SDL2 Cross-Platform App

A small C++/SDL2 rendering experiment that builds as a native desktop app or as a WebAssembly app with Emscripten.

The project code lives in src/. SDL2 is vendored under ext/SDL2-2.30.2/.

What It Does

The app opens an SDL window or browser canvas and renders an animated abstract scene:

• rotating color-cycling radial lines
• pulsing rings
• orbiting blocks
• close-window and Esc quit handling

Requirements

For native macOS builds:

• CMake
• a C++ compiler, such as Apple Clang from Xcode Command Line Tools

For WebAssembly builds:

• CMake
• Emscripten, with emcmake and emrun available on PATH

Build

Use the Python helper from the repo root.

Native macOS debug build:

python3 builder.py macos

WebAssembly debug build:

python3 builder.py web

Release builds:

python3 builder.py macos --type release
python3 builder.py web --type release

Run

Run the web build with Emscripten's local server:

python3 builder.py web --run

To force a specific browser:

python3 builder.py web --run --browser "/path/to/browser"

For macOS, run the installed binary after building:

./out/bin/app

You can quit the running app by closing the window or pressing Esc.

Project Layout

.
├── CMakeLists.txt              # Top-level platform configuration
├── builder.py                  # Small build helper for macOS and web targets
├── simple_shell.html           # Emscripten HTML shell
├── src/
│   ├── CMakeLists.txt          # App executable and dependency wiring
│   ├── main.cpp                # Platform-aware main loop entry point
│   └── renderloop/
│       ├── CMakeLists.txt      # Render library target
│       ├── renderloop.hpp      # Render class interface
│       └── renderloop.cpp      # SDL setup, events, drawing, shutdown
└── ext/
    └── SDL2-2.30.2/            # Vendored SDL2 source