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thebookofshaders/11/voronoi/2d-voronoi-02.frag

75 lines
1.9 KiB
GLSL

#ifdef GL_ES
precision mediump float;
#endif
uniform vec2 u_resolution;
uniform vec2 u_mouse;
uniform float u_time;
vec2 random2( vec2 p ) {
return fract(sin(vec2(dot(p,vec2(127.1,311.7)),dot(p,vec2(269.5,183.3))))*43758.5453);
}
#define ANIMATE
vec3 voronoi( in vec2 x, float rnd ) {
vec2 n = floor(x);
vec2 f = fract(x);
// first pass: regular voronoi
vec2 mg = vec2(0.0);
vec2 mr = vec2(0.0);
float md = 8.0;
for (int j=-1; j<=1; j++ ) {
for (int i=-1; i<=1; i++ ) {
vec2 g = vec2(float(i),float(j));
vec2 o = random2( n + g )*rnd;
#ifdef ANIMATE
o = 0.5 + 0.5*sin( u_time + 6.2831*o );
#endif
vec2 r = g + o - f;
float d = dot(r,r);
if( d<md ) {
md = d;
mr = r;
mg = g;
}
}
}
return vec3( md, mr );
// // second pass: distance to borders
// md = 8.0;
// for (int j=-2; j<=2; j++ ) {
// for (int i=-2; i<=2; i++ ) {
// vec2 g = mg + vec2(float(i),float(j));
// vec2 o = random2(n + g)*rnd;
// #ifdef ANIMATE
// o = 0.5 + 0.5*sin( u_time + 6.2831*o );
// #endif
// vec2 r = g + o - f;
// if( dot(mr-r,mr-r)>0.00001 )
// md = min( md, dot( 0.5*(mr+r), normalize(r-mr) ) );
// }
// }
// return vec3( md, mr );
}
void main() {
vec2 st = gl_FragCoord.xy/u_resolution.xy;
vec3 color = vec3(0.0);
float d = dot(st-.5,st-.5);
vec3 c = voronoi( 10.*st, 1.);//pow(d,.4) );
// isolines
color = c.x*(0.5 + 0.5*sin(64.0*c.x))*vec3(1.0);
// borders
color = mix( vec3(1.0), color, smoothstep( 0.01, 0.02, c.x ) );
// feature points
// float dd = length( c.yz );
// color += vec3(1.)*(1.0-smoothstep( 0.0, 0.1, dd));
gl_FragColor = vec4(color,1.0);
}