Files
oak-editor/app/shaders/blur.frag
T
itsmattkc 065fc9e10e miscellaneous shader changes
Since sequence resolution is provided to the nodes now, it no longer needs to be a global in the shaders
Removed some unused shaders
Added default params to ShaderCode to allow skipping types that aren't used
2020-11-22 10:31:37 +11:00

126 lines
3.1 KiB
GLSL

uniform sampler2D tex_in;
uniform int method_in;
uniform float radius_in;
uniform bool horiz_in;
uniform bool vert_in;
uniform bool repeat_edge_pixels_in;
uniform vec2 resolution_in;
uniform int ove_iteration;
in vec2 ove_texcoord;
out vec4 fragColor;
// Gaussian function uses PI
#define M_PI 3.1415926535897932384626433832795
// Methods
#define METHOD_BOX_BLUR 0
#define METHOD_GAUSSIAN_BLUR 1
// Mode
#define MODE_NONE 0
#define MODE_HORIZONTAL 1
#define MODE_VERTICAL 2
// Single gaussian formula (unused, mainly here for documentation/just in case)
//float gaussian(float x, float sigma) {
// return (1.0/(sigma*sqrt(2.0*M_PI)))*exp(-0.5*pow(x/sigma, 2.0));
//}
// Double gaussian formula, actually used in the code below
// Should be faster than the single gaussian above since it doesn't need sqrt()
float gaussian2(float x, float y, float sigma) {
return (1.0/((sigma*sigma)*2.0*M_PI))*exp(-0.5*(((x*x) + (y*y))/(sigma*sigma)));
}
int determine_mode() {
if (radius_in == 0.0) {
return MODE_NONE;
}
if (!horiz_in && !vert_in) {
return MODE_NONE;
}
if (horiz_in && !vert_in) {
return MODE_HORIZONTAL;
}
if (vert_in && !horiz_in) {
return MODE_VERTICAL;
}
if (ove_iteration == 0) {
return MODE_HORIZONTAL;
}
if (ove_iteration == 1) {
return MODE_VERTICAL;
}
}
void main(void) {
int mode = determine_mode();
if (mode == MODE_NONE) {
fragColor = texture(tex_in, ove_texcoord);
return;
}
// We only sample on hard pixels, so we don't accept decimal radii
float real_radius = ceil(radius_in);
vec4 composite = vec4(0.0);
float divider, sigma;
if (method_in == METHOD_BOX_BLUR) {
// Calculate the weight of each pixel based on the radius
divider = 1.0 / real_radius;
} else if (method_in == METHOD_GAUSSIAN_BLUR) {
// Using (radius = 3 * sigma) because 3 standard deviations covers 97% of the blur according to this document:
// http://chemaguerra.com/gaussian-filter-radius/
sigma = real_radius;
real_radius *= 3.0;
// Use gaussian formula to calculate the weight of all pixels
divider = 0.0;
for (float i = -real_radius + 0.5; i <= real_radius; i += 2.0) {
divider += gaussian2(i, 0.0, sigma);
}
}
for (float i = -real_radius + 0.5; i <= real_radius; i += 2.0) {
float weight;
if (method_in == METHOD_BOX_BLUR) {
weight = divider;
} else if (method_in == METHOD_GAUSSIAN_BLUR) {
weight = gaussian2(i, 0.0, sigma) / divider;
}
vec2 pixel_coord = ove_texcoord;
if (mode == MODE_HORIZONTAL) {
pixel_coord.x += i / resolution_in.x;
} else if (mode == MODE_VERTICAL) {
pixel_coord.y += i / resolution_in.y;
}
if (repeat_edge_pixels_in
|| (pixel_coord.x >= 0.0
&& pixel_coord.x < 1.0
&& pixel_coord.y >= 0.0
&& pixel_coord.y < 1.0)) {
composite += texture(tex_in, pixel_coord) * weight;
}
}
fragColor = composite;
}