[cairo] [PATCH pixman 10/13] pixman-filter: BOX.IMPULSE is same as IMPULSE.IMPULSE

[Bill Spitzak]

The subsampling can be ignored as all the filters are identical.
Code trying to duplicate PIXMAN_FILTER_NEAREST may generate this, so
it may pay off to have this optimization.
---
 pixman/pixman-filter.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/pixman/pixman-filter.c b/pixman/pixman-filter.c
index 78ea72d..d763138 100644
--- a/pixman/pixman-filter.c
+++ b/pixman/pixman-filter.c
@@ -230,6 +230,8 @@ filter_width (pixman_kernel_t reconstruct,
 	      pixman_kernel_t sample,
 	      double scale)
 {
+    if (reconstruct == PIXMAN_KERNEL_BOX && sample == PIXMAN_KERNEL_IMPULSE)
+	return 0;
     return ceil(scale * filters[sample].width + filters[reconstruct].width);
 }
 
-- 
1.7.9.5