33 lines
893 B
GLSL
33 lines
893 B
GLSL
#define TAU 6.283185307179586476925286766559005768394338798750211641949
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#define MAX_RESOLUTION 64
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extern int resolution;
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extern float sigma;
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extern float amplitudes[MAX_RESOLUTION];
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extern float offsets[MAX_RESOLUTION];
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extern float range_min, range_max;
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extern bool draw_outline = false;
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float cdf(float x) {
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return .5 + .5*sign(x)*sqrt(1.-exp(-4./TAU * x*x));
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}
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float noise1d(float x) {
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float noise = 0.;
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for (int i=0; i < resolution; i++) {
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float a = amplitudes[i];
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noise += a*cos(x/a + offsets[i]);
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}
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return cdf(noise/sigma);
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}
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vec4 effect(vec4 color, Image texture, vec2 texture_coords, vec2 pixel_coords)
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{
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float x = mix(range_min,range_max,texture_coords.x);
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float n = noise1d(x);
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if (draw_outline) {
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return texture_coords.y > (1.-n) ? vec4(1.,1.,1.,1.) : vec4(0.,0.,0.,1.);
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} else {
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return vec4(n,n,n,1.);
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}
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}
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