include/SDL_rwops.h
author Tim Angus <tim@blackcompanystudios.co.uk>
Fri, 10 Jun 2011 14:23:24 +0100
changeset 5554 4b4258be8699
parent 5535 96594ac5fd1a
child 5582 1281a3f1f0a6
permissions -rw-r--r--
* SDL_IOS_ORIENTATIONS hint
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2011 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 #ifdef __WIN32__
    86         struct
    87         {
    88             SDL_bool append;
    89             void *h;
    90             struct
    91             {
    92                 void *data;
    93                 size_t size;
    94                 size_t left;
    95             } buffer;
    96         } windowsio;
    97 #endif
    98 #ifdef HAVE_STDIO_H
    99         struct
   100         {
   101             SDL_bool autoclose;
   102             FILE *fp;
   103         } stdio;
   104 #endif
   105         struct
   106         {
   107             Uint8 *base;
   108             Uint8 *here;
   109             Uint8 *stop;
   110         } mem;
   111         struct
   112         {
   113             void *data1;
   114         } unknown;
   115     } hidden;
   116 
   117 } SDL_RWops;
   118 
   119 
   120 /**
   121  *  \name RWFrom functions
   122  *  
   123  *  Functions to create SDL_RWops structures from various data streams.
   124  */
   125 /*@{*/
   126 
   127 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFile(const char *file,
   128                                                   const char *mode);
   129 
   130 #ifdef HAVE_STDIO_H
   131 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(FILE * fp,
   132                                                 SDL_bool autoclose);
   133 #else
   134 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(void * fp,
   135                                                 SDL_bool autoclose);
   136 #endif
   137 
   138 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromMem(void *mem, int size);
   139 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromConstMem(const void *mem,
   140                                                       int size);
   141 
   142 /*@}*//*RWFrom functions*/
   143 
   144 
   145 extern DECLSPEC SDL_RWops *SDLCALL SDL_AllocRW(void);
   146 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops * area);
   147 
   148 #define RW_SEEK_SET	0       /**< Seek from the beginning of data */
   149 #define RW_SEEK_CUR	1       /**< Seek relative to current read point */
   150 #define RW_SEEK_END	2       /**< Seek relative to the end of data */
   151 
   152 /**
   153  *  \name Read/write macros
   154  *  
   155  *  Macros to easily read and write from an SDL_RWops structure.
   156  */
   157 /*@{*/
   158 #define SDL_RWseek(ctx, offset, whence)	(ctx)->seek(ctx, offset, whence)
   159 #define SDL_RWtell(ctx)			(ctx)->seek(ctx, 0, RW_SEEK_CUR)
   160 #define SDL_RWread(ctx, ptr, size, n)	(ctx)->read(ctx, ptr, size, n)
   161 #define SDL_RWwrite(ctx, ptr, size, n)	(ctx)->write(ctx, ptr, size, n)
   162 #define SDL_RWclose(ctx)		(ctx)->close(ctx)
   163 /*@}*//*Read/write macros*/
   164 
   165 
   166 /** 
   167  *  \name Read endian functions
   168  *  
   169  *  Read an item of the specified endianness and return in native format.
   170  */
   171 /*@{*/
   172 extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops * src);
   173 extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops * src);
   174 extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops * src);
   175 extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops * src);
   176 extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops * src);
   177 extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops * src);
   178 /*@}*//*Read endian functions*/
   179 
   180 /** 
   181  *  \name Write endian functions
   182  *  
   183  *  Write an item of native format to the specified endianness.
   184  */
   185 /*@{*/
   186 extern DECLSPEC size_t SDLCALL SDL_WriteLE16(SDL_RWops * dst, Uint16 value);
   187 extern DECLSPEC size_t SDLCALL SDL_WriteBE16(SDL_RWops * dst, Uint16 value);
   188 extern DECLSPEC size_t SDLCALL SDL_WriteLE32(SDL_RWops * dst, Uint32 value);
   189 extern DECLSPEC size_t SDLCALL SDL_WriteBE32(SDL_RWops * dst, Uint32 value);
   190 extern DECLSPEC size_t SDLCALL SDL_WriteLE64(SDL_RWops * dst, Uint64 value);
   191 extern DECLSPEC size_t SDLCALL SDL_WriteBE64(SDL_RWops * dst, Uint64 value);
   192 /*@}*//*Write endian functions*/
   193 
   194 
   195 /* Ends C function definitions when using C++ */
   196 #ifdef __cplusplus
   197 /* *INDENT-OFF* */
   198 }
   199 /* *INDENT-ON* */
   200 #endif
   201 #include "close_code.h"
   202 
   203 #endif /* _SDL_rwops_h */
   204 
   205 /* vi: set ts=4 sw=4 expandtab: */