1 /* 2 SDL - Simple DirectMedia Layer 3 Copyright (C) 1997-2012 Sam Lantinga 4 5 This library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 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 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with this library; if not, write to the Free Software 17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 18 19 Sam Lantinga 20 slouken (at) libsdl.org 21 */ 22 23 /** @file SDL_rwops.h 24 * This file provides a general interface for SDL to read and write 25 * data sources. It can easily be extended to files, memory, etc. 26 */ 27 28 #ifndef _SDL_rwops_h 29 #define _SDL_rwops_h 30 31 #include "SDL_stdinc.h" 32 #include "SDL_error.h" 33 34 #include "begin_code.h" 35 /* Set up for C function definitions, even when using C++ */ 36 #ifdef __cplusplus 37 extern "C" { 38 #endif 39 40 /** This is the read/write operation structure -- very basic */ 41 42 typedef struct SDL_RWops { 43 /** Seek to 'offset' relative to whence, one of stdio's whence values: 44 * SEEK_SET, SEEK_CUR, SEEK_END 45 * Returns the final offset in the data source. 46 */ 47 int (SDLCALL *seek)(struct SDL_RWops *context, int offset, int whence); 48 49 /** Read up to 'maxnum' objects each of size 'size' from the data 50 * source to the area pointed at by 'ptr'. 51 * Returns the number of objects read, or -1 if the read failed. 52 */ 53 int (SDLCALL *read)(struct SDL_RWops *context, void *ptr, int size, int maxnum); 54 55 /** Write exactly 'num' objects each of size 'objsize' from the area 56 * pointed at by 'ptr' to data source. 57 * Returns 'num', or -1 if the write failed. 58 */ 59 int (SDLCALL *write)(struct SDL_RWops *context, const void *ptr, int size, int num); 60 61 /** Close and free an allocated SDL_FSops structure */ 62 int (SDLCALL *close)(struct SDL_RWops *context); 63 64 Uint32 type; 65 union { 66 #if defined(__WIN32__) && !defined(__SYMBIAN32__) 67 struct { 68 int append; 69 void *h; 70 struct { 71 void *data; 72 int size; 73 int left; 74 } buffer; 75 } win32io; 76 #endif 77 #ifdef HAVE_STDIO_H 78 struct { 79 int autoclose; 80 FILE *fp; 81 } stdio; 82 #endif 83 struct { 84 Uint8 *base; 85 Uint8 *here; 86 Uint8 *stop; 87 } mem; 88 struct { 89 void *data1; 90 } unknown; 91 } hidden; 92 93 } SDL_RWops; 94 95 96 /** @name Functions to create SDL_RWops structures from various data sources */ 97 /*@{*/ 98 99 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFile(const char *file, const char *mode); 100 101 #ifdef HAVE_STDIO_H 102 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromFP(FILE *fp, int autoclose); 103 #endif 104 105 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromMem(void *mem, int size); 106 extern DECLSPEC SDL_RWops * SDLCALL SDL_RWFromConstMem(const void *mem, int size); 107 108 extern DECLSPEC SDL_RWops * SDLCALL SDL_AllocRW(void); 109 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops *area); 110 111 /*@}*/ 112 113 /** @name Seek Reference Points */ 114 /*@{*/ 115 #define RW_SEEK_SET 0 /**< Seek from the beginning of data */ 116 #define RW_SEEK_CUR 1 /**< Seek relative to current read point */ 117 #define RW_SEEK_END 2 /**< Seek relative to the end of data */ 118 /*@}*/ 119 120 /** @name Macros to easily read and write from an SDL_RWops structure */ 121 /*@{*/ 122 #define SDL_RWseek(ctx, offset, whence) (ctx)->seek(ctx, offset, whence) 123 #define SDL_RWtell(ctx) (ctx)->seek(ctx, 0, RW_SEEK_CUR) 124 #define SDL_RWread(ctx, ptr, size, n) (ctx)->read(ctx, ptr, size, n) 125 #define SDL_RWwrite(ctx, ptr, size, n) (ctx)->write(ctx, ptr, size, n) 126 #define SDL_RWclose(ctx) (ctx)->close(ctx) 127 /*@}*/ 128 129 /** @name Read an item of the specified endianness and return in native format */ 130 /*@{*/ 131 extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops *src); 132 extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops *src); 133 extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops *src); 134 extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops *src); 135 extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops *src); 136 extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops *src); 137 /*@}*/ 138 139 /** @name Write an item of native format to the specified endianness */ 140 /*@{*/ 141 extern DECLSPEC int SDLCALL SDL_WriteLE16(SDL_RWops *dst, Uint16 value); 142 extern DECLSPEC int SDLCALL SDL_WriteBE16(SDL_RWops *dst, Uint16 value); 143 extern DECLSPEC int SDLCALL SDL_WriteLE32(SDL_RWops *dst, Uint32 value); 144 extern DECLSPEC int SDLCALL SDL_WriteBE32(SDL_RWops *dst, Uint32 value); 145 extern DECLSPEC int SDLCALL SDL_WriteLE64(SDL_RWops *dst, Uint64 value); 146 extern DECLSPEC int SDLCALL SDL_WriteBE64(SDL_RWops *dst, Uint64 value); 147 /*@}*/ 148 149 /* Ends C function definitions when using C++ */ 150 #ifdef __cplusplus 151 } 152 #endif 153 #include "close_code.h" 154 155 #endif /* _SDL_rwops_h */ 156
