mattdesl

// each pixel is assigned 4 random u32 values per frame
@group(0) @binding(1)
var<storage, read> rnd_state: array<u32>;

// the current state within this pixel
var<private> local_rnd_state:vec4u;

fn random_u32(state:ptr<private,vec4u>) -> u32 {
  var st:vec4u = *state;
  /* Algorithm "xor128" from p. 5 of Marsaglia, "Xorshift RNGs" */