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1 /* |
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2 SDL - Simple DirectMedia Layer |
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3 Copyright (C) 1997-2009 Sam Lantinga |
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4 |
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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 Lesser General Public |
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7 License as published by the Free Software Foundation; either |
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8 version 2.1 of the License, or (at your option) any later version. |
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9 |
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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 Lesser General Public License for more details. |
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14 |
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15 You should have received a copy of the GNU Lesser General Public |
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16 License along with this library; if not, write to the Free Software |
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17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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18 |
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19 Sam Lantinga |
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20 slouken@libsdl.org |
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21 */ |
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22 |
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23 /** @file SDL_rwops.h |
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24 * This file provides a general interface for SDL to read and write |
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25 * data sources. It can easily be extended to files, memory, etc. |
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26 */ |
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27 |
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28 #ifndef _SDL_rwops_h |
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29 #define _SDL_rwops_h |
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30 |
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31 #include "SDL_stdinc.h" |
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32 #include "SDL_error.h" |
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33 |
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34 #include "begin_code.h" |
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35 /* Set up for C function definitions, even when using C++ */ |
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36 #ifdef __cplusplus |
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37 extern "C" { |
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38 #endif |
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39 |
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40 /** This is the read/write operation structure -- very basic */ |
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41 |
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42 typedef struct SDL_RWops { |
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43 /** Seek to 'offset' relative to whence, one of stdio's whence values: |
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44 * SEEK_SET, SEEK_CUR, SEEK_END |
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45 * Returns the final offset in the data source. |
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46 */ |
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47 int (SDLCALL *seek)(struct SDL_RWops *context, int offset, int whence); |
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48 |
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49 /** Read up to 'maxnum' objects each of size 'size' from the data |
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50 * source to the area pointed at by 'ptr'. |
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51 * Returns the number of objects read, or -1 if the read failed. |
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52 */ |
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53 int (SDLCALL *read)(struct SDL_RWops *context, void *ptr, int size, int maxnum); |
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54 |
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55 /** Write exactly 'num' objects each of size 'objsize' from the area |
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56 * pointed at by 'ptr' to data source. |
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57 * Returns 'num', or -1 if the write failed. |
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58 */ |
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59 int (SDLCALL *write)(struct SDL_RWops *context, const void *ptr, int size, int num); |
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60 |
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61 /** Close and free an allocated SDL_FSops structure */ |
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62 int (SDLCALL *close)(struct SDL_RWops *context); |
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63 |
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64 Uint32 type; |
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65 union { |
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66 #if defined(__WIN32__) && !defined(__SYMBIAN32__) |
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67 struct { |
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68 int append; |
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69 void *h; |
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70 struct { |
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71 void *data; |
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72 int size; |
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73 int left; |
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74 } buffer; |
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75 } win32io; |
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76 #endif |
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77 #ifdef HAVE_STDIO_H |
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78 struct { |
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79 int autoclose; |
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80 FILE *fp; |
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81 } stdio; |
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82 #endif |
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83 struct { |
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84 Uint8 *base; |
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85 Uint8 *here; |
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86 Uint8 *stop; |
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87 } mem; |
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88 struct { |
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89 void *data1; |
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90 } unknown; |
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91 } hidden; |
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92 |
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93 } SDL_RWops; |
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94 |
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95 |
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96 /** @name Functions to create SDL_RWops structures from various data sources */ |
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97 /*@{*/ |
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98 |
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99 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFile(const char *file, const char *mode); |
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100 |
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101 #ifdef HAVE_STDIO_H |
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102 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFP(FILE *fp, int autoclose); |
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103 #endif |
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104 |
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105 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromMem(void *mem, int size); |
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106 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromConstMem(const void *mem, int size); |
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107 |
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108 extern DECLSPEC SDL_RWops * SDLCALL SDL_AllocRW(void); |
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109 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops *area); |
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110 |
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111 /*@}*/ |
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112 |
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113 /** @name Seek Reference Points */ |
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114 /*@{*/ |
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115 #define RW_SEEK_SET 0 /**< Seek from the beginning of data */ |
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116 #define RW_SEEK_CUR 1 /**< Seek relative to current read point */ |
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117 #define RW_SEEK_END 2 /**< Seek relative to the end of data */ |
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118 /*@}*/ |
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119 |
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120 /** @name Macros to easily read and write from an SDL_RWops structure */ |
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121 /*@{*/ |
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122 #define SDL_RWseek(ctx, offset, whence) (ctx)->seek(ctx, offset, whence) |
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123 #define SDL_RWtell(ctx) (ctx)->seek(ctx, 0, RW_SEEK_CUR) |
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124 #define SDL_RWread(ctx, ptr, size, n) (ctx)->read(ctx, ptr, size, n) |
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125 #define SDL_RWwrite(ctx, ptr, size, n) (ctx)->write(ctx, ptr, size, n) |
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126 #define SDL_RWclose(ctx) (ctx)->close(ctx) |
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127 /*@}*/ |
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128 |
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129 /** @name Read an item of the specified endianness and return in native format */ |
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130 /*@{*/ |
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131 extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops *src); |
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132 extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops *src); |
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133 extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops *src); |
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134 extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops *src); |
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135 extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops *src); |
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136 extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops *src); |
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137 /*@}*/ |
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138 |
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139 /** @name Write an item of native format to the specified endianness */ |
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140 /*@{*/ |
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141 extern DECLSPEC int SDLCALL SDL_WriteLE16(SDL_RWops *dst, Uint16 value); |
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142 extern DECLSPEC int SDLCALL SDL_WriteBE16(SDL_RWops *dst, Uint16 value); |
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143 extern DECLSPEC int SDLCALL SDL_WriteLE32(SDL_RWops *dst, Uint32 value); |
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144 extern DECLSPEC int SDLCALL SDL_WriteBE32(SDL_RWops *dst, Uint32 value); |
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145 extern DECLSPEC int SDLCALL SDL_WriteLE64(SDL_RWops *dst, Uint64 value); |
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146 extern DECLSPEC int SDLCALL SDL_WriteBE64(SDL_RWops *dst, Uint64 value); |
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147 /*@}*/ |
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148 |
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149 /* Ends C function definitions when using C++ */ |
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150 #ifdef __cplusplus |
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151 } |
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152 #endif |
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153 #include "close_code.h" |
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154 |
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155 #endif /* _SDL_rwops_h */ |