[ros-diffs] [gadamopoulos] 75688: [UXTHEME] -Ignore the alpha channel so that TrasnparentBlt will be used when a bitmap has an alpha channel but no pixel has alpha transparency. CORE-13464

[gadamopoulos]

Author: gadamopoulos
Date: Sun Aug 27 10:55:30 2017
New Revision: 75688

URL: http://svn.reactos.org/svn/reactos?rev=75688&view=rev
Log:
[UXTHEME] -Ignore the alpha channel so that TrasnparentBlt will be used when a 
bitmap has an alpha channel but no pixel has alpha transparency. CORE-13464

Modified:
    trunk/reactos/dll/win32/uxtheme/msstyles.c

Modified: trunk/reactos/dll/win32/uxtheme/msstyles.c
URL: 
http://svn.reactos.org/svn/reactos/trunk/reactos/dll/win32/uxtheme/msstyles.c?rev=75688&r1=75687&r2=75688&view=diff
==============================================================================
--- trunk/reactos/dll/win32/uxtheme/msstyles.c  [iso-8859-1] (original)
+++ trunk/reactos/dll/win32/uxtheme/msstyles.c  [iso-8859-1] Sun Aug 27 
10:55:30 2017
@@ -875,7 +875,6 @@
         /* nothing to do */
         return TRUE;
 
-    *hasAlpha = TRUE;
     p = dib.dsBm.bmBits;
     n = dib.dsBmih.biHeight * dib.dsBmih.biWidth;
     /* AlphaBlend() wants premultiplied alpha, so do that now */
@@ -886,6 +885,9 @@
         p[1] = (p[1] * a) >> 8;
         p[2] = (p[2] * a) >> 8;
         p += 4;
+
+        if (a != 256)
+            *hasAlpha = TRUE;
     }
 
     return TRUE;