include/SDL_rwops.h
author Ryan C. Gordon <icculus@icculus.org>
Sun, 12 Apr 2015 20:28:28 -0400
changeset 9553 75dca0c33be6
parent 8850 7e248a233387
child 9619 b94b6d0bff0f
permissions -rw-r--r--
Merged.
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2014 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 extern "C" {
    39 #endif
    40 
    41 /* RWops Types */
    42 #define SDL_RWOPS_UNKNOWN   0   /* Unknown stream type */
    43 #define SDL_RWOPS_WINFILE   1   /* Win32 file */
    44 #define SDL_RWOPS_STDFILE   2   /* Stdio file */
    45 #define SDL_RWOPS_JNIFILE   3   /* Android asset */
    46 #define SDL_RWOPS_MEMORY    4   /* Memory stream */
    47 #define SDL_RWOPS_MEMORY_RO 5   /* Read-Only memory stream */
    48 
    49 /**
    50  * This is the read/write operation structure -- very basic.
    51  */
    52 typedef struct SDL_RWops
    53 {
    54     /**
    55      *  Return the size of the file in this rwops, or -1 if unknown
    56      */
    57     Sint64 (SDLCALL * size) (struct SDL_RWops * context);
    58 
    59     /**
    60      *  Seek to \c offset relative to \c whence, one of stdio's whence values:
    61      *  RW_SEEK_SET, RW_SEEK_CUR, RW_SEEK_END
    62      *
    63      *  \return the final offset in the data stream, or -1 on error.
    64      */
    65     Sint64 (SDLCALL * seek) (struct SDL_RWops * context, Sint64 offset,
    66                              int whence);
    67 
    68     /**
    69      *  Read up to \c maxnum objects each of size \c size from the data
    70      *  stream to the area pointed at by \c ptr.
    71      *
    72      *  \return the number of objects read, or 0 at error or end of file.
    73      */
    74     size_t (SDLCALL * read) (struct SDL_RWops * context, void *ptr,
    75                              size_t size, size_t maxnum);
    76 
    77     /**
    78      *  Write exactly \c num objects each of size \c size from the area
    79      *  pointed at by \c ptr to data stream.
    80      *
    81      *  \return the number of objects written, or 0 at error or end of file.
    82      */
    83     size_t (SDLCALL * write) (struct SDL_RWops * context, const void *ptr,
    84                               size_t size, size_t num);
    85 
    86     /**
    87      *  Close and free an allocated SDL_RWops structure.
    88      *
    89      *  \return 0 if successful or -1 on write error when flushing data.
    90      */
    91     int (SDLCALL * close) (struct SDL_RWops * context);
    92 
    93     Uint32 type;
    94     union
    95     {
    96 #if defined(__ANDROID__)
    97         struct
    98         {
    99             void *fileNameRef;
   100             void *inputStreamRef;
   101             void *readableByteChannelRef;
   102             void *readMethod;
   103             void *assetFileDescriptorRef;
   104             long position;
   105             long size;
   106             long offset;
   107             int fd;
   108         } androidio;
   109 #elif defined(__WIN32__)
   110         struct
   111         {
   112             SDL_bool append;
   113             void *h;
   114             struct
   115             {
   116                 void *data;
   117                 size_t size;
   118                 size_t left;
   119             } buffer;
   120         } windowsio;
   121 #endif
   122 
   123 #ifdef HAVE_STDIO_H
   124         struct
   125         {
   126             SDL_bool autoclose;
   127             FILE *fp;
   128         } stdio;
   129 #endif
   130         struct
   131         {
   132             Uint8 *base;
   133             Uint8 *here;
   134             Uint8 *stop;
   135         } mem;
   136         struct
   137         {
   138             void *data1;
   139             void *data2;
   140         } unknown;
   141     } hidden;
   142 
   143 } SDL_RWops;
   144 
   145 
   146 /**
   147  *  \name RWFrom functions
   148  *
   149  *  Functions to create SDL_RWops structures from various data streams.
   150  */
   151 /* @{ */
   152 
   153 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFile(const char *file,
   154                                                   const char *mode);
   155 
   156 #ifdef HAVE_STDIO_H
   157 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(FILE * fp,
   158                                                 SDL_bool autoclose);
   159 #else
   160 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(void * fp,
   161                                                 SDL_bool autoclose);
   162 #endif
   163 
   164 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromMem(void *mem, int size);
   165 extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromConstMem(const void *mem,
   166                                                       int size);
   167 
   168 /* @} *//* RWFrom functions */
   169 
   170 
   171 extern DECLSPEC SDL_RWops *SDLCALL SDL_AllocRW(void);
   172 extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops * area);
   173 
   174 #define RW_SEEK_SET 0       /**< Seek from the beginning of data */
   175 #define RW_SEEK_CUR 1       /**< Seek relative to current read point */
   176 #define RW_SEEK_END 2       /**< Seek relative to the end of data */
   177 
   178 /**
   179  *  \name Read/write macros
   180  *
   181  *  Macros to easily read and write from an SDL_RWops structure.
   182  */
   183 /* @{ */
   184 #define SDL_RWsize(ctx)         (ctx)->size(ctx)
   185 #define SDL_RWseek(ctx, offset, whence) (ctx)->seek(ctx, offset, whence)
   186 #define SDL_RWtell(ctx)         (ctx)->seek(ctx, 0, RW_SEEK_CUR)
   187 #define SDL_RWread(ctx, ptr, size, n)   (ctx)->read(ctx, ptr, size, n)
   188 #define SDL_RWwrite(ctx, ptr, size, n)  (ctx)->write(ctx, ptr, size, n)
   189 #define SDL_RWclose(ctx)        (ctx)->close(ctx)
   190 /* @} *//* Read/write macros */
   191 
   192 
   193 /**
   194  *  \name Read endian functions
   195  *
   196  *  Read an item of the specified endianness and return in native format.
   197  */
   198 /* @{ */
   199 extern DECLSPEC Uint8 SDLCALL SDL_ReadU8(SDL_RWops * src);
   200 extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops * src);
   201 extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops * src);
   202 extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops * src);
   203 extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops * src);
   204 extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops * src);
   205 extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops * src);
   206 /* @} *//* Read endian functions */
   207 
   208 /**
   209  *  \name Write endian functions
   210  *
   211  *  Write an item of native format to the specified endianness.
   212  */
   213 /* @{ */
   214 extern DECLSPEC size_t SDLCALL SDL_WriteU8(SDL_RWops * dst, Uint8 value);
   215 extern DECLSPEC size_t SDLCALL SDL_WriteLE16(SDL_RWops * dst, Uint16 value);
   216 extern DECLSPEC size_t SDLCALL SDL_WriteBE16(SDL_RWops * dst, Uint16 value);
   217 extern DECLSPEC size_t SDLCALL SDL_WriteLE32(SDL_RWops * dst, Uint32 value);
   218 extern DECLSPEC size_t SDLCALL SDL_WriteBE32(SDL_RWops * dst, Uint32 value);
   219 extern DECLSPEC size_t SDLCALL SDL_WriteLE64(SDL_RWops * dst, Uint64 value);
   220 extern DECLSPEC size_t SDLCALL SDL_WriteBE64(SDL_RWops * dst, Uint64 value);
   221 /* @} *//* Write endian functions */
   222 
   223 /* Ends C function definitions when using C++ */
   224 #ifdef __cplusplus
   225 }
   226 #endif
   227 #include "close_code.h"
   228 
   229 #endif /* _SDL_rwops_h */
   230 
   231 /* vi: set ts=4 sw=4 expandtab: */