31 lines
828 B
Plaintext
31 lines
828 B
Plaintext
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const float PHI = 1.61803398874989484820459; // Φ = Golden Ratio
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const float INV_PI = 0.31830988618379067153776752674503;
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const float INV_SQRT_OF_2PI = 0.39894228040143267793994605993439;
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const float PI = 3.141592653589793;
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float seed = 0.0;
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vec2 xy = vec2(0.0);
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// based on https://www.shadertoy.com/view/ltB3zD
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//
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// Gold Noise ©2015 dcerisano@standard3d.com
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// - based on the Golden Ratio
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// - uniform normalized distribution
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// - fastest static noise generator function (also runs at low precision)
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// - use with indicated fractional seeding method.
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float gold_noise(){
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seed += 0.1;
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return fract(tan(distance(xy * PHI, xy) * seed)*xy.x);
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}
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void init_random_state(in vec2 st, in float s)
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{
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xy = st;
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seed = s * 0.01;
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}
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float luminance(in vec3 col)
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{
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return dot(col, vec3(0.2126, 0.7152, 0.0722));
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}
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