1 files changed, 44 insertions, 0 deletions
diff --git a/gsk/gl/resources/inset_shadow.glsl b/gsk/gl/resources/inset_shadow.glsl
new file mode 100644
index 0000000000..f052a08580
--- /dev/null
+++ b/gsk/gl/resources/inset_shadow.glsl
@@ -0,0 +1,44 @@
+// VERTEX_SHADER:
+// inset_shadow.glsl
+
+uniform float u_spread;
+uniform vec2 u_offset;
+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, vec4(u_spread));
+
+  gsk_rounded_rect_offset(inside, u_offset);
+
+  gsk_rounded_rect_transform(outside, u_modelview);
+  gsk_rounded_rect_transform(inside, u_modelview);
+
+  gsk_rounded_rect_encode(outside, transformed_outside_outline);
+  gsk_rounded_rect_encode(inside, transformed_inside_outline);
+}
+
+// FRAGMENT_SHADER:
+// inset_shadow.glsl
+
+_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 alpha = clamp(gsk_rounded_rect_coverage(gsk_decode_rect(transformed_outside_outline), frag) -
+                      gsk_rounded_rect_coverage(gsk_decode_rect(transformed_inside_outline), frag),
+                      0.0, 1.0);
+
+  gskSetScaledOutputColor(final_color, alpha);
+}