[mutter] clutter/stage-cogl: Don't loop through region rects twice

[Jonas Ådahl <jadahl src gnome org>]

commit 434845dbe5ae1609daad256a6285f1b9af5f0bd4
Author: Jonas Dreßler <verdre v0yd nl>
Date:   Wed May 13 11:02:56 2020 +0200

    clutter/stage-cogl: Don't loop through region rects twice
    
    There's no reason for using two loops to fill the rects array in
    offset_scale_and_clamp_region(), we can do that using only one loop.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1113

 clutter/clutter/cogl/clutter-stage-cogl.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)
---
diff --git a/clutter/clutter/cogl/clutter-stage-cogl.c b/clutter/clutter/cogl/clutter-stage-cogl.c
index fbd1bdf3f..8bc0aba3e 100644
--- a/clutter/clutter/cogl/clutter-stage-cogl.c
+++ b/clutter/clutter/cogl/clutter-stage-cogl.c
@@ -450,17 +450,17 @@ offset_scale_and_clamp_region (const cairo_region_t *region,
   else
     rects = freeme = g_new (cairo_rectangle_int_t, n_rects);
 
-  for (i = 0; i < n_rects; i++)
-    cairo_region_get_rectangle (region, i, &rects[i]);
-
   for (i = 0; i < n_rects; i++)
     {
+      cairo_rectangle_int_t *rect = &rects[i];
       graphene_rect_t tmp;
 
-      _clutter_util_rect_from_rectangle (&rects[i], &tmp);
+      cairo_region_get_rectangle (region, i, rect);
+
+      _clutter_util_rect_from_rectangle (rect, &tmp);
       graphene_rect_offset (&tmp, offset_x, offset_y);
       graphene_rect_scale (&tmp, scale, scale, &tmp);
-      _clutter_util_rectangle_int_extents (&tmp, &rects[i]);
+      _clutter_util_rectangle_int_extents (&tmp, rect);
     }
 
   return cairo_region_create_rectangles (rects, n_rects);