| 1 | /* |
| 2 | SDL - Simple DirectMedia Layer |
| 3 | Copyright (C) 1997-2009 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@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 */ |