From: Søren Sandmann Pedersen <ssp@redhat.com>
Date: Tue, 20 Dec 2011 11:32:26 +0000 (-0500)
Subject: Fix rounding for DIV_UNc()
X-Git-Tag: pixman-0.25.2~39
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=37572455866114cbb8bb1bf3acfb1c61d200f98c;p=platform%2Fupstream%2Fpixman.git

Fix rounding for DIV_UNc()

We need to compute floor (a/b * 255 + 0.5), not floor (a / b * 255),
so add b/2 to the numerator in the DIV_UNc() macro.
---

diff --git a/pixman/pixman-combine.h.template b/pixman/pixman-combine.h.template
index 53afcd2..20f784b 100644
--- a/pixman/pixman-combine.h.template
+++ b/pixman/pixman-combine.h.template
@@ -28,7 +28,7 @@
     ((t) = (a) * (comp2_t)(b) + ONE_HALF, ((((t) >> G_SHIFT ) + (t) ) >> G_SHIFT ))
 
 #define DIV_UNc(a, b)							\
-    (((comp2_t) (a) * MASK) / (b))
+    (((comp2_t) (a) * MASK + ((b) / 2)) / (b))
 
 #define ADD_UNc(x, y, t)				     \
     ((t) = (x) + (y),					     \
diff --git a/test/blitters-test.c b/test/blitters-test.c
index fd62c67..feea308 100644
--- a/test/blitters-test.c
+++ b/test/blitters-test.c
@@ -424,6 +424,6 @@ main (int argc, const char *argv[])
     }
 
     return fuzzer_test_main("blitters", 2000000,
-			    0x3EDA4108,
+			    0xA364B5BF,
 			    test_composite, argc, argv);
 }