From: Grigori Goronzy <greg@blackbox>
Date: Fri, 2 Oct 2009 02:12:03 +0000 (+0200)
Subject: Fix alpha calculation in some cases
X-Git-Tag: 0.9.9~30
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=caa7eb70c4d5c71bfdb879e95285bdbe680a0458;p=libass

Fix alpha calculation in some cases

Picked up from XBMC svn.  This should especially fix MPlayer's direct3d
video output (untested).
---

diff --git a/libass/ass_parse.c b/libass/ass_parse.c
index 535e16f..8c43d0b 100644
--- a/libass/ass_parse.c
+++ b/libass/ass_parse.c
@@ -163,8 +163,8 @@ static void change_color(uint32_t *var, uint32_t new, double pwr)
 inline void change_alpha(uint32_t *var, uint32_t new, double pwr)
 {
     *var =
-        (_r(*var) << 24) + (_g(*var) << 16) + (_b(*var) << 8) +
-        (_a(*var) * (1 - pwr) + _a(new) * pwr);
+        (uint32_t) (_r(*var) << 24) + (_g(*var) << 16) + (_b(*var) << 8) +
+        (uint32_t) (_a(*var) * (1 - pwr) + _a(new) * pwr);
 }
 
 /**