mirror of
https://github.com/patriciogonzalezvivo/thebookofshaders
synced 2024-11-01 21:40:27 +00:00
57 lines
1.2 KiB
GLSL
57 lines
1.2 KiB
GLSL
// Author @patriciogv - 2015
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// http://patriciogonzalezvivo.com
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#ifdef GL_ES
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precision mediump float;
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#endif
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#define PI 3.14159265359
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uniform sampler2D u_tex0;
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uniform vec2 u_tex0Resolution;
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uniform vec2 u_resolution;
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uniform vec2 u_mouse;
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uniform float u_time;
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// Based on Morgan
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// https://www.shadertoy.com/view/4dS3Wd
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float random (in vec2 st) {
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return fract(sin(dot(st.xy,
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vec2(12.9898,78.233)))*
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43758.5453123);
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}
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float noise (in vec2 st) {
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vec2 i = floor(st);
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vec2 f = fract(st);
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// Four corners in 2D of a tile
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float a = random(i);
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float b = random(i + vec2(1.0, 0.0));
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float c = random(i + vec2(0.0, 1.0));
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float d = random(i + vec2(1.0, 1.0));
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vec2 u = f * f * (3.0 - 2.0 * f);
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return mix(a, b, u.x) +
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(c - a)* u.y * (1.0 - u.x) +
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(d - b) * u.x * u.y;
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}
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void main () {
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vec2 st = gl_FragCoord.xy/u_resolution.xy;
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float scale = 2.0;
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float offset = 0.5;
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float angle = noise( st + u_time * 0.1 )*PI;
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float radius = offset;
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st *= scale;
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st += radius * vec2(cos(angle),sin(angle));
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vec4 color = texture2D(u_tex0,st);
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gl_FragColor = color;
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} |