include/SDL_rwops.h
author Sam Lantinga <slouken@libsdl.org>
Sat, 31 Dec 2011 09:28:07 -0500
changeset 6138 4c64952a58fb
parent 5993 c9cb52d6d864
child 6308 263e2c049c22
permissions -rw-r--r--
Happy New Year!
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2012 Sam Lantinga <slouken@libsdl.org>
     4 
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     8 
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    12 
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    21 
    22 /**
    23  *  \file SDL_rwops.h
    24  *  
    25  *  This file provides a general interface for SDL to read and write
    26  *  data streams.  It can easily be extended to files, memory, etc.
    27  */
    28 
    29 #ifndef _SDL_rwops_h
    30 #define _SDL_rwops_h
    31 
    32 #include "SDL_stdinc.h"
    33 #include "SDL_error.h"
    34 
    35 #include "begin_code.h"
    36 /* Set up for C function definitions, even when using C++ */
    37 #ifdef __cplusplus
    38 /* *INDENT-OFF* */
    39 extern "C" {
    40 /* *INDENT-ON* */
    41 #endif
    42 
    43 /**
    44  * This is the read/write operation structure -- very basic.
    45  */
    46 typedef struct SDL_RWops
    47 {
    48     /**
    49      *  Seek to \c offset relative to \c whence, one of stdio's whence values:
    50      *  RW_SEEK_SET, RW_SEEK_CUR, RW_SEEK_END
    51      *  
    52      *  \return the final offset in the data stream.
    53      */
    54     long (SDLCALL * seek) (struct SDL_RWops * context, long offset,
    55                            int whence);
    56 
    57     /**
    58      *  Read up to \c maxnum objects each of size \c size from the data
    59      *  stream to the area pointed at by \c ptr.
    60      *  
    61      *  \return the number of objects read, or 0 at error or end of file.
    62      */
    63     size_t(SDLCALL * read) (struct SDL_RWops * context, void *ptr,
    64                             size_t size, size_t maxnum);
    65 
    66     /**
    67      *  Write exactly \c num objects each of size \c size from the area
    68      *  pointed at by \c ptr to data stream.
    69      *  
    70      *  \return the number of objects written, or 0 at error or end of file.
    71      */
    72     size_t(SDLCALL * write) (struct SDL_RWops * context, const void *ptr,
    73                              size_t size, size_t num);
    74 
    75     /**
    76      *  Close and free an allocated SDL_RWops structure.
    77      *  
    78      *  \return 0 if successful or -1 on write error when flushing data.
    79      */
    80     int (SDLCALL * close) (struct SDL_RWops * context);
    81 
    82     Uint32 type;
    83     union
    84     {
    85 #if defined(ANDROID)
    86         struct
    87         {
    88             void *fileName;
    89             void *fileNameRef;
    90             void *inputStream;
    91             void *inputStreamRef;
    92             void *readableByteChannel;
    93             void *readableByteChannelRef;
    94             void *readMethod;
    95             long position;
    96             int size;
    97         } androidio;
    98 #elif defined(__WIN32__)
    99         struct
   100         {
   101             SDL_bool append;
   102             void *h;
   103             struct
   104             {
   105                 void *data;
   106                 size_t size;
   107                 size_t left;
   108             } buffer;
   109         } windowsio;
   110 #endif
   111 
   112 #ifdef HAVE_STDIO_H
   113         struct
   114         {
   115             SDL_bool autoclose;
   116             FILE *fp;
   117         } stdio;
   118 #endif
   119         struct
   120         {
   121             Uint8 *base;
   122             Uint8 *here;
   123             Uint8 *stop;
   124         } mem;
   125         struct
   126         {
   127             void *data1;
   128         } unknown;
   129     } hidden;
   130 
   131 } SDL_RWops;
   132 
   133 
   134 /**
   135  *  \name RWFrom functions
   136  *  
   137  *  Functions to create SDL_RWops structures from various data streams.
   138  */
   139 /*@{*/
   140 
   141 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFile(const char *file,
   142                                                   const char *mode);
   143 
   144 #ifdef HAVE_STDIO_H
   145 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(FILE * fp,
   146                                                 SDL_bool autoclose);
   147 #else
   148 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(void * fp,
   149                                                 SDL_bool autoclose);
   150 #endif
   151 
   152 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromMem(void *mem, int size);
   153 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromConstMem(const void *mem,
   154                                                       int size);
   155 
   156 /*@}*//*RWFrom functions*/
   157 
   158 
   159 extern DECLSPEC SDL_RWops *SDLCALL SDL_AllocRW(void);
   160 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops * area);
   161 
   162 #define RW_SEEK_SET	0       /**< Seek from the beginning of data */
   163 #define RW_SEEK_CUR	1       /**< Seek relative to current read point */
   164 #define RW_SEEK_END	2       /**< Seek relative to the end of data */
   165 
   166 /**
   167  *  \name Read/write macros
   168  *  
   169  *  Macros to easily read and write from an SDL_RWops structure.
   170  */
   171 /*@{*/
   172 #define SDL_RWseek(ctx, offset, whence)	(ctx)->seek(ctx, offset, whence)
   173 #define SDL_RWtell(ctx)			(ctx)->seek(ctx, 0, RW_SEEK_CUR)
   174 #define SDL_RWread(ctx, ptr, size, n)	(ctx)->read(ctx, ptr, size, n)
   175 #define SDL_RWwrite(ctx, ptr, size, n)	(ctx)->write(ctx, ptr, size, n)
   176 #define SDL_RWclose(ctx)		(ctx)->close(ctx)
   177 /*@}*//*Read/write macros*/
   178 
   179 
   180 /** 
   181  *  \name Read endian functions
   182  *  
   183  *  Read an item of the specified endianness and return in native format.
   184  */
   185 /*@{*/
   186 extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops * src);
   187 extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops * src);
   188 extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops * src);
   189 extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops * src);
   190 extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops * src);
   191 extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops * src);
   192 /*@}*//*Read endian functions*/
   193 
   194 /** 
   195  *  \name Write endian functions
   196  *  
   197  *  Write an item of native format to the specified endianness.
   198  */
   199 /*@{*/
   200 extern DECLSPEC size_t SDLCALL SDL_WriteLE16(SDL_RWops * dst, Uint16 value);
   201 extern DECLSPEC size_t SDLCALL SDL_WriteBE16(SDL_RWops * dst, Uint16 value);
   202 extern DECLSPEC size_t SDLCALL SDL_WriteLE32(SDL_RWops * dst, Uint32 value);
   203 extern DECLSPEC size_t SDLCALL SDL_WriteBE32(SDL_RWops * dst, Uint32 value);
   204 extern DECLSPEC size_t SDLCALL SDL_WriteLE64(SDL_RWops * dst, Uint64 value);
   205 extern DECLSPEC size_t SDLCALL SDL_WriteBE64(SDL_RWops * dst, Uint64 value);
   206 /*@}*//*Write endian functions*/
   207 
   208 
   209 /* Ends C function definitions when using C++ */
   210 #ifdef __cplusplus
   211 /* *INDENT-OFF* */
   212 }
   213 /* *INDENT-ON* */
   214 #endif
   215 #include "close_code.h"
   216 
   217 #endif /* _SDL_rwops_h */
   218 
   219 /* vi: set ts=4 sw=4 expandtab: */