sdl

Emscripten is an awesome tool for porting existing native codebases to the browser. There are a bunch of cool projects using it to port graphical applications such as games and emulators, especially those which already use the SDL library as a cross-platform video, sound and I/O abstraction. Leveraging the fact that the SDL abstractions provide portability across different OS platforms means that by implementing of parts of SDL in Javascript and compiling the code via Emscripten, the browser can become (with some caveats) another SDL target platform. However, Emscripten's SDL 'shims' are still very much a work in progress, and in a current project of my own (porting a classic Mac OS emulator), I've run into some parts where I've had to fill in the gaps myself.

Specifically, if you're finding your SDL-based, Emscripten compiled app is failing to render to the canvas, the issue may be that the app is trying to use the incomplete SDL_CreateRGBSurfaceFrom method to create an SDL surface from a buffer of pixels.