21 lines
612 B
GLSL
21 lines
612 B
GLSL
// edge detection based on http://williamchyr.com/tag/unity/page/2/
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uniform sampler2D tDiffuse;
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uniform float threshold;
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uniform vec2 aspect;
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varying vec2 vUv;
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void main() {
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float w = (1.0 / aspect.x);
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float h = (1.0 / aspect.y);
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// vec4 a = texture2D(tDiffuse, vUv);
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vec4 b = texture2D(tDiffuse, vUv + vec2(-w, -h));
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vec4 c = texture2D(tDiffuse, vUv + vec2(w, -h));
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vec4 d = texture2D(tDiffuse, vUv + vec2(-w, h));
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vec4 e = texture2D(tDiffuse, vUv + vec2(w, h));
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float difference = length(b - e) + length(c - d);
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gl_FragColor = difference > threshold ? vec4(vec3(1.0), 0.0) : vec4(0.0);
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}
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