[Pixman] [PATCH pixman 06/15] pixman-filter: reduced number of samples in Simpson's integration

Bill Spitzak spitzak at gmail.com
Wed Apr 29 12:04:54 PDT 2015


With the cubic fix this is plenty accurate enough, far in excess of the pixman
fixed-point error limit. Likely even 16 samples is too many.
---
 pixman/pixman-filter.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pixman/pixman-filter.c b/pixman/pixman-filter.c
index 7c1da0d..4aafa51 100644
--- a/pixman/pixman-filter.c
+++ b/pixman/pixman-filter.c
@@ -190,7 +190,7 @@ integral (pixman_kernel_t reconstruct, double x1,
     else
     {
 	/* Integration via Simpson's rule */
-#define N_SEGMENTS 128
+#define N_SEGMENTS 16
 #define SAMPLE(a1, a2)							\
 	(filters[reconstruct].func ((a1)) * filters[sample].func ((a2) / scale))
 	
-- 
1.7.9.5



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