Learning_GTK4_tree/gsk/gl/resources/border.glsl

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2023-12-12 11:36:42 +01:00
// VERTEX_SHADER:
// border.glsl
uniform vec4 u_widths;
uniform vec4[3] u_outline_rect;
_OUT_ vec4 final_color;
_OUT_ _GSK_ROUNDED_RECT_UNIFORM_ transformed_outside_outline;
_OUT_ _GSK_ROUNDED_RECT_UNIFORM_ transformed_inside_outline;
void main() {
gl_Position = u_projection * u_modelview * vec4(aPosition, 0.0, 1.0);
final_color = gsk_scaled_premultiply(aColor, u_alpha);
GskRoundedRect outside = gsk_create_rect(u_outline_rect);
GskRoundedRect inside = gsk_rounded_rect_shrink (outside, u_widths);
gsk_rounded_rect_transform(outside, u_modelview);
gsk_rounded_rect_transform(inside, u_modelview);
gsk_rounded_rect_normalize(outside);
gsk_rounded_rect_normalize(inside);
gsk_rounded_rect_encode(outside, transformed_outside_outline);
gsk_rounded_rect_encode(inside, transformed_inside_outline);
}
// FRAGMENT_SHADER:
// border.glsl
uniform vec4[3] u_outline_rect;
_IN_ vec4 final_color;
_IN_ _GSK_ROUNDED_RECT_UNIFORM_ transformed_outside_outline;
_IN_ _GSK_ROUNDED_RECT_UNIFORM_ transformed_inside_outline;
void main() {
vec2 frag = gsk_get_frag_coord();
float outer_coverage = gsk_rounded_rect_coverage(gsk_decode_rect(transformed_outside_outline), frag);
float inner_coverage = gsk_rounded_rect_coverage(gsk_decode_rect(transformed_inside_outline), frag);
float alpha = clamp(outer_coverage - inner_coverage, 0.0, 1.0);
gskSetScaledOutputColor(final_color, alpha);
}