GLSL noise

gistfile1.txt

float snoise(vec3 uv, float res)  // by trisomie21
{
	const vec3 s = vec3(1e0, 1e2, 1e4);
	
	uv *= res;
	
	vec3 uv0 = floor(mod(uv, res))*s;
	vec3 uv1 = floor(mod(uv+vec3(1.), res))*s;
	
	vec3 f = fract(uv); f = f*f*(3.0-2.0*f);
	
	vec4 v = vec4(uv0.x+uv0.y+uv0.z, uv1.x+uv0.y+uv0.z,
		      	  uv0.x+uv1.y+uv0.z, uv1.x+uv1.y+uv0.z);
	
	vec4 r = fract(sin(v*1e-3)*1e5);
	float r0 = mix(mix(r.x, r.y, f.x), mix(r.z, r.w, f.x), f.y);
	
	r = fract(sin((v + uv1.z - uv0.z)*1e-3)*1e5);
	float r1 = mix(mix(r.x, r.y, f.x), mix(r.z, r.w, f.x), f.y);
	
	return mix(r0, r1, f.z)*2.-1.;
}