get-memory-optimized-32.glsl

float getMemoryOptimized32(sampler2D tex, ivec2 texSize, ivec3 texDim, int z, int y, int x) {
  ivec3 xyz = ivec3(x, y, z);
  __GET_WRAPAROUND__;
  int index = xyz.x + texDim.x * (xyz.y + texDim.y * xyz.z);
  int channel = integerMod(index, 4);
  index = index / 4;
  int w = texSize.x;
  vec2 st = vec2(float(integerMod(index, w)), float(index / w)) + 0.5;
  vec4 texel = texture2D(tex, st / vec2(texSize));
  if (channel == 0) return texel.r;
  if (channel == 1) return texel.g;
  if (channel == 2) return texel.b;
  if (channel == 3) return texel.a;
  return 0.0;
}