gtk2/gsk/resources/vulkan/blur.frag
Matthias Clasen 7bb5b8df0b A somewhat working blur shader
This is a very direct implementation of a Gaussian blur,
without any optimizations.
2017-09-04 23:32:31 -04:00

51 lines
1.3 KiB
GLSL

#version 420 core
#include "clip.frag.glsl"
layout(location = 0) in vec2 inPos;
layout(location = 1) in flat vec2 inSize;
layout(location = 2) in vec2 inTexCoord;
layout(location = 3) in float inRadius;
layout(set = 0, binding = 0) uniform sampler2D inTexture;
layout(location = 0) out vec4 color;
const int samples_x = 15; // must be odd
const int samples_y = 15; // must be odd
const int half_samples_x = samples_x / 2;
const int half_samples_y = samples_y / 2;
float Gaussian (float sigma, float x)
{
return exp ( - (x * x) / (2.0 * sigma * sigma));
}
vec4 blur_pixel (in vec2 uv)
{
float total = 0.0;
vec4 ret = vec4 (0);
float pixel_size_x = (1.0 / inSize.x);
float pixel_size_y = (1.0 / inSize.y);
for (int y = 0; y < samples_y; ++y)
{
float fy = Gaussian (inRadius, float(y) - float(half_samples_x));
float offset_y = float(y - half_samples_y) * pixel_size_y;
for (int x = 0; x < samples_x; ++x)
{
float fx = Gaussian (inRadius, float(x) - float(half_samples_x));
float offset_x = float(x - half_samples_x) * pixel_size_x;
total += fx * fy;
ret += texture(inTexture, uv + vec2(offset_x, offset_y)) * fx * fy;
}
}
return ret / total;
}
void main()
{
color = clip (inPos, blur_pixel (inTexCoord));
}