How a voxel sandbox game works in 62k lines of x86-64 assembly - no compiler, no C runtime, no asset files

Author here. A few things I find most interesting in the code:

Lighting

Lighting is a BFS over a 5x5 window of chunks with positions packed into one dword (wx | wz<<7 | y<<14 | value<<21), so a neighbour step is a single add and crossing a chunk border is a pointer swap.

Meshing

The mesher copies the 3x3 neighbouring chunks into an 18^3 padded volume so every neighbour lookup is one movzx at a constant offset (+1, +18, +324).

ABI Checks

The ABI is checked by machine:

• sentinel values in every nonvolatile register
• plus a counter for calls made with a misaligned stack

Explosions

Explosions cast 1352 rays (the surface cells of a 16^3 grid: no trig) and dedupe hits in a hash set that is "cleared" by bumping a generation stamp.

Repo + download: https://github.com/BaramiDev/MineAssembly