Date: Sat, 27 Nov 2004 13:35:43 +0100
authorSam Lantinga <slouken@libsdl.org>
Tue, 30 Nov 2004 14:28:20 +0000
changeset 997 3bf4103b2b89
parent 996 54bb19455081
child 998 0e6627072f7a
Date: Sat, 27 Nov 2004 13:35:43 +0100 From: "Martin Bickel" Subject: [SDL] Patch: fixing uninitilized palette while running Valgrind over my application I found the following problem in SDL: The function MapNto1 allocates SDL_Color colors[256] but does not initialize it. SDL_DitherColors is then called which initialized the r, g and b component, but not the 'unused' component of each color. When Map1to1 is called from MapNto1, it runs a memcmp on the colors, which also evaluates the unused component and therefor returns differences much more often than necessary. So the 'unused' component of SDL_Color should be initialized. This patch does this by calling memset for the whole array in MapNto1 .
src/video/SDL_pixels.c
--- a/src/video/SDL_pixels.c	Tue Nov 30 13:04:22 2004 +0000
+++ b/src/video/SDL_pixels.c	Tue Nov 30 14:28:20 2004 +0000
@@ -494,6 +494,10 @@
 	/* Generate a 256 color dither palette */
 	SDL_Palette dithered;
 	SDL_Color colors[256];
+	
+	/* SDL_DitherColors does not initialize the 'unused' component of colors,
+	   but Map1to1 compares it against dst, so we should initialize it. */  
+	memset(colors, 0, sizeof(colors));
 
 	dithered.ncolors = 256;
 	SDL_DitherColors(colors, 8);