21 lines
679 B
SourcePawn
21 lines
679 B
SourcePawn
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//
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void runAlphaTest(float alpha, float alphaThreshold)
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{
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if (alphaThreshold > 0.0) {
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// http://alex-charlton.com/posts/Dithering_on_the_GPU/
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// https://forums.khronos.org/showthread.php/5091-screen-door-transparency
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mat4 thresholdMatrix = mat4(
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1.0 / 17.0, 9.0 / 17.0, 3.0 / 17.0, 11.0 / 17.0,
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13.0 / 17.0, 5.0 / 17.0, 15.0 / 17.0, 7.0 / 17.0,
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4.0 / 17.0, 12.0 / 17.0, 2.0 / 17.0, 10.0 / 17.0,
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16.0 / 17.0, 8.0 / 17.0, 14.0 / 17.0, 6.0 / 17.0
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);
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alpha = clamp(alpha - 0.5 * thresholdMatrix[int(mod(gl_FragCoord.x, 4.0))][int(mod(gl_FragCoord.y, 4.0))], 0.0, 1.0);
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if (alpha < alphaThreshold)
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discard;
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}
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}
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