0,0 → 1,152 |
/* |
SDL - Simple DirectMedia Layer |
Copyright (C) 1997-2004 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: SDL_endian.h,v 1.6 2004/01/04 16:49:07 slouken Exp $"; |
#endif |
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/* Functions for reading and writing endian-specific values */ |
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#ifndef _SDL_endian_h |
#define _SDL_endian_h |
|
/* These functions read and write data of the specified endianness, |
dynamically translating to the host machine endianness. |
|
e.g.: If you want to read a 16 bit value on big-endian machine from |
an open file containing little endian values, you would use: |
value = SDL_ReadLE16(rp); |
Note that the read/write functions use SDL_RWops pointers |
instead of FILE pointers. This allows you to read and write |
endian values from large chunks of memory as well as files |
and other data sources. |
*/ |
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#include <stdio.h> |
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#include "SDL_types.h" |
#include "SDL_rwops.h" |
#include "SDL_byteorder.h" |
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#include "begin_code.h" |
/* Set up for C function definitions, even when using C++ */ |
#ifdef __cplusplus |
extern "C" { |
#endif |
|
/* The macros used to swap values */ |
/* Try to use superfast macros on systems that support them */ |
#ifndef __MENUETOS__ |
#ifdef linux |
#include <asm/byteorder.h> |
#ifdef __arch__swab16 |
#define SDL_Swap16 __arch__swab16 |
#endif |
#ifdef __arch__swab32 |
#define SDL_Swap32 __arch__swab32 |
#endif |
#endif /* linux */ |
#endif |
|
/* Use inline functions for compilers that support them, and static |
functions for those that do not. Because these functions become |
static for compilers that do not support inline functions, this |
header should only be included in files that actually use them. |
*/ |
#ifndef SDL_Swap16 |
static __inline__ Uint16 SDL_Swap16(Uint16 D) { |
return((D<<8)|(D>>8)); |
} |
#endif |
#ifndef SDL_Swap32 |
static __inline__ Uint32 SDL_Swap32(Uint32 D) { |
return((D<<24)|((D<<8)&0x00FF0000)|((D>>8)&0x0000FF00)|(D>>24)); |
} |
#endif |
#ifdef SDL_HAS_64BIT_TYPE |
#ifndef SDL_Swap64 |
static __inline__ Uint64 SDL_Swap64(Uint64 val) { |
Uint32 hi, lo; |
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/* Separate into high and low 32-bit values and swap them */ |
lo = (Uint32)(val&0xFFFFFFFF); |
val >>= 32; |
hi = (Uint32)(val&0xFFFFFFFF); |
val = SDL_Swap32(lo); |
val <<= 32; |
val |= SDL_Swap32(hi); |
return(val); |
} |
#endif |
#else |
#ifndef SDL_Swap64 |
/* This is mainly to keep compilers from complaining in SDL code. |
If there is no real 64-bit datatype, then compilers will complain about |
the fake 64-bit datatype that SDL provides when it compiles user code. |
*/ |
#define SDL_Swap64(X) (X) |
#endif |
#endif /* SDL_HAS_64BIT_TYPE */ |
|
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/* Byteswap item from the specified endianness to the native endianness */ |
#if SDL_BYTEORDER == SDL_LIL_ENDIAN |
#define SDL_SwapLE16(X) (X) |
#define SDL_SwapLE32(X) (X) |
#define SDL_SwapLE64(X) (X) |
#define SDL_SwapBE16(X) SDL_Swap16(X) |
#define SDL_SwapBE32(X) SDL_Swap32(X) |
#define SDL_SwapBE64(X) SDL_Swap64(X) |
#else |
#define SDL_SwapLE16(X) SDL_Swap16(X) |
#define SDL_SwapLE32(X) SDL_Swap32(X) |
#define SDL_SwapLE64(X) SDL_Swap64(X) |
#define SDL_SwapBE16(X) (X) |
#define SDL_SwapBE32(X) (X) |
#define SDL_SwapBE64(X) (X) |
#endif |
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/* Read an item of the specified endianness and return in native format */ |
extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops *src); |
extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops *src); |
extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops *src); |
extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops *src); |
extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops *src); |
extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops *src); |
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/* Write an item of native format to the specified endianness */ |
extern DECLSPEC int SDLCALL SDL_WriteLE16(SDL_RWops *dst, Uint16 value); |
extern DECLSPEC int SDLCALL SDL_WriteBE16(SDL_RWops *dst, Uint16 value); |
extern DECLSPEC int SDLCALL SDL_WriteLE32(SDL_RWops *dst, Uint32 value); |
extern DECLSPEC int SDLCALL SDL_WriteBE32(SDL_RWops *dst, Uint32 value); |
extern DECLSPEC int SDLCALL SDL_WriteLE64(SDL_RWops *dst, Uint64 value); |
extern DECLSPEC int SDLCALL SDL_WriteBE64(SDL_RWops *dst, Uint64 value); |
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/* Ends C function definitions when using C++ */ |
#ifdef __cplusplus |
} |
#endif |
#include "close_code.h" |
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#endif /* _SDL_endian_h */ |