5_4_blending

Code 5.5, Figure 5.7:

5_4_blending.frag

#version 300 es precision highp float; precision highp int; out vec4 fragColor; uniform float u_time; uniform vec2 u_resolution; int channel; const float PI = 3.1415926; //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 //start vnoise float vnoise21(vec2 p){ vec2 n = floor(p); float[4] v; for (int j = 0; j < 2; j ++){ for (int i = 0; i < 2; i++){ v[i+2*j] = hash21(n + vec2(i, j)); } } vec2 f = fract(p); f = f * f * f * (10.0 - 15.0 * f + 6.0 * f * f); return mix(mix(v[0], v[1], f[0]), mix(v[2], v[3], f[0]), f[1]); } //end vnoise //start pnoise float gtable2(vec2 lattice, vec2 p){ uvec2 n = floatBitsToUint(lattice); uint ind = uhash22(n).x >> 29; float u = 0.92387953 * (ind < 4u ? p.x : p.y); //0.92387953 = cos(pi/8) float v = 0.38268343 * (ind < 4u ? p.y : p.x); //0.38268343 = sin(pi/8) return ((ind & 1u) == 0u ? u : -u) + ((ind & 2u) == 0u? v : -v); } float pnoise21(vec2 p){ vec2 n = floor(p); vec2 f = fract(p); float[4] v; for (int j = 0; j < 2; j ++){ for (int i = 0; i < 2; i++){ v[i+2*j] = gtable2(n + vec2(i, j), f - vec2(i, j)); } } f = f * f * f * (10.0 - 15.0 * f + 6.0 * f * f); return 0.5 * mix(mix(v[0], v[1], f[0]), mix(v[2], v[3], f[0]), f[1]) + 0.5; } //end pnoise float fbm21(vec2 p, float g){ float val = 0.0; float amp = 1.0; float freq = 1.0; for (int i = 0; i < 4; i++){ val += amp * (vnoise21(freq * p) - 0.5); amp *= g; freq *= 2.01; } return 0.5 * val + 0.5; } float base21(vec2 p){ return mod(u_time, 20.0) < 10.0 ? fbm21(p, 0.5) : pnoise21(p); } float warp21(vec2 p, float g){ float val = 0.0; for (int i = 0; i < 4; i++){ val = base21(p + g * vec2(cos(2.0 * PI * val), sin(2.0 * PI * val))); } return val; } vec3 blend(float a, float b){ float time = abs(mod(0.1 * u_time, 2.0) - 1.0); vec3[2] col2 = vec3[]( vec3(a, a, 1), vec3(0, b, b) ); return channel == 0 ? mix(col2[0], col2[1], time): mix(col2[0], col2[1], smoothstep(0.5 - 0.5 * time, 0.5 + 0.5 * time, b / (a + b))) ; } void main(){ vec2 pos = gl_FragCoord.xy/min(u_resolution.x, u_resolution.y); channel = int(2.0 * gl_FragCoord.x / u_resolution.x); pos = 10.0 * pos + u_time; float a = warp21(pos, 1.0); float b = warp21(pos + 10.0, 1.0); fragColor.rgb = blend(a, b); fragColor.a = 1.0; }

#version 300 es
precision highp float;
precision highp int;
out vec4 fragColor;
uniform float u_time;
uniform vec2 u_resolution;
int channel;
const float PI = 3.1415926;

//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

//start vnoise
float vnoise21(vec2 p){
  vec2 n = floor(p);
  float[4] v;
  for (int j = 0; j < 2; j ++){
    for (int i = 0; i < 2; i++){
      v[i+2*j] = hash21(n + vec2(i, j));
    }
  }
  vec2 f = fract(p);
  f = f * f * f * (10.0 - 15.0 * f + 6.0 * f * f);
  return mix(mix(v[0], v[1], f[0]), mix(v[2], v[3], f[0]), f[1]);
}
//end vnoise

//start pnoise
float gtable2(vec2 lattice, vec2 p){
  uvec2 n = floatBitsToUint(lattice);
  uint ind = uhash22(n).x >> 29;
  float u = 0.92387953 * (ind < 4u ? p.x : p.y);  //0.92387953 = cos(pi/8)
  float v = 0.38268343 * (ind < 4u ? p.y : p.x);  //0.38268343 = sin(pi/8)
  return ((ind & 1u) == 0u ? u : -u) + ((ind & 2u) == 0u? v : -v);
}

float pnoise21(vec2 p){
  vec2 n = floor(p);
  vec2 f = fract(p);
  float[4] v;
  for (int j = 0; j < 2; j ++){
    for (int i = 0; i < 2; i++){
      v[i+2*j] = gtable2(n + vec2(i, j), f - vec2(i, j));
    }
  }
  f = f * f * f * (10.0 - 15.0 * f + 6.0 * f * f);
  return 0.5 * mix(mix(v[0], v[1], f[0]), mix(v[2], v[3], f[0]), f[1]) + 0.5;
}
//end pnoise

float fbm21(vec2 p, float g){
  float val = 0.0;
  float amp = 1.0;
  float freq = 1.0;
  for (int i = 0; i < 4; i++){
    val += amp * (vnoise21(freq * p) - 0.5);
    amp *= g;
    freq *= 2.01;
  }
  return 0.5 * val + 0.5;
}

float base21(vec2 p){
  return mod(u_time, 20.0) < 10.0 ?
  fbm21(p, 0.5) : 
  pnoise21(p);
}

float warp21(vec2 p, float g){
  float val = 0.0;
  for (int i = 0; i < 4; i++){
    val = base21(p + g * vec2(cos(2.0 * PI * val), sin(2.0 * PI * val)));
  }
  return val;
}

vec3 blend(float a, float b){
  float time = abs(mod(0.1 * u_time, 2.0) - 1.0);
  vec3[2] col2 = vec3[](
    vec3(a, a, 1),
    vec3(0, b, b)
  );
  return channel == 0 ? mix(col2[0], col2[1], time):
    mix(col2[0], col2[1], smoothstep(0.5 - 0.5 * time, 0.5 + 0.5 * time, b / (a + b)))
  ;
}

void main(){
  vec2 pos = gl_FragCoord.xy/min(u_resolution.x, u_resolution.y);
  channel = int(2.0 * gl_FragCoord.x / u_resolution.x);
  pos = 10.0 * pos + u_time;
  float a = warp21(pos, 1.0);
  float b = warp21(pos + 10.0, 1.0);
  fragColor.rgb = blend(a, b);
  fragColor.a = 1.0;
}