Here is a screenshot:
Emscripten is amazing. The guys did a really good job to wraps useful libraries like SDL, SDL_mixer and so on.
On my side, most of the effort was therefore basically on adapting the old OGL 1.x code to a more recent webGL like version of it.
Emscripten developers put a large effort on making OGL 1.x directly running in the browser but I wanted to have a cleaner and faster implementation only using webgl features
Cube is an interesting code base compiler wise. It is indeed pretty CPU bound since a large time is spent to build the vertex arrays for every frame instead of caching them into VBOs as every game does today.
On my machine (Intel NUC with i3 IVB), the code is mostly 4 times slower than the native version. I tried asm.js with the latest nightly build but with no performance difference. Not sure why.
Code is slow on Chrome.
Code is here:
You need to download cube data yourself here: