Fix UV shadow drawing not respecting 'UV Opacity' setting

reapply changes from 30cbbccc6002 / D7764 that were only meant for
master. Sorry for the noise!

1 files changed, 8 insertions, 0 deletions

diff --git a/source/blender/editors/uvedit/uvedit_draw.c b/source/blender/editors/uvedit/uvedit_draw.c
index dcc9082d3dd..f8cef95c776 100644
--- a/source/blender/editors/uvedit/uvedit_draw.c
+++ b/source/blender/editors/uvedit/uvedit_draw.c
@@ -223,6 +223,7 @@ static void draw_uvs_shadow(SpaceImage *sima,
 {
   Object *ob_eval = DEG_get_evaluated_object(depsgraph, obedit);
   Mesh *me = ob_eval->data;
+  const float overlay_alpha = sima->uv_opacity;
   float col[4];
   UI_GetThemeColor4fv(TH_UV_SHADOW, col);
 
@@ -235,7 +236,11 @@ static void draw_uvs_shadow(SpaceImage *sima,
       GPU_line_smooth(true);
       GPU_blend(true);
     }
+    else if (overlay_alpha < 1.0f) {
+      GPU_blend(true);
+    }
 
+    col[3] = overlay_alpha;
     GPU_batch_program_set_builtin(edges, GPU_SHADER_2D_UV_UNIFORM_COLOR);
     GPU_batch_uniform_4fv(edges, "color", col);
     GPU_batch_draw(edges);
@@ -244,6 +249,9 @@ static void draw_uvs_shadow(SpaceImage *sima,
       GPU_line_smooth(false);
       GPU_blend(false);
     }
+    else if (overlay_alpha < 1.0f) {
+      GPU_blend(false);
+    }
   }
 }