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1 /* |
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2 SDL - Simple DirectMedia Layer |
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3 Copyright (C) 1997-2006 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 /* This file provides a general interface for SDL to read and write |
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24 data sources. It can easily be extended to files, memory, etc. |
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25 */ |
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26 |
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27 #ifndef _SDL_rwops_h |
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28 #define _SDL_rwops_h |
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29 |
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30 #include "SDL_stdinc.h" |
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31 #include "SDL_error.h" |
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32 |
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33 #include "begin_code.h" |
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34 /* Set up for C function definitions, even when using C++ */ |
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35 #ifdef __cplusplus |
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36 extern "C" { |
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37 #endif |
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38 |
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39 /* This is the read/write operation structure -- very basic */ |
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40 |
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41 typedef struct SDL_RWops { |
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42 /* Seek to 'offset' relative to whence, one of stdio's whence values: |
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43 SEEK_SET, SEEK_CUR, SEEK_END |
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44 Returns the final offset in the data source. |
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45 */ |
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46 int (SDLCALL *seek)(struct SDL_RWops *context, int offset, int whence); |
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47 |
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48 /* Read up to 'num' objects each of size 'objsize' from the data |
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49 source to the area pointed at by 'ptr'. |
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50 Returns the number of objects read, or -1 if the read failed. |
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51 */ |
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52 int (SDLCALL *read)(struct SDL_RWops *context, void *ptr, int size, int maxnum); |
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53 |
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54 /* Write exactly 'num' objects each of size 'objsize' from the area |
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55 pointed at by 'ptr' to data source. |
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56 Returns 'num', or -1 if the write failed. |
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57 */ |
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58 int (SDLCALL *write)(struct SDL_RWops *context, const void *ptr, int size, int num); |
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59 |
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60 /* Close and free an allocated SDL_FSops structure */ |
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61 int (SDLCALL *close)(struct SDL_RWops *context); |
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62 |
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63 Uint32 type; |
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64 union { |
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65 #if defined(__WIN32__) && !defined(__SYMBIAN32__) |
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66 struct { |
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67 int append; |
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68 void *h; |
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69 struct { |
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70 void *data; |
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71 int size; |
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72 int left; |
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73 } buffer; |
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74 } win32io; |
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75 #endif |
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76 #ifdef HAVE_STDIO_H |
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77 struct { |
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78 int autoclose; |
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79 FILE *fp; |
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80 } stdio; |
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81 #endif |
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82 struct { |
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83 Uint8 *base; |
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84 Uint8 *here; |
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85 Uint8 *stop; |
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86 } mem; |
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87 struct { |
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88 void *data1; |
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89 } unknown; |
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90 } hidden; |
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91 |
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92 } SDL_RWops; |
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93 |
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94 |
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95 /* Functions to create SDL_RWops structures from various data sources */ |
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96 |
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97 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFile(const char *file, const char *mode); |
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98 |
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99 #ifdef HAVE_STDIO_H |
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100 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFP(FILE *fp, int autoclose); |
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101 #endif |
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102 |
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103 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromMem(void *mem, int size); |
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104 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromConstMem(const void *mem, int size); |
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105 |
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106 extern DECLSPEC SDL_RWops * SDLCALL SDL_AllocRW(void); |
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107 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops *area); |
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108 |
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109 #define RW_SEEK_SET 0 /* Seek from the beginning of data */ |
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110 #define RW_SEEK_CUR 1 /* Seek relative to current read point */ |
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111 #define RW_SEEK_END 2 /* Seek relative to the end of data */ |
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112 |
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113 /* Macros to easily read and write from an SDL_RWops structure */ |
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114 #define SDL_RWseek(ctx, offset, whence) (ctx)->seek(ctx, offset, whence) |
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115 #define SDL_RWtell(ctx) (ctx)->seek(ctx, 0, RW_SEEK_CUR) |
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116 #define SDL_RWread(ctx, ptr, size, n) (ctx)->read(ctx, ptr, size, n) |
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117 #define SDL_RWwrite(ctx, ptr, size, n) (ctx)->write(ctx, ptr, size, n) |
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118 #define SDL_RWclose(ctx) (ctx)->close(ctx) |
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119 |
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120 |
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121 /* Read an item of the specified endianness and return in native format */ |
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122 extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops *src); |
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123 extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops *src); |
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124 extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops *src); |
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125 extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops *src); |
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126 extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops *src); |
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127 extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops *src); |
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128 |
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129 /* Write an item of native format to the specified endianness */ |
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130 extern DECLSPEC int SDLCALL SDL_WriteLE16(SDL_RWops *dst, Uint16 value); |
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131 extern DECLSPEC int SDLCALL SDL_WriteBE16(SDL_RWops *dst, Uint16 value); |
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132 extern DECLSPEC int SDLCALL SDL_WriteLE32(SDL_RWops *dst, Uint32 value); |
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133 extern DECLSPEC int SDLCALL SDL_WriteBE32(SDL_RWops *dst, Uint32 value); |
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134 extern DECLSPEC int SDLCALL SDL_WriteLE64(SDL_RWops *dst, Uint64 value); |
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135 extern DECLSPEC int SDLCALL SDL_WriteBE64(SDL_RWops *dst, Uint64 value); |
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136 |
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137 |
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138 /* Ends C function definitions when using C++ */ |
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139 #ifdef __cplusplus |
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140 } |
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141 #endif |
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142 #include "close_code.h" |
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143 |
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144 #endif /* _SDL_rwops_h */ |