147 lines
3.8 KiB
GLSL
147 lines
3.8 KiB
GLSL
#ifdef GL_ES
|
|
precision mediump float;
|
|
#extension GL_OES_standard_derivatives : enable
|
|
#endif
|
|
|
|
uniform float time;
|
|
uniform vec2 mouse;
|
|
uniform vec2 resolution;
|
|
|
|
|
|
// START ASHIMA
|
|
|
|
//
|
|
// Description : Array and textureless GLSL 2D/3D/4D simplex
|
|
// noise functions.
|
|
// Author : Ian McEwan, Ashima Arts.
|
|
// Maintainer : ijm
|
|
// Lastmod : 20110822 (ijm)
|
|
// License : Copyright (C) 2011 Ashima Arts. All rights reserved.
|
|
// Distributed under the MIT License. See LICENSE file.
|
|
// https://github.com/ashima/webgl-noise
|
|
//
|
|
|
|
vec3 mod289(vec3 x) {
|
|
return x - floor(x * (1.0 / 289.0)) * 289.0;
|
|
}
|
|
|
|
vec4 mod289(vec4 x) {
|
|
return x - floor(x * (1.0 / 289.0)) * 289.0;
|
|
}
|
|
|
|
vec4 permute(vec4 x) {
|
|
return mod289(((x*34.0)+1.0)*x);
|
|
}
|
|
|
|
vec4 taylorInvSqrt(vec4 r)
|
|
{
|
|
return 1.79284291400159 - 0.85373472095314 * r;
|
|
}
|
|
|
|
float snoise(vec3 v)
|
|
{
|
|
const vec2 C = vec2(1.0/6.0, 1.0/3.0) ;
|
|
const vec4 D = vec4(0.0, 0.5, 1.0, 2.0);
|
|
|
|
// First corner
|
|
vec3 i = floor(v + dot(v, C.yyy) );
|
|
vec3 x0 = v - i + dot(i, C.xxx) ;
|
|
|
|
// Other corners
|
|
vec3 g = step(x0.yzx, x0.xyz);
|
|
vec3 l = 1.0 - g;
|
|
vec3 i1 = min( g.xyz, l.zxy );
|
|
vec3 i2 = max( g.xyz, l.zxy );
|
|
|
|
// x0 = x0 - 0.0 + 0.0 * C.xxx;
|
|
// x1 = x0 - i1 + 1.0 * C.xxx;
|
|
// x2 = x0 - i2 + 2.0 * C.xxx;
|
|
// x3 = x0 - 1.0 + 3.0 * C.xxx;
|
|
vec3 x1 = x0 - i1 + C.xxx;
|
|
vec3 x2 = x0 - i2 + C.yyy; // 2.0*C.x = 1/3 = C.y
|
|
vec3 x3 = x0 - D.yyy; // -1.0+3.0*C.x = -0.5 = -D.y
|
|
|
|
// Permutations
|
|
i = mod289(i);
|
|
vec4 p = permute( permute( permute(
|
|
i.z + vec4(0.0, i1.z, i2.z, 1.0 ))
|
|
+ i.y + vec4(0.0, i1.y, i2.y, 1.0 ))
|
|
+ i.x + vec4(0.0, i1.x, i2.x, 1.0 ));
|
|
|
|
// Gradients: 7x7 points over a square, mapped onto an octahedron.
|
|
// The ring size 17*17 = 289 is close to a multiple of 49 (49*6 = 294)
|
|
float n_ = 0.142857142857; // 1.0/7.0
|
|
vec3 ns = n_ * D.wyz - D.xzx;
|
|
|
|
vec4 j = p - 49.0 * floor(p * ns.z * ns.z); // mod(p,7*7)
|
|
|
|
vec4 x_ = floor(j * ns.z);
|
|
vec4 y_ = floor(j - 7.0 * x_ ); // mod(j,N)
|
|
|
|
vec4 x = x_ *ns.x + ns.yyyy;
|
|
vec4 y = y_ *ns.x + ns.yyyy;
|
|
vec4 h = 1.0 - abs(x) - abs(y);
|
|
|
|
vec4 b0 = vec4( x.xy, y.xy );
|
|
vec4 b1 = vec4( x.zw, y.zw );
|
|
|
|
//vec4 s0 = vec4(lessThan(b0,0.0))*2.0 - 1.0;
|
|
//vec4 s1 = vec4(lessThan(b1,0.0))*2.0 - 1.0;
|
|
vec4 s0 = floor(b0)*2.0 + 1.0;
|
|
vec4 s1 = floor(b1)*2.0 + 1.0;
|
|
vec4 sh = -step(h, vec4(0.0));
|
|
|
|
vec4 a0 = b0.xzyw + s0.xzyw*sh.xxyy ;
|
|
vec4 a1 = b1.xzyw + s1.xzyw*sh.zzww ;
|
|
|
|
vec3 p0 = vec3(a0.xy,h.x);
|
|
vec3 p1 = vec3(a0.zw,h.y);
|
|
vec3 p2 = vec3(a1.xy,h.z);
|
|
vec3 p3 = vec3(a1.zw,h.w);
|
|
|
|
//Normalise gradients
|
|
vec4 norm = taylorInvSqrt(vec4(dot(p0,p0), dot(p1,p1), dot(p2, p2), dot(p3,p3)));
|
|
p0 *= norm.x;
|
|
p1 *= norm.y;
|
|
p2 *= norm.z;
|
|
p3 *= norm.w;
|
|
|
|
// Mix final noise value
|
|
vec4 m = max(0.6 - vec4(dot(x0,x0), dot(x1,x1), dot(x2,x2), dot(x3,x3)), 0.0);
|
|
m = m * m;
|
|
return 42.0 * dot( m*m, vec4( dot(p0,x0), dot(p1,x1),
|
|
dot(p2,x2), dot(p3,x3) ) );
|
|
}
|
|
|
|
// END ASHIMA
|
|
|
|
vec3 rgb2hsv(vec3 c)
|
|
{
|
|
vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
|
|
vec4 p = mix(vec4(c.bg, K.wz), vec4(c.gb, K.xy), step(c.b, c.g));
|
|
vec4 q = mix(vec4(p.xyw, c.r), vec4(c.r, p.yzx), step(p.x, c.r));
|
|
|
|
float d = q.x - min(q.w, q.y);
|
|
float e = 1.0e-10;
|
|
return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
|
|
}
|
|
|
|
vec3 hsv2rgb(vec3 c) {
|
|
vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
|
|
vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
|
|
return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
|
|
}
|
|
|
|
void main(void) {
|
|
vec2 position = gl_FragCoord.xy / min(resolution.x, resolution.y);
|
|
|
|
const float scale = 0.5;
|
|
float x = position.x * scale;
|
|
float y = position.y * scale;
|
|
float t = time;
|
|
|
|
float hue = snoise(vec3(x, y, t));
|
|
vec3 rgb = hsv2rgb(vec3(hue, 1.0, 1.0));
|
|
|
|
gl_FragColor = vec4(rgb, 1.0);
|
|
}
|