23 lines
642 B
Text
23 lines
642 B
Text
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//!DESC Reduce static noise (luma)
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//!HOOK LUMA
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//!BIND HOOKED
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// Change this to tune the strength of the noise
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// Apparently this has to be float on some setups
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#define STRENGTH 48.0
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// PRNG taken from mpv's deband shader
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float mod289(float x) { return x - floor(x / 289.0) * 289.0; }
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float permute(float x) { return mod289((34.0*x + 1.0) * x); }
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float rand(float x) { return fract(x / 41.0); }
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vec4 hook() {
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vec3 _m = vec3(HOOKED_pos, 1.0) + vec3(1.0);
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float h = permute(permute(permute(_m.x)+_m.y)+_m.z);
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vec4 noise;
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noise.x = rand(h);
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return HOOKED_tex(HOOKED_pos) + vec4(STRENGTH/8192.0) * (noise - 0.5);
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}
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