[PATCH libXrender] Fix alpha premultiplication in XRenderParseColor.
Emanuele Giaquinta
emanuele.giaquinta at gmail.com
Mon Jan 2 11:58:15 PST 2012
Due to C arithmetic conversion rules we must use an unsigned constant (or a
cast) to perform the multiplication using unsigned arithmetic.
---
src/Color.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/src/Color.c b/src/Color.c
index 9c76e58..23ef800 100644
--- a/src/Color.c
+++ b/src/Color.c
@@ -85,8 +85,8 @@ XRenderParseColor(Display *dpy, char *spec, XRenderColor *def)
def->blue = coreColor.blue;
def->alpha = 0xffff;
}
- def->red = (def->red * def->alpha) / 65535;
- def->green = (def->green * def->alpha) / 65535;
- def->blue = (def->blue * def->alpha) / 65535;
+ def->red = (def->red * def->alpha) / 0xffffU;
+ def->green = (def->green * def->alpha) / 0xffffU;
+ def->blue = (def->blue * def->alpha) / 0xffffU;
return 1;
}
--
1.7.7.3
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