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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 5131 | clevermous | 1 | /* |
| 2 | SDL - Simple DirectMedia Layer |
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| 3 | Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga |
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| 4 | |||
| 5 | This library is free software; you can redistribute it and/or |
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| 6 | modify it under the terms of the GNU Library General Public |
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| 7 | License as published by the Free Software Foundation; either |
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| 8 | version 2 of the License, or (at your option) any later version. |
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| 9 | |||
| 10 | This library is distributed in the hope that it will be useful, |
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | Library General Public License for more details. |
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| 14 | |||
| 15 | You should have received a copy of the GNU Library General Public |
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| 16 | License along with this library; if not, write to the Free |
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| 17 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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| 18 | |||
| 19 | Sam Lantinga |
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| 20 | slouken@devolution.com |
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| 21 | */ |
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| 22 | |||
| 23 | #ifdef SAVE_RCSID |
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| 24 | static char rcsid = |
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| 25 | "@(#) $Id: SDL_endian.h,v 1.2 2001/04/26 16:50:17 hercules Exp $"; |
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| 26 | #endif |
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| 27 | |||
| 28 | /* Functions for reading and writing endian-specific values */ |
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| 29 | |||
| 30 | #ifndef _SDL_endian_h |
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| 31 | #define _SDL_endian_h |
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| 32 | |||
| 33 | /* These functions read and write data of the specified endianness, |
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| 34 | dynamically translating to the host machine endianness. |
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| 35 | |||
| 36 | e.g.: If you want to read a 16 bit value on big-endian machine from |
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| 37 | an open file containing little endian values, you would use: |
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| 38 | value = SDL_ReadLE16(rp); |
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| 39 | Note that the read/write functions use SDL_RWops pointers |
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| 40 | instead of FILE pointers. This allows you to read and write |
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| 41 | endian values from large chunks of memory as well as files |
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| 42 | and other data sources. |
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| 43 | */ |
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| 44 | |||
| 45 | #include |
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| 46 | |||
| 47 | #include "SDL_types.h" |
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| 48 | #include "SDL_rwops.h" |
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| 49 | #include "SDL_byteorder.h" |
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| 50 | |||
| 51 | #include "begin_code.h" |
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| 52 | /* Set up for C function definitions, even when using C++ */ |
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| 53 | #ifdef __cplusplus |
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| 54 | extern "C" { |
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| 55 | #endif |
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| 56 | |||
| 57 | /* Use inline functions for compilers that support them, and static |
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| 58 | functions for those that do not. Because these functions become |
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| 59 | static for compilers that do not support inline functions, this |
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| 60 | header should only be included in files that actually use them. |
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| 61 | */ |
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| 62 | #ifndef SDL_Swap16 |
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| 63 | static __inline__ Uint16 SDL_Swap16(Uint16 D) { |
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| 64 | return((D<<8)|(D>>8)); |
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| 65 | } |
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| 66 | #endif |
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| 67 | #ifndef SDL_Swap32 |
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| 68 | static __inline__ Uint32 SDL_Swap32(Uint32 D) { |
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| 69 | return((D<<24)|((D<<8)&0x00FF0000)|((D>>8)&0x0000FF00)|(D>>24)); |
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| 70 | } |
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| 71 | #endif |
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| 72 | #ifdef SDL_HAS_64BIT_TYPE |
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| 73 | #ifndef SDL_Swap64 |
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| 74 | static __inline__ Uint64 SDL_Swap64(Uint64 val) { |
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| 75 | Uint32 hi, lo; |
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| 76 | |||
| 77 | /* Separate into high and low 32-bit values and swap them */ |
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| 78 | lo = (Uint32)(val&0xFFFFFFFF); |
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| 79 | val >>= 32; |
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| 80 | hi = (Uint32)(val&0xFFFFFFFF); |
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| 81 | val = SDL_Swap32(lo); |
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| 82 | val <<= 32; |
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| 83 | val |= SDL_Swap32(hi); |
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| 84 | return(val); |
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| 85 | } |
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| 86 | #endif |
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| 87 | #else |
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| 88 | #ifndef SDL_Swap64 |
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| 89 | /* This is mainly to keep compilers from complaining in SDL code. |
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| 90 | If there is no real 64-bit datatype, then compilers will complain about |
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| 91 | the fake 64-bit datatype that SDL provides when it compiles user code. |
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| 92 | */ |
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| 93 | #define SDL_Swap64(X) (X) |
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| 94 | #endif |
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| 95 | #endif /* SDL_HAS_64BIT_TYPE */ |
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| 96 | |||
| 97 | |||
| 98 | /* Byteswap item from the specified endianness to the native endianness */ |
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| 99 | #if SDL_BYTEORDER == SDL_LIL_ENDIAN |
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| 100 | #define SDL_SwapLE16(X) (X) |
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| 101 | #define SDL_SwapLE32(X) (X) |
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| 102 | #define SDL_SwapLE64(X) (X) |
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| 103 | #define SDL_SwapBE16(X) SDL_Swap16(X) |
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| 104 | #define SDL_SwapBE32(X) SDL_Swap32(X) |
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| 105 | #define SDL_SwapBE64(X) SDL_Swap64(X) |
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| 106 | #else |
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| 107 | #define SDL_SwapLE16(X) SDL_Swap16(X) |
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| 108 | #define SDL_SwapLE32(X) SDL_Swap32(X) |
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| 109 | #define SDL_SwapLE64(X) SDL_Swap64(X) |
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| 110 | #define SDL_SwapBE16(X) (X) |
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| 111 | #define SDL_SwapBE32(X) (X) |
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| 112 | #define SDL_SwapBE64(X) (X) |
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| 113 | #endif |
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| 114 | |||
| 115 | /* Read an item of the specified endianness and return in native format */ |
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| 116 | extern DECLSPEC Uint16 SDL_ReadLE16(SDL_RWops *src); |
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| 117 | extern DECLSPEC Uint16 SDL_ReadBE16(SDL_RWops *src); |
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| 118 | extern DECLSPEC Uint32 SDL_ReadLE32(SDL_RWops *src); |
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| 119 | extern DECLSPEC Uint32 SDL_ReadBE32(SDL_RWops *src); |
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| 120 | extern DECLSPEC Uint64 SDL_ReadLE64(SDL_RWops *src); |
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| 121 | extern DECLSPEC Uint64 SDL_ReadBE64(SDL_RWops *src); |
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| 122 | |||
| 123 | /* Write an item of native format to the specified endianness */ |
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| 124 | extern DECLSPEC int SDL_WriteLE16(SDL_RWops *dst, Uint16 value); |
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| 125 | extern DECLSPEC int SDL_WriteBE16(SDL_RWops *dst, Uint16 value); |
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| 126 | extern DECLSPEC int SDL_WriteLE32(SDL_RWops *dst, Uint32 value); |
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| 127 | extern DECLSPEC int SDL_WriteBE32(SDL_RWops *dst, Uint32 value); |
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| 128 | extern DECLSPEC int SDL_WriteLE64(SDL_RWops *dst, Uint64 value); |
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| 129 | extern DECLSPEC int SDL_WriteBE64(SDL_RWops *dst, Uint64 value); |
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| 130 | |||
| 131 | |||
| 132 | /* Ends C function definitions when using C++ */ |
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| 133 | #ifdef __cplusplus |
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| 134 | } |
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| 135 | #endif |
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| 136 | #include "close_code.h" |
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| 137 | |||
| 138 | #endif /* _SDL_endian_h */ |