gtk/gsk/vulkan/resources/rounded-rect.glsl
Benjamin Otte 87c9503293 vulkan: Rewrite AA shaders to respect scale
The border and color shaders - the ones that do AA - now multiply their
coordinates by the scale factor, which gives them better rounding
capabilities.

This in particular improves the case where they are used in fractional
scaling situations, where the scale is defined at the root element.
2023-06-04 19:42:01 +02:00

66 lines
2.1 KiB
GLSL

#ifndef _ROUNDED_RECT_
#define _ROUNDED_RECT_
#include "ellipse.glsl"
#include "rect.glsl"
struct RoundedRect
{
vec4 bounds;
vec4 corner_widths;
vec4 corner_heights;
};
float
rounded_rect_distance (RoundedRect r, vec2 p)
{
Rect bounds = Rect(vec4(r.bounds));
float bounds_distance = rect_distance (bounds, p);
Ellipse tl = Ellipse (r.bounds.xy + vec2( r.corner_widths.x, r.corner_heights.x),
vec2(r.corner_widths.x, r.corner_heights.x));
Ellipse tr = Ellipse (r.bounds.zy + vec2(-r.corner_widths.y, r.corner_heights.y),
vec2(r.corner_widths.y, r.corner_heights.y));
Ellipse br = Ellipse (r.bounds.zw + vec2(-r.corner_widths.z, -r.corner_heights.z),
vec2(r.corner_widths.z, r.corner_heights.z));
Ellipse bl = Ellipse (r.bounds.xw + vec2( r.corner_widths.w, -r.corner_heights.w),
vec2(r.corner_widths.w, r.corner_heights.w));
vec4 distances = vec4(ellipse_distance (tl, p),
ellipse_distance (tr, p),
ellipse_distance (br, p),
ellipse_distance (bl, p));
bvec4 is_out = bvec4(p.x < tl.center.x && p.y < tl.center.y,
p.x > tr.center.x && p.y < tr.center.y,
p.x > br.center.x && p.y > br.center.y,
p.x < bl.center.x && p.y > bl.center.y);
distances = mix (vec4(bounds_distance), distances, is_out);
vec2 max2 = max (distances.xy, distances.zw);
return max (max2.x, max2.y);
}
RoundedRect
rounded_rect_scale (RoundedRect r, vec2 scale)
{
r.bounds *= scale.xyxy;
r.corner_widths *= scale.xxxx;
r.corner_heights *= scale.yyyy;
return r;
}
RoundedRect
rounded_rect_shrink (RoundedRect r, vec4 amount)
{
vec4 new_bounds = r.bounds + vec4(1.0,1.0,-1.0,-1.0) * amount.wxyz;
vec4 new_widths = max (r.corner_widths - sign (r.corner_widths) * amount.wyyw, 0.0);
vec4 new_heights = max (r.corner_heights - sign (r.corner_heights) * amount.xxzz, 0.0);
return RoundedRect (new_bounds, new_widths, new_heights);
}
#endif