Mercurial > sdl-ios-xcode
view src/endian/SDL_endian.c @ 688:c0522010bb6d
Date: Tue, 12 Aug 2003 14:26:19 +0200 (MEST)
From: "Mattias Engdeg?rd"
Subject: bug in SDL_GetRGB/GetRGBA
There's an embarrassing bug in GetRGB/GetRGBA which apparently has been there
for years. It incorrectly converts colours with < 8 bits/channel.
It came to my attention today in #sdl.
What it does now is (for each channel):
rv = (pixel & fmt->Rmask) >> fmt->Rshift;
*r = (rv << fmt->Rloss) + (rv >> (8 - fmt->Rloss));
which is wrong; the last line should be
*r = (rv << fmt->Rloss) + (rv >> (8 - (fmt->Rloss << 1)));
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Tue, 12 Aug 2003 15:17:20 +0000 |
parents | f6ffac90895c |
children | b8d311d90021 |
line wrap: on
line source
/* SDL - Simple DirectMedia Layer Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this library; if not, write to the Free Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Sam Lantinga slouken@libsdl.org */ #ifdef SAVE_RCSID static char rcsid = "@(#) $Id$"; #endif /* Functions for dynamically reading and writing endian-specific values */ #include "SDL_endian.h" Uint16 SDL_ReadLE16 (SDL_RWops *src) { Uint16 value; SDL_RWread(src, &value, (sizeof value), 1); return(SDL_SwapLE16(value)); } Uint16 SDL_ReadBE16 (SDL_RWops *src) { Uint16 value; SDL_RWread(src, &value, (sizeof value), 1); return(SDL_SwapBE16(value)); } Uint32 SDL_ReadLE32 (SDL_RWops *src) { Uint32 value; SDL_RWread(src, &value, (sizeof value), 1); return(SDL_SwapLE32(value)); } Uint32 SDL_ReadBE32 (SDL_RWops *src) { Uint32 value; SDL_RWread(src, &value, (sizeof value), 1); return(SDL_SwapBE32(value)); } Uint64 SDL_ReadLE64 (SDL_RWops *src) { Uint64 value; SDL_RWread(src, &value, (sizeof value), 1); return(SDL_SwapLE64(value)); } Uint64 SDL_ReadBE64 (SDL_RWops *src) { Uint64 value; SDL_RWread(src, &value, (sizeof value), 1); return(SDL_SwapBE64(value)); } int SDL_WriteLE16 (SDL_RWops *dst, Uint16 value) { value = SDL_SwapLE16(value); return(SDL_RWwrite(dst, &value, (sizeof value), 1)); } int SDL_WriteBE16 (SDL_RWops *dst, Uint16 value) { value = SDL_SwapBE16(value); return(SDL_RWwrite(dst, &value, (sizeof value), 1)); } int SDL_WriteLE32 (SDL_RWops *dst, Uint32 value) { value = SDL_SwapLE32(value); return(SDL_RWwrite(dst, &value, (sizeof value), 1)); } int SDL_WriteBE32 (SDL_RWops *dst, Uint32 value) { value = SDL_SwapBE32(value); return(SDL_RWwrite(dst, &value, (sizeof value), 1)); } int SDL_WriteLE64 (SDL_RWops *dst, Uint64 value) { value = SDL_SwapLE64(value); return(SDL_RWwrite(dst, &value, (sizeof value), 1)); } int SDL_WriteBE64 (SDL_RWops *dst, Uint64 value) { value = SDL_SwapBE64(value); return(SDL_RWwrite(dst, &value, (sizeof value), 1)); }