gtk/gsk/gpu/shaders/gskgpuborder.glsl
Benjamin Otte 3efe1bef93 gpu: Add a border shader
Pretty much a copy of the Vulkan border shader.

A notable change is that the input arguments are changed, because GL
gets confused if you put a mat4 at the end.
2024-01-07 07:22:50 +01:00

85 lines
1.7 KiB
GLSL

#include "common.glsl"
PASS(0) vec2 _pos;
PASS_FLAT(1) vec4 _color;
PASS_FLAT(2) RoundedRect _outside;
PASS_FLAT(5) RoundedRect _inside;
#ifdef GSK_VERTEX_SHADER
IN(0) mat4 in_border_colors;
IN(4) mat3x4 in_outline;
IN(7) vec4 in_border_widths;
vec4
compute_color (void)
{
uint triangle_index = uint (GSK_VERTEX_INDEX) / 3u;
uint index;
switch (triangle_index)
{
case 2u * SLICE_TOP_LEFT + 1u:
case 2u * SLICE_TOP:
case 2u * SLICE_TOP + 1u:
case 2u * SLICE_TOP_RIGHT:
index = TOP;
break;
case 2u * SLICE_TOP_RIGHT + 1u:
case 2u * SLICE_RIGHT:
case 2u * SLICE_RIGHT + 1u:
case 2u * SLICE_BOTTOM_RIGHT:
index = RIGHT;
break;
case 2u * SLICE_BOTTOM_RIGHT + 1u:
case 2u * SLICE_BOTTOM:
case 2u * SLICE_BOTTOM + 1u:
case 2u * SLICE_BOTTOM_LEFT:
index = BOTTOM;
break;
case 2u * SLICE_BOTTOM_LEFT + 1u:
case 2u * SLICE_LEFT:
case 2u * SLICE_LEFT + 1u:
case 2u * SLICE_TOP_LEFT:
index = LEFT;
break;
}
return color_premultiply (in_border_colors[index]);
}
void
run (out vec2 pos)
{
vec4 border_widths = in_border_widths * push.scale.yxyx;
RoundedRect outside = rounded_rect_from_gsk (in_outline);
RoundedRect inside = rounded_rect_shrink (outside, border_widths);
pos = border_get_position (outside, border_widths);
_pos = pos;
_color = compute_color ();
_outside = outside;
_inside = inside;
}
#endif
#ifdef GSK_FRAGMENT_SHADER
void
run (out vec4 color,
out vec2 position)
{
float alpha = clamp (rounded_rect_coverage (_outside, _pos) -
rounded_rect_coverage (_inside, _pos),
0.0, 1.0);
position = _pos;
color = _color * alpha;
}
#endif