6_4_fdist4

Code 6.4, Figure 6.12:

6_4_fdist4.frag

#version 300 es precision highp float; precision highp int; out vec4 fragColor; uniform float u_time; uniform vec2 u_resolution; ivec2 channel; //start hash uvec3 k = uvec3(0x456789abu, 0x6789ab45u, 0x89ab4567u); uvec3 u = uvec3(1, 2, 3); const uint UINT_MAX = 0xffffffffu; uint uhash11(uint n){ n ^= (n << u.x); n ^= (n >> u.x); n *= k.x; n ^= (n << u.x); return n * k.x; } uvec2 uhash22(uvec2 n){ n ^= (n.yx << u.xy); n ^= (n.yx >> u.xy); n *= k.xy; n ^= (n.yx << u.xy); return n * k.xy; } uvec3 uhash33(uvec3 n){ n ^= (n.yzx << u); n ^= (n.yzx >> u); n *= k; n ^= (n.yzx << u); return n * k; } float hash11(float p){ uint n = floatBitsToUint(p); return float(uhash11(n)) / float(UINT_MAX); } float hash21(vec2 p){ uvec2 n = floatBitsToUint(p); return float(uhash22(n).x) / float(UINT_MAX); } float hash31(vec3 p){ uvec3 n = floatBitsToUint(p); return float(uhash33(n).x) / float(UINT_MAX); } vec2 hash22(vec2 p){ uvec2 n = floatBitsToUint(p); return vec2(uhash22(n)) / vec2(UINT_MAX); } vec3 hash33(vec3 p){ uvec3 n = floatBitsToUint(p); return vec3(uhash33(n)) / vec3(UINT_MAX); } //end hash vec4 sort(vec4 list, float v){ bvec4 res = bvec4(step(v, list)); return res.x ? vec4(v, list.xyz): res.y ? vec4(list.x, v, list.yz): res.z ? vec4(list.xy, v, list.z): res.w ? vec4(list.xyz, v): list; } vec4 fdist24(vec2 p){ vec2 n = floor(p + 0.5); vec4 dist4 = vec4(length(1.5 - abs(p - n))); for(float j = 0.0; j <= 4.0; j ++ ){ vec2 glid; glid.y = n.y + sign(mod(j, 2.0) - 0.5) * ceil(j * 0.5); if (abs(glid.y - p.y) - 0.5 > dist4.w){ continue; } for(float i = -2.0; i <= 2.0; i ++ ){ glid.x = n.x + i; vec2 jitter = hash22(glid) - 0.5; dist4 = sort(dist4, length(glid + jitter - p)); } } return dist4; } vec4 fdist34(vec3 p){ vec3 n = floor(p + 0.5); vec4 dist4 = vec4(length(1.5 - abs(p - n))); for(float k = 0.0; k <= 4.0; k ++ ){ vec3 glid; glid.z = n.z + sign(mod(k, 2.0) - 0.5) * ceil(k * 0.5); if (abs(glid.z - p.z) - 0.5 > dist4.w){ continue; } for(float j = 0.0; j <= 4.0; j ++ ){ glid.y = n.y + sign(mod(j, 2.0) - 0.5) * ceil(j * 0.5); if (abs(glid.y - p.y) - 0.5 > dist4.w){ continue; } for(float i = -2.0; i <= 2.0; i ++ ){ glid.x = n.x + i; vec3 jitter = hash33(glid) - 0.5; dist4 = sort(dist4, length(glid + jitter - p)); } } } return dist4; } void main(){ vec2 pos = gl_FragCoord.xy/ min(u_resolution.x, u_resolution.y); channel = ivec2(vec2(4, 2) * gl_FragCoord.xy/ u_resolution.xy); pos *= 10.0; pos += u_time; fragColor = channel.y == 0 ? vec4(fdist24(pos)[channel.x % 4]) : vec4(fdist34(vec3(pos, u_time))[channel.x % 4]); fragColor.a = 1.0; }

#version 300 es
precision highp float;
precision highp int;
out vec4 fragColor;
uniform float u_time;
uniform vec2 u_resolution;
ivec2 channel;
//start hash
uvec3 k = uvec3(0x456789abu, 0x6789ab45u, 0x89ab4567u);
uvec3 u = uvec3(1, 2, 3);
const uint UINT_MAX = 0xffffffffu;

uint uhash11(uint n){
  n ^= (n << u.x);
  n ^= (n >> u.x);
  n *= k.x;
  n ^= (n << u.x);
  return n * k.x;
}

uvec2 uhash22(uvec2 n){
  n ^= (n.yx << u.xy);
  n ^= (n.yx >> u.xy);
  n *= k.xy;
  n ^= (n.yx << u.xy);
  return n * k.xy;
}

uvec3 uhash33(uvec3 n){
  n ^= (n.yzx << u);
  n ^= (n.yzx >> u);
  n *= k;
  n ^= (n.yzx << u);
  return n * k;
}

float hash11(float p){
  uint n = floatBitsToUint(p);
  return float(uhash11(n)) / float(UINT_MAX);
}

float hash21(vec2 p){
  uvec2 n = floatBitsToUint(p);
  return float(uhash22(n).x) / float(UINT_MAX);
}

float hash31(vec3 p){
  uvec3 n = floatBitsToUint(p);
  return float(uhash33(n).x) / float(UINT_MAX);
}

vec2 hash22(vec2 p){
  uvec2 n = floatBitsToUint(p);
  return vec2(uhash22(n)) / vec2(UINT_MAX);
}

vec3 hash33(vec3 p){
  uvec3 n = floatBitsToUint(p);
  return vec3(uhash33(n)) / vec3(UINT_MAX);
}
//end hash

vec4 sort(vec4 list, float v){
  bvec4 res = bvec4(step(v, list));
  return res.x ? vec4(v, list.xyz):
    res.y ? vec4(list.x, v, list.yz):
    res.z ? vec4(list.xy, v, list.z):
    res.w ? vec4(list.xyz, v):
    list;
}

vec4 fdist24(vec2 p){
  vec2 n = floor(p + 0.5);
  vec4 dist4 = vec4(length(1.5 - abs(p - n)));
  for(float j = 0.0; j <= 4.0; j ++ ){
    vec2 glid;
    glid.y = n.y + sign(mod(j, 2.0) - 0.5) * ceil(j * 0.5);
    if (abs(glid.y - p.y) - 0.5 > dist4.w){
      continue;
    }
    for(float i = -2.0; i <= 2.0; i ++ ){
      glid.x = n.x + i;
      vec2 jitter = hash22(glid) - 0.5;
      dist4 = sort(dist4, length(glid + jitter - p));
    }
  }
  return dist4;
}

vec4 fdist34(vec3 p){
  vec3 n = floor(p + 0.5);
  vec4 dist4 = vec4(length(1.5 - abs(p - n)));
  for(float k = 0.0; k <= 4.0; k ++ ){
      vec3 glid;
      glid.z = n.z + sign(mod(k, 2.0) - 0.5) * ceil(k * 0.5);
      if (abs(glid.z - p.z) - 0.5 > dist4.w){
        continue;
      }
    for(float j = 0.0; j <= 4.0; j ++ ){
      glid.y = n.y + sign(mod(j, 2.0) - 0.5) * ceil(j * 0.5);
      if (abs(glid.y - p.y) - 0.5 > dist4.w){
        continue;
      }
      for(float i = -2.0; i <= 2.0; i ++ ){
        glid.x = n.x + i;
        vec3 jitter = hash33(glid) - 0.5;
        dist4 = sort(dist4, length(glid + jitter - p));
      }
    }
  }
  return dist4;
}

void main(){
  vec2 pos = gl_FragCoord.xy/ min(u_resolution.x, u_resolution.y);
  channel = ivec2(vec2(4, 2) * gl_FragCoord.xy/ u_resolution.xy); 
  pos *= 10.0;
  pos += u_time;
  fragColor = channel.y == 0 ? vec4(fdist24(pos)[channel.x % 4]) : vec4(fdist34(vec3(pos, u_time))[channel.x % 4]);
  fragColor.a = 1.0;
}