SDL_rwops.h 7.07 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231
/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/

/**
 *  \file SDL_rwops.h
 *
 *  This file provides a general interface for SDL to read and write
 *  data streams.  It can easily be extended to files, memory, etc.
 */

#ifndef _SDL_rwops_h
#define _SDL_rwops_h

#include "SDL_stdinc.h"
#include "SDL_error.h"

#include "begin_code.h"
/* Set up for C function definitions, even when using C++ */
#ifdef __cplusplus
extern "C" {
#endif

/* RWops Types */
#define SDL_RWOPS_UNKNOWN   0   /* Unknown stream type */
#define SDL_RWOPS_WINFILE   1   /* Win32 file */
#define SDL_RWOPS_STDFILE   2   /* Stdio file */
#define SDL_RWOPS_JNIFILE   3   /* Android asset */
#define SDL_RWOPS_MEMORY    4   /* Memory stream */
#define SDL_RWOPS_MEMORY_RO 5   /* Read-Only memory stream */

/**
 * This is the read/write operation structure -- very basic.
 */
typedef struct SDL_RWops
{
    /**
     *  Return the size of the file in this rwops, or -1 if unknown
     */
    Sint64 (SDLCALL * size) (struct SDL_RWops * context);

    /**
     *  Seek to \c offset relative to \c whence, one of stdio's whence values:
     *  RW_SEEK_SET, RW_SEEK_CUR, RW_SEEK_END
     *
     *  \return the final offset in the data stream, or -1 on error.
     */
    Sint64 (SDLCALL * seek) (struct SDL_RWops * context, Sint64 offset,
                             int whence);

    /**
     *  Read up to \c maxnum objects each of size \c size from the data
     *  stream to the area pointed at by \c ptr.
     *
     *  \return the number of objects read, or 0 at error or end of file.
     */
    size_t (SDLCALL * read) (struct SDL_RWops * context, void *ptr,
                             size_t size, size_t maxnum);

    /**
     *  Write exactly \c num objects each of size \c size from the area
     *  pointed at by \c ptr to data stream.
     *
     *  \return the number of objects written, or 0 at error or end of file.
     */
    size_t (SDLCALL * write) (struct SDL_RWops * context, const void *ptr,
                              size_t size, size_t num);

    /**
     *  Close and free an allocated SDL_RWops structure.
     *
     *  \return 0 if successful or -1 on write error when flushing data.
     */
    int (SDLCALL * close) (struct SDL_RWops * context);

    Uint32 type;
    union
    {
#if defined(__ANDROID__)
        struct
        {
            void *fileNameRef;
            void *inputStreamRef;
            void *readableByteChannelRef;
            void *readMethod;
            void *assetFileDescriptorRef;
            long position;
            long size;
            long offset;
            int fd;
        } androidio;
#elif defined(__WIN32__)
        struct
        {
            SDL_bool append;
            void *h;
            struct
            {
                void *data;
                size_t size;
                size_t left;
            } buffer;
        } windowsio;
#endif

#ifdef HAVE_STDIO_H
        struct
        {
            SDL_bool autoclose;
            FILE *fp;
        } stdio;
#endif
        struct
        {
            Uint8 *base;
            Uint8 *here;
            Uint8 *stop;
        } mem;
        struct
        {
            void *data1;
            void *data2;
        } unknown;
    } hidden;

} SDL_RWops;


/**
 *  \name RWFrom functions
 *
 *  Functions to create SDL_RWops structures from various data streams.
 */
/* @{ */

extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFile(const char *file,
                                                  const char *mode);

#ifdef HAVE_STDIO_H
extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(FILE * fp,
                                                SDL_bool autoclose);
#else
extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromFP(void * fp,
                                                SDL_bool autoclose);
#endif

extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromMem(void *mem, int size);
extern DECLSPEC SDL_RWops *SDLCALL SDL_RWFromConstMem(const void *mem,
                                                      int size);

/* @} *//* RWFrom functions */


extern DECLSPEC SDL_RWops *SDLCALL SDL_AllocRW(void);
extern DECLSPEC void SDLCALL SDL_FreeRW(SDL_RWops * area);

#define RW_SEEK_SET 0       /**< Seek from the beginning of data */
#define RW_SEEK_CUR 1       /**< Seek relative to current read point */
#define RW_SEEK_END 2       /**< Seek relative to the end of data */

/**
 *  \name Read/write macros
 *
 *  Macros to easily read and write from an SDL_RWops structure.
 */
/* @{ */
#define SDL_RWsize(ctx)         (ctx)->size(ctx)
#define SDL_RWseek(ctx, offset, whence) (ctx)->seek(ctx, offset, whence)
#define SDL_RWtell(ctx)         (ctx)->seek(ctx, 0, RW_SEEK_CUR)
#define SDL_RWread(ctx, ptr, size, n)   (ctx)->read(ctx, ptr, size, n)
#define SDL_RWwrite(ctx, ptr, size, n)  (ctx)->write(ctx, ptr, size, n)
#define SDL_RWclose(ctx)        (ctx)->close(ctx)
/* @} *//* Read/write macros */


/**
 *  \name Read endian functions
 *
 *  Read an item of the specified endianness and return in native format.
 */
/* @{ */
extern DECLSPEC Uint8 SDLCALL SDL_ReadU8(SDL_RWops * src);
extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops * src);
extern DECLSPEC Uint16 SDLCALL SDL_ReadBE16(SDL_RWops * src);
extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops * src);
extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops * src);
extern DECLSPEC Uint64 SDLCALL SDL_ReadLE64(SDL_RWops * src);
extern DECLSPEC Uint64 SDLCALL SDL_ReadBE64(SDL_RWops * src);
/* @} *//* Read endian functions */

/**
 *  \name Write endian functions
 *
 *  Write an item of native format to the specified endianness.
 */
/* @{ */
extern DECLSPEC size_t SDLCALL SDL_WriteU8(SDL_RWops * dst, Uint8 value);
extern DECLSPEC size_t SDLCALL SDL_WriteLE16(SDL_RWops * dst, Uint16 value);
extern DECLSPEC size_t SDLCALL SDL_WriteBE16(SDL_RWops * dst, Uint16 value);
extern DECLSPEC size_t SDLCALL SDL_WriteLE32(SDL_RWops * dst, Uint32 value);
extern DECLSPEC size_t SDLCALL SDL_WriteBE32(SDL_RWops * dst, Uint32 value);
extern DECLSPEC size_t SDLCALL SDL_WriteLE64(SDL_RWops * dst, Uint64 value);
extern DECLSPEC size_t SDLCALL SDL_WriteBE64(SDL_RWops * dst, Uint64 value);
/* @} *//* Write endian functions */

/* Ends C function definitions when using C++ */
#ifdef __cplusplus
}
#endif
#include "close_code.h"

#endif /* _SDL_rwops_h */

/* vi: set ts=4 sw=4 expandtab: */