noise_voronoy.frag

precision mediump float;
// Simplex 2D noise
//
vec3 permute(vec3 x) { return mod(((x*34.0)+1.0)*x, 289.0); }

float snoise(vec2 v){
  const vec4 C = vec4(0.211324865405187, 0.366025403784439,
           -0.577350269189626, 0.024390243902439);
  vec2 i  = floor(v + dot(v, C.yy) );
  vec2 x0 = v -   i + dot(i, C.xx);
  vec2 i1;
  i1 = (x0.x > x0.y) ? vec2(1.0, 0.0) : vec2(0.0, 1.0);
  vec4 x12 = x0.xyxy + C.xxzz;
  x12.xy -= i1;
  i = mod(i, 289.0);
  vec3 p = permute( permute( i.y + vec3(0.0, i1.y, 1.0 ))
  + i.x + vec3(0.0, i1.x, 1.0 ));
  vec3 m = max(0.5 - vec3(dot(x0,x0), dot(x12.xy,x12.xy),
    dot(x12.zw,x12.zw)), 0.0);
  m = m*m ;
  m = m*m ;
  vec3 x = 2.0 * fract(p * C.www) - 1.0;
  vec3 h = abs(x) - 0.5;
  vec3 ox = floor(x + 0.5);
  vec3 a0 = x - ox;
  m *= 1.79284291400159 - 0.85373472095314 * ( a0*a0 + h*h );
  vec3 g;
  g.x  = a0.x  * x0.x  + h.x  * x0.y;
  g.yz = a0.yz * x12.xz + h.yz * x12.yw;
  return 130.0 * dot(m, g);
}

vec3 hash3( vec2 p ){
    vec3 q = vec3( dot(p,vec2(127.1,311.7)),
				   dot(p,vec2(269.5,183.3)),
				   dot(p,vec2(419.2,371.9)) );
	return fract(sin(q)*43758.5453);
}

float iqnoise( in vec2 x, float u, float v ){
    vec2 p = floor(x);
    vec2 f = fract(x);

	float k = 1.0+63.0*pow(1.0-v,4.0);

	float va = 0.0;
	float wt = 0.0;
    for( int j=-2; j<=2; j++ )
    for( int i=-2; i<=2; i++ )
    {
        vec2 g = vec2( float(i),float(j) );
		vec3 o = hash3( p + g )*vec3(u,u,1.0);
		vec2 r = g - f + o.xy;
		float d = dot(r,r);
		float ww = pow( 1.0-smoothstep(0.0,1.414,sqrt(d)), k );
		va += o.z*ww;
		wt += ww;
    }

    return va/wt;
}

void mainImage( out vec4 fragColor, in vec2 fragCoord )
{

    vec2 uv = fragCoord.xy / iResolution.xy - 0.5;
    uv.x *= iResolution.x / iResolution.y;

    vec3 color = vec3(uv.x + 0.5, uv.y + 0.5, uv.x*uv.y + 0.5);

    float scale = 10.;

    color = vec3(snoise(vec2(uv.x * scale, uv.y * scale)));

	color = vec3(iqnoise(vec2(uv.x * scale, uv.y * scale), .3, .7));

    fragColor = vec4(color, 1.0);

}