mirror of
https://github.com/patriciogonzalezvivo/thebookofshaders
synced 2024-11-03 23:15:23 +00:00
95 lines
2.9 KiB
GLSL
95 lines
2.9 KiB
GLSL
// Author @patriciogv - 2015
|
|
// http://patriciogonzalezvivo.com
|
|
|
|
#ifdef GL_ES
|
|
precision mediump float;
|
|
#endif
|
|
|
|
uniform vec2 u_resolution;
|
|
uniform vec2 u_mouse;
|
|
uniform float u_time;
|
|
|
|
//
|
|
// Description : Array and textureless GLSL 2D simplex noise function.
|
|
// 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; }
|
|
vec2 mod289(vec2 x) { return x - floor(x * (1.0 / 289.0)) * 289.0; }
|
|
vec3 permute(vec3 x) { return mod289(((x*34.0)+1.0)*x); }
|
|
|
|
float snoise(vec2 v) {
|
|
const vec4 C = vec4(0.211324865405187, // (3.0-sqrt(3.0))/6.0
|
|
0.366025403784439, // 0.5*(sqrt(3.0)-1.0)
|
|
-0.577350269189626, // -1.0 + 2.0 * C.x
|
|
0.024390243902439); // 1.0 / 41.0
|
|
// First corner
|
|
vec2 i = floor(v + dot(v, C.yy) );
|
|
vec2 x0 = v - i + dot(i, C.xx);
|
|
|
|
// Other corners
|
|
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;
|
|
|
|
// Permutations
|
|
i = mod289(i); // Avoid truncation effects in permutation
|
|
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 ;
|
|
|
|
// Gradients: 41 points uniformly over a line, mapped onto a diamond.
|
|
// The ring size 17*17 = 289 is close to a multiple of 41 (41*7 = 287)
|
|
|
|
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;
|
|
|
|
// Normalise gradients implicitly by scaling m
|
|
// Approximation of: m *= inversesqrt( a0*a0 + h*h );
|
|
m *= 1.79284291400159 - 0.85373472095314 * ( a0*a0 + h*h );
|
|
|
|
// Compute final noise value at P
|
|
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);
|
|
}
|
|
|
|
float cascade(vec2 st, vec2 zoom, float time, float warp) {
|
|
vec2 pos = st*zoom*vec2(1.,pow(st.y,warp))+vec2(0.,time);
|
|
return (.5+snoise(pos)*.5)*(st.y);
|
|
}
|
|
|
|
void main() {
|
|
vec2 st = gl_FragCoord.xy/u_resolution.xy;
|
|
if (u_resolution.x>u_resolution.y) {
|
|
st.x *= u_resolution.x/u_resolution.y;
|
|
} else {
|
|
st.y *= u_resolution.y/u_resolution.x;
|
|
}
|
|
vec3 color = vec3(0.0);
|
|
vec2 pos = st-vec2(.5);
|
|
float r = dot(pos,pos);
|
|
float a = atan(pos.y,pos.x);
|
|
|
|
st = vec2(a,r*8.);
|
|
|
|
color = vec3(1.)*smoothstep(.5,.8, cascade(st,vec2(30.,3.),u_time*3.,5.));
|
|
color += vec3(.5)*smoothstep(.6,.7, cascade(st,vec2(50.,5.),u_time*2.,1.));
|
|
color += smoothstep(.03,.20,r)*.5;
|
|
color *= 1.0-smoothstep(.11,.13,r);
|
|
|
|
gl_FragColor = vec4(color,1.0);
|
|
}
|