6_6_cnoise
Code 6.6, Figure 6.14:​
6_6_cnoise.frag
#version 300 esprecision highp float;precision highp int;out vec4 fragColor;uniform float u_time;uniform vec2 u_resolution;ivec2 channel;//start hashuvec3 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 hashvec4 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;}vec4 wt;float cnoise21(vec2 p){return abs(dot(wt, fdist24(p)));}float cnoise31(vec3 p){return abs(dot(wt, fdist34(p)));}void main(){vec2 pos = gl_FragCoord.xy/ min(u_resolution.x, u_resolution.y);channel = ivec2(vec2(3, 2) * gl_FragCoord.xy/ u_resolution.xy);pos *= 10.0;pos += u_time;wt = channel.x == 0 ? vec4(0.2):channel.x == 1 ? vec4(0.5, -1.0, 1.4, -0.1):vec4(-0.3, -0.5, -1.2, 1.0);fragColor = vec4(channel.y == 0 ? cnoise21(pos) : cnoise31(vec3(pos, u_time)));fragColor.a = 1.0;}