SML port of the 128-byte raytracer wolf128. See http://finalpatch.blogspot.dk/2014/06/dissecting-128-byte-raycaster.html. Uses the InstagraML library: https://github.com/DIKU-IP/InstagraML

wolf128.sml

(* ex: set ts=2 sw=2 et ai: *)

use "InstagraML.sml";

local
  fun rayMarch (x,y,z) =
    let
      val xdist0 = (((x-160) * z + 4096) div 256) mod 256
      val ydist = (((y-100) * z + 4096) div 256) mod 256
      val xdist = case z div 64 of
          0 => xdist0 - 10
        | 1 => xdist0 - 40
        | 2 => xdist0 - 20
        | _ => xdist0 - 30
    in
      if (xdist >= 32 andalso ((z div 32) mod 2 <> 0)) orelse ydist >= 32
        orelse z > 255 then
        (xdist,ydist,z)
      else
        rayMarch (x, y, z+1)
    end
in
  fun shadeFragment (x,y) =
    let
      val (xdist,ydist,z) = rayMarch(x,y,0)
      val texel0 = Word8.xorb(
        Word8.xorb(Word8.fromInt(xdist),Word8.fromInt(ydist)),Word8.fromInt(z))
      val texel = Word8.toInt(texel0) mod 16
    in
      (texel*16, texel*16, texel*16)
    end
end;


val img = InstagraML.fromFunction (320, 200, shadeFragment);
InstagraML.writeBMP ("wolf128.bmp", img);