gl renderer: Render unblurred outset shadows differently

We don't need to draw anything to a texure for those.

1 files changed, 25 insertions, 0 deletions

diff --git a/gsk/resources/glsl/unblurred_outset_shadow.fs.glsl b/gsk/resources/glsl/unblurred_outset_shadow.fs.glsl
new file mode 100644
index 0000000000..1ae48ecb49
--- /dev/null
+++ b/gsk/resources/glsl/unblurred_outset_shadow.fs.glsl
@@ -0,0 +1,25 @@
+uniform float u_spread;
+uniform vec4 u_color;
+uniform vec2 u_offset;
+uniform vec4 u_outline;
+uniform vec4 u_corner_widths;
+uniform vec4 u_corner_heights;
+
+
+void main() {
+  vec4 f = gl_FragCoord;
+
+  f.x += u_viewport.x;
+  f.y = (u_viewport.y + u_viewport.w) - f.y;
+
+  RoundedRect outline = RoundedRect(vec4(u_outline.xy, u_outline.xy + u_outline.zw),
+                                    u_corner_widths, u_corner_heights);
+  RoundedRect inside = rounded_rect_shrink(outline, vec4(u_spread));
+
+  vec2 offset = vec2(u_offset.x, - u_offset.y);
+  vec4 color = vec4(u_color.rgb * u_color.a, u_color.a);
+  color = color * clamp (rounded_rect_coverage (outline, f.xy - offset) -
+                         rounded_rect_coverage (inside, f.xy),
+                         0.0, 1.0);
+  setOutputColor(color * u_alpha);
+}