Mercurial > sdl-ios-xcode
view docs/man3/SDL_CreateRGBSurfaceFrom.3 @ 997:3bf4103b2b89
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 .
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Tue, 30 Nov 2004 14:28:20 +0000 |
| parents | e5bc29de3f0a |
| children | 546f7c1eb755 |
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.TH "SDL_CreateRGBSurfaceFrom" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" .SH "NAME" SDL_CreateRGBSurfaceFrom\- Create an SDL_Surface from pixel data .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBSDL_Surface *\fBSDL_CreateRGBSurfaceFrom\fP\fR(\fBvoid *pixels, int width, int height, int depth, int pitch, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask\fR); .SH "DESCRIPTION" .PP Creates an SDL_Surface from the provided pixel data\&. .PP The data stored in \fBpixels\fR is assumed to be of the \fBdepth\fR specified in the parameter list\&. The pixel data is not copied into the \fBSDL_Surface\fR structure so it should not be freed until the surface has been freed with a called to \fISDL_FreeSurface\fR\&. \fBpitch\fR is the length of each scanline in bytes\&. .PP See \fI\fBSDL_CreateRGBSurface\fP\fR for a more detailed description of the other parameters\&. .SH "RETURN VALUE" .PP Returns the created surface, or \fBNULL\fR upon error\&. .SH "SEE ALSO" .PP \fI\fBSDL_CreateRGBSurface\fP\fR, \fI\fBSDL_FreeSurface\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01