forked from AuroraMiddleware/gtk
40 lines
1.0 KiB
GLSL
40 lines
1.0 KiB
GLSL
uniform float u_blur_radius;// = 40.0;
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uniform vec2 u_blur_size;// = vec2(393, 393);
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float Gaussian (float sigma, float x) {
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return exp ( - (x * x) / (2.0 * sigma * sigma));
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}
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vec4 blur_pixel (in vec2 uv) {
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float total = 0.0;
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vec4 ret = vec4 (0);
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float pixel_size_x = (1.0 / u_blur_size.x);
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float pixel_size_y = (1.0 / u_blur_size.y);
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// XXX The magic value here is GAUSSIAN_SCALE_FACTOR from gskcairoblur.c
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float radius = u_blur_radius * 2.30348;
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int half_radius = max(int(radius / 2.0), 1);
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for (int y = -half_radius; y < half_radius; y ++) {
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float fy = Gaussian (radius / 2.0, float(y));
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float offset_y = float(y) * pixel_size_y;
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for (int x = -half_radius; x < half_radius; x ++) {
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float fx = Gaussian (radius / 2.0, float(x));
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float offset_x = float(x) * pixel_size_x;
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vec4 c = Texture(u_source, uv + vec2(offset_x, offset_y));
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total += fx * fy;
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ret += c * fx * fy;
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}
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}
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return ret / total;
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}
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void main() {
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vec4 color = blur_pixel(vUv);
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setOutputColor(color);
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}
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