes are created they will scan the environment for collision the next time step. This can significantly slow down
429     /// static body creation when there are many static shapes.
430     /// This is flag is ignored for dynamic and kinematic shapes which always invoke contact creation.
431     bool invokeContactCreation;
432 
433     /// Should the body update the mass properties when this shape is created. Default is true.
434     /// Warning: if this is true, you MUST call b2Body_ApplyMassFromShapes before simulating the world.

6035     PhysicsTag* tag = physics_tag_get_by_name(tag_name);
6036        if (!tag) return luaL_error(L, "Unknown physics tag: %s", tag_name);
6037    
6038        float width = (float)luaL_checknumber(L, 3);
6039        float height = (float)luaL_checknumber(L, 4);
6040    
6041        // Parse options table (5th argument, optional)
6042        bool is_sensor = false;
6043        float offset_x = 0, offset_y = 0;
6044        float angle = 0;
6045        if (lua_istable(L, 5)) {
6046            lua_getfield(L, 5, "sensor");
6047            if (!lua_isnil(L, -1)) is_sensor = lua_toboolean(L, -1);
6048            lua_pop(L, 1);
6049    
6050            lua_getfield(L, 5, "offset_x");
6051            if (!lua_isnil(L, -1)) offset_x = (float)lua_tonumber(L, -1);
6052            lua_pop(L, 1);
6053    
6054            lua_getfield(L, 5, "offset_y");
6055            if (!lua_isnil(L, -1)) offset_y = (float)lua_tonumber(L, -1);
6056            lua_pop(L, 1);
6057    
6058            lua_getfield(L, 5, "angle");
6059            if (!lua_isnil(L, -1)) angle = (float)lua_tonumber(L, -1);
6060            lua_pop(L, 1);
6061        }
6062    
6063        // Create shape def
6064        b2ShapeDef shape_def = b2DefaultShapeDef();
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E:\a327ex\Anchor2\engine\include\box2d\types.h:409:  /// Sensors do not have continuous collision. Instead, use a ray or shape cast for those scenarios.
E:\a327ex\Anchor2\engine\include\box2d\types.h:940:///  a filter. You will also get an end event if the sensor or visitor are destroyed.

Found it — Box2D 3 explicitly says "Sensors do not have continuous collision" in the type definitions. The projectile (sensor) at 500 px/sec moves ~4 px per physics step, and the chamber walls are 4 px thick, so it can tunnel through without ever firing a sensor begin event.

Switching to a manual position-based check inside projectile:update. Tracks previous frame's position and "was-inside" state; when the projectile crosses from outside the chamber bounds to inside, it ricochets. Removing the sensor approach since it can't be made to work reliably.

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The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now update the projectile in entities.lua: track prev position + was-inside state, do the chamber crossing check in update, rewrite ricochet_chamber to use the previous position to figure out which axes were crossed.

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The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done. Summary of the fix:

• Removed the sensor approach for projectile/chamber — Box2D 3 sensors don't have CCD, so a fast projectile would tunnel through the 4-px-thick chamber walls without firing any begin event.
• Added a manual position-based check in projectile:update. Tracks was_inside_chamber across frames; the false → true transition (projectile center entered the 240×240 chamber bounds this frame) triggers the bounce.
• Rewrote ricochet_chamber to use the previous-frame position to figure out which axes were crossed. If prev_x was outside the chamber's x-range, flip vx; same for y. Both flip on a corner entry — so a projectile coming in diagonally bounces back the way it came rather than picking one axis arbitrarily.
• Border check still uses position-based detection (it always did), and ricochet projectiles still survive enemy kills via on_enemy_hit.

Edge cases:

1. Ricochet projectile re-entering after exiting. Once the projectile moves out of the chamber bounds, was_inside_chamber resets to false, so the next entry triggers another bounce. So a ricochet projectile bouncing through the playfield can hit the chamber multiple times during its budget.
2. No position snap. The projectile briefly enters the chamber by 1–4 px (whatever it moved this physics step) before bouncing. With BORDER_HAIRLINE = 1 and the chamber stroke at 1 px, this should be visually invisible. Tell me if you see projectiles disappear inside the chamber for a frame.

Why not just make it physical collision versus projectiles?

Good question. A few reasons it's not as simple as it sounds:

Projectiles are sensor bodies. That's how the projectile↔enemy hit pipeline works — sensor events on overlap. Making the projectile shape non-sensor (which is required for physical collision with the chamber) would also disable sensor events between projectile and enemy, so enemy hit detection breaks.

The fixes would all cascade:

• Switch projectile↔enemy from sensor events to collision events. But then projectiles physically bounce off enemies on contact instead of passing through, so you'd need to also tune restitution/density to fake the "kill and continue" behavior, or kill the projectile in the collision handler before Box2D resolves the bounce. Doable but fiddly.
• The projectile's "passes through the ball" behavior would also flip — you'd need to disable projectile↔ball pair explicitly to keep that working.
• And you can only set one body type per projectile, so applying the chamber-bounce behavior only to ricochet projectiles (not homing/spread/plain) would still need an extra mechanism — filter groups, separate tags, or a per-frame collision-skip in the handler.

The border check is already manual and can't be physical (the border zone isn't a physics body — it's just a coordinate boundary). So we already have a manual position-based ricochet path. Reusing the same mechanism for the chamber check keeps both ricochet flavors using one piece of logic; switching only the chamber to physical would split them across two systems.

Box2D 3 sensors don't have CCD specifically, but non-sensor dynamic bodies with bullet=true do — so a physical projectile-chamber pair would handle tunneling natively, which is the one real win.

So it'd work, but it's a bigger rewrite than it looks (sensor pipeline → collision pipeline). The manual check is ~10 lines and uses the same machinery as the border check. Tell me if you'd rather have the bigger rewrite anyway — I'd estimate it's an hour of work and a couple of unrelated visual side effects to debug afterward, but it'd be more "physical" and feel cleaner architecturally.

Can't we make the border zone a physical object? It should be one anyways, eventually I want to be able to both resize it and rotate it.

Yes, that makes sense — and if you want to resize/rotate it eventually, having it as a physics body is the right architecture. Let me lay out what this means concretely so you know the full scope before I commit:

The refactor:

1. New border class — 4 thin static walls forming a rectangle around the gameplay area. Top/bottom walls visible via the existing hairlines; left/right walls sit just past the screen edges (since the gameplay area extends edge-to-edge). Same construction pattern as chamber.
2. Projectile becomes physical, with a two-shape design:
   • Main shape: non-sensor circle, tag projectile_solid. Box2D handles the bounce off chamber + border natively (restitution=1, bullet=true for CCD).
   • Sub-shape: sensor circle, tag projectile_sensor. Fires sensor events with enemies, so we can kill enemies without bouncing the projectile off them.
3. New tags / pair changes:
   • Add: border, projectile_solid, projectile_sensor
   • Remove: projectile
   • Add collisions: (projectile_solid, chamber), (projectile_solid, border)
   • Add sensor: (projectile_sensor, enemy)
   • Remove sensor: (projectile, enemy)
4. Collision handlers: new (projectile_solid, border) and (projectile_solid, chamber) collision drains in main.lua; both call projectile:on_wall_bounce(x, y).
5. Remove the manual ricochet code: ricochet, ricochet_chamber, prev_x/y, was_inside_chamber, the border-crossing check in update. All replaced by Box2D's native bounce.
6. Bump projectile spawn distance by 4 px so they don't touch the chamber wall on spawn (Box2D would fire a spurious collision event otherwise).

Behavior changes you'll see:

• Non-ricochet projectiles (homing, spread, plain) now visibly bounce one frame before dying when they hit a wall, since Box2D resolves the contact before our handler runs. Slight visual difference vs. current "vanish at border" — likely reads as "hit wall and burst" since the burst still fires at the bounce point.
• Ricochet projectiles now bounce off everything natively. Off the chamber, off the border, off both — no more weird "passes through chamber" issue. Each bounce decrements ricochet_count; when it's 0, next bounce kills.
• Projectile-on-enemy hit unchanged — sensor sub-shape carries the same logic.

I'll skip the visual weirdness with non-ricochet projectiles for now; if it bothers you, we can add a pre-solve cancel later (requires engine work to expose Box2D pre-solve callbacks).

Going ahead?

Make projectiles ricochetable only

[Request interrupted by user]

By that I mean, when spawning a projectile, make ricochet for all of them, don't change the inner workings at all

Got it — much simpler. Just always pass ricochet_count when spawning, regardless of mode. Inner workings (manual position checks, etc.) stay as they are.

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done. Every spawned projectile now gets ricochet_count = random_int(1, MAX_RICOCHETS) — homing, spread, plain, and ricochet alike. The chamber and border bouncing logic in projectile:update (manual position checks) takes over from there.

Side effect: the 'ricochet' mode label is now mostly redundant (every mode behaves "ricochet-y"). It still exists as one of the three random outcomes — it's just the variant with no homing turn and no spread fan. If you want to remove it from the mode rotation entirely (since it's no longer distinct), that's a one-line change to random_choice.

OK, you need to refactor the code. There should be no concept of a "mode". The projectile either has homing or ricochet, and both can happen at the same time, there's no mode. Similarly, there's no spread, spreading is just something that happens at the caller, before any projectile is spawned, you just spawn N projectiles instead.

Got it — collapsing to two independent per-projectile properties (homing bool, ricochet_count int), and moving spread to a pure caller-side concern.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now the projectile class — drop mode, replace with independent homing and ricochet_count:

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now ball:on_wall_hit — collapse to "always spawn N projectiles in a fan", each with independent random homing + ricochet:

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done. Refactor summary:

• projectile.mode is gone. Replaced with two independent per-projectile properties:
  • self.homing (bool) — gates the homing-cone-and-turn logic in update.
  • self.ricochet_count (int) — bounce budget for chamber and border (unchanged).
• ball:on_wall_hit no longer picks a "mode". Instead it always runs the spread loop: random N ∈ [1, MAX_SPREAD] projectiles in a fan. Each projectile independently rolls homing = random_bool(HOMING_CHANCE) and ricochet_count = random_int(1, MAX_RICOCHETS).
• New constant HOMING_CHANCE = 0.5 controls the per-projectile homing probability. Easy knob to turn if homing feels too common or too rare.

So a single wall-hit can produce, say, 3 projectiles where one homes and ricochets 2 times, one neither homes nor ricochets, and one homes with 4 ricochets. Each behaves independently.

Side effect: the wall-hit loadout is much more variable now. With every projectile having 1–5 ricochets, the playfield will get busier — projectiles linger longer. If it feels too dense, drop MAX_RICOCHETS or MAX_SPREAD.

Perfect, now you said that projectiles are physical objects, right?

No, the opposite — projectiles are still sensor bodies (sensor=true), not physical. They pass through everything physically.

What's actually happening:

• Enemy hits: sensor event (projectile/enemy sensor pair).
• Chamber bounce: manual position check inside projectile:update. Each frame, compares was_inside_chamber from last frame to a fresh inside-bounds check this frame; on the false → true transition (just entered), ricochet_chamber() reflects the velocity using the previous-frame position to figure out which axes were crossed.
• Border bounce: same idea — when the projectile crosses any GAME_AREA_* bound, ricochet() reflects velocity and snaps the position back inside.

We discussed making them physical (and making the border a physics body) but didn't actually do that refactor — you redirected to "just pass ricochet for all projectiles, don't change inner workings". So the manual ricochet code is what's running.

If you do want them physical now, that's the bigger refactor we sketched out earlier (border physics body, two-shape projectile design, switch to collision events for chamber/border, keep sensor sub-shape for enemies). Otherwise, current setup is what bounces them.

Well, eventually I'll want to both change the size of the chamber and rotate it. Can you support that feature now? If you can without making things physical objects, great.

Yes, can support both without making projectiles physical. Two pieces:

1. Resize — destroy and rebuild the chamber's collider with the new size. (Box2D shapes don't support runtime resize, but the wrapper can do destroy+rebuild.)
2. Rotate — set_angle on the chamber's body rotates all 4 walls automatically (Box2D handles physics), and the visual draw uses a rotated push transform. The manual projectile checks need to do the bounds test and velocity reflection in chamber-local space (rotate, check, rotate back).

I'll add chamber helper methods so the rotated math lives in one place — chamber:contains(x, y) for the inside check, chamber:wall_normal_for(x, y) for the outward normal at a point. Projectile and ball both call those and stop knowing about chamber internals.

Plus chamber:resize(new_half) and chamber:set_angle(new_angle) so future code can drive both at runtime.

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now ball:on_wall_hit — replace the inline wall-normal calc with the chamber helper:

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now the projectile — use chamber:contains for the inside check, and rewrite ricochet_chamber to do the velocity reflection in chamber-local space:

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Now the enemy — replace CHAMBER_X / CHAMBER_Y constants with the_chamber.x / the_chamber.y so seek + initial facing follow the chamber if it moves:

516:  self.r           = math.angle_to_point(x, y, CHAMBER_X, CHAMBER_Y)
545:  local sx, sy = self.collider:steering_seek(CHAMBER_X, CHAMBER_Y, self.speed, ENEMY_STEER_FORCE)

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done. Summary of what's now supported:

Chamber methods (all dynamic):

• the_chamber:resize(new_half) — destroys + rebuilds the wall colliders at the new size. Caller's responsibility to keep the ball inside if shrinking aggressively.
• the_chamber:set_angle(new_angle) — rotates the body; Box2D rotates all 4 walls automatically. Ball will physically interact with the rotated walls.
• the_chamber:set_position(x, y) — moves it. Bonus, came essentially for free.
• the_chamber:contains(x, y) — point-inside-bounds check, rotation-aware.
• the_chamber:wall_normal_for(x, y) — outward wall normal at a point, rotation-aware.

Callers updated:

• ball:on_wall_hit uses the_chamber:wall_normal_for instead of inlining the dominant-axis math.
• projectile chamber-crossing check uses the_chamber:contains; ricochet_chamber does the velocity reflection in chamber-local space (rotate prev position + velocity into local, flip components, rotate back).
• enemy reads the_chamber.x / .y for initial facing and steering_seek target.

Caveats:

1. Ball clipping during resize/rotate. If you shrink the chamber while the ball is near an edge, the ball ends up outside and Box2D will resolve by pushing it. Could end up outside the new chamber. Same for fast rotation — walls sweep across ball position. If you only do small per-frame changes, it's fine.
2. Enemies hitting a rotated chamber. Enemies still die on enemy↔chamber collision, which fires correctly for rotated walls. The e:die(ev.x, ev.y) uses Box2D's contact point (world-space), so the death burst lands at the right spot.
3. CHAMBER_X / CHAMBER_Y / CHAMBER_HALF constants are now only used at init (for the initial chamber spawn). All runtime references go through the_chamber.x/y/half/angle.

Try the_chamber:set_angle(math.pi/8) somewhere after init to see the rotation, or the_chamber:resize(180) for a bigger chamber.

Let's add permanent rotation to the chamber in one direction.

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Done. Chamber now rotates at 0.3 rad/sec (~17°/sec, full revolution every ~21 sec) in the positive direction (counterclockwise mathematically — clockwise on screen because y points down).

The ball's bouncing inside should adapt automatically since Box2D rotates the wall colliders with the body. Enemies still die on chamber contact at the (now-rotating) wall surfaces. Projectile chamber-ricochet uses chamber:contains and the rotated reflection math, so ricochets stay correct as the chamber turns.

Tunable knobs:

• CHAMBER_ROTATION_RATE = 0 to stop.
• Negative value to reverse direction.
• Larger absolute value (try 1.0) for a faster spin.

Watch for: with rapid rotation, the ball may get nudged by the rotating walls (Box2D's correction pushes it). At 0.3 it should be subtle. If you want a faster rotation without disturbing the ball, that needs more thought (separate the visual angle from the physics angle, or put the ball in a kinematic body with the chamber).

Now give me two keys, one to increase another to decrease the chamber's size.

2649:    if (strcmp(name, "minus") == 0 || strcmp(name, "-") == 0) return SDL_SCANCODE_MINUS;
2651:    if (strcmp(name, "leftbracket") == 0 || strcmp(name, "[") == 0) return SDL_SCANCODE_LEFTBRACKET;
2652:    if (strcmp(name, "rightbracket") == 0 || strcmp(name, "]") == 0) return SDL_SCANCODE_RIGHTBRACKET;
2674:    if (strcmp(name, "kpminus") == 0) return SDL_SCANCODE_KP_MINUS;
4439:            glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA,  // RGB
4440:                                GL_ONE, GL_ONE_MINUS_SRC_ALPHA);       // Alpha
5674:    glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA,  // RGB
5675:                        GL_ONE, GL_ONE_MINUS_SRC_ALPHA);       // Alpha
8564:    glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
8598:    glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
8677:    glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
8706:    glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
8808:    glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
10256:        glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
10309:        glBlendFuncSeparate(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA,  // RGB

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[ and ] are supported as key names. Adding the bindings + resize keys with min/max bounds.

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Now add the bindings (somewhere after the require('anchor') so the framework's bind is available) and the input handling in update:

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The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done.

• [ — shrink chamber by 15 px (down to a 60×60 minimum).
• ] — grow chamber by 15 px (up to a 560×560 maximum, sized so the rotated diagonal stays inside the gameplay area's vertical bound).

Each press triggers a full resize (destroy + rebuild collider). Tunable: CHAMBER_RESIZE_STEP for granularity, CHAMBER_HALF_MIN/MAX for the bounds.

Watch for the ball getting caught outside the new walls when shrinking aggressively — Box2D will resolve the penetration but might push the ball outside the smaller chamber, after which it'd just fly off until physics decides what to do with it. If you want to be safe, hold shrink presses while the ball isn't right against a wall, or we can add a "snap ball back inside" call to :resize.

Add a way to ensure that the ball can't ever leave the chamber, which can happen on resizing down, as you previously mentioned.

Adding a defensive per-frame containment check on ball:update. Clamps position in chamber-local space (handling rotation) and reflects any outward-pointing velocity components so the ball doesn't immediately push back out next frame.

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done. Each frame at the end of ball:update:

• Transform ball position into chamber-local space (rotation-aware).
• Clamp local x/y to ±(half - ball_radius - 1). The -1 is small clearance so the ball doesn't sit exactly on the wall (which can fire spurious Box2D contact events and accidentally trigger on_wall_hit, which spawns a stray projectile).
• If anything was clamped, snap the world position back and reflect any velocity component that was pointing outward in the dimension that got clamped.

This catches:

• Resize-down while ball is near a wall — ball gets pulled back inside instantly.
• Fast rotation sweeping past the ball — ball is shoved inside on the same frame.
• Tunneling at high speed — even if bullet=true CCD fails, the per-frame check catches escapees.

Edge case: if you shrink the chamber so small that half ≤ ball_radius + 1, containment quietly does nothing (early return). The ball will be physics-ejected by the chamber walls collapsing on it. So CHAMBER_HALF_MIN = 30 (vs BALL_RADIUS = 6) gives plenty of headroom.

ERROR: anchor/physics.lua:31: Invalid body stack traceback: [C]: in function 'physics_get_user_data' anchor/physics.lua:31: in upvalue 'body_to_entity' anchor/physics.lua:148: in function 'collision_entities_begin' main.lua:220: in function 'update'

After decreasing the chamber a few times.

Order-of-operations bug: the chamber's body gets destroyed inside chamber:resize, but then the collision drain a few lines later in the same update tries to read user_data from those now-dead body handles.

Let me check collection_update to understand the right fix without breaking the _dying/_dead lifecycle:

E:\a327ex\Anchor2\framework\anchor\helpers.lua:10:function collection_update(list, dt, method)
E:\a327ex\Anchor2\framework\anchor\helpers.lua-11-  method = method or 'update'
E:\a327ex\Anchor2\framework\anchor\helpers.lua-12-  for i = #list, 1, -1 do
E:\a327ex\Anchor2\framework\anchor\helpers.lua-13-    local e = list[i]
E:\a327ex\Anchor2\framework\anchor\helpers.lua-14-    if e._dead then
E:\a327ex\Anchor2\framework\anchor\helpers.lua-15-      table.remove(list, i)
E:\a327ex\Anchor2\framework\anchor\helpers.lua-16-    else
E:\a327ex\Anchor2\framework\anchor\helpers.lua-17-      local fn = e[method]
E:\a327ex\Anchor2\framework\anchor\helpers.lua-18-      if fn then fn(e, dt) end
E:\a327ex\Anchor2\framework\anchor\helpers.lua-19-    end
E:\a327ex\Anchor2\framework\anchor\helpers.lua-20-  end
E:\a327ex\Anchor2\framework\anchor\helpers.lua-21-end

collection_update only filters on _dead, not _dying. So the right fix is just to move the input-driven resize to the end of update — after all event drains and process_destroy_queue — so we don't destroy the chamber's body while there are still pending event handles referring to it.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done. Resize input now runs at the very end of update, after all collision drains and process_destroy_queue. This frame's events finish processing against the still-existing chamber body, the destroy queue runs, and only then do we destroy/rebuild the chamber collider. Next frame's physics step uses the new chamber.

Should fix the "Invalid body" error. Try shrinking down a few times again to confirm.

Perfect, what's left to do?

Tracking against the original plan plus everything added since:

Done so far (in rough order built):

• Phases 1–4 (chamber + ball + projectiles + enemies)
• Border zone (asymmetric, HUD-reserved top/bottom)
• Dot-grid reveal shader as visual motif
• Spawn fade-in via dot pattern
• Hit-burst FX (ball wall, enemy death, projectile death)
• Combat loop (homing + ricochet + spread, all per-projectile rolls)
• Chamber dynamics: rotate continuously, resize via [/]
• Ball containment defensive check
• File split (main / entities / dot_shader)

Core gameplay still missing:

1. Fail state. The game can't be lost. No chamber HP, no game-over — enemies just stream in, die, repeat. From design.md open questions: does the chamber have HP? Other fail state?
2. Wave system. Spawn rate is a flat 1/sec forever. The mockup HUD shows "WAVE 07 · 00:42 UNTIL NEXT WAVE" — implying a structured wave cadence. From open questions: wave-based? real-time with timer? on-demand?
3. Reset. Hot-restart key (the prototype had R; we haven't wired it).
4. Card layer. The main player-agency loop. Drafting before a run, drawing 2 cards/turn, mana pool, playing cards to mod the autopilot engine. Completely untouched.

HUD + typography (was planned phase 7):

1. Pick the actual condensed-sans + neutral-sans fonts.
2. Wave / timer / score readouts (top bar).
3. Health / currency / pickup chips / enemy count (bottom bar).
4. Inner-bar dividers and structure from the mockup image.

Content variety:

1. Enemy families. Currently one arrowhead. Design says "each shape = a family" — diamonds, triangles, circles, hexes; each could imply different speed/HP/behavior.
2. Pickups / tokens. Currency, mana drops, shields. Per the mockup HUD references.

Polish / parking lot:

1. More FX moments. Chamber resize/rotate could have visual feedback. Enemy hit (non-killing) feedback when we add HP > 1.
2. Real MSAA — deferred earlier; only relevant if the smooth-filter still feels jaggy at non-1080p windows.
3. Render interpolation between physics steps — sketched but not built; would smooth motion under high load on high-refresh monitors.
4. Pre-solve callback exposure in the engine — only matters if we ever switch projectiles to physical.

My recommendation for what's next: fail state + wave system + reset as a small group, since they're tightly related and would let the game be played as an actual session-with-a-beginning-and-end. After that, HUD (now reporting on real game state), then the card layer as the big subsequent project.

But it's your call — happy to start with HUD if you'd rather see the visual layer first, or jump to enemy variety to test the dot-fade-in spawn against different shapes.

Let's do one last task before ending the session. Make projectiles look like a filled rectangle instead of their current shape.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done.

• Chevron replaced with a filled 10 × 4 ink rectangle centered on the projectile, with the length axis aligned to travel direction.
• Old PROJECTILE_LEG / PROJECTILE_HALF_ANGLE / PROJECTILE_STROKE constants replaced with PROJECTILE_LENGTH and PROJECTILE_THICKNESS.

Tunable knobs if it doesn't read right: PROJECTILE_LENGTH (longer = more streaky/dart-like, shorter = more dot-like), PROJECTILE_THICKNESS (heavier or thinner). For a more "bullet" look try 12 × 3; for a "brick" look try 8 × 6.

Oops, I meant triangle instead of rectangle.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done. Filled ink triangle pointing along travel direction — tip at the front, base behind. Same LENGTH × THICKNESS constants but now interpreted as "tip-to-base" and "base width" respectively.

At 10 × 4 it'll read as a narrow dart. If you want a stubbier arrowhead-feeling triangle, bump PROJECTILE_THICKNESS to 6 or 8.

I want an equilateral one I think.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done. Equilateral triangle, side length PROJECTILE_SIZE = 10. Centered on the centroid so it rotates around its visual center cleanly. Tip leads, base trails.

LENGTH and THICKNESS constants are gone — collapsed into the single PROJECTILE_SIZE since equilateral has only one dimension.

Bump PROJECTILE_SIZE for a bigger projectile, drop it for smaller. Want it taller/thinner instead of equilateral, that's a different shape so we'd reintroduce two constants.

14 size

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Bumped to 14.

Let's go back to what it was before, the chevron.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Reverted. Back to the open chevron — leg 10, 100° opening, 2 px stroke.

Let's try 80 degree opening and 2.5px.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

Done — 80° total opening (40° half-angle), 2.5 px stroke.

Perfect, create a todo.md file with the things to be done that you just mentioned, so the next instance can know where to start from. Also, we need to rename this game. Chamber is very bad. I want an alien but cool name like Thalien Lune that matches the visuals of the game somewhat.

Writing todo.md now, then a name shortlist.

File created successfully at: E:\a327ex\chamber\todo.md (file state is current in your context — no need to Read it back)

Name suggestions — same cadence as "Thalien Lune" (alien-feeling word + softer second word, melodic together). All reach toward the visuals: schematic calm, halftone atmosphere, geometric defense, paper/ink palette.

1. Vellith Lune — "vellith" alien-sounding, with a hint of vellum (the warm paper background); "lune" matches your example's cadence directly.
2. Norien Aether — celestial-leaning, atmospheric; the chamber as a singular point in an empty field of dots.
3. Caelin Halo — caelin derived from celestial roots, halo picks up the geometric/orbital feel of the bouncing ball.
4. Sylven Glyph — alien + schematic, leans into the technical-drawing register.
5. Thavren Aria — strong alien word + aria (a single voice, unaccompanied — matches the autopilot solo loop).
6. Aerolith Veyl — aerolith = "stone from the air", a real but obscure word for meteorite; veyl is invented.

If you want single-word: Vellune, Aerolith, Carillun (after carillon — calm bell-set), or Halicene.

My personal pick is Vellith Lune — closest to your reference, and "vellith → vellum" pulls the paper background into the name without being literal. But all six fit the brief.

Once you pick, I can do the rename pass next session: folder, window title, headers, design.md / todo.md references.

Try lots of variations, whateve ryou think will fit. Doesn't need to follow this template at all, just whatever seems like it would be a reaosnable name for a game like this. Use other games as examples and change them to fit the gameplay + style. Try 20 variations. Be creative and don't make all variations follow the same creation pattern.

20 with varied creation patterns + a hint at what kind of game-name reference each is leaning on. Some lean on the visuals, some on the gameplay, some on pure sound.

1. Halion — invented compound (halo + ion); celestial-geometric, in the Hyper Light Drifter register.
2. Vellum — real obscure word for parchment; literally references the paper background. Tunic-style oddity-noun.
3. Sanctum — single Latin word, calm-defense feel. Hades-register.
4. Norien — pure invented; soft melodic alien word. NieR-style short coined.
5. Codex — single technical/ritual word; pairs with the schematic look. Inscryption-flavored.
6. Carillon — real but obscure (a tuned bell-set); calm + sacred. Cocoon-style.
7. Inkwell — concrete cozy noun; ink + container. Limbo-style minimalist.
8. Solith — invented (solid + monolith); weighty alien word.
9. Cipher Lune — two-word mysterious + celestial; dot patterns do look like ciphers.
10. Aetherline — atmospheric compound; suggests the line-art style.
11. Polara — invented short; polar/orbital implication for the bouncing ball.
12. Hyperhalo — coined compound, sci-fi energy. Hyper Light Breaker register.
13. The Ink Vault — fantasy article-title; paper + container. Cult of the Lamb-style.
14. Hold the Lune — imperative + place; Slay the Spire construction, but calmer.
15. Glyph & Halo — ampersand title pairing two motif words. Risk of Rain construction.
16. Vespers — Latin "evening prayers"; calm + sacred + plural. Distinctive.
17. Stipple — the actual technique word for dot-shading. Direct visual reference.
18. Lumen Drift — compound noun + verbal; Hyper Light Drifter twist.
19. Atrium — classical interior chamber. Inside-style internal place.
20. Last Halo — Last X defense construction; final-stand framing for the chamber.

If pressed for my top three: Norien (most distinctive sound, blank-slate identity), Vellum (literal-but-unexpected, matches the paper aesthetic perfectly), Hold the Lune (most descriptive of the gameplay loop, with character).

When you pick, the rename touches the folder, window title, file headers, and design.md / todo.md references — happy to do that pass next session.

How about more literal names like Slay the Spire or Mini Metro or Artifact and so on. It is a game about a ball bouncing inside a square, after all.

Right — literal/mechanical, naming the actual thing the game is.

1. Rebound — single verb at the heart of every interaction. Artifact-style minimalism.
2. Ricochet — what both the ball and the projectiles do. Direct.
3. Trajectory — the path lines on screen are basically the game.
4. Square — deadpan; the central element, unadorned.
5. Reverb — bouncing turned into a single noun. Slight musical tilt.
6. Hollow Square — describes the chamber literally. Hollow Knight construction.
7. Closed Loop — the autopilot ball ↔ chamber feedback, in two words.
8. Inner Square — adjective + noun, calm.
9. Tiny Chamber — Mini Metro construction, scale + thing.
10. Hold the Square — Slay the Spire construction; defense-game imperative + the literal object you're holding.
11. Defend the Box — same construction, plainer word, more arcade-y.
12. Bounceback — single compound noun; what the entire engine is doing.
13. Polyball — poly + ball; geometric defense flavor, Geometry Wars-ish.
14. Bouncefield — invented compound, the play space and mechanic in one.
15. Halftone — names the visual identity. Tells you what the game looks like.
16. Schematic — single word for the look + the implied system.
17. Auto Bouncer — describes the autopilot mechanic + the player's relationship to it.
18. Square Defense — Plants vs Zombies-flat genre name.
19. Wireframe — names the visual style; could be a game called Wireframe.
20. The Bounce — The Witness-style article + noun.

If pressed, my top three of this batch:

• Rebound — short, mechanical, a verb you can say in one breath.
• Halftone — names what makes the game look like itself, in one word.
• Hold the Square — most descriptive of the actual gameplay loop with character; reads as a game name immediately.

Let's call it Ricochet

Doing the rename now — touching the player-facing identity (window title, doc titles, file-header comments) but keeping the in-game chamber object and its class as-is (still called chamber because that's what it literally is). Folder name stays for dev infrastructure unless you tell me to move it.

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\main.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\entities.lua has been updated successfully. (file state is current in your context — no need to Read it back)

The file E:\a327ex\chamber\design.md has been updated successfully. (file state is current in your context — no need to Read it back)

Done. Summary of the rename pass:

• Window title: "chamber" → "Ricochet" (capitalized, since it's player-facing).
• main.lua header: "chamber — Anchor 2 physics-ball survivor" → "Ricochet — …"
• entities.lua header: "Game entity classes for chamber" → "Game entity classes for Ricochet".
• design.md heading: "# chamber — design" → "# Ricochet — design".
• Kept as-is (because they refer to the in-game object, not the project): the chamber class, the_chamber global, CHAMBER_* constants, all references inside game code.
• Folder still E:\a327ex\chamber\ and run.bat still passes chamber to the engine. Rename whenever convenient — would require renaming the folder, updating run.bat, and the project loads fine again.

Project now identifies as Ricochet in everything player-facing. Good session — gameplay loop substantially up, dot motif locked in, chamber dynamics, file split, todo for the next chapter. Enjoy the bouncing.

Rename the folder and create a private git repo for it.

Doing the folder move, updating run.bat, then setting up the private repo.

Exit code 1
mv: cannot move 'E:/a327ex/chamber' to 'E:/a327ex/ricochet': Device or resource busy

/e/a327ex

Move-Item : The process cannot access the file because it is being used by another process.

At line:1 char:1

+ Move-Item -Path "E:\a327ex\chamber" -Destination "E:\a327ex\ricochet" ...

+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    + CategoryInfo          : WriteError: (E:\a327ex\chamber:DirectoryInfo) [Move-Item], IOException

    + FullyQualifiedErrorId : MoveDirectoryItemIOError,Microsoft.PowerShell.Commands.MoveItemCommand

 

FAIL

Something's holding the folder open. Let me check if the game is running:

(PowerShell completed with no output)

(PowerShell completed with no output)

INFO: No tasks are running which match the specified criteria.

Could be a terminal or file watcher holding it. Let me set up the git repo in place first, then attempt the rename once the lock is gone.

File created successfully at: E:\a327ex\chamber\.gitignore (file state is current in your context — no need to Read it back)

Initialized empty Git repository in E:/a327ex/chamber/.git/
On branch master

No commits yet

Untracked files:
  (use "git add <file>..." to include in what will be committed)
    .gitignore
    anchor.exe
    anchor/
    assets/

Switched to a new branch 'main'
warning: in the working copy of '.gitignore', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'anchor/animation.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'anchor/camera.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'anchor/class.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'anchor/collider.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'anchor/color.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'anchor/font.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'anchor/image.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'anchor/init.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'anchor/input.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'anchor/memory.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'anchor/object.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'anchor/physics.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'anchor/shake.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'anchor/spring.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'anchor/spritesheet.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'anchor/timer.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'design.md', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'dot_shader.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'entities.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'main.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'reference/main.lua', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'run.bat', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'todo.md', LF will be replaced by CRLF the next time Git touches it
A  .gitignore
A  anchor.exe
A  anchor/animation.lua
A  anchor/array.lua
A  anchor/camera.lua
... [25 more lines]

 create mode 100644 reference/05 - GAME OBJECTS.png
 create mode 100644 reference/06 - TEMPLATES AND USAGE (dotted).png
 create mode 100644 reference/main.lua
 create mode 100644 run.bat
 create mode 100644 todo.md

Now create the private GitHub repo and push:

https://github.com/a327ex/ricochet
branch 'main' set up to track 'origin/main'.
To github.com:a327ex/ricochet.git
 * [new branch]      HEAD -> main

Repo's up. Now let me retry the folder rename:

Exit code 1
Move-Item : Cannot move item because the item at 'E:\a327ex\chamber' is in use.

At line:1 char:1

+ Move-Item -Path "E:\a327ex\chamber" -Destination "E:\a327ex\ricochet" ...

+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    + CategoryInfo          : InvalidOperation: (:) [Move-Item], PSInvalidOperationException

    + FullyQualifiedErrorId : InvalidOperation,Microsoft.PowerShell.Commands.MoveItemCommand

Repo is up at github.com/a327ex/ricochet (private), but the folder rename keeps failing — something's holding a lock on E:\a327ex\chamber. Most likely culprit is this conversation's own filesystem handles (the Read/Edit history keeps file handles open). Won't release until the session ends.

Status:

• ✅ .gitignore written (OS junk + editor temp files; engine binary and framework copy intentionally tracked).
• ✅ Repo initialized on main branch.
• ✅ Initial commit made.
• ✅ Private GitHub repo a327ex/ricochet created and pushed.
• ❌ Folder rename chamber/ → ricochet/ blocked by file lock.
• ⏸️ run.bat still references chamber as the game folder argument.

To finish the rename after the session ends (in any new terminal):

cd /e/a327ex
mv chamber ricochet
# Then edit ricochet/run.bat, change the last line to:
#   "%~dp0anchor.exe" ricochet

Optionally cd /e/a327ex/ricochet && git pull after to confirm git's happy with the new path.

I renamed it. Need to do anything else before finishing the session? If not, the session should be named "Ricochet 1"

Quick check — run.bat still references the old folder name. Let me update it, then we can wrap.

@echo off
REM Run chamber prototype. CWD must be repo root; engine receives the game folder name.

cd /d "%~dp0.."
"%~dp0anchor.exe" chamber

<tool_use_error>File has not been read yet. Read it first before writing to it.</tool_use_error>

1    @echo off
2   REM Run chamber prototype. CWD must be repo root; engine receives the game folder name.
3   
4   cd /d "%~dp0.."
5   "%~dp0anchor.exe" chamber
6   

The file E:\a327ex\ricochet\run.bat has been updated successfully. (file state is current in your context — no need to Read it back)

 M run.bat
6936838 Initial commit — Ricochet

Just run.bat changed (chamber → ricochet references). Git is happy with the renamed folder — .git moved with it, no path issues. The end-session skill will pick up the run.bat change in its commit pass.

Nothing else outstanding. Invoking end-session now.

Launching skill: end-session

# End Session Workflow

This skill is invoked from the **same conversation** where the work was done. You already have the full session context in memory — you do NOT need to read the transcript.

## Step 1: Get Session Info

Ask the user for the **session title** (max 30 characters). Examples: "Anchor Phase 10 Part 5", "Physics Arena Setup", "Timer System Fix", "Thalien Lune Design".

**Determine the project yourself from your session context** — you know which repo(s) were worked on, which files were created/modified, and where they live. No need to ask. See Step 6 for the list of known project roots; if the session touched something outside the list, infer the root from the paths you actually edited.

## Step 2: Write Summary

Write the summary from your conversation memory. You have the full session context — no need to read any files.

The summary should be **thorough and detailed**. Each major topic deserves its own section with multiple specific bullet points. Don't compress — expand.

**Purpose:** These summaries serve as searchable records. Future Claude instances will grep through past logs to find how specific topics were handled. The more detail you include, the more useful the summary becomes for finding relevant context later.

Format (this is just an example structure — adapt sections to match what actually happened):

```markdown
# [Title]

## Summary

[1-2 sentence overview of the session's main focus]

**[Topic 1 - e.g., "Spring Module Implementation"]:**
- First specific detail about what was done
- Second detail - include file names, function names
- User correction or feedback (quote if notable)
- Technical decisions and why

**[Topic 2 - e.g., "Camera Research"]:**
- What was researched
- Key findings
- How it influenced implementation

**[Topic 3 - e.g., "Errors and Fixes"]:**
- Specific error message encountered
- Root cause identified
- How it was fixed

[Continue for each major topic...]

---

[Rest of transcript follows]
```

Rules:

- **Be thorough** — If in doubt, include more detail, not less. Each topic should be as detailed as possible while still being a summary.
- **Think searchability** — Future instances will search these logs. Include keywords, function names, error messages that someone might grep for.
- **One section per major topic** — Don't combine unrelated work into one section
- **Chronological order** — Sections should match conversation flow
- **Specific details** — Error messages, file names, function names, parameter values
- **Include user quotes** — When user gave notable feedback, quote it (e.g., "k/d variables are not intuitive at all")
- **Weight planning equally** — Research, proposals, alternatives considered, user feedback on approach are as important as implementation
- **Weight problems solved** — Errors, root causes, fixes, user corrections all matter
- **Technical specifics** — Include formulas, API signatures, parameter changes when relevant

## Step 3: Get User Approval

Show the title and summary to the user. Wait for approval before proceeding. If they have corrections, fix them.

## Step 4: Convert Transcript and Write Log File

```bash
# Find recent sessions (Claude + Cursor; see script). Same script lives in Anchor2:
python E:/a327ex/Anchor2/scripts/find-recent-session.py --limit 5
# or: python E:/a327ex/Anchor/scripts/find-recent-session.py --limit 5
```

The script shows sessions sorted by when they ended. The **first result** is the current conversation (since end-session was invoked here). Use it.

Convert the transcript to markdown and write the log file with the approved summary as header:

```bash
python E:/a327ex/Anchor2/scripts/jsonl-to-markdown.py [SESSION_PATH] E:/a327ex/anchor.blot.im/logs/[slug].md
# or: python E:/a327ex/Anchor/scripts/jsonl-to-markdown.py ...
```

The same script **auto-detects** Claude Code JSONL vs Cursor/Composer agent JSONL (`~/.cursor/projects/.../agent-transcripts/...`). For Composer sessions, use `find-recent-session.py` (it merges both sources) and pick the `[cursor]` line for the current chat.

Use lowercase hyphenated slug derived from the title (e.g., "anchor-primitives-hitstop-animation").

Then replace the default header (`# Session YYYY-MM-DD...`) with the approved title and summary.

## Step 5: Sync Context Files to Blot

```bash
cp E:/a327ex/.claude/CLAUDE.md E:/a327ex/anchor.blot.im/context/CLAUDE.md
cp E:/a327ex/Anchor/docs/* E:/a327ex/anchor.blot.im/context/
```

**When the session was Anchor2** (optional):

```bash
cp E:/a327ex/Anchor2/.claude/CLAUDE.md E:/a327ex/anchor.blot.im/context/CLAUDE_ANCHOR2.md
```

## Step 6: Commit Project Repo

Identify the project repo(s) worked on this session from your own context — you already know which repos were touched and which files changed. For the common projects, here are the canonical staging commands:

| Project | Root | Stage command |
|---|---|---|
| Anchor | `E:/a327ex/Anchor` | `git add docs/ framework/ engine/ scripts/ reference/` |
| Anchor2 | `E:/a327ex/Anchor2` | `git add framework/ engine/ arena/ reference/ scripts/ docs/ .claude/` |
| emoji-ball-battles | `E:/a327ex/emoji-ball-battles` | `git add -A` |
| orblike | `E:/a327ex/orblike` | `git add -A` |
| thalien-lune | `E:/a327ex/thalien-lune` | `git add -A` |

For a project not listed, infer the root from the files you actually created or modified this session and stage those. If multiple candidate roots look valid, ask the user which files to stage.

`cd` into the project root, stage, run `git status` to verify before committing.

**IMPORTANT — FULL SUMMARY IN COMMIT:** The commit message MUST include the FULL summary from the log file. Read the summary back from the log file to ensure nothing is missing.

**IMPORTANT — COMMIT METHOD:** The summary contains backticks, special characters, and markdown that WILL break heredocs and `git commit -m`. ALWAYS use the file-based method below. NEVER try a heredoc first — it will fail and produce a malformed commit that needs amending.

Commit using a temporary file (extracts only the summary text, not the markdown heading or `## Summary` line):

```bash
# Extract summary: skip line 1 (# Title) and line 3 (## Summary), take lines 4 onward until the --- separator
awk 'NR>=4 && /^---$/{exit} NR>=4{print}' E:/a327ex/anchor.blot.im/logs/[slug].md > /tmp/commit_msg.txt

# Prepend the title (plain text, no #) and append attribution
sed -i "1i [Title]\n" /tmp/commit_msg.txt
printf "\nGenerated with [Claude Code](https://claude.com/claude-code)\n\nCo-Authored-By: Claude <[email protected]>\n" >> /tmp/commit_msg.txt

git commit -F /tmp/commit_msg.txt
```

## Step 7: Push Both Repos

```bash
# Push project repo to GitHub
git push origin main

# Push Blot repo (logs and context are already there)
cd E:/a327ex/anchor.blot.im && git add -A && git commit -m "[Title]" && git push origin master
```

## Step 8: Confirm

Tell the user:

- Commit hash
- That GitHub push succeeded
- That Blot push succeeded


ARGUMENTS: Ricochet 1

Writing the summary first for approval, then proceeding with the rest.

Ricochet 1

Summary

First major session on Ricochet — went from scratch to a playable bounce-and-shoot prototype with custom dot-halftone shader, dynamic resizable/rotating chamber, full combat loop, three-file split, and a private GitHub repo. Game was named "chamber" throughout the session and renamed to "Ricochet" at the end.

Visual design rules (design.md):

• Wrote a detailed Visual Design section based on five existing reference sheets (reference/01-05): overall direction (calm minimal abstract defense), neutral palette (paper #F6F4F0, ink #111111, charcoal #4A4A4A, light grey #DADADA), accent palette, typography (tall condensed sans + neutral sans/mono-like).
• User added typography specifics from sheet 03: primary "TALL CONDENSED SANS" for headings, secondary "NEUTRAL SANS / MONO-LIKE" for labels, with a 6-step size ladder (64/72 → 8/11).
• User refined hex values manually after my first-pass guesses.
• Later expanded with the dotted motif as a first-class visual language alongside line work, after user added new "(dotted)" reference sheet variants (01-06).
• Stroke weight hierarchy iterated multiple times: started as structure (2px) > actors (1.5px) > annotation (1px), eventually inverted to actors (1.5px / thin) being the loudest tier with structure also at hairline (1px), reasoning that the dot motif provides the visual mass once otherwise carried by chamber stroke.
• Mid grey #8A8A8A added later as a fifth neutral tier.

Phase 1 — scaffold + chamber:

• Set up main.lua with require('anchor')({width=1920, height=1080, scale=1, filter="smooth"}).
• Drew chamber as a square outline at screen center with charcoal corner brackets just outside each corner (CORNER_TICK_LEN=18, CORNER_TICK_GAP=10, 1px stroke).
• Sized at 240×240 (CHAMBER_HALF=120); user wanted slightly smaller after first version.

Phase 2 — ball physics:

• Added physics_init, registered tags 'ball'/'chamber', enabled collision pair.
• Built chamber as 4-wall static body with overlapping corners, restitution=1, friction=0 per shape.
• Ball: BALL_RADIUS=6, BALL_SPEED=800, dynamic circle, bullet=true for CCD, set_fixed_rotation.
• Per-frame velocity normalization to counter Box2D's energy bleed at restitution=1.
• Bounce angle jitter (±5° via BALL_BOUNCE_JITTER = math.pi/36) added so ball can't settle into repeating paths.
• Ball spring squash on wall hit (spring_pull(self.spring, 'hit', 0.3)).

Phase 3 — projectiles (heavy iteration):

• Sensor body, fires from wall-hit position, flies outward.
• Initial: 10×2 blue capsule at 850 px/sec. User: "shouldn't be blue, should be black, filled, like a v but more open and with shorter legs".
• Iterated to ink chevron: arms drawn with layer_line, opening angle 120° → 100° → 80° (math.rad(40) half-angle final).
• Stroke width: 2.5 → 3.5 → 1.5 → 2 → 2.5 across multiple iterations as user composed the visual.
• Speed reduced to 500 px/sec (user: projectiles "too fast" caused choppiness).
• Spawn position: initially at ball position, then offset by BALL_RADIUS + CORNER_TICK_GAP = 16 along wall normal (so the chevron emerges at the corner-tick ring distance regardless of bounce angle).
• Projectile angle rule (significant deliberation): initially math.angle_to_point(CHAMBER_X, CHAMBER_Y, ball.x, ball.y) (radial outward). User wanted midpoint of wall normal + ball's outgoing direction. First attempt averaged wall normal with post-bounce velocity → caused parallel-to-wall results because perpendicular hits gave (0,-1) + (0,1) = (0,0). Fixed by reflecting post-bounce velocity across wall normal first to recover pre-bounce (outward) direction, THEN averaging unit vectors via math.atan(sin(a)+sin(b), cos(a)+cos(b)).

Engine fix — render uncap + display selection:

• User reported choppiness when streaming Twitch on second monitor. Investigated anchor.c: physics steps at 120Hz, render is hard-capped at 60Hz with comment "for chunky pixel movement on high-refresh monitors".
• Found scripts/monitor_sim.c documenting the timing decision (Tyler Glaiel's "How to make your game run at 60fps"). The 60Hz cap is for pixel-art games; doesn't apply to smooth-filter games.
• Added engine flag render_uncapped (default false to preserve all existing pixel-art games), with engine_set_render_uncapped(bool) Lua binding. When true, render fires every main-loop iteration and vsync paces the rate.
• Added display init flag with engine_set_display(int) for opening on a specific monitor; clamps to display 0 if invalid.
• Bug fixed: display refresh rate query was hardcoded to SDL_GetCurrentDisplayMode(0, ...) regardless of which display the window opened on. Changed to SDL_GetWindowDisplayIndex(window) so vsync snap frequencies align with the actual monitor's refresh rate.
• Engine rebuilt; new anchor.exe and updated init.lua deployed to chamber project.

Phase 4 — enemies:

• Added 'enemy' physics tag with collision('enemy','chamber') and ('enemy','enemy').
• Initial: hollow ink circles with seek+separate steering toward chamber center.
• Speed 200-280 random, spawn rate 1/sec, ENEMY_STEER_FORCE=1200, damping 3.
• Originally bounced off chamber via push impulse; user changed to dying on chamber contact ("when they hit the box, they should be killed").
• Shape iteration: circle → diamond (4-vertex polygon, axis-aligned, no rotation since 4-fold symmetric) → directional arrowhead with notched base (4 vertices: tip, top-back, notch, bottom-back). User described shape as "a triangle but at the base it goes inside a little". Final: 24px length × 18px wide × 5px notch depth × 1.5px stroke.
• Re-enabled velocity-direction tracking for the directional arrowhead: self.r = math.lerp_angle_dt(0.99, 0.1, dt, self.r, math.atan(vy, vx)).
• Enemies spawn already facing the chamber to avoid first-frame snap.

Border zone + asymmetric layout:

• Originally 80px symmetric border on all sides for UI/cards.
• User changed to asymmetric: thick top/bottom (120/150px), no left/right border. Enemies spawn from left/right screen edges only.
• GAME_AREA_LEFT/RIGHT/TOP/BOTTOM constants; chamber center computed from gameplay-area center: (GAME_AREA_LEFT + GAME_AREA_RIGHT) / 2.
• draw_border_zone draws hairlines only at top and bottom (not a full rectangle).
• Light grey 1px hairlines, eventually changed.

Dot-grid reveal shader (major addition):

• Custom GLSL fragment shader loaded via shader_load_string with screen vertex shader.
• Architecture: dedicated mask_layer. Game code draws shapes (circles, polygons) into mask_layer; shader runs over it via layer_apply_shader(mask_layer, dot_shader) and outputs a dotted-grid pattern wherever mask alpha is non-zero.
• Shader logic: per-fragment, sample mask alpha; if > threshold, compute grid cell coords from frag_px / spacing, find dot center, distance to center, modulate dot radius via static value-noise.
• Final params: GRID_SPACING=5, GRID_BASE_RADIUS=1.2, GRID_NOISE_SCALE=0.05, GRID_NOISE_AMOUNT=0.7.
• Critical fix per user feedback ("rectangle in the middle is jarring with dot effect layered on top"): shader outputs mix(u_paper_color, u_dot_color, dot_alpha) in mask region (not transparent in gaps), with fragment alpha = mask_a. So fully opaque mask cleanly carves out a paper-and-dots patch over chamber lines; partially opaque blends.
• Static noise (no time uniform): same noise field every frame, but different per dot.

Hit FX redesign — dot motif as primary effect language:

• Replaced traditional particles entirely. User: "the way enemies spawn should be... they should fade into the world, modulated by the dot effect."
• hit_burst class: filled diamond (4 vertices: top/right/bottom/left), shrinks to 0 over duration, drawn into mask_layer.
• Initially circle, then changed to diamond after user request: "let's have the hit circle actually be a diamond, so a rotated square, to match the fact that enemies aren't circles."
• Three sizes: enemy death HIT_BURST_RADIUS=22 × 0.3s, ball wall hit BALL_HIT_BURST_RADIUS=14 × 0.18s, projectile death PROJECTILE_DEATH_BURST_RADIUS=14 × 0.18s.
• hit_line class (thick capsule line particles) was added then removed — user wanted ONLY hit_burst, no flying particles. Removed all HIT_LINE_* constants too.
• Enemy spawn fade-in: crossfade from dot silhouette to solid line over ENEMY_SPAWN_FADE_TIME=0.5. Mask alpha: lerp(t, 0.5, 0) (faint dot blob → 0). Solid alpha: t (0 → 1). User: "both should also be alpha'd so that their relative darkness is lower". Required shader change to multiply dot output by mask_a (not binary cutoff).
• Enemy death burst spawned at chamber wall contact point (ev.x, ev.y), not enemy center, for visual consistency with ball wall hits.

Combat loop — phase 5:

• Added physics_enable_sensor('projectile', 'enemy'). Sensor handler in main.lua: e:die(p.x, p.y); p:on_enemy_hit(e).
• Three modifier modes initially: homing, ricochet, spread. Each ball wall-hit randomly picked one via random_choice.
  • Homing: turns toward nearest enemy in HOMING_CONE_HALF=π/6 (60° total cone) at HOMING_TURN_RATE=8 rad/sec. pick_homing_target scans enemies. Used math.angle_to_point, angle_diff helper, math.sign(delta) * math.min(abs(delta), max_turn).
  • Ricochet (initially): on enemy kill, redirected to nearest un-hit enemy (1-5 redirects). Used hit_enemy_ids set on projectile.
  • Spread: 1-5 projectiles in a 60° fan, evenly distributed.
• User clarification: "For ricochet I meant against walls only, against enemies it would be called chain." Removed chain logic entirely (hit_enemy_ids, pick_ricochet_target). Reimplemented ricochet as wall bouncing: on border crossing, if ricochet_count > 0, reflect velocity off the crossed border, decrement count, emit small dot-burst.
• Eventually all projectiles got ricochet (user: "make ricochet for all of them, don't change inner workings").
• Final refactor — collapsed mode concept (user: "There should be no concept of a 'mode'. The projectile either has homing or ricochet, and both can happen at the same time"): removed self.mode, replaced with independent self.homing (bool, HOMING_CHANCE=0.5) and self.ricochet_count (int, random 1-MAX_RICOCHETS=5). Spread is purely caller-side (just spawn N projectiles instead of 1).

Projectile chamber ricochet:

• User: "Ricochet projectiles should also ricochet against the central chamber."
• First tried physics_enable_sensor('projectile', 'chamber'). Failed: Box2D 3 sensors don't have continuous collision detection (per types.h line 409: "Sensors do not have continuous collision"). Fast projectile (500 px/sec, ~4px per physics step) tunneled through 4px-thick chamber walls without firing sensor begin events.
• User asked: "Why not just make it physical collision versus projectiles?" — discussed extensively. Would require restructuring projectile↔enemy hit pipeline (sensor → collision events) and other changes. User then asked: "Can't we make the border zone a physical object? It should be one anyways, eventually I want to be able to both resize it and rotate it." Outlined full physics refactor.
• User redirected to simpler path: keep projectiles as sensor + manual checks. Implemented manual chamber-crossing check using was_inside_chamber state flag. Each frame: compute now_inside (axis-aligned point-in-bounds check); on false → true transition, call ricochet_chamber(). Track prev_x/prev_y to determine which axis was crossed, flip those velocity components.

File split:

• User asked: "do a general pass on the main.lua file and split it into relevant files."
• Split into 3 files:
  • main.lua (237 lines): config, palette, constants, physics setup, layers, camera, requires, entity collections, draw_border_zone helper, init, main loop.
  • entities.lua (411 lines): chamber, ball, projectile, hit_burst, enemy classes + spawn helpers + angle_diff helper.
  • dot_shader.lua (83 lines): GLSL source as Lua string + shader_load_string + immediate uniform setters.
• Order in main.lua: framework → palette → constants → physics → layers/camera → require('dot_shader') → collections → require('entities') → init → loop.
• Anchor 2 framework convention used: classes defined as globals, modules called for side effects.

Dynamic chamber (resize + rotate):

• User: "Eventually I'll want to both change the size of the chamber and rotate it. Can you support that feature now?"
• Restructured chamber class:
  • Added self.angle = 0 field.
  • Extracted chamber:_build_collider() for destroy+rebuild on resize.
  • Added methods: :resize(new_half), :set_angle(new_angle), :set_position(x, y).
  • Added helpers: :contains(px, py) (rotation-aware point-in-bounds), :wall_normal_for(px, py) (rotation-aware outward normal at a point).
  • Drawing uses layer_push(game_layer, self.x, self.y, self.angle, 1, 1) + local-coord drawing.
• All callers updated to use chamber instance methods instead of constants:
  • ball:on_wall_hit uses the_chamber:wall_normal_for.
  • projectile:update uses the_chamber:contains.
  • projectile:ricochet_chamber rotates prev position + velocity into chamber-local space, flips crossed components, rotates back.
  • enemy uses the_chamber.x/y for steering target.
• Continuous rotation: CHAMBER_ROTATION_RATE=0.3 rad/sec (positive = CCW math / CW screen). chamber:update advances angle.
• Resize keys: [ and ] bind to chamber_smaller/chamber_bigger. Step 15px, bounds 30 to 280.
• Bug fix — "Invalid body" error after multiple resizes: Error was physics.lua:31: Invalid body from body_to_entity calls inside collision_entities_begin('ball', 'chamber') after chamber:resize destroyed and rebuilt the body mid-update. The events from the physics step held references to the now-dead body. Fix: moved input-driven resize to the END of update(dt), after collision drains and process_destroy_queue, so this frame's events finish processing against the still-existing body before destruction.
• Defensive ball containment: ball:contain_in_chamber() runs every frame at end of ball:update. Clamps ball position to ±(half - radius - 1) in chamber-local space; if clamped, snaps position back via set_position and reflects outward velocity components. Catches resize-down, fast rotation, and CCD failures.

Final projectile shape iteration:

• User experimented with non-chevron shapes:
  • Filled rectangle (10×4)
  • Triangle (10×4 isoceles)
  • Equilateral triangle (PROJECTILE_SIZE=14, computed vertices using sqrt(3))
  • Reverted to chevron with 80° opening (40° half-angle), 2.5px stroke.

Game rename — chamber → Ricochet:

• User: "We need to rename this game. Chamber is very bad. I want an alien but cool name like Thalien Lune that matches the visuals of the game somewhat."
• First batch (alien names): Vellith Lune, Norien Aether, Caelin Halo, Sylven Glyph, Thavren Aria, Aerolith Veyl, Vellune, Aerolith, Carillun, Halicene.
• User: "How about more literal names like Slay the Spire or Mini Metro or Artifact and so on. It is a game about a ball bouncing inside a square, after all."
• Second batch (literal): Rebound, Ricochet, Trajectory, Square, Reverb, Hollow Square, Closed Loop, Inner Square, Tiny Chamber, Hold the Square, Defend the Box, Bounceback, Polyball, Bouncefield, Halftone, Schematic, Auto Bouncer, Square Defense, Wireframe, The Bounce.
• User picked Ricochet.
• Updated: window title (title = "Ricochet"), file headers in main.lua and entities.lua, design.md heading. Kept chamber class name and the_chamber global since they refer to the in-game object, not the project.

todo.md created:

• Listed for future sessions: fail state (chamber HP?), wave system, reset key, card/mana layer, HUD + typography phase, enemy families, pickups, FX polish, real MSAA, render interpolation between physics steps, pre-solve callback exposure.
• Included three suggested next-session groupings: (A) playable session loop, (B) HUD, (C) card layer.

Folder rename + private GitHub repo:

• User: "Rename the folder and create a private git repo for it."
• Folder rename via mv and PowerShell Move-Item blocked by file lock — likely the conversation's own filesystem handles. User performed the rename manually.
• Created .gitignore (OS junk + editor temp; engine binary + framework copy intentionally tracked).
• git init, switched to main branch, staged everything, made initial commit with detailed multi-paragraph message.
• gh repo create ricochet --private --source=. --remote=origin --push → github.com/a327ex/ricochet.
• run.bat updated chamber → ricochet references after folder rename.

Approve and I'll proceed to convert the transcript and push everything.

Yes.

2026-04-25T15:06:39.978Z 8151f13d-f586-41bb-aa59-9a8f0893861c [claude] <-- MOST RECENT

   C:\Users\adn\.claude\projects\E--a327ex\8151f13d-f586-41bb-aa59-9a8f0893861c.jsonl



2026-04-25T14:29:03.496Z 8f867da8-6295-4e85-8aa6-d0f5774e6771 [claude]

   C:\Users\adn\.claude\projects\E--a327ex\8f867da8-6295-4e85-8aa6-d0f5774e6771.jsonl



2026-04-25T12:38:01.536Z 912387ca-0211-4705-92c2-37f6cd3dd2d9 [claude]

   C:\Users\adn\.claude\projects\E--a327ex\912387ca-0211-4705-92c2-37f6cd3dd2d9.jsonl



2026-04-25T11:33:16.293Z e626cc5f-5ae5-48da-a5f4-ec598acd729c [claude]

   C:\Users\adn\.claude\projects\E--a327ex\e626cc5f-5ae5-48da-a5f4-ec598acd729c.jsonl



2026-04-24T14:12:21.568Z cf916903-bcd2-4e6f-aef1-81964a9ad44d [claude]

   C:\Users\adn\.claude\projects\E--a327ex\cf916903-bcd2-4e6f-aef1-81964a9ad44d.jsonl

Written to E:/a327ex/anchor.blot.im/logs/ricochet-1.md

# Session 2026-04-24 13:52



---

Now write the approved title + summary at the top of the log file, replacing the default header.

File created successfully at: E:\a327ex\anchor.blot.im\context\ricochet-summary-temp.md (file state is current in your context — no need to Read it back)

# Ricochet 1

## Summary
---
5507 logs/ricochet-1.md

Step 5 — sync context files to Blot:

OK

Step 6 — commit project repo (Ricochet) with full summary in message:

149 /tmp/commit_msg.txt
Ricochet 1

warning: in the working copy of 'run.bat', LF will be replaced by CRLF the next time Git touches it
M  run.bat
---
[main 0cf7e1e] Ricochet 1
 1 file changed, 2 insertions(+), 2 deletions(-)

Step 7 — push both repos:

To github.com:a327ex/ricochet.git
   6936838..0cf7e1e  main -> main

warning: in the working copy of 'context/ANCHOR_CONTEXT_BRIEF.md', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'context/CLAUDE_ANCHOR2.md', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'context/ENGINE_API.md', LF will be replaced by CRLF the next time Git touches it
warning: in the working copy of 'context/ENGINE_API_QUICK.md', LF will be replaced by CRLF the next time Git touches it
A  logs/ricochet-1.md
---
[master 9c0ed8b] Ricochet 1
 1 file changed, 5507 insertions(+)
 create mode 100644 logs/ricochet-1.md
To https://blot.im/clients/git/end/anchor.git
   0c549c8..9c0ed8b  master -> master

Done. Session ended cleanly.

• Ricochet commit: 0cf7e1e — pushed to github.com/a327ex/ricochet (private).
• Blot log: logs/ricochet-1.md (5507 lines), commit 9c0ed8b — pushed to Blot.
• Context files synced (CLAUDE.md, Anchor docs, CLAUDE_ANCHOR2.md).

Good session. Picking up next session: see todo.md for the next chapter — fail state + waves + reset is the suggested first group, then HUD, then the card layer.