mirror of
https://github.com/Ttanasart-pt/Pixel-Composer.git
synced 2024-11-14 14:33:53 +01:00
109 lines
2.6 KiB
GLSL
109 lines
2.6 KiB
GLSL
/*
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Generalized Kuwahara filter, based on work of Acerola
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Basically Acerola code rewritten to Shadertoy
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- https://www.youtube.com/watch?v=LDhN-JK3U9g
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- https://github.com/GarrettGunnell/Post-Processing/tree/main/Assets/Kuwahara%20Filter
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*/
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varying vec2 v_vTexcoord;
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varying vec4 v_vColour;
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#define PI 3.14159265358979323846;
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#define MAX_RAD 64
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const float q = 18.;
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uniform vec2 dimension;
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uniform int radius;
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void main () {
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vec2 tx = 1. / dimension;
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float zeta = 2. / float(radius);
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float zeroCross = 2.;
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float sinZeroCross = sin(zeroCross);
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float eta = 0.;
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vec4 m[8];
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vec3 s[8];
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for (int k = 0; k < 8; ++k) {
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m[k] = vec4(0.);
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s[k] = vec3(0.);
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}
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for (int y = -MAX_RAD; y <= MAX_RAD; y++)
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for (int x = -MAX_RAD; x <= MAX_RAD; x++) {
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if(y < -radius) continue;
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if(x < -radius) continue;
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if(x > radius) continue;
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if(y > radius) break;
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vec2 v = vec2(x, y) / float(radius);
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vec3 c = texture2D( gm_BaseTexture, v_vTexcoord + vec2(x, y) * tx).xyz;
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c = clamp(c, 0., 1.);
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float sum = 0.;
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float w[8];
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float z, vxx, vyy;
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/* Calculate Polynomial Weights */
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vxx = zeta - eta * v.x * v.x;
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vyy = zeta - eta * v.y * v.y;
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z = max(0., v.y + vxx);
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w[0] = z * z;
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sum += w[0];
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z = max(0., -v.x + vyy);
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w[2] = z * z;
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sum += w[2];
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z = max(0., -v.y + vxx);
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w[4] = z * z;
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sum += w[4];
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z = max(0., v.x + vyy);
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w[6] = z * z;
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sum += w[6];
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v = sqrt(2.0) / 2.0 * vec2(v.x - v.y, v.x + v.y);
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vxx = zeta - eta * v.x * v.x;
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vyy = zeta - eta * v.y * v.y;
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z = max(0., v.y + vxx);
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w[1] = z * z;
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sum += w[1];
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z = max(0., -v.x + vyy);
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w[3] = z * z;
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sum += w[3];
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z = max(0., -v.y + vxx);
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w[5] = z * z;
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sum += w[5];
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z = max(0., v.x + vyy);
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w[7] = z * z;
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sum += w[7];
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float g = exp(-3.125 * dot(v, v)) / (sum + 0.0001);
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for (int k = 0; k < 8; k++) {
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float wk = w[k] * g;
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m[k] += vec4(c * wk, wk);
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s[k] += c * c * wk;
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}
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}
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vec4 ou = vec4(0.);
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for (int k = 0; k < 8; k++) {
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m[k].rgb /= m[k].w;
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s[k] = abs(s[k] / m[k].w - m[k].rgb * m[k].rgb);
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float sigma2 = s[k].r + s[k].g + s[k].b;
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float w = 1.0 / (1.0 + pow(1000.0 * sigma2, 0.5 * q));
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ou += vec4(m[k].rgb * w, w);
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}
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gl_FragColor = clamp((ou / ou.w), 0.0, 1.0);
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} |