25 lines
465 B
Plaintext
25 lines
465 B
Plaintext
/*
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* simulate scanlines by darkening every other line.
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*
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*/
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kernel vec4 scanline(sampler image, float l, float d)
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{
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vec4 light, dark;
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vec2 coord = samplerCoord(image);
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vec4 pixel = sample(image, coord);
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pixel = unpremultiply(pixel);
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light = dark = pixel;
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dark.rgb = pixel.rgb * (1.0 - d);
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light.rgb = pixel.rgb * (1.0 - l) + l;
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pixel.rgb = mod(coord.y, 2.0) < 1.0 ? light.rgb : dark.rgb;
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return premultiply(pixel);
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}
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