gtk/gsk/vulkan/resources/blur.frag
Benjamin Otte 8207c548cc vulkan: Combine textures and samplers again
This reverts most of commit f420c143e0
again because it turns out GPUs like combined images and samplers.

But: The one thing we don't revert is allowing the C code to select any
combination of sampler and image:
gsk_vulkan_render_get_image_descriptor() now takes a 2nd argument
specifying the sampler.

This allows the same flexibility as before, we just combine things
early.

This change was inspired by
https://developer.nvidia.com/blog/vulkan-dos-donts/
2023-07-16 12:12:36 +02:00

51 lines
1.3 KiB
GLSL

#version 450
#include "common.frag.glsl"
#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(location = 4) in flat uint inTexId;
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(get_sampler (inTexId), uv + vec2(offset_x, offset_y)) * fx * fy;
}
}
return ret / total;
}
void main()
{
color = clip (inPos, blur_pixel (inTexCoord));
}