59 lines
1014 B
JavaScript
59 lines
1014 B
JavaScript
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/**
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* Kaleidoscope Shader
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* Radial reflection around center point
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* Ported from: http://pixelshaders.com/editor/
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* by Toby Schachman / http://tobyschachman.com/
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*
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* sides: number of reflections
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* angle: initial angle in radians
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*/
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const KaleidoShader = {
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name: 'KaleidoShader',
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uniforms: {
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'tDiffuse': { value: null },
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'sides': { value: 6.0 },
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'angle': { value: 0.0 }
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},
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vertexShader: /* glsl */`
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varying vec2 vUv;
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void main() {
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vUv = uv;
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gl_Position = projectionMatrix * modelViewMatrix * vec4( position, 1.0 );
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}`,
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fragmentShader: /* glsl */`
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uniform sampler2D tDiffuse;
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uniform float sides;
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uniform float angle;
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varying vec2 vUv;
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void main() {
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vec2 p = vUv - 0.5;
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float r = length(p);
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float a = atan(p.y, p.x) + angle;
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float tau = 2. * 3.1416 ;
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a = mod(a, tau/sides);
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a = abs(a - tau/sides/2.) ;
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p = r * vec2(cos(a), sin(a));
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vec4 color = texture2D(tDiffuse, p + 0.5);
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gl_FragColor = color;
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}`
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};
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export { KaleidoShader };
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