thebookofshaders/11/2d-noise.frag
Patricio Gonzalez Vivo a8ef0b6741 optical toys
2015-05-05 10:19:16 -04:00

46 lines
1006 B
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;
float random (in vec2 st) {
return fract(sin(dot(st.xy,
vec2(12.9898,78.233)))*
43758.5453123);
}
// Based on Morgan McGuire @morgan3d
// https://www.shadertoy.com/view/4dS3Wd
float noise (in vec2 st) {
vec2 i = floor(st);
vec2 f = fract(st);
// Four corners in 2D of a tile
float a = random(i);
float b = random(i + vec2(1.0, 0.0));
float c = random(i + vec2(0.0, 1.0));
float d = random(i + vec2(1.0, 1.0));
vec2 u = f * f * (3.0 - 2.0 * f);
return mix(a, b, u.x) +
(c - a)* u.y * (1.0 - u.x) +
(d - b) * u.x * u.y;
}
void main() {
vec2 st = gl_FragCoord.xy/u_resolution.xy;
vec3 color = vec3(0.0);
vec2 pos = vec2(st*5.0+u_time);
color = vec3( noise(pos) );
gl_FragColor = vec4(color,1.0);
}