gl renderer: Fix linear gradient shader color calculation

This fixes both the wrong headerbar color and the broken border color in
of the circular button in the widget-factory.

diff --git a/gsk/resources/glsl/linear_gradient.fs.glsl b/gsk/resources/glsl/linear_gradient.fs.glsl
index 2e8450753a689e98af0dc2a2dce8ebd6afcb51b0..0b1f1cc0c17ede4354f93aa0c1149ca82d613861 100644 (file)
--- a/gsk/resources/glsl/linear_gradient.fs.glsl
+++ b/gsk/resources/glsl/linear_gradient.fs.glsl
@@ -34,7 +34,7 @@ void main() {
   for (int i = 1; i < u_num_color_stops; i ++) {
     if (offset >= u_color_offsets[i - 1])  {
       float o = (offset - u_color_offsets[i - 1]) / (u_color_offsets[i] - u_color_offsets[i - 1]);
-      color = mix(u_color_stops[i - 1], u_color_stops[i], o);
+      color = mix(u_color_stops[i - 1], u_color_stops[i], clamp(o, 0.0, 1.0));
     }
   }