From 09589e20e14476df609581027d14628f52091e71 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed, 10 Dec 2008 23:45:44 +0000
Subject: [PATCH] [clip] Intersect to region extents.

When querying the intersection of a rectangle with the clip region, the
result only depends upon the region extents so we do not need to perform
an expensive region-region intersection computation.
---
 src/cairo-clip.c             | 18 +++++-------------
 src/cairo-surface-fallback.c |  1 -
 2 files changed, 5 insertions(+), 14 deletions(-)

diff --git a/src/cairo-clip.c b/src/cairo-clip.c
index cd423a443..c679e9fb2 100644
--- a/src/cairo-clip.c
+++ b/src/cairo-clip.c
@@ -179,20 +179,12 @@ _cairo_clip_intersect_to_rectangle (cairo_clip_t            *clip,
     }
 
     if (clip->has_region) {
-	cairo_region_t intersection;
+	cairo_rectangle_int_t extents;
 
-	_cairo_region_init_rect (&intersection, rectangle);
-
-	status = _cairo_region_intersect (&intersection, &clip->region,
-					  &intersection);
-
-	if (!status)
-	    _cairo_region_get_extents (&intersection, rectangle);
-
-        _cairo_region_fini (&intersection);
-
-        if (unlikely (status))
-            return status;
+	_cairo_region_get_extents (&clip->region, &extents);
+	is_empty = _cairo_rectangle_intersect (rectangle, &extents);
+	if (is_empty)
+	    return CAIRO_STATUS_SUCCESS;
     }
 
     if (clip->surface)
diff --git a/src/cairo-surface-fallback.c b/src/cairo-surface-fallback.c
index f21c6ea45..b48435df7 100644
--- a/src/cairo-surface-fallback.c
+++ b/src/cairo-surface-fallback.c
@@ -578,7 +578,6 @@ _clip_and_composite_trapezoids (const cairo_pattern_t *src,
 
             has_clear_region = TRUE;
             status = _cairo_clip_intersect_to_region (clip, &clear_region);
-
             if (unlikely (status))
                 goto out;