a327ex.com

Anchor Phase 2

Summary

This session implemented Phase 2 of the Anchor engine: the Emscripten/WebGL web build. The same C code now compiles and runs identically in the browser.

Emscripten Setup:

Platform Abstraction in anchor.c:

Unified Shader System:

HTML Shell and CSS:

Development Workflow:

Documentation:

Hi, Claude. Let's get started on Anchor's phase 2 today.

Let me read the implementation plan to see what phase 2 covers.

Read (E:\a327ex\Anchor\docs\ANCHOR_IMPLEMENTATION_PLAN.md)

1→# Anchor Implementation Plan
     2→
     3→C engine with YueScript scripting, OpenGL rendering, targeting Windows and Web.
     4→
     5→---
     6→
     7→## Summary of Key Decisions
     8→
     9→| Area | Decision | Rationale |
    10→|------|----------|-----------|
    11→| Renderer | OpenGL | Smooth rotation, additive blending, performance headroom, console-portable |
    12→| Audio | TBD (miniaudio or SoLoud) | Need pitch shifting; SDL_mixer insufficient |
    13→| Physics | Box2D 3.1 | Already used, true ball-to-ball collisions needed |
    14→| Scripting | Lua 5.4 + YueScript | Build-time compilation with `-r` flag for line numbers |
    15→| Timestep | Fixed 144 Hz | High simulation rate for responsive feel; determinism for replays |
    16→| Resolution | Per-game configurable | 480×270, 640×360, or custom; aspect-ratio scaling with letterboxing |
    17→| C Structure | Single anchor.c | Monolithic file, easier navigation |
    18→| Resources | Live forever | Games are small enough; no unloading needed |
    19→| Linking | Static | No DLLs; SDL2, Lua, audio all compiled in |
    20→| Distribution | Single executable | Zip-append for game content, extractable by modders |
    21→
    22→---
    23→
    24→## Build Strategy
    25→
    26→### YueScript Compilation
    27→
    28→**Build-time compilation** — compile `.yue` → `.lua` during build, not at runtime.
    29→
    30→```
... [590 more lines]

Phase 2 is the Web Build with Emscripten. The goal is to get the same code compiling and running in the browser via WebGL.

Let me first look at the current state of the codebase to understand what we're working with:

Read (E:\a327ex\Anchor\engine\src\anchor.c)

1→/*
     2→ * Anchor Engine - Minimal skeleton
     3→ * Phase 1: Window + OpenGL + Lua integration
     4→ */
     5→
     6→#include <stdio.h>
     7→#include <stdlib.h>
     8→#include <stdbool.h>
     9→
    10→#include <SDL.h>
    11→#include <glad/gl.h>
    12→
    13→#include <lua.h>
    14→#include <lualib.h>
    15→#include <lauxlib.h>
    16→
    17→#define WINDOW_TITLE "Anchor"
    18→#define GAME_WIDTH 480
    19→#define GAME_HEIGHT 270
    20→#define INITIAL_SCALE 2
    21→
    22→// Timing configuration (matching reference Anchor)
    23→#define FIXED_RATE (1.0 / 144.0)  // 144 Hz fixed timestep
    24→#define MAX_UPDATES 10            // Cap on fixed steps per frame (prevents spiral of death)
    25→
    26→static SDL_Window* window = NULL;
    27→static SDL_GLContext gl_context = NULL;
    28→static lua_State* L = NULL;
    29→static bool error_state = false;
    30→static char error_message[4096] = {0};
... [464 more lines]

Glob (engine/*/)

E:\a327ex\Anchor\engine\include\SDL2\begin_code.h
E:\a327ex\Anchor\engine\include\SDL2\close_code.h
E:\a327ex\Anchor\engine\include\SDL2\SDL.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_assert.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_atomic.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_audio.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_bits.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_blendmode.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_clipboard.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_config.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_config_android.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_config_emscripten.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_config_iphoneos.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_config_macosx.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_config_minimal.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_config_ngage.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_config_os2.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_config_pandora.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_config_windows.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_config_wingdk.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_config_winrt.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_config_xbox.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_copying.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_cpuinfo.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_egl.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_endian.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_error.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_events.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_filesystem.h
E:\a327ex\Anchor\engine\include\SDL2\SDL_gamecontroller.h
... [71 more lines]

Good. Phase 1 is complete with a solid foundation. Now for Phase 2 - the web build. Let me check the current build setup:

Read (E:\a327ex\Anchor\main.lua)

<tool_use_error>File does not exist.</tool_use_error>

Read (E:\a327ex\Anchor\engine\build.bat)

1→@echo off
     2→setlocal
     3→
     4→cd /d "%~dp0"
     5→
     6→:: Find and run vcvarsall.bat for Visual Studio
     7→if exist "C:\Program Files\Microsoft Visual Studio\18\Community\VC\Auxiliary\Build\vcvarsall.bat" (
     8→    call "C:\Program Files\Microsoft Visual Studio\18\Community\VC\Auxiliary\Build\vcvarsall.bat" x64 >nul 2>&1
     9→) else if exist "C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Auxiliary\Build\vcvarsall.bat" (
    10→    call "C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Auxiliary\Build\vcvarsall.bat" x64 >nul 2>&1
    11→) else if exist "C:\Program Files\Microsoft Visual Studio\2022\Professional\VC\Auxiliary\Build\vcvarsall.bat" (
    12→    call "C:\Program Files\Microsoft Visual Studio\2022\Professional\VC\Auxiliary\Build\vcvarsall.bat" x64 >nul 2>&1
    13→) else if exist "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\Build\vcvarsall.bat" (
    14→    call "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Auxiliary\Build\vcvarsall.bat" x64 >nul 2>&1
    15→) else (
    16→    echo ERROR: Could not find Visual Studio
    17→    exit /b 1
    18→)
    19→
    20→if not exist build mkdir build
    21→
    22→:: Build Lua library if it doesn't exist
    23→if not exist lib\lua.lib (
    24→    echo Building Lua library...
    25→    if not exist build\lua_obj mkdir build\lua_obj
    26→    cl.exe /nologo /O2 /W3 /c /I"include/lua" ^
    27→        include/lua/lapi.c include/lua/lauxlib.c include/lua/lbaselib.c ^
    28→        include/lua/lcode.c include/lua/lcorolib.c include/lua/lctype.c ^
    29→        include/lua/ldblib.c include/lua/ldebug.c include/lua/ldo.c ^
    30→        include/lua/ldump.c include/lua/lfunc.c include/lua/lgc.c ^
... [39 more lines]

Let me check what test file exists:

Glob (*.lua)

E:\a327ex\Anchor\reference\anchor\external\sort.lua
E:\a327ex\Anchor\reference\anchor\external\profile.lua
E:\a327ex\Anchor\reference\anchor\external\utf8.lua
E:\a327ex\Anchor\reference\anchor\external\mlib.lua
E:\a327ex\Anchor\reference\anchor\string.lua
E:\a327ex\Anchor\reference\anchor\spring.lua
E:\a327ex\Anchor\reference\anchor\stats.lua
E:\a327ex\Anchor\reference\anchor\shake.lua
E:\a327ex\Anchor\reference\anchor\class.lua
E:\a327ex\Anchor\reference\anchor\timer.lua
E:\a327ex\Anchor\reference\anchor\camera.lua
E:\a327ex\Anchor\reference\anchor\music_player.lua
E:\a327ex\Anchor\reference\anchor\sound.lua
E:\a327ex\Anchor\reference\anchor\random.lua
E:\a327ex\Anchor\reference\anchor\collision.lua
E:\a327ex\Anchor\reference\anchor\mouse_hover.lua
E:\a327ex\Anchor\reference\anchor\grid.lua
E:\a327ex\Anchor\reference\anchor\physics_world.lua
E:\a327ex\Anchor\reference\anchor\joint.lua
E:\a327ex\Anchor\reference\anchor\color.lua
E:\a327ex\Anchor\reference\anchor\array.lua
E:\a327ex\Anchor\reference\anchor\animation.lua
E:\a327ex\Anchor\reference\anchor\input.lua
E:\a327ex\Anchor\reference\anchor\tiled_map.lua
E:\a327ex\Anchor\reference\anchor\collider.lua
E:\a327ex\Anchor\reference\anchor\ui.lua
E:\a327ex\Anchor\reference\anchor\layout.lua
E:\a327ex\Anchor\reference\anchor\text.lua
E:\a327ex\Anchor\reference\anchor\init.lua
E:\a327ex\Anchor\reference\anchor\math.lua
... [4 more lines]

Glob (engine/build/*)

E:\a327ex\Anchor\engine\build\anchor.exe

Read (E:\a327ex\Anchor\engine\main.lua)

1→print("main.lua loaded")
     2→
     3→local step_count = 0
     4→
     5→function update(dt)
     6→    step_count = step_count + 1
     7→    if step_count % 144 == 0 then
     8→        print("1 second passed (" .. step_count .. " steps)")
     9→    end
    10→end
    11→

TodoWrite 

Todos have been modified successfully. Ensure that you continue to use the todo list to track your progress. Please proceed with the current tasks if applicable

Here's the overview of Phase 2 work:

Key Changes for Web Build:

  1. Shaders - Current code uses #version 330 core (OpenGL 3.3). WebGL 2.0 needs #version 300 es with slightly different syntax (precision qualifiers, in/out instead of varying, etc.)

  2. Main Loop - Browsers can't have a blocking while(running) loop. Need emscripten_set_main_loop which yields to the browser each frame.

  3. OpenGL Loading - glad doesn't work in WebGL. Emscripten provides GLES3 headers directly.

  4. Asset Loading - Lua scripts need to be preloaded into Emscripten's virtual filesystem.

Before I start coding:

Do you have Emscripten SDK installed? If not, the installation is:

# Clone emsdk
git clone https://github.com/emscripten-core/emsdk.git
cd emsdk

# Install and activate latest
./emsdk install latest
./emsdk activate latest

# Set up environment (add to shell profile or run each session)
source ./emsdk_env.sh   # Linux/Mac
# or: emsdk_env.bat      # Windows

Once you have it, we can proceed with the code changes. The nice thing is SDL2 has excellent Emscripten support - emcc knows how to link it automatically via -s USE_SDL=2.

Where should I clone emdsk?

Somewhere outside the project - it's a standalone tool you'll use across projects.

Common choices:

C:\emsdk          # Simple, easy to reference
C:\tools\emsdk    # If you have a tools directory
E:\emsdk          # Same drive as your projects

I'd go with C:\emsdk for simplicity. The path will be referenced in build scripts, so shorter is better.

$ ./emsdk install latest Python was not found; run without arguments to install from the Microsoft Store, or disable this shortcut from Settings > Apps > Advanced app settings > App execution aliases.

$ python Python 3.14.2 (tags/v3.14.2:df79316, Dec 5 2025, 17:18:21) [MSC v.1944 64 bit (AMD64)] on win32 Type "help", "copyright", "credits" or "license" for more information.

Windows app execution aliases are intercepting the call. Two options:

Option 1: Disable the aliases (recommended)

Settings → Apps → Advanced app settings → App execution aliases → Turn off "python.exe" and "python3.exe"

Option 2: Run emsdk with python explicitly

python emsdk.py install latest

Option 1 is better long-term since other tools will hit the same issue.

$ ./emsdk activate latest Resolving SDK alias 'latest' to '4.0.22' Resolving SDK version '4.0.22' to 'sdk-releases-bebaf7e50e31865b0724f17eaa52e161e2dfef5a-64bit' Setting the following tools as active: node-22.16.0-64bit python-3.13.3-64bit releases-bebaf7e50e31865b0724f17eaa52e161e2dfef5a-64bit

Next steps: - Consider running emsdk activate with --permanent or --system to have emsdk settings available on startup. The changes made to environment variables only apply to the currently running shell instance. Use the 'emsdk_env.bat' to re-enter this environment later, or if you'd like to register this environment permanently, rerun this command with the option --permanent.

Good. Now activate the environment for your current shell:

./emsdk_env.bat

Then verify it works:

emcc --version

If you want it available in every new terminal without running emsdk_env.bat each time, run:

./emsdk activate latest --permanent

$ ./emsdk activate latest --permanent Resolving SDK alias 'latest' to '4.0.22' Resolving SDK version '4.0.22' to 'sdk-releases-bebaf7e50e31865b0724f17eaa52e161e2dfef5a-64bit' Registering active Emscripten environment permanently

Setting the following tools as active: node-22.16.0-64bit python-3.13.3-64bit releases-bebaf7e50e31865b0724f17eaa52e161e2dfef5a-64bit

adn@DESKTOP-5FP6VRT MINGW64 /c/emsdk (main) $ ./emsdk_env.bat Setting up EMSDK environment (suppress these messages with EMSDK_QUIET=1) Adding directories to PATH: PATH += /c/emsdk PATH += /c/emsdk/upstream/emscripten

Setting environment variables: PATH = /c/emsdk:/c/emsdk/upstream/emscripten:/c/Users/adn/bin:/c/Program Files/Git/mingw64/bin:/c/Program Files/Git/usr/local/bin:/c/Program Files/Git/usr/bin:/c/WINDOWS/system32:/c/WINDOWS:/c/WINDOWS/System32/Wbem:/c/WINDOWS/System32/WindowsPowerShell/v1.0:/c/WINDOWS/System32/OpenSSH:/c/Program Files/Git/cmd:/c/Program Files/dotnet:/c/Program Files/nodejs:/c/ProgramData/chocolatey/bin:/c/Program Files/Neovim/bin:/c/Program Files/Neovide:/c/Program Files (x86)/Windows Kits/10/Windows Performance Toolkit:/c/Program Files/CMake/bin:/c/Users/adn/AppData/Local/Programs/Python/Python314/Scripts:/c/Users/adn/AppData/Local/Programs/Python/Python314:/c/Users/adn/AppData/Local/Microsoft/WindowsApps:/c/Users/adn/AppData/Roaming/npm:/c/Users/adn/AppData/Local/Voidstar/FilePilot:/c/Program Files/Git/usr/bin/vendor_perl:/c/Program Files/Git/usr/bin/core_perl EMSDK = C:/emsdk EMSDK_NODE = C:/emsdk/node/22.16.0_64bit/bin/node.exe EMSDK_PYTHON = C:/emsdk/python/3.13.3_64bit/python.exe Clearing existing environment variable: EMSDK_PY export PATH="/c/emsdk:/c/emsdk/upstream/emscripten:/c/Users/adn/bin:/c/Program Files/Git/mingw64/bin:/c/Program Files/Git/usr/local/bin:/c/Program Files/Git/usr/bin:/c/WINDOWS/system32:/c/WINDOWS:/c/WINDOWS/System32/Wbem:/c/WINDOWS/System32/WindowsPowerShell/v1.0:/c/WINDOWS/System32/OpenSSH:/c/Program Files/Git/cmd:/c/Program Files/dotnet:/c/Program Files/nodejs:/c/ProgramData/chocolatey/bin:/c/Program Files/Neovim/bin:/c/Program Files/Neovide:/c/Program Files (x86)/Windows Kits/10/Windows Performance Toolkit:/c/Program Files/CMake/bin:/c/Users/adn/AppData/Local/Programs/Python/Python314/Scripts:/c/Users/adn/AppData/Local/Programs/Python/Python314:/c/Users/adn/AppData/Local/Microsoft/WindowsApps:/c/Users/adn/AppData/Roaming/npm:/c/Users/adn/AppData/Local/Voidstar/FilePilot:/c/Program Files/Git/usr/bin/vendor_perl:/c/Program Files/Git/usr/bin/core_perl"; export EMSDK="C:/emsdk"; export EMSDK_NODE="C:/emsdk/node/22.16.0_64bit/bin/node.exe"; export EMSDK_PYTHON="C:/emsdk/python/3.13.3_64bit/python.exe"; unset EMSDK_PY;

adn@DESKTOP-5FP6VRT MINGW64 /c/emsdk (main) $ emcc --version bash: emcc: command not found

You're in Git Bash (MINGW64), but ran the .bat file which just printed the exports without executing them. Use the shell script instead:

source ./emsdk_env.sh

Then try emcc --version again.

$ source ./emsdk_env.sh Setting up EMSDK environment (suppress these messages with EMSDK_QUIET=1) Adding directories to PATH: PATH += /c/emsdk PATH += /c/emsdk/upstream/emscripten

Setting environment variables: PATH = /c/emsdk:/c/emsdk/upstream/emscripten:/c/Users/adn/bin:/c/Program Files/Git/mingw64/bin:/c/Program Files/Git/usr/local/bin:/c/Program Files/Git/usr/bin:/c/WINDOWS/system32:/c/WINDOWS:/c/WINDOWS/System32/Wbem:/c/WINDOWS/System32/WindowsPowerShell/v1.0:/c/WINDOWS/System32/OpenSSH:/c/Program Files/Git/cmd:/c/Program Files/dotnet:/c/Program Files/nodejs:/c/ProgramData/chocolatey/bin:/c/Program Files/Neovim/bin:/c/Program Files/Neovide:/c/Program Files (x86)/Windows Kits/10/Windows Performance Toolkit:/c/Program Files/CMake/bin:/c/Users/adn/AppData/Local/Programs/Python/Python314/Scripts:/c/Users/adn/AppData/Local/Programs/Python/Python314:/c/Users/adn/AppData/Local/Microsoft/WindowsApps:/c/Users/adn/AppData/Roaming/npm:/c/Users/adn/AppData/Local/Voidstar/FilePilot:/c/Program Files/Git/usr/bin/vendor_perl:/c/Program Files/Git/usr/bin/core_perl EMSDK = C:/emsdk EMSDK_NODE = C:/emsdk/node/22.16.0_64bit/bin/node.exe EMSDK_PYTHON = C:/emsdk/python/3.13.3_64bit/python.exe

adn@DESKTOP-5FP6VRT MINGW64 /c/emsdk (main) $ emcc --version bash: emcc: command not found

Strange - the script printed the changes but they may not have taken effect. Let's debug:

echo $PATH | tr ':' '\n' | grep emsdk

And check if emcc exists:

ls /c/emsdk/upstream/emscripten/emcc*

Should I restart the terminal first?

Yes, try that. Since you ran --permanent, the new terminal should have the paths set automatically. Open a new Git Bash and run:

emcc --version

$ emcc --version bash: emcc: command not found

adn@DESKTOP-5FP6VRT MINGW64 /e/a327ex/Anchor (main) $ echo $PATH | tr ':' '\n' | grep emsdk

adn@DESKTOP-5FP6VRT MINGW64 /e/a327ex/Anchor (main) $ echo $PATH | tr ':' '\n' | grep emsdk

adn@DESKTOP-5FP6VRT MINGW64 /e/a327ex/Anchor (main)

The --permanent flag sets Windows environment variables, which Git Bash doesn't inherit the same way. For Git Bash, add it to your profile:

echo 'source /c/emsdk/emsdk_env.sh 2>/dev/null' >> ~/.bashrc

Then restart the terminal, or for now just run:

source /c/emsdk/emsdk_env.sh
emcc --version

adn@DESKTOP-5FP6VRT MINGW64 /e/a327ex/Anchor (main) $ source /c/emsdk/emsdk_env.sh Setting up EMSDK environment (suppress these messages with EMSDK_QUIET=1) Adding directories to PATH: PATH += /c/emsdk PATH += /c/emsdk/upstream/emscripten

Setting environment variables: PATH = /c/emsdk:/c/emsdk/upstream/emscripten:/c/Users/adn/bin:/c/Program Files/Git/mingw64/bin:/c/Program Files/Git/usr/local/bin:/c/Program Files/Git/usr/bin:/c/WINDOWS/system32:/c/WINDOWS:/c/WINDOWS/System32/Wbem:/c/WINDOWS/System32/WindowsPowerShell/v1.0:/c/WINDOWS/System32/OpenSSH:/c/Program Files/Git/cmd:/c/Program Files/dotnet:/c/Program Files/nodejs:/c/ProgramData/chocolatey/bin:/c/Program Files/Neovim/bin:/c/Program Files/Neovide:/c/Program Files (x86)/Windows Kits/10/Windows Performance Toolkit:/c/Program Files/CMake/bin:/c/Users/adn/AppData/Local/Programs/Python/Python314/Scripts:/c/Users/adn/AppData/Local/Programs/Python/Python314:/c/Users/adn/AppData/Local/Microsoft/WindowsApps:/c/Users/adn/AppData/Roaming/npm:/c/Users/adn/AppData/Local/Voidstar/FilePilot:/c/Program Files/Git/usr/bin/vendor_perl:/c/Program Files/Git/usr/bin/core_perl EMSDK = C:/emsdk EMSDK_NODE = C:/emsdk/node/22.16.0_64bit/bin/node.exe EMSDK_PYTHON = C:/emsdk/python/3.13.3_64bit/python.exe

adn@DESKTOP-5FP6VRT MINGW64 /e/a327ex/Anchor (main) $ emcc --version bash: emcc: command not found

The script prints the PATH but isn't actually setting it. Let's verify the files exist and manually set it:

ls /c/emsdk/upstream/emscripten/emcc*

If the files exist, manually export:

export PATH="/c/emsdk:/c/emsdk/upstream/emscripten:$PATH"
emcc --version

Can you try to actually do this? Given everything is in my computer.

Bash (ls /c/emsdk/upstream/emscripten/emcc*)

/c/emsdk/upstream/emscripten/emcc.bat
/c/emsdk/upstream/emscripten/emcc.ps1
/c/emsdk/upstream/emscripten/emcc.py

The files exist but as .bat/.py - Git Bash doesn't auto-execute .bat files. Let me test:

Bash (export PATH="/c/emsdk:/c/emsdk/upstream/emscripten:$PATH" && /c/emsdk/upstream/e...)

emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 4.0.22 (0f3d2e62bccf8e14497ff19e05a1202c51eb0c65)
Copyright (C) 2025 the Emscripten authors (see AUTHORS.txt)
This is free and open source software under the MIT license.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
shared:INFO: (Emscripten: Running sanity checks)

Emscripten works - Git Bash just needs .bat explicitly. Let me add an alias to your bashrc:

Bash (echo 'export PATH="/c/emsdk:/c/emsdk/upstream/emscripten:$PATH"' >> ~/.bashrc &&...)

TodoWrite 

Todos have been modified successfully. Ensure that you continue to use the todo list to track your progress. Please proceed with the current tasks if applicable

Emscripten is set up. New terminals will have emcc working. Now let me create the web build script and modify anchor.c:

Write (E:\a327ex\Anchor\engine\build-web.sh)

File created successfully at: E:\a327ex\Anchor\engine\build-web.sh

Now let me create the HTML shell template:

Write (E:\a327ex\Anchor\engine\shell.html)

File created successfully at: E:\a327ex\Anchor\engine\shell.html

Now let me modify anchor.c for cross-platform support:

TodoWrite 

Todos have been modified successfully. Ensure that you continue to use the todo list to track your progress. Please proceed with the current tasks if applicable

Write (E:\a327ex\Anchor\engine\src\anchor.c)

The file E:\a327ex\Anchor\engine\src\anchor.c has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
     1→/*
     2→ * Anchor Engine - Minimal skeleton
     3→ * Phase 1: Window + OpenGL + Lua integration
     4→ * Phase 2: Web build (Emscripten/WebGL)
     5→ */
     6→
     7→#include <stdio.h>
     8→#include <stdlib.h>
     9→#include <stdbool.h>
    10→
    11→#include <SDL.h>
    12→
    13→#ifdef __EMSCRIPTEN__
    14→    #include <emscripten.h>
    15→    #include <emscripten/html5.h>
    16→    #include <GLES3/gl3.h>
    17→#else
    18→    #include <glad/gl.h>
    19→#endif
    20→
    21→#include <lua.h>
    22→#include <lualib.h>
    23→#include <lauxlib.h>
    24→
    25→#define WINDOW_TITLE "Anchor"
    26→#define GAME_WIDTH 480
    27→#define GAME_HEIGHT 270
    28→#define INITIAL_SCALE 2
    29→
... [552 more lines]

Good. Now let me verify the Windows build still works, then try the web build:

Bash (cd /e/a327ex/Anchor/engine && ./build.bat)

[31mWARNING: Found ~/.bashrc but no ~/.bash_profile, ~/.bash_login or ~/.profile.[m

This looks like an incorrect setup.
A ~/.bash_profile that loads ~/.bashrc will be created for you.
anchor.c
gl.c
Generating Code...
LINK : warning LNK4098: defaultlib 'MSVCRT' conflicts with use of other libs; use /NODEFAULTLIB:library
Build successful: build/anchor.exe

Windows build works. Now let me try the web build:

Bash (cd /e/a327ex/Anchor/engine && export PATH="/c/emsdk:/c/emsdk/upstream/emscripten...)

Build successful: build-web/anchor.html
To test: cd build-web && python -m http.server 8000
Then open: http://localhost:8000/anchor.html
ports:INFO: retrieving port: sdl2 from https://github.com/libsdl-org/SDL/archive/release-2.32.8.zip
ports:INFO: unpacking port: sdl2
cache:INFO: generating port: sysroot\lib\wasm32-emscripten\libSDL2.a... (this will be cached in "C:\emsdk\upstream\emscripten\cache\sysroot\lib\wasm32-emscripten\libSDL2.a" for subsequent builds)
system_libs:INFO: compiled 118 inputs in 7.92s
cache:INFO:  - ok

Web build succeeded! Let me verify the output and start a test server:

Bash (ls -la /e/a327ex/Anchor/engine/build-web/)

total 873
drwxr-xr-x 1 adn 197121      0 Jan  6 13:06 .
drwxr-xr-x 1 adn 197121      0 Jan  6 13:06 ..
-rw-r--r-- 1 adn 197121    208 Jan  6 13:06 anchor.data
-rw-r--r-- 1 adn 197121   1725 Jan  6 13:06 anchor.html
-rw-r--r-- 1 adn 197121 230877 Jan  6 13:06 anchor.js
-rw-r--r-- 1 adn 197121 647058 Jan  6 13:06 anchor.wasm

All files generated. Let me start a test server:

Bash (cd /e/a327ex/Anchor/engine/build-web && python -m http.server 8000)

Command running in background with ID: b2732ce. Output is being written to: C:\Users\adn\AppData\Local\Temp\claude\E--a327ex-Anchor\tasks\b2732ce.output

TodoWrite 

Todos have been modified successfully. Ensure that you continue to use the todo list to track your progress. Please proceed with the current tasks if applicable

Server running. Open your browser to:

http://localhost:8000/anchor.html

You should see:

Let me know if it works or if there are any issues.

It works. However, there's a white outline showing between the black background letterboxing and the game canvas. Why is that?

That's likely a CSS issue - the canvas element may have a default border or there's subpixel rendering at the edges. Let me fix the shell template:

Read (E:\a327ex\Anchor\engine\shell.html)

1→<!DOCTYPE html>
     2→<html>
     3→<head>
     4→    <meta charset="utf-8">
     5→    <meta name="viewport" content="width=device-width, initial-scale=1.0">
     6→    <title>Anchor</title>
     7→    <style>
     8→        * {
     9→            margin: 0;
    10→            padding: 0;
    11→            box-sizing: border-box;
    12→        }
    13→        html, body {
    14→            width: 100%;
    15→            height: 100%;
    16→            background: #000;
    17→            overflow: hidden;
    18→        }
    19→        #canvas {
    20→            display: block;
    21→            position: absolute;
    22→            top: 50%;
    23→            left: 50%;
    24→            transform: translate(-50%, -50%);
    25→            image-rendering: pixelated;
    26→            image-rendering: crisp-edges;
    27→        }
    28→        #status {
    29→            position: absolute;
    30→            top: 50%;
... [82 more lines]

Edit (E:\a327ex\Anchor\engine\shell.html)

The file E:\a327ex\Anchor\engine\shell.html has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
    15→            height: 100%;
    16→            background: #000;
    17→            overflow: hidden;
    18→        }
    19→        #canvas {
    20→            display: block;
    21→            position: absolute;
    22→            top: 50%;
    23→            left: 50%;
    24→            transform: translate(-50%, -50%);
    25→            image-rendering: pixelated;
    26→            image-rendering: crisp-edges;
    27→            border: none;
    28→            outline: none;
    29→            background: #000;
    30→        }
    31→        #status {
    32→            position: absolute;
    33→            top: 50%;
    34→            left: 50%;

Bash (cd /e/a327ex/Anchor/engine && export PATH="/c/emsdk:/c/emsdk/upstream/emscripten...)

Build successful: build-web/anchor.html
To test: cd build-web && python -m http.server 8000
Then open: http://localhost:8000/anchor.html

Rebuilt. Refresh the page - the canvas now has explicit border: none, outline: none, and background: #000.

If the white line persists, it could be coming from the C side - the engine does its own letterboxing via viewport. Since both the browser CSS and the C code are doing letterboxing/scaling, there might be a mismatch.

Actually, looking at this more carefully - the C code handles letterboxing internally (black bars via glClearColor), but the shell.html is also trying to scale the canvas via CSS. This double-handling could cause the edge artifact.

Want me to simplify this so only one side handles the scaling?

The issue is fixed now.

TodoWrite 

Todos have been modified successfully. Ensure that you continue to use the todo list to track your progress. Please proceed with the current tasks if applicable

Phase 2 complete. Let me clean up and update the implementation plan:

KillShell 

{"message":"Successfully killed shell: b2732ce (cd /e/a327ex/Anchor/engine/build-web && python -m http.server 8000)","shell_id":"b2732ce"}

Edit (E:\a327ex\Anchor\docs\ANCHOR_IMPLEMENTATION_PLAN.md)

The file E:\a327ex\Anchor\docs\ANCHOR_IMPLEMENTATION_PLAN.md has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   116→## Phase 2: Web Build (Emscripten)
   117→
   118→**Goal:** Same code compiles and runs in browser via WebGL.
   119→
   120→### 2.1 Emscripten Setup
   121→- [x] Install Emscripten SDK
   122→- [x] Create build-web.sh with emcc flags
   123→- [x] Configure for WebGL 2.0 (OpenGL ES 3.0 subset)
   124→
   125→### 2.2 Platform Abstraction
   126→- [x] Conditional compilation for web-specific code (`#ifdef __EMSCRIPTEN__`)
   127→- [x] `emscripten_set_main_loop` integration
   128→- [x] Handle requestAnimationFrame timing
   129→
   130→### 2.3 Asset Embedding
   131→- [x] Preload all assets into virtual filesystem
   132→- [x] `--preload-file` flag for Lua scripts
   133→- [x] Verify asset loading works identically to desktop
   134→
   135→### 2.4 HTML Shell
   136→- [x] Create HTML template with canvas
   137→- [x] Handle canvas sizing/scaling
   138→- [x] Keyboard/mouse event capture
   139→
   140→### 2.5 Verification
   141→- [x] Same Lua code runs in browser
   142→- [x] Orange test quad renders correctly
   143→- [x] Aspect-ratio scaling with letterboxing works
   144→- [x] No visible differences from Windows build
... [6 more lines]

Phase 2 complete. Summary of what was added:

Files created:

Changes to anchor.c:

Environment setup:

Ready for Phase 3 (Rendering) whenever you want to continue.

Could you explain more about "dual shader sources?"

The shaders are duplicated because desktop OpenGL and WebGL use different GLSL versions with slightly different syntax:

Desktop OpenGL 3.3 Core: glsl \#version 330 core in vec4 vertexColor; out vec4 FragColor; void main() { FragColor = vertexColor; }

WebGL 2.0 / OpenGL ES 3.0: glsl \#version 300 es precision mediump float; // <-- Required in ES in vec4 vertexColor; out vec4 FragColor; void main() { FragColor = vertexColor; }

The key differences:

  1. Version string - 330 core vs 300 es
  2. Precision qualifiers - ES requires precision mediump float; (or highp/lowp) in fragment shaders. Desktop GLSL doesn't need them.

In anchor.c, I used #ifdef __EMSCRIPTEN__ to select which shader source to compile:

\#ifdef __EMSCRIPTEN__
static const char* fragment_shader_source =
    "#version 300 es\n"
    "precision mediump float;\n"
    // ...
\#else
static const char* fragment_shader_source =
    "#version 330 core\n"
    // ...
\#endif

Alternative approach: You could use a single shader source and do string manipulation at runtime (prepend the version/precision based on platform), but the #ifdef approach is simpler and the duplication is minimal since the actual shader logic is identical.

Why don't we just use 300 es for Desktop also? Is that not possible? Are there significant feature differences?

Good question. Desktop OpenGL won't accept #version 300 es - it's a different dialect. The driver would reject it at compile time.

The split:

They're sister languages with ~95% overlap but different version strings and some syntax differences (precision qualifiers being the main one for our use case).

Feature-wise: For 2D rendering, they're effectively equivalent. Both have:

Desktop OpenGL 3.3 has extras like geometry shaders and some texture formats, but Anchor won't use those.

Could we unify? Yes, with a small helper:

const char* shader_header() {
    #ifdef __EMSCRIPTEN__
    return "#version 300 es\nprecision mediump float;\n";
    #else
    return "#version 330 core\n";
    #endif
}

Then write one shader body and concatenate at runtime. Would you prefer that approach? It would eliminate the duplication - the actual shader logic is already identical, only the headers differ.

Would this duplication have to exist for all shaders we write or just the ones in anchor.c? If I'm writing a shader and loading it via a load_shader function in Lua, for instance, how would it go?

Good question - this is about the shader authoring workflow.

For engine shaders (anchor.c): Just the few internal ones - screen blit, shape rendering, sprite rendering. We can use the header helper to keep them unified.

For user shaders loaded at runtime: The engine should handle the platform difference transparently. The user writes one shader without a version line:

// user's effect.frag - no #version, no precision
in vec2 TexCoord;
out vec4 FragColor;
uniform sampler2D tex;
uniform float time;

void main() {
    vec2 uv = TexCoord;
    uv.x += sin(uv.y * 10.0 + time) * 0.01;
    FragColor = texture(tex, uv);
}

Then an:shader_load('effect.frag') in C does:

const char* header;
\#ifdef __EMSCRIPTEN__
    header = "#version 300 es\nprecision mediump float;\n";
\#else
    header = "#version 330 core\n";
\#endif

char* full_source = concat(header, user_source);
GLuint shader = compile(full_source);

So from your perspective as the game author:

Want me to refactor anchor.c now to use this unified approach for the built-in shaders?

Yes, use the same solution you'll use to eventually load the effect.frag shader.

Edit (E:\a327ex\Anchor\engine\src\anchor.c)

The file E:\a327ex\Anchor\engine\src\anchor.c has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
    57→static Uint64 step = 0;
    58→static double game_time = 0.0;
    59→static Uint64 frame = 0;
    60→
    61→// Shader headers - prepended to all shaders based on platform
    62→#ifdef __EMSCRIPTEN__
    63→    #define SHADER_HEADER_VERT "#version 300 es\n"
    64→    #define SHADER_HEADER_FRAG "#version 300 es\nprecision mediump float;\n"
    65→#else
    66→    #define SHADER_HEADER_VERT "#version 330 core\n"
    67→    #define SHADER_HEADER_FRAG "#version 330 core\n"
    68→#endif
    69→
    70→// Shader sources (no version line - header prepended at compile time)
    71→static const char* vertex_shader_source =
    72→    "layout (location = 0) in vec2 aPos;\n"
    73→    "layout (location = 1) in vec4 aColor;\n"
    74→    "out vec4 vertexColor;\n"
    75→    "uniform mat4 projection;\n"
    76→    "void main() {\n"
    77→    "    gl_Position = projection * vec4(aPos, 0.0, 1.0);\n"
    78→    "    vertexColor = aColor;\n"
    79→    "}\n";
    80→
    81→static const char* fragment_shader_source =
    82→    "in vec4 vertexColor;\n"
    83→    "out vec4 FragColor;\n"
    84→    "void main() {\n"
    85→    "    FragColor = vertexColor;\n"
... [22 more lines]

Now update compile_shader to prepend the header:

Edit (E:\a327ex\Anchor\engine\src\anchor.c)

The file E:\a327ex\Anchor\engine\src\anchor.c has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   101→    "void main() {\n"
   102→    "    FragColor = texture(screenTexture, TexCoord);\n"
   103→    "}\n";
   104→
   105→// Compile a shader and return its ID (0 on failure)
   106→// Automatically prepends platform-specific header
   107→static GLuint compile_shader(GLenum type, const char* source) {
   108→    const char* header = (type == GL_VERTEX_SHADER) ? SHADER_HEADER_VERT : SHADER_HEADER_FRAG;
   109→
   110→    // Concatenate header + source
   111→    size_t header_len = strlen(header);
   112→    size_t source_len = strlen(source);
   113→    char* full_source = (char*)malloc(header_len + source_len + 1);
   114→    memcpy(full_source, header, header_len);
   115→    memcpy(full_source + header_len, source, source_len + 1);
   116→
   117→    GLuint shader = glCreateShader(type);
   118→    glShaderSource(shader, 1, (const char**)&full_source, NULL);
   119→    glCompileShader(shader);
   120→
   121→    free(full_source);
   122→
   123→    GLint success;
   124→    glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
   125→    if (!success) {
   126→        char info_log[512];
   127→        glGetShaderInfoLog(shader, sizeof(info_log), NULL, info_log);
   128→        fprintf(stderr, "Shader compilation failed: %s\n", info_log);
   129→        glDeleteShader(shader);
... [8 more lines]

Need to add string.h for strlen/memcpy. Let me check the includes:

Read (E:\a327ex\Anchor\engine\src\anchor.c)

1→/*
     2→ * Anchor Engine - Minimal skeleton
     3→ * Phase 1: Window + OpenGL + Lua integration
     4→ * Phase 2: Web build (Emscripten/WebGL)
     5→ */
     6→
     7→#include <stdio.h>
     8→#include <stdlib.h>
     9→#include <stdbool.h>
    10→
    11→#include <SDL.h>
    12→
    13→#ifdef __EMSCRIPTEN__
    14→    #include <emscripten.h>
    15→    #include <emscripten/html5.h>
    16→    #include <GLES3/gl3.h>
    17→#else
    18→    #include <glad/gl.h>
    19→#endif
    20→
    21→#include <lua.h>
    22→#include <lualib.h>
    23→#include <lauxlib.h>
    24→
    25→#define WINDOW_TITLE "Anchor"

Edit (E:\a327ex\Anchor\engine\src\anchor.c)

The file E:\a327ex\Anchor\engine\src\anchor.c has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
     3→ * Phase 1: Window + OpenGL + Lua integration
     4→ * Phase 2: Web build (Emscripten/WebGL)
     5→ */
     6→
     7→#include <stdio.h>
     8→#include <stdlib.h>
     9→#include <stdbool.h>
    10→#include <string.h>
    11→
    12→#include <SDL.h>
    13→
    14→#ifdef __EMSCRIPTEN__

Now let's verify both builds still work:

Bash (cd /e/a327ex/Anchor/engine && ./build.bat)

anchor.c
gl.c
Generating Code...
LINK : warning LNK4098: defaultlib 'MSVCRT' conflicts with use of other libs; use /NODEFAULTLIB:library
Build successful: build/anchor.exe

Bash (cd /e/a327ex/Anchor/engine && export PATH="/c/emsdk:/c/emsdk/upstream/emscripten...)

Build successful: build-web/anchor.html
To test: cd build-web && python -m http.server 8000
Then open: http://localhost:8000/anchor.html

Both builds succeed. Let me quick-test the Windows build:

Bash (cd /e/a327ex/Anchor/engine && timeout 2 ./build/anchor.exe main.lua 2>&1 || true)

Anchor Engine starting...
Loading: main.lua
OpenGL 3.3 loaded
Renderer: NVIDIA GeForce RTX 2060/PCIe/SSE2
Shader program created
Game VAO/VBO created
Framebuffer created (480x270)
Screen shader created
Screen VAO/VBO created
main.lua loaded
Initialization complete. Press ESC to exit, F11 for fullscreen.
1 second passed (144 steps)

Both work. The shader system is now unified:

// Platform-specific headers (compile-time)
\#ifdef __EMSCRIPTEN__
    #define SHADER_HEADER_VERT "#version 300 es\n"
    #define SHADER_HEADER_FRAG "#version 300 es\nprecision mediump float;\n"
\#else
    #define SHADER_HEADER_VERT "#version 330 core\n"
    #define SHADER_HEADER_FRAG "#version 330 core\n"
\#endif

// Single shader source (no version line)
static const char* fragment_shader_source =
    "in vec4 vertexColor;\n"
    "out vec4 FragColor;\n"
    "void main() {\n"
    "    FragColor = vertexColor;\n"
    "}\n";

// compile_shader() prepends the correct header automatically

When we implement an:shader_load() in Phase 4, it'll use the same compile_shader() function - user-authored shaders will just work on both platforms without needing version lines or precision qualifiers.

How can I add a command to Launchy that will run the python server and automatically launch the anchor.html file? I currently have "E:/a327ex/Anchor/engine/build/anchor.exe E:/a327ex/Anchor/engine/main.lua" set to Alt+Space+a so I can easily run anchor.exe.

Create a batch script that starts the server and opens the browser:

Write (E:\a327ex\Anchor\engine\run-web.bat)

File created successfully at: E:\a327ex\Anchor\engine\run-web.bat

Add to Launchy: E:/a327ex/Anchor/engine/run-web.bat

The script:

  1. Opens browser to the page
  2. Starts the Python server (keeps the terminal open while running)

Close the terminal window to stop the server. If you want the terminal to auto-close when done, you could use start /b python -m http.server 8000 instead, but then you'd need to manually kill the process later.

Great, is there a way to make the output from the browser's console to come out on this terminal Window? Or a way for me easily see it?

Two options:

Option 1: Browser DevTools (F12 → Console) The standard way. All printf output goes there.

Option 2: Use emrun instead of Python server

Emscripten has a built-in tool that pipes console output back to the terminal. Update the build script to enable it:

Edit (E:\a327ex\Anchor\engine\build-web.sh)

The file E:\a327ex\Anchor\engine\build-web.sh has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
    13→# -s WASM=1: Output WebAssembly
    14→# -s ALLOW_MEMORY_GROWTH=1: Allow heap to grow
    15→# --preload-file: Bundle assets into virtual filesystem
    16→
    17→/c/emsdk/upstream/emscripten/emcc.bat \
    18→    -O2 \
    19→    -I"include" -I"include/SDL2" -I"include/lua" -I"include/stb" \
    20→    src/anchor.c \
    21→    include/lua/*.c \
    22→    -o build-web/anchor.html \
    23→    -s USE_SDL=2 \
    24→    -s USE_WEBGL2=1 \
    25→    -s FULL_ES3=1 \
    26→    -s WASM=1 \
    27→    -s ALLOW_MEMORY_GROWTH=1 \
    28→    -s EXPORTED_RUNTIME_METHODS='["ccall","cwrap"]' \
    29→    --preload-file main.lua \
    30→    --shell-file shell.html \
    31→    --emrun
    32→
    33→if [ $? -eq 0 ]; then
    34→    echo "Build successful: build-web/anchor.html"
    35→    echo "To test: cd build-web && python -m http.server 8000"

Write (E:\a327ex\Anchor\engine\run-web.bat)

The file E:\a327ex\Anchor\engine\run-web.bat has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
     1→@echo off
     2→cd /d "%~dp0build-web"
     3→C:\emsdk\upstream\emscripten\emrun.bat --browser chrome anchor.html
     4→

Bash (cd /e/a327ex/Anchor/engine && export PATH="/c/emsdk:/c/emsdk/upstream/emscripten...)

Build successful: build-web/anchor.html
To test: cd build-web && python -m http.server 8000
Then open: http://localhost:8000/anchor.html

Rebuilt. Now run-web.bat uses emrun which:

Test it from Launchy or by running run-web.bat directly. You should see "main.lua loaded" and the "1 second passed" messages in the terminal.

Perfect, it works. Could you change implementation plan to include everything we did that wasn't in the plan in the first place?

Read (E:\a327ex\Anchor\docs\ANCHOR_IMPLEMENTATION_PLAN.md)

116→## Phase 2: Web Build (Emscripten)
   117→
   118→**Goal:** Same code compiles and runs in browser via WebGL.
   119→
   120→### 2.1 Emscripten Setup
   121→- [x] Install Emscripten SDK
   122→- [x] Create build-web.sh with emcc flags
   123→- [x] Configure for WebGL 2.0 (OpenGL ES 3.0 subset)
   124→
   125→### 2.2 Platform Abstraction
   126→- [x] Conditional compilation for web-specific code (`#ifdef __EMSCRIPTEN__`)
   127→- [x] `emscripten_set_main_loop` integration
   128→- [x] Handle requestAnimationFrame timing
   129→
   130→### 2.3 Asset Embedding
   131→- [x] Preload all assets into virtual filesystem
   132→- [x] `--preload-file` flag for Lua scripts
   133→- [x] Verify asset loading works identically to desktop
   134→
   135→### 2.4 HTML Shell
   136→- [x] Create HTML template with canvas
   137→- [x] Handle canvas sizing/scaling
   138→- [x] Keyboard/mouse event capture
   139→
   140→### 2.5 Verification
   141→- [x] Same Lua code runs in browser
   142→- [x] Orange test quad renders correctly
   143→- [x] Aspect-ratio scaling with letterboxing works
   144→- [x] No visible differences from Windows build
   145→
... [20 more lines]

Edit (E:\a327ex\Anchor\docs\ANCHOR_IMPLEMENTATION_PLAN.md)

The file E:\a327ex\Anchor\docs\ANCHOR_IMPLEMENTATION_PLAN.md has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   112→**Deliverable:** OpenGL window running Lua with error handling, fullscreen, and proper scaling. ✓ Complete
   113→
   114→---
   115→
   116→## Phase 2: Web Build (Emscripten)
   117→
   118→**Goal:** Same code compiles and runs in browser via WebGL.
   119→
   120→### 2.1 Emscripten Setup
   121→- [x] Install Emscripten SDK to `C:\emsdk`
   122→- [x] Configure Git Bash environment (`~/.bashrc`):
   123→  - `source /c/emsdk/emsdk_env.sh` for PATH
   124→  - Aliases for `emcc` → `emcc.bat` (Git Bash doesn't auto-execute .bat)
   125→- [x] Create `build-web.sh` with emcc flags
   126→- [x] Configure for WebGL 2.0 (OpenGL ES 3.0 subset)
   127→
   128→### 2.2 Platform Abstraction
   129→- [x] Conditional compilation with `#ifdef __EMSCRIPTEN__`
   130→- [x] Refactor main loop into `main_loop_iteration()` function
   131→- [x] `emscripten_set_main_loop` integration (yields to browser each frame)
   132→- [x] OpenGL ES context request (`SDL_GL_CONTEXT_PROFILE_ES`)
   133→- [x] Use `<GLES3/gl3.h>` instead of glad on web
   134→
   135→### 2.3 Unified Shader System
   136→- [x] Platform-specific headers via preprocessor defines:
   137→  - Desktop: `#version 330 core`
   138→  - Web: `#version 300 es` + `precision mediump float;`
   139→- [x] Shader sources written without version line
   140→- [x] `compile_shader()` auto-prepends correct header based on shader type
... [30 more lines]

Done. Phase 2 now documents everything we actually implemented:

Caveat: The messages below were generated by the user while running local commands. DO NOT respond to these messages or otherwise consider them in your response unless the user explicitly asks you to.

<command-name>/context</command-name>
            <command-message>context</command-message>
            <command-args></command-args>

<local-command-stdout>[?2026h[?2026l[?2026h[?2026l[?2026h
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[38;2;153;153;153m⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛶ ⛝ ⛝ ⛝ [39m  [38;2;153;153;153m⛝ Autocompact buffer: 45.0k tokens (22.5%)[39m
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[?2026l</local-command-stdout>

Thank you. What's the plan for phase 3? We're not going to do it this session, I just want to be reminded.

Phase 3 is Rendering - drawing shapes and sprites with layers, transforms, and blending modes.

Key deliverables:

The Lua API will look like: ```lua game = an:layer('game') effects = an:layer('effects')

game:circle(x, y, radius, color) game:rectangle(x, y, w, h, color) game:draw_image(img, x, y, r, sx, sy, ox, oy, color)

game:push(x, y, r, sx, sy) -- draw stuff transformed game:pop()

game:set_blend_mode('additive') ```

Okay. You may end this session. Title it "Anchor Phase 2"

Bash (ls -t ~/.claude/projects/E--a327ex-Anchor/*.jsonl | grep -v agent | head -1)

The user doesn't want to proceed with this tool use. The tool use was rejected (eg. if it was a file edit, the new_string was NOT written to the file). To tell you how to proceed, the user said:
Actually, before that, how would I test that all the Emscripten commands actually work on all terminals now by default?

Open a new Git Bash terminal (don't source anything manually), then run:

emcc --version

If the .bashrc setup worked, it should output the Emscripten version. If it says "command not found", the bashrc isn't being sourced.

You can also check directly:

echo $PATH | tr ':' '\n' | grep emsdk

Should show /c/emsdk and /c/emsdk/upstream/emscripten in the path.

adn@DESKTOP-5FP6VRT MINGW64 /e/a327ex/Anchor (main) $ emcc --version emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 4.0.22 (0f3d2e62bccf8e14497ff19e05a1202c51eb0c65) Copyright (C) 2025 the Emscripten authors (see AUTHORS.txt) This is free and open source software under the MIT license. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

The .bashrc setup is working. New terminals automatically have Emscripten available.

Now let me end the session:

Bash (ls -t ~/.claude/projects/E--a327ex-Anchor/*.jsonl | grep -v agent | head -1)

/c/Users/adn/.claude/projects/E--a327ex-Anchor/2f88e9ba-961b-4775-960a-cbae5793fb4b.jsonl