[gtk+/wip/baedert/gl: 1/2] snapshot: Directly clip color nodes

[Timm Bäder <baedert src gnome org>]

commit 1618b1275c9fe7809cefa3587099995feea5f43a
Author: Timm Bäder <mail baedert org>
Date:   Tue Dec 12 20:33:53 2017 +0100

    snapshot: Directly clip color nodes
    
    Clipping a color node is trivial so we do it here directly since that
    might later save the entire clip node as well as freeing the fragment
    shaders from coloring lots of pixels that will be clipped away.

 gtk/gtksnapshot.c |   16 ++++++++++++++++
 1 files changed, 16 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtksnapshot.c b/gtk/gtksnapshot.c
index d632ef6..c3f9295 100644
--- a/gtk/gtksnapshot.c
+++ b/gtk/gtksnapshot.c
@@ -1345,7 +1345,23 @@ gtk_snapshot_append_color (GtkSnapshot           *snapshot,
   g_return_if_fail (color != NULL);
   g_return_if_fail (bounds != NULL);
 
+
   graphene_rect_offset_r (bounds, current_state->translate_x, current_state->translate_y, &real_bounds);
+
+  /* Color nodes are trivially "clippable" so we do it now */
+  if (current_state->clip_region)
+    {
+      cairo_rectangle_int_t clip_extents;
+      cairo_region_get_extents (current_state->clip_region, &clip_extents);
+      graphene_rect_intersection (&GRAPHENE_RECT_INIT (
+                                    clip_extents.x,
+                                    clip_extents.y,
+                                    clip_extents.width,
+                                    clip_extents.height
+                                  ),
+                                  &real_bounds, &real_bounds);
+    }
+
   node = gsk_color_node_new (color, &real_bounds);
 
   if (name && snapshot->record_names)