SDL 3.0
SDL_rwops.h File Reference
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Data Structures

struct  SDL_RWops
 

Macros

#define SDL_RWOPS_UNKNOWN   0
 
#define SDL_RWOPS_WINFILE   1
 
#define SDL_RWOPS_STDFILE   2
 
#define SDL_RWOPS_JNIFILE   3
 
#define SDL_RWOPS_MEMORY   4
 
#define SDL_RWOPS_MEMORY_RO   5
 
#define SDL_RWOPS_STATUS_READY   0
 
#define SDL_RWOPS_STATUS_ERROR   1
 
#define SDL_RWOPS_STATUS_EOF   2
 
#define SDL_RWOPS_STATUS_NOT_READY   3
 
#define SDL_RWOPS_STATUS_READONLY   4
 
#define SDL_RWOPS_STATUS_WRITEONLY   5
 

Functions

Read endian functions

Read an item of the specified endianness and return in native format.

SDL_bool SDL_ReadU8 (SDL_RWops *src, Uint8 *value)
 
SDL_bool SDL_ReadU16LE (SDL_RWops *src, Uint16 *value)
 
SDL_bool SDL_ReadS16LE (SDL_RWops *src, Sint16 *value)
 
SDL_bool SDL_ReadU16BE (SDL_RWops *src, Uint16 *value)
 
SDL_bool SDL_ReadS16BE (SDL_RWops *src, Sint16 *value)
 
SDL_bool SDL_ReadU32LE (SDL_RWops *src, Uint32 *value)
 
SDL_bool SDL_ReadS32LE (SDL_RWops *src, Sint32 *value)
 
SDL_bool SDL_ReadU32BE (SDL_RWops *src, Uint32 *value)
 
SDL_bool SDL_ReadS32BE (SDL_RWops *src, Sint32 *value)
 
SDL_bool SDL_ReadU64LE (SDL_RWops *src, Uint64 *value)
 
SDL_bool SDL_ReadS64LE (SDL_RWops *src, Sint64 *value)
 
SDL_bool SDL_ReadU64BE (SDL_RWops *src, Uint64 *value)
 
SDL_bool SDL_ReadS64BE (SDL_RWops *src, Sint64 *value)
 
Write endian functions

Write an item of native format to the specified endianness.

SDL_bool SDL_WriteU8 (SDL_RWops *dst, Uint8 value)
 
SDL_bool SDL_WriteU16LE (SDL_RWops *dst, Uint16 value)
 
SDL_bool SDL_WriteS16LE (SDL_RWops *dst, Sint16 value)
 
SDL_bool SDL_WriteU16BE (SDL_RWops *dst, Uint16 value)
 
SDL_bool SDL_WriteS16BE (SDL_RWops *dst, Sint16 value)
 
SDL_bool SDL_WriteU32LE (SDL_RWops *dst, Uint32 value)
 
SDL_bool SDL_WriteS32LE (SDL_RWops *dst, Sint32 value)
 
SDL_bool SDL_WriteU32BE (SDL_RWops *dst, Uint32 value)
 
SDL_bool SDL_WriteS32BE (SDL_RWops *dst, Sint32 value)
 
SDL_bool SDL_WriteU64LE (SDL_RWops *dst, Uint64 value)
 
SDL_bool SDL_WriteS64LE (SDL_RWops *dst, Sint64 value)
 
SDL_bool SDL_WriteU64BE (SDL_RWops *dst, Uint64 value)
 
SDL_bool SDL_WriteS64BE (SDL_RWops *dst, Sint64 value)
 

RWFrom functions

Functions to create SDL_RWops structures from various data streams.

#define SDL_RW_SEEK_SET   0
 
#define SDL_RW_SEEK_CUR   1
 
#define SDL_RW_SEEK_END   2
 
SDL_RWopsSDL_RWFromFile (const char *file, const char *mode)
 
SDL_RWopsSDL_RWFromMem (void *mem, size_t size)
 
SDL_RWopsSDL_RWFromConstMem (const void *mem, size_t size)
 
SDL_RWopsSDL_CreateRW (void)
 
void SDL_DestroyRW (SDL_RWops *context)
 
Sint64 SDL_RWsize (SDL_RWops *context)
 
Sint64 SDL_RWseek (SDL_RWops *context, Sint64 offset, int whence)
 
Sint64 SDL_RWtell (SDL_RWops *context)
 
size_t SDL_RWread (SDL_RWops *context, void *ptr, size_t size)
 
size_t SDL_RWwrite (SDL_RWops *context, const void *ptr, size_t size)
 
int SDL_RWclose (SDL_RWops *context)
 
void * SDL_LoadFile_RW (SDL_RWops *src, size_t *datasize, SDL_bool freesrc)
 
void * SDL_LoadFile (const char *file, size_t *datasize)
 

Detailed Description

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

Definition in file SDL_rwops.h.

Macro Definition Documentation

◆ SDL_RW_SEEK_CUR

#define SDL_RW_SEEK_CUR   1

Seek relative to current read point

Definition at line 335 of file SDL_rwops.h.

◆ SDL_RW_SEEK_END

#define SDL_RW_SEEK_END   2

Seek relative to the end of data

Definition at line 336 of file SDL_rwops.h.

◆ SDL_RW_SEEK_SET

#define SDL_RW_SEEK_SET   0

Seek from the beginning of data

Definition at line 334 of file SDL_rwops.h.

◆ SDL_RWOPS_JNIFILE

#define SDL_RWOPS_JNIFILE   3

Android asset

Definition at line 45 of file SDL_rwops.h.

◆ SDL_RWOPS_MEMORY

#define SDL_RWOPS_MEMORY   4

Memory stream

Definition at line 46 of file SDL_rwops.h.

◆ SDL_RWOPS_MEMORY_RO

#define SDL_RWOPS_MEMORY_RO   5

Read-Only memory stream

Definition at line 47 of file SDL_rwops.h.

◆ SDL_RWOPS_STATUS_EOF

#define SDL_RWOPS_STATUS_EOF   2

End of file

Definition at line 52 of file SDL_rwops.h.

◆ SDL_RWOPS_STATUS_ERROR

#define SDL_RWOPS_STATUS_ERROR   1

Read or write I/O error

Definition at line 51 of file SDL_rwops.h.

◆ SDL_RWOPS_STATUS_NOT_READY

#define SDL_RWOPS_STATUS_NOT_READY   3

Non blocking I/O, not ready

Definition at line 53 of file SDL_rwops.h.

◆ SDL_RWOPS_STATUS_READONLY

#define SDL_RWOPS_STATUS_READONLY   4

Tried to write a read-only buffer

Definition at line 54 of file SDL_rwops.h.

◆ SDL_RWOPS_STATUS_READY

#define SDL_RWOPS_STATUS_READY   0

Everything is ready

Definition at line 50 of file SDL_rwops.h.

◆ SDL_RWOPS_STATUS_WRITEONLY

#define SDL_RWOPS_STATUS_WRITEONLY   5

Tried to read a write-only buffer

Definition at line 55 of file SDL_rwops.h.

◆ SDL_RWOPS_STDFILE

#define SDL_RWOPS_STDFILE   2

Stdio file

Definition at line 44 of file SDL_rwops.h.

◆ SDL_RWOPS_UNKNOWN

#define SDL_RWOPS_UNKNOWN   0

Unknown stream type

Definition at line 42 of file SDL_rwops.h.

◆ SDL_RWOPS_WINFILE

#define SDL_RWOPS_WINFILE   1

Win32 file

Definition at line 43 of file SDL_rwops.h.

Function Documentation

◆ SDL_CreateRW()

SDL_RWops * SDL_CreateRW ( void  )
extern

Use this function to allocate an empty, unpopulated SDL_RWops structure.

Applications do not need to use this function unless they are providing their own SDL_RWops implementation. If you just need an SDL_RWops to read/write a common data source, you should use the built-in implementations in SDL, like SDL_RWFromFile() or SDL_RWFromMem(), etc.

You must free the returned pointer with SDL_DestroyRW(). Depending on your operating system and compiler, there may be a difference between the malloc() and free() your program uses and the versions SDL calls internally. Trying to mix the two can cause crashing such as segmentation faults. Since all SDL_RWops must free themselves when their close method is called, all SDL_RWops must be allocated through this function, so they can all be freed correctly with SDL_DestroyRW().

Returns
a pointer to the allocated memory on success, or NULL on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.
See also
SDL_DestroyRW

◆ SDL_DestroyRW()

void SDL_DestroyRW ( SDL_RWops context)
extern

Use this function to free an SDL_RWops structure allocated by SDL_CreateRW().

Applications do not need to use this function unless they are providing their own SDL_RWops implementation. If you just need an SDL_RWops to read/write a common data source, you should use the built-in implementations in SDL, like SDL_RWFromFile() or SDL_RWFromMem(), etc, and call the close method on those SDL_RWops pointers when you are done with them.

Only use SDL_DestroyRW() on pointers returned by SDL_CreateRW(). The pointer is invalid as soon as this function returns. Any extra memory allocated during creation of the SDL_RWops is not freed by SDL_DestroyRW(); the programmer must be responsible for managing that memory in their close method.

Parameters
contextthe SDL_RWops structure to be freed
Since
This function is available since SDL 3.0.0.
See also
SDL_CreateRW

◆ SDL_LoadFile()

void * SDL_LoadFile ( const char *  file,
size_t *  datasize 
)
extern

Load all the data from a file path.

The data is allocated with a zero byte at the end (null terminated) for convenience. This extra byte is not included in the value reported via datasize.

The data should be freed with SDL_free().

Parameters
filethe path to read all available data from
datasizeif not NULL, will store the number of bytes read
Returns
the data, or NULL if there was an error.
Since
This function is available since SDL 3.0.0.

◆ SDL_LoadFile_RW()

void * SDL_LoadFile_RW ( SDL_RWops src,
size_t *  datasize,
SDL_bool  freesrc 
)
extern

Load all the data from an SDL data stream.

The data is allocated with a zero byte at the end (null terminated) for convenience. This extra byte is not included in the value reported via datasize.

The data should be freed with SDL_free().

Parameters
srcthe SDL_RWops to read all available data from
datasizeif not NULL, will store the number of bytes read
freesrcif SDL_TRUE, calls SDL_RWclose() on src before returning, even in the case of an error
Returns
the data, or NULL if there was an error.
Since
This function is available since SDL 3.0.0.

◆ SDL_ReadS16BE()

SDL_bool SDL_ReadS16BE ( SDL_RWops src,
Sint16 value 
)
extern

Use this function to read 16 bits of big-endian data from an SDL_RWops and return in native format.

SDL byteswaps the data only if necessary, so the data returned will be in the native byte order.

Parameters
srcthe stream from which to read data
valuea pointer filled in with the data read
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_ReadS16LE()

SDL_bool SDL_ReadS16LE ( SDL_RWops src,
Sint16 value 
)
extern

Use this function to read 16 bits of little-endian data from an SDL_RWops and return in native format.

SDL byteswaps the data only if necessary, so the data returned will be in the native byte order.

Parameters
srcthe stream from which to read data
valuea pointer filled in with the data read
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_ReadS32BE()

SDL_bool SDL_ReadS32BE ( SDL_RWops src,
Sint32 value 
)
extern

Use this function to read 32 bits of big-endian data from an SDL_RWops and return in native format.

SDL byteswaps the data only if necessary, so the data returned will be in the native byte order.

Parameters
srcthe stream from which to read data
valuea pointer filled in with the data read
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_ReadS32LE()

SDL_bool SDL_ReadS32LE ( SDL_RWops src,
Sint32 value 
)
extern

Use this function to read 32 bits of little-endian data from an SDL_RWops and return in native format.

SDL byteswaps the data only if necessary, so the data returned will be in the native byte order.

Parameters
srcthe stream from which to read data
valuea pointer filled in with the data read
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_ReadS64BE()

SDL_bool SDL_ReadS64BE ( SDL_RWops src,
Sint64 value 
)
extern

Use this function to read 64 bits of big-endian data from an SDL_RWops and return in native format.

SDL byteswaps the data only if necessary, so the data returned will be in the native byte order.

Parameters
srcthe stream from which to read data
valuea pointer filled in with the data read
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_ReadS64LE()

SDL_bool SDL_ReadS64LE ( SDL_RWops src,
Sint64 value 
)
extern

Use this function to read 64 bits of little-endian data from an SDL_RWops and return in native format.

SDL byteswaps the data only if necessary, so the data returned will be in the native byte order.

Parameters
srcthe stream from which to read data
valuea pointer filled in with the data read
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_ReadU16BE()

SDL_bool SDL_ReadU16BE ( SDL_RWops src,
Uint16 value 
)
extern

Use this function to read 16 bits of big-endian data from an SDL_RWops and return in native format.

SDL byteswaps the data only if necessary, so the data returned will be in the native byte order.

Parameters
srcthe stream from which to read data
valuea pointer filled in with the data read
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_ReadU16LE()

SDL_bool SDL_ReadU16LE ( SDL_RWops src,
Uint16 value 
)
extern

Use this function to read 16 bits of little-endian data from an SDL_RWops and return in native format.

SDL byteswaps the data only if necessary, so the data returned will be in the native byte order.

Parameters
srcthe stream from which to read data
valuea pointer filled in with the data read
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_ReadU32BE()

SDL_bool SDL_ReadU32BE ( SDL_RWops src,
Uint32 value 
)
extern

Use this function to read 32 bits of big-endian data from an SDL_RWops and return in native format.

SDL byteswaps the data only if necessary, so the data returned will be in the native byte order.

Parameters
srcthe stream from which to read data
valuea pointer filled in with the data read
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_ReadU32LE()

SDL_bool SDL_ReadU32LE ( SDL_RWops src,
Uint32 value 
)
extern

Use this function to read 32 bits of little-endian data from an SDL_RWops and return in native format.

SDL byteswaps the data only if necessary, so the data returned will be in the native byte order.

Parameters
srcthe stream from which to read data
valuea pointer filled in with the data read
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_ReadU64BE()

SDL_bool SDL_ReadU64BE ( SDL_RWops src,
Uint64 value 
)
extern

Use this function to read 64 bits of big-endian data from an SDL_RWops and return in native format.

SDL byteswaps the data only if necessary, so the data returned will be in the native byte order.

Parameters
srcthe stream from which to read data
valuea pointer filled in with the data read
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_ReadU64LE()

SDL_bool SDL_ReadU64LE ( SDL_RWops src,
Uint64 value 
)
extern

Use this function to read 64 bits of little-endian data from an SDL_RWops and return in native format.

SDL byteswaps the data only if necessary, so the data returned will be in the native byte order.

Parameters
srcthe stream from which to read data
valuea pointer filled in with the data read
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_ReadU8()

SDL_bool SDL_ReadU8 ( SDL_RWops src,
Uint8 value 
)
extern

Use this function to read a byte from an SDL_RWops.

Parameters
srcthe SDL_RWops to read from
valuea pointer filled in with the data read
Returns
SDL_TRUE on success or SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_RWclose()

int SDL_RWclose ( SDL_RWops context)
extern

Close and free an allocated SDL_RWops structure.

SDL_RWclose() closes and cleans up the SDL_RWops stream. It releases any resources used by the stream and frees the SDL_RWops itself with SDL_DestroyRW(). This returns 0 on success, or -1 if the stream failed to flush to its output (e.g. to disk).

Note that if this fails to flush the stream to disk, this function reports an error, but the SDL_RWops is still invalid once this function returns.

Parameters
contextSDL_RWops structure to close
Returns
0 on success or a negative error code on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.
See also
SDL_RWFromConstMem
SDL_RWFromFile
SDL_RWFromMem
SDL_RWread
SDL_RWseek
SDL_RWwrite

◆ SDL_RWFromConstMem()

SDL_RWops * SDL_RWFromConstMem ( const void *  mem,
size_t  size 
)
extern

Use this function to prepare a read-only memory buffer for use with RWops.

This function sets up an SDL_RWops struct based on a memory area of a certain size. It assumes the memory area is not writable.

Attempting to write to this RWops stream will report an error without writing to the memory buffer.

This memory buffer is not copied by the RWops; the pointer you provide must remain valid until you close the stream. Closing the stream will not free the original buffer.

If you need to write to a memory buffer, you should use SDL_RWFromMem() with a writable buffer of memory instead.

Parameters
mema pointer to a read-only buffer to feed an SDL_RWops stream
sizethe buffer size, in bytes
Returns
a pointer to a new SDL_RWops structure, or NULL if it fails; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.
See also
SDL_RWclose
SDL_RWFromConstMem
SDL_RWFromFile
SDL_RWFromMem
SDL_RWread
SDL_RWseek
SDL_RWtell

◆ SDL_RWFromFile()

SDL_RWops * SDL_RWFromFile ( const char *  file,
const char *  mode 
)
extern

Use this function to create a new SDL_RWops structure for reading from and/or writing to a named file.

The mode string is treated roughly the same as in a call to the C library's fopen(), even if SDL doesn't happen to use fopen() behind the scenes.

Available mode strings:

  • "r": Open a file for reading. The file must exist.
  • "w": Create an empty file for writing. If a file with the same name already exists its content is erased and the file is treated as a new empty file.
  • "a": Append to a file. Writing operations append data at the end of the file. The file is created if it does not exist.
  • "r+": Open a file for update both reading and writing. The file must exist.
  • "w+": Create an empty file for both reading and writing. If a file with the same name already exists its content is erased and the file is treated as a new empty file.
  • "a+": Open a file for reading and appending. All writing operations are performed at the end of the file, protecting the previous content to be overwritten. You can reposition (fseek, rewind) the internal pointer to anywhere in the file for reading, but writing operations will move it back to the end of file. The file is created if it does not exist.

NOTE: In order to open a file as a binary file, a "b" character has to be included in the mode string. This additional "b" character can either be appended at the end of the string (thus making the following compound modes: "rb", "wb", "ab", "r+b", "w+b", "a+b") or be inserted between the letter and the "+" sign for the mixed modes ("rb+", "wb+", "ab+"). Additional characters may follow the sequence, although they should have no effect. For example, "t" is sometimes appended to make explicit the file is a text file.

This function supports Unicode filenames, but they must be encoded in UTF-8 format, regardless of the underlying operating system.

As a fallback, SDL_RWFromFile() will transparently open a matching filename in an Android app's assets.

Closing the SDL_RWops will close the file handle SDL is holding internally.

Parameters
filea UTF-8 string representing the filename to open
modean ASCII string representing the mode to be used for opening the file.
Returns
a pointer to the SDL_RWops structure that is created, or NULL on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.
See also
SDL_RWclose
SDL_RWFromConstMem
SDL_RWFromMem
SDL_RWread
SDL_RWseek
SDL_RWtell
SDL_RWwrite

◆ SDL_RWFromMem()

SDL_RWops * SDL_RWFromMem ( void *  mem,
size_t  size 
)
extern

Use this function to prepare a read-write memory buffer for use with SDL_RWops.

This function sets up an SDL_RWops struct based on a memory area of a certain size, for both read and write access.

This memory buffer is not copied by the RWops; the pointer you provide must remain valid until you close the stream. Closing the stream will not free the original buffer.

If you need to make sure the RWops never writes to the memory buffer, you should use SDL_RWFromConstMem() with a read-only buffer of memory instead.

Parameters
mema pointer to a buffer to feed an SDL_RWops stream
sizethe buffer size, in bytes
Returns
a pointer to a new SDL_RWops structure, or NULL if it fails; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.
See also
SDL_RWclose
SDL_RWFromConstMem
SDL_RWFromFile
SDL_RWFromMem
SDL_RWread
SDL_RWseek
SDL_RWtell
SDL_RWwrite

◆ SDL_RWread()

size_t SDL_RWread ( SDL_RWops context,
void *  ptr,
size_t  size 
)
extern

Read from a data source.

This function reads up size bytes from the data source to the area pointed at by ptr. This function may read less bytes than requested. It will return zero when the data stream is completely read, or -1 on error. For streams that support non-blocking operation, if nothing was read because it would require blocking, this function returns -2 to distinguish that this is not an error or end-of-file, and the caller can try again later.

SDL_RWread() is actually a function wrapper that calls the SDL_RWops's read method appropriately, to simplify application development.

It is an error to specify a negative size, but this parameter is signed so you definitely cannot overflow the return value on a successful run with enormous amounts of data.

Parameters
contexta pointer to an SDL_RWops structure
ptra pointer to a buffer to read data into
sizethe number of bytes to read from the data source.
Returns
the number of bytes read, or 0 on end of file or other error.
Since
This function is available since SDL 3.0.0.
See also
SDL_RWclose
SDL_RWFromConstMem
SDL_RWFromFile
SDL_RWFromMem
SDL_RWseek
SDL_RWwrite

◆ SDL_RWseek()

Sint64 SDL_RWseek ( SDL_RWops context,
Sint64  offset,
int  whence 
)
extern

Seek within an SDL_RWops data stream.

This function seeks to byte offset, relative to whence.

whence may be any of the following values:

  • SDL_RW_SEEK_SET: seek from the beginning of data
  • SDL_RW_SEEK_CUR: seek relative to current read point
  • SDL_RW_SEEK_END: seek relative to the end of data

If this stream can not seek, it will return -1.

SDL_RWseek() is actually a wrapper function that calls the SDL_RWops's seek method appropriately, to simplify application development.

Parameters
contexta pointer to an SDL_RWops structure
offsetan offset in bytes, relative to whence location; can be negative
whenceany of SDL_RW_SEEK_SET, SDL_RW_SEEK_CUR, SDL_RW_SEEK_END
Returns
the final offset in the data stream after the seek or a negative error code on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.
See also
SDL_RWclose
SDL_RWFromConstMem
SDL_RWFromFile
SDL_RWFromMem
SDL_RWread
SDL_RWtell
SDL_RWwrite

◆ SDL_RWsize()

Sint64 SDL_RWsize ( SDL_RWops context)
extern

Use this function to get the size of the data stream in an SDL_RWops.

Parameters
contextthe SDL_RWops to get the size of the data stream from
Returns
the size of the data stream in the SDL_RWops on success or a negative error code on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_RWtell()

Sint64 SDL_RWtell ( SDL_RWops context)
extern

Determine the current read/write offset in an SDL_RWops data stream.

SDL_RWtell is actually a wrapper function that calls the SDL_RWops's seek method, with an offset of 0 bytes from SDL_RW_SEEK_CUR, to simplify application development.

Parameters
contextan SDL_RWops data stream object from which to get the current offset
Returns
the current offset in the stream, or -1 if the information can not be determined.
Since
This function is available since SDL 3.0.0.
See also
SDL_RWclose
SDL_RWFromConstMem
SDL_RWFromFile
SDL_RWFromMem
SDL_RWread
SDL_RWseek
SDL_RWwrite

◆ SDL_RWwrite()

size_t SDL_RWwrite ( SDL_RWops context,
const void *  ptr,
size_t  size 
)
extern

Write to an SDL_RWops data stream.

This function writes exactly size bytes from the area pointed at by ptr to the stream. If this fails for any reason, it'll return less than size to demonstrate how far the write progressed. On success, it returns num.

On error, this function still attempts to write as much as possible, so it might return a positive value less than the requested write size. If the function failed to write anything and there was an actual error, it will return -1. For streams that support non-blocking operation, if nothing was written because it would require blocking, this function returns -2 to distinguish that this is not an error and the caller can try again later.

SDL_RWwrite is actually a function wrapper that calls the SDL_RWops's write method appropriately, to simplify application development.

It is an error to specify a negative size, but this parameter is signed so you definitely cannot overflow the return value on a successful run with enormous amounts of data.

Parameters
contexta pointer to an SDL_RWops structure
ptra pointer to a buffer containing data to write
sizethe number of bytes to write
Returns
the number of bytes written, which will be less than num on error; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.
See also
SDL_RWclose
SDL_RWFromConstMem
SDL_RWFromFile
SDL_RWFromMem
SDL_RWread
SDL_RWseek

◆ SDL_WriteS16BE()

SDL_bool SDL_WriteS16BE ( SDL_RWops dst,
Sint16  value 
)
extern

Use this function to write 16 bits in native format to an SDL_RWops as big-endian data.

SDL byteswaps the data only if necessary, so the application always specifies native format, and the data written will be in big-endian format.

Parameters
dstthe stream to which data will be written
valuethe data to be written, in native format
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_WriteS16LE()

SDL_bool SDL_WriteS16LE ( SDL_RWops dst,
Sint16  value 
)
extern

Use this function to write 16 bits in native format to an SDL_RWops as little-endian data.

SDL byteswaps the data only if necessary, so the application always specifies native format, and the data written will be in little-endian format.

Parameters
dstthe stream to which data will be written
valuethe data to be written, in native format
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_WriteS32BE()

SDL_bool SDL_WriteS32BE ( SDL_RWops dst,
Sint32  value 
)
extern

Use this function to write 32 bits in native format to an SDL_RWops as big-endian data.

SDL byteswaps the data only if necessary, so the application always specifies native format, and the data written will be in big-endian format.

Parameters
dstthe stream to which data will be written
valuethe data to be written, in native format
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_WriteS32LE()

SDL_bool SDL_WriteS32LE ( SDL_RWops dst,
Sint32  value 
)
extern

Use this function to write 32 bits in native format to an SDL_RWops as little-endian data.

SDL byteswaps the data only if necessary, so the application always specifies native format, and the data written will be in little-endian format.

Parameters
dstthe stream to which data will be written
valuethe data to be written, in native format
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_WriteS64BE()

SDL_bool SDL_WriteS64BE ( SDL_RWops dst,
Sint64  value 
)
extern

Use this function to write 64 bits in native format to an SDL_RWops as big-endian data.

SDL byteswaps the data only if necessary, so the application always specifies native format, and the data written will be in big-endian format.

Parameters
dstthe stream to which data will be written
valuethe data to be written, in native format
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_WriteS64LE()

SDL_bool SDL_WriteS64LE ( SDL_RWops dst,
Sint64  value 
)
extern

Use this function to write 64 bits in native format to an SDL_RWops as little-endian data.

SDL byteswaps the data only if necessary, so the application always specifies native format, and the data written will be in little-endian format.

Parameters
dstthe stream to which data will be written
valuethe data to be written, in native format
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_WriteU16BE()

SDL_bool SDL_WriteU16BE ( SDL_RWops dst,
Uint16  value 
)
extern

Use this function to write 16 bits in native format to an SDL_RWops as big-endian data.

SDL byteswaps the data only if necessary, so the application always specifies native format, and the data written will be in big-endian format.

Parameters
dstthe stream to which data will be written
valuethe data to be written, in native format
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_WriteU16LE()

SDL_bool SDL_WriteU16LE ( SDL_RWops dst,
Uint16  value 
)
extern

Use this function to write 16 bits in native format to an SDL_RWops as little-endian data.

SDL byteswaps the data only if necessary, so the application always specifies native format, and the data written will be in little-endian format.

Parameters
dstthe stream to which data will be written
valuethe data to be written, in native format
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_WriteU32BE()

SDL_bool SDL_WriteU32BE ( SDL_RWops dst,
Uint32  value 
)
extern

Use this function to write 32 bits in native format to an SDL_RWops as big-endian data.

SDL byteswaps the data only if necessary, so the application always specifies native format, and the data written will be in big-endian format.

Parameters
dstthe stream to which data will be written
valuethe data to be written, in native format
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_WriteU32LE()

SDL_bool SDL_WriteU32LE ( SDL_RWops dst,
Uint32  value 
)
extern

Use this function to write 32 bits in native format to an SDL_RWops as little-endian data.

SDL byteswaps the data only if necessary, so the application always specifies native format, and the data written will be in little-endian format.

Parameters
dstthe stream to which data will be written
valuethe data to be written, in native format
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_WriteU64BE()

SDL_bool SDL_WriteU64BE ( SDL_RWops dst,
Uint64  value 
)
extern

Use this function to write 64 bits in native format to an SDL_RWops as big-endian data.

SDL byteswaps the data only if necessary, so the application always specifies native format, and the data written will be in big-endian format.

Parameters
dstthe stream to which data will be written
valuethe data to be written, in native format
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_WriteU64LE()

SDL_bool SDL_WriteU64LE ( SDL_RWops dst,
Uint64  value 
)
extern

Use this function to write 64 bits in native format to an SDL_RWops as little-endian data.

SDL byteswaps the data only if necessary, so the application always specifies native format, and the data written will be in little-endian format.

Parameters
dstthe stream to which data will be written
valuethe data to be written, in native format
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.

◆ SDL_WriteU8()

SDL_bool SDL_WriteU8 ( SDL_RWops dst,
Uint8  value 
)
extern

Use this function to write a byte to an SDL_RWops.

Parameters
dstthe SDL_RWops to write to
valuethe byte value to write
Returns
SDL_TRUE on successful write, SDL_FALSE on failure; call SDL_GetError() for more information.
Since
This function is available since SDL 3.0.0.