slang-shaders/border/shaders/blur_fill/scaling.slang
fishcu b9d89d63db
Add blur fill (#446)
* Initial commit, WIP

* First working version; stretching the blur will require some refactoring

* Add blur extension to borders

* Implement 'trippy mode' (disable blur, show tiled)

* Implement proper scaling, cropping, and centering independent of viewport res

* Clean up; Fix bug with small blur pass resolutions

* Add blur strength presets; Polish

* Add background gamma adjustment
2023-06-14 14:21:36 -05:00

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#include "parameters.slang"
// See compose.slang for copyright and other information.
// Pixels in input coord. space
vec2 eff_input_res() {
if (param.CENTER_CROP > 0.5) {
return param.InputSize.xy -
vec2(param.OS_CROP_LEFT + param.OS_CROP_RIGHT,
param.OS_CROP_TOP + param.OS_CROP_BOTTOM);
}
return param.InputSize.xy -
2.0 * vec2(min(param.OS_CROP_LEFT, param.OS_CROP_RIGHT),
min(param.OS_CROP_TOP, param.OS_CROP_BOTTOM));
}
// Output to input scaling, in unit coordinate systems.
vec2 scale_o2i() {
const vec2 eff_input_res = eff_input_res();
const vec2 eff_aspect =
vec2(eff_input_res.x, param.FORCE_ASPECT_RATIO > 0.5
? eff_input_res.y / param.InputSize.y *
param.InputSize.x * param.ASPECT_V /
param.ASPECT_H
: eff_input_res.y);
if (param.FinalViewportSize.x / eff_aspect.x <
param.FinalViewportSize.y / eff_aspect.y) {
// Scale will be limited by width. Calc x scale, then derive y scale
// using aspect ratio.
const float scale_x =
param.FORCE_INTEGER_SCALING > 0.5
? floor(param.FinalViewportSize.x / eff_input_res.x)
: param.FinalViewportSize.x / eff_input_res.x;
const float scale_y = scale_x * eff_input_res.x * eff_aspect.y /
(eff_input_res.y * eff_aspect.x);
return param.FinalViewportSize.xy * param.InputSize.zw /
vec2(scale_x, scale_y);
} else {
// Scale will be limited by height.
const float scale_y =
param.FORCE_INTEGER_SCALING > 0.5
? floor(param.FinalViewportSize.y / eff_input_res.y)
: param.FinalViewportSize.y / eff_input_res.y;
const float scale_x = scale_y * eff_input_res.y * eff_aspect.x /
(eff_input_res.x * eff_aspect.y);
return param.FinalViewportSize.xy * param.InputSize.zw /
vec2(scale_x, scale_y);
}
}
// In unit space (output to input)
// coord_in_input_space = o2i(coord_in_output_space)
// This is used to sample from the input texture in the output pass.
vec2 o2i(vec2 x) {
const vec2 center_in =
param.CENTER_CROP > 0.5
? 0.5 * param.InputSize.zw *
vec2(param.OS_CROP_LEFT + param.InputSize.x -
param.OS_CROP_RIGHT,
param.OS_CROP_TOP + param.InputSize.y -
param.OS_CROP_BOTTOM)
: vec2(0.49999);
return (x - 0.49999) * scale_o2i() + center_in;
}