clip: Use the boxes-intersection routine for computing the clip polygon

If we have more than a single box, run the boxes intersection as a
post-processing step on the clip polygon, as it should be faster than
doing it inline.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 18 insertions, 8 deletions

diff --git a/src/cairo-clip-polygon.c b/src/cairo-clip-polygon.c
index 0e1968d05..db0298f6e 100644
--- a/src/cairo-clip-polygon.c
+++ b/src/cairo-clip-polygon.c
@@ -88,15 +88,23 @@ _cairo_clip_get_polygon (const cairo_clip_t *clip,
     if (! can_convert_to_polygon (clip))
 	return CAIRO_INT_STATUS_UNSUPPORTED;
 
-    _cairo_polygon_init_with_clip (polygon, clip);
+    if (clip->num_boxes < 2)
+	_cairo_polygon_init_with_clip (polygon, clip);
+    else
+	_cairo_polygon_init_with_clip (polygon, NULL);
 
     clip_path = clip->path;
     status = _cairo_path_fixed_fill_to_polygon (&clip_path->path,
 						clip_path->tolerance,
 						polygon);
-    if (unlikely (status)) {
-	_cairo_polygon_fini (polygon);
-	return status;
+    if (unlikely (status))
+	goto err;
+
+    if (clip->num_boxes > 1) {
+	status = _cairo_polygon_intersect_with_boxes (polygon, fill_rule,
+						      clip->boxes, clip->num_boxes);
+	if (unlikely (status))
+	    goto err;
     }
 
     polygon->limits = NULL;
@@ -115,15 +123,17 @@ _cairo_clip_get_polygon (const cairo_clip_t *clip,
 		status = _cairo_polygon_intersect (polygon, *fill_rule,
 						   &next, clip_path->fill_rule);
 	_cairo_polygon_fini (&next);
-	if (unlikely (status)) {
-	    _cairo_polygon_fini (polygon);
-	    return status;
-	}
+	if (unlikely (status))
+	    goto err;
 
 	*fill_rule = CAIRO_FILL_RULE_WINDING;
     }
 
     return CAIRO_STATUS_SUCCESS;
+
+err:
+    _cairo_polygon_fini (polygon);
+    return status;
 }
 
 cairo_bool_t