Mercurial > sdl-ios-xcode
annotate include/SDL_endian.h @ 297:f6ffac90895c
Updated copyright information for 2002
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Wed, 06 Mar 2002 11:23:08 +0000 |
| parents | b8688cfdc232 |
| children | 9154ec9ca3d2 |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
|
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Updated copyright information for 2002
Sam Lantinga <slouken@libsdl.org>
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3 Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 Sam Lantinga |
| 0 | 4 |
| 5 This library is free software; you can redistribute it and/or | |
| 6 modify it under the terms of the GNU Library General Public | |
| 7 License as published by the Free Software Foundation; either | |
| 8 version 2 of the License, or (at your option) any later version. | |
| 9 | |
| 10 This library is distributed in the hope that it will be useful, | |
| 11 but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 13 Library General Public License for more details. | |
| 14 | |
| 15 You should have received a copy of the GNU Library General Public | |
| 16 License along with this library; if not, write to the Free | |
| 17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 18 | |
| 19 Sam Lantinga | |
|
251
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Updated the headers with the correct e-mail address
Sam Lantinga <slouken@libsdl.org>
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20 slouken@libsdl.org |
| 0 | 21 */ |
| 22 | |
| 23 #ifdef SAVE_RCSID | |
| 24 static char rcsid = | |
| 25 "@(#) $Id$"; | |
| 26 #endif | |
| 27 | |
| 28 /* Functions for reading and writing endian-specific values */ | |
| 29 | |
| 30 #ifndef _SDL_endian_h | |
| 31 #define _SDL_endian_h | |
| 32 | |
| 33 /* These functions read and write data of the specified endianness, | |
| 34 dynamically translating to the host machine endianness. | |
| 35 | |
| 36 e.g.: If you want to read a 16 bit value on big-endian machine from | |
| 37 an open file containing little endian values, you would use: | |
| 38 value = SDL_ReadLE16(rp); | |
| 39 Note that the read/write functions use SDL_RWops pointers | |
| 40 instead of FILE pointers. This allows you to read and write | |
| 41 endian values from large chunks of memory as well as files | |
| 42 and other data sources. | |
| 43 */ | |
| 44 | |
| 45 #include <stdio.h> | |
| 46 | |
| 47 #include "SDL_types.h" | |
| 48 #include "SDL_rwops.h" | |
| 49 #include "SDL_byteorder.h" | |
| 50 | |
| 51 #include "begin_code.h" | |
| 52 /* Set up for C function definitions, even when using C++ */ | |
| 53 #ifdef __cplusplus | |
| 54 extern "C" { | |
| 55 #endif | |
| 56 | |
| 57 /* The macros used to swap values */ | |
| 58 /* Try to use superfast macros on systems that support them */ | |
| 59 #ifdef linux | |
| 60 #include <asm/byteorder.h> | |
| 61 #ifdef __arch__swab16 | |
| 62 #define SDL_Swap16 __arch__swab16 | |
| 63 #endif | |
| 64 #ifdef __arch__swab32 | |
| 65 #define SDL_Swap32 __arch__swab32 | |
| 66 #endif | |
| 67 #endif /* linux */ | |
| 68 /* Use inline functions for compilers that support them, and static | |
| 69 functions for those that do not. Because these functions become | |
| 70 static for compilers that do not support inline functions, this | |
| 71 header should only be included in files that actually use them. | |
| 72 */ | |
| 73 #ifndef SDL_Swap16 | |
| 74 static __inline__ Uint16 SDL_Swap16(Uint16 D) { | |
| 75 return((D<<8)|(D>>8)); | |
| 76 } | |
| 77 #endif | |
| 78 #ifndef SDL_Swap32 | |
| 79 static __inline__ Uint32 SDL_Swap32(Uint32 D) { | |
| 80 return((D<<24)|((D<<8)&0x00FF0000)|((D>>8)&0x0000FF00)|(D>>24)); | |
| 81 } | |
| 82 #endif | |
| 83 #ifdef SDL_HAS_64BIT_TYPE | |
| 84 #ifndef SDL_Swap64 | |
| 85 static __inline__ Uint64 SDL_Swap64(Uint64 val) { | |
| 86 Uint32 hi, lo; | |
| 87 | |
| 88 /* Separate into high and low 32-bit values and swap them */ | |
| 89 lo = (Uint32)(val&0xFFFFFFFF); | |
| 90 val >>= 32; | |
| 91 hi = (Uint32)(val&0xFFFFFFFF); | |
| 92 val = SDL_Swap32(lo); | |
| 93 val <<= 32; | |
| 94 val |= SDL_Swap32(hi); | |
| 95 return(val); | |
| 96 } | |
| 97 #endif | |
| 98 #else | |
| 99 #ifndef SDL_Swap64 | |
| 100 /* This is mainly to keep compilers from complaining in SDL code. | |
| 101 If there is no real 64-bit datatype, then compilers will complain about | |
| 102 the fake 64-bit datatype that SDL provides when it compiles user code. | |
| 103 */ | |
| 104 #define SDL_Swap64(X) (X) | |
| 105 #endif | |
| 106 #endif /* SDL_HAS_64BIT_TYPE */ | |
| 107 | |
| 108 | |
| 109 /* Byteswap item from the specified endianness to the native endianness */ | |
| 110 #if SDL_BYTEORDER == SDL_LIL_ENDIAN | |
| 111 #define SDL_SwapLE16(X) (X) | |
| 112 #define SDL_SwapLE32(X) (X) | |
| 113 #define SDL_SwapLE64(X) (X) | |
| 114 #define SDL_SwapBE16(X) SDL_Swap16(X) | |
| 115 #define SDL_SwapBE32(X) SDL_Swap32(X) | |
| 116 #define SDL_SwapBE64(X) SDL_Swap64(X) | |
| 117 #else | |
| 118 #define SDL_SwapLE16(X) SDL_Swap16(X) | |
| 119 #define SDL_SwapLE32(X) SDL_Swap32(X) | |
| 120 #define SDL_SwapLE64(X) SDL_Swap64(X) | |
| 121 #define SDL_SwapBE16(X) (X) | |
| 122 #define SDL_SwapBE32(X) (X) | |
| 123 #define SDL_SwapBE64(X) (X) | |
| 124 #endif | |
| 125 | |
| 126 /* Read an item of the specified endianness and return in native format */ | |
| 127 extern DECLSPEC Uint16 SDL_ReadLE16(SDL_RWops *src); | |
| 128 extern DECLSPEC Uint16 SDL_ReadBE16(SDL_RWops *src); | |
| 129 extern DECLSPEC Uint32 SDL_ReadLE32(SDL_RWops *src); | |
| 130 extern DECLSPEC Uint32 SDL_ReadBE32(SDL_RWops *src); | |
| 131 extern DECLSPEC Uint64 SDL_ReadLE64(SDL_RWops *src); | |
| 132 extern DECLSPEC Uint64 SDL_ReadBE64(SDL_RWops *src); | |
| 133 | |
| 134 /* Write an item of native format to the specified endianness */ | |
| 135 extern DECLSPEC int SDL_WriteLE16(SDL_RWops *dst, Uint16 value); | |
| 136 extern DECLSPEC int SDL_WriteBE16(SDL_RWops *dst, Uint16 value); | |
| 137 extern DECLSPEC int SDL_WriteLE32(SDL_RWops *dst, Uint32 value); | |
| 138 extern DECLSPEC int SDL_WriteBE32(SDL_RWops *dst, Uint32 value); | |
| 139 extern DECLSPEC int SDL_WriteLE64(SDL_RWops *dst, Uint64 value); | |
| 140 extern DECLSPEC int SDL_WriteBE64(SDL_RWops *dst, Uint64 value); | |
| 141 | |
| 142 | |
| 143 /* Ends C function definitions when using C++ */ | |
| 144 #ifdef __cplusplus | |
| 145 } | |
| 146 #endif | |
| 147 #include "close_code.h" | |
| 148 | |
| 149 #endif /* _SDL_endian_h */ |