PlanetEditor/grk/cw 6/shaders/shader_bloom.frag
2024-01-22 16:54:33 +01:00

58 lines
1.8 KiB
GLSL

#version 430 core
out vec4 FragColor;
in vec2 texCoords;
uniform sampler2D screenTexture;
uniform bool horizontal;
// How far from the center to take samples from the fragment you are currently on
const int radius = 6;
// Keep it between 1.0f and 2.0f (the higher this is the further the blur reaches)
float spreadBlur = 2.0f;
float weights[radius];
void main()
{
// Calculate the weights using the Gaussian equation
float x = 0.0f;
for (int i = 0; i < radius; i++)
{
// Decides the distance between each sample on the Gaussian function
if (spreadBlur <= 2.0f)
x += 3.0f / radius;
else
x += 6.0f / radius;
weights[i] = exp(-0.5f * pow(x / spreadBlur, 2.0f)) / (spreadBlur * sqrt(2 * 3.14159265f));
}
vec2 tex_offset = 1.0f / textureSize(screenTexture, 0);
vec3 result = texture(screenTexture, texCoords).rgb * weights[0];
// Calculate horizontal blur
if(horizontal)
{
for(int i = 1; i < radius; i++)
{
// Take into account pixels to the right
result += texture(screenTexture, texCoords + vec2(tex_offset.x * i, 0.0)).rgb * weights[i];
// Take into account pixels on the left
result += texture(screenTexture, texCoords - vec2(tex_offset.x * i, 0.0)).rgb * weights[i];
}
}
// Calculate vertical blur
else
{
for(int i = 1; i < radius; i++)
{
// Take into account pixels above
result += texture(screenTexture, texCoords + vec2(0.0, tex_offset.y * i)).rgb * weights[i];
// Take into account pixels below
result += texture(screenTexture, texCoords - vec2(0.0, tex_offset.y * i)).rgb * weights[i];
}
}
result = vec3(0, 1, 0);
FragColor = vec4(result, 1.0f);
}