mirror of
https://github.com/DanielnetoDotCom/YouPHPTube
synced 2025-10-04 10:19:24 +02:00
91 lines
3 KiB
JavaScript
91 lines
3 KiB
JavaScript
/**
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* Edge Detection Shader using Frei-Chen filter
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* Based on http://rastergrid.com/blog/2011/01/frei-chen-edge-detector
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*
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* aspect: vec2 of (1/width, 1/height)
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*/
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THREE.FreiChenShader = {
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uniforms: {
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'tDiffuse': { value: null },
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'aspect': { value: new THREE.Vector2( 512, 512 ) }
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},
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vertexShader: [
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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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].join( '\n' ),
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fragmentShader: [
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'uniform sampler2D tDiffuse;',
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'varying vec2 vUv;',
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'uniform vec2 aspect;',
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'vec2 texel = vec2(1.0 / aspect.x, 1.0 / aspect.y);',
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'mat3 G[9];',
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// hard coded matrix values!!!! as suggested in https://github.com/neilmendoza/ofxPostProcessing/blob/master/src/EdgePass.cpp#L45
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'const mat3 g0 = mat3( 0.3535533845424652, 0, -0.3535533845424652, 0.5, 0, -0.5, 0.3535533845424652, 0, -0.3535533845424652 );',
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'const mat3 g1 = mat3( 0.3535533845424652, 0.5, 0.3535533845424652, 0, 0, 0, -0.3535533845424652, -0.5, -0.3535533845424652 );',
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'const mat3 g2 = mat3( 0, 0.3535533845424652, -0.5, -0.3535533845424652, 0, 0.3535533845424652, 0.5, -0.3535533845424652, 0 );',
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'const mat3 g3 = mat3( 0.5, -0.3535533845424652, 0, -0.3535533845424652, 0, 0.3535533845424652, 0, 0.3535533845424652, -0.5 );',
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'const mat3 g4 = mat3( 0, -0.5, 0, 0.5, 0, 0.5, 0, -0.5, 0 );',
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'const mat3 g5 = mat3( -0.5, 0, 0.5, 0, 0, 0, 0.5, 0, -0.5 );',
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'const mat3 g6 = mat3( 0.1666666716337204, -0.3333333432674408, 0.1666666716337204, -0.3333333432674408, 0.6666666865348816, -0.3333333432674408, 0.1666666716337204, -0.3333333432674408, 0.1666666716337204 );',
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'const mat3 g7 = mat3( -0.3333333432674408, 0.1666666716337204, -0.3333333432674408, 0.1666666716337204, 0.6666666865348816, 0.1666666716337204, -0.3333333432674408, 0.1666666716337204, -0.3333333432674408 );',
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'const mat3 g8 = mat3( 0.3333333432674408, 0.3333333432674408, 0.3333333432674408, 0.3333333432674408, 0.3333333432674408, 0.3333333432674408, 0.3333333432674408, 0.3333333432674408, 0.3333333432674408 );',
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'void main(void)',
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'{',
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' G[0] = g0,',
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' G[1] = g1,',
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' G[2] = g2,',
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' G[3] = g3,',
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' G[4] = g4,',
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' G[5] = g5,',
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' G[6] = g6,',
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' G[7] = g7,',
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' G[8] = g8;',
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' mat3 I;',
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' float cnv[9];',
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' vec3 sample;',
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/* fetch the 3x3 neighbourhood and use the RGB vector's length as intensity value */
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' for (float i=0.0; i<3.0; i++) {',
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' for (float j=0.0; j<3.0; j++) {',
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' sample = texture2D(tDiffuse, vUv + texel * vec2(i-1.0,j-1.0) ).rgb;',
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' I[int(i)][int(j)] = length(sample);',
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' }',
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' }',
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/* calculate the convolution values for all the masks */
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' for (int i=0; i<9; i++) {',
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' float dp3 = dot(G[i][0], I[0]) + dot(G[i][1], I[1]) + dot(G[i][2], I[2]);',
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' cnv[i] = dp3 * dp3;',
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' }',
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' float M = (cnv[0] + cnv[1]) + (cnv[2] + cnv[3]);',
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' float S = (cnv[4] + cnv[5]) + (cnv[6] + cnv[7]) + (cnv[8] + M);',
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' gl_FragColor = vec4(vec3(sqrt(M/S)), 1.0);',
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'}'
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].join( '\n' )
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};
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