WhatsNew
author Sam Lantinga <slouken@libsdl.org>
Thu, 10 Jul 2003 07:46:19 +0000
changeset 648 12a21d82a060
parent 451 24edec3cafe4
child 655 9c42ee1b7d77
permissions -rw-r--r--
Exposed SDL_LoadObject(), SDL_LoadFunction(), and SDL_UnloadObject() APIs
     1 
     2 This is a list of API changes in SDL's version history.
     3 
     4 Version 1.0:
     5 
     6 1.2.6:
     7 	Added SDL_LoadObject(), SDL_LoadFunction(), and SDL_UnloadObject()
     8 
     9 1.2.5:
    10 	Added SDL_BUTTON_WHEELUP (4) and SDL_BUTTON_WHEELDOWN (5)
    11 
    12 	Added SDL_GL_STEREO for stereoscopic OpenGL contexts
    13 
    14 1.2.0:
    15 	Added SDL_VIDEOEXPOSE event to signal that the screen needs to
    16 	be redrawn.  This is currently only delivered to OpenGL windows
    17 	on X11, though it may be delivered in the future when the video
    18 	memory is lost under DirectX.
    19 
    20 1.1.8:
    21 	You can pass SDL_NOFRAME to SDL_VideoMode() to create a window
    22 	that has no title bar or frame decoration.  Fullscreen video
    23 	modes automatically have this flag set.
    24 
    25 	Added a function to query the clipping rectangle for a surface:
    26 		void SDL_GetClipRect(SDL_Surface *surface, SDL_Rect *rect)
    27 
    28 	Added a function to query the current event filter:
    29 		SDL_EventFilter SDL_GetEventFilter(void)
    30 
    31 	If you pass -1 to SDL_ShowCursor(), it won't change the current
    32 	cursor visibility state, but will still return it.
    33 
    34 	SDL_LockSurface() and SDL_UnlockSurface() are recursive, meaning
    35 	you can nest them as deep as you want, as long as each lock call
    36 	has a matching unlock call.  The surface remains locked until the
    37 	last matching unlock call.
    38 
    39 	Note that you may not blit to or from a locked surface.
    40 
    41 1.1.7:
    42 	The SDL_SetGammaRamp() and SDL_GetGammaRamp() functions now take
    43 	arrays of Uint16 values instead of Uint8 values.  For the most part,
    44 	you can just take your old values and shift them up 8 bits to get
    45 	new correct values for your gamma ramps.
    46 
    47 	You can pass SDL_RLEACCEL in flags passed to SDL_ConvertSurface()
    48         and SDL will try to RLE accelerate colorkey and alpha blits in the
    49 	resulting surface.
    50 
    51 1.1.6:
    52 	Added a function to return the thread ID of a specific thread:
    53 		Uint32 SDL_GetThreadID(SDL_Thread *thread)
    54 	If 'thread' is NULL, this function returns the id for this thread.
    55 
    56 1.1.5:
    57 	The YUV overlay structure has been changed to use an array of
    58 	pitches and pixels representing the planes of a YUV image, to
    59 	better enable hardware acceleration.  The YV12 and IYUV formats
    60 	each have three planes, corresponding to the Y, U, and V portions
    61 	of the image, while packed pixel YUV formats just have one plane.
    62 
    63 	For palettized mode (8bpp), the screen colormap is now split in
    64 	a physical and a logical palette. The physical palette determines
    65 	what colours the screen pixels will get when displayed, and the
    66 	logical palette controls the mapping from blits to/from the screen.
    67 	A new function, SDL_SetPalette() has been added to change
    68 	logical and physical palettes separately. SDL_SetColors() works
    69 	just as before, and is equivalent to calling SDL_SetPalette() with
    70 	a flag argument of (SDL_LOGPAL|SDL_PHYSPAL).
    71 
    72 	SDL_BlitSurface() no longer modifies the source rectangle, only the
    73 	destination rectangle. The width/height members of the destination
    74 	rectangle are ignored, only the position is used.
    75 
    76 	The old source clipping function SDL_SetClipping() has been replaced
    77 	with a more useful function to set the destination clipping rectangle:
    78 		SDL_bool SDL_SetClipRect(SDL_Surface *surface, SDL_Rect *rect)
    79 		
    80 	Added a function to see what subsystems have been initialized:
    81 		Uint32 SDL_WasInit(Uint32 flags)
    82 
    83 	The Big Alpha Flip: SDL now treats alpha as opacity like everybody
    84 	else, and not as transparency:
    85 
    86 	A new cpp symbol: SDL_ALPHA_OPAQUE is defined as 255
    87 	A new cpp symbol: SDL_ALPHA_TRANSPARENT is defined as 0
    88 	Values between 0 and 255 vary from fully transparent to fully opaque.
    89 
    90 	New functions:
    91 	SDL_DisplayFormatAlpha()
    92 	    Returns a surface converted to a format with alpha-channel
    93 	    that can be blit efficiently to the screen. (In other words,
    94 	    like SDL_DisplayFormat() but the resulting surface has
    95 	    an alpha channel.)  This is useful for surfaces with alpha.
    96 	SDL_MapRGBA()
    97 	    Works as SDL_MapRGB() but takes an additional alpha parameter.
    98 	SDL_GetRGBA()
    99 	    Works as SDL_GetRGB() but also returns the alpha value
   100 	    (SDL_ALPHA_OPAQUE for formats without an alpha channel)
   101 
   102 	Both SDL_GetRGB() and SDL_GetRGBA() now always return values in
   103 	the [0..255] interval. Previously, SDL_GetRGB() would return
   104 	(0xf8, 0xfc, 0xf8) for a completely white pixel in RGB565 format.
   105 	(N.B.: This is broken for bit fields < 3 bits.)
   106 
   107 	SDL_MapRGB() returns pixels in which the alpha channel is set opaque.
   108 
   109 	SDL_SetAlpha() can now be used for both setting the per-surface
   110 	alpha, using the new way of thinking of alpha, and also to enable
   111 	and disable per-pixel alpha blending for surfaces with an alpha
   112 	channel:
   113 		To disable alpha blending:
   114 			SDL_SetAlpha(surface, 0, 0);
   115 		To re-enable alpha blending:
   116 			SDL_SetAlpha(surface, SDL_SRCALPHA, 0);
   117 	Surfaces with an alpha channel have blending enabled by default.
   118 
   119 	SDL_SetAlpha() now accepts SDL_RLEACCEL as a flag, which requests
   120 	RLE acceleration of blits, just as like with SDL_SetColorKey().
   121 	This flag can be set for both surfaces with an alpha channel
   122 	and surfaces with an alpha value set by SDL_SetAlpha().
   123 	As always, RLE surfaces must be locked before pixel access is
   124 	allowed, and unlocked before any other SDL operations are done
   125 	on it.
   126 
   127 	The blit semantics for surfaces with and without alpha and colorkey
   128 	have now been defined:
   129 
   130 	RGBA->RGB:
   131 	    SDL_SRCALPHA set:
   132 		alpha-blend (using alpha-channel).
   133 		SDL_SRCCOLORKEY ignored.
   134 	    SDL_SRCALPHA not set:
   135 		copy RGB.
   136 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   137 		RGB values of the source colour key, ignoring alpha in the
   138 		comparison.
   139 
   140 	RGB->RGBA:
   141 	    SDL_SRCALPHA set:
   142 		alpha-blend (using the source per-surface alpha value);
   143 		set destination alpha to opaque.
   144 	    SDL_SRCALPHA not set:
   145 		copy RGB, set destination alpha to opaque.
   146 	    both:
   147 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   148 		source colour key.
   149 
   150 	RGBA->RGBA:
   151 	    SDL_SRCALPHA set:
   152 		alpha-blend (using the source alpha channel) the RGB values;
   153 		leave destination alpha untouched. [Note: is this correct?]
   154 		SDL_SRCCOLORKEY ignored.
   155 	    SDL_SRCALPHA not set:
   156 		copy all of RGBA to the destination.
   157 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   158 		RGB values of the source colour key, ignoring alpha in the
   159 		comparison.
   160 
   161 	RGB->RGB: 
   162 	    SDL_SRCALPHA set:
   163 		alpha-blend (using the source per-surface alpha value).
   164 	    SDL_SRCALPHA not set:
   165 		copy RGB.
   166 	    both:
   167 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   168 		source colour key.
   169 
   170 	As a special case, blits from surfaces with per-surface alpha
   171 	value of 128 (50% transparency) are optimised and much faster
   172 	than other alpha values. This does not apply to surfaces with
   173 	alpha channels (per-pixel alpha).
   174 
   175 	New functions for manipulating the gamma of the display have
   176 	been added:
   177 		int SDL_SetGamma(float red, float green, float blue);
   178 		int SDL_SetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   179 		int SDL_GetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   180 	Gamma ramps are tables with 256 entries which map the screen color
   181 	components into actually displayed colors.  For an example of
   182 	implementing gamma correction and gamma fades, see test/testgamma.c
   183 	Gamma control is not supported on all hardware.
   184 
   185 1.1.4:
   186 	The size of the SDL_CDtrack structure changed from 8 to 12 bytes
   187 	as the size of the length member was extended to 32 bits.
   188 
   189         You can now use SDL for 2D blitting with a GL mode by passing the
   190 	SDL_OPENGLBLIT flag to SDL_SetVideoMode().  You can specify 16 or
   191 	32 bpp, and the data in the framebuffer is put into the GL scene
   192 	when you call SDL_UpdateRects(), and the scene will be visible
   193 	when you call SDL_GL_SwapBuffers().
   194 
   195 	Run the "testgl" test program with the -logo command line option
   196 	to see an example of this blending of 2D and 3D in SDL.
   197 
   198 1.1.3:
   199 	Added SDL_FreeRW() to the API, to complement SDL_AllocRW()
   200 
   201 	Added resizable window support - just add SDL_RESIZABLE to the
   202 	SDL_SetVideoMode() flags, and then wait for SDL_VIDEORESIZE events.
   203 	See SDL_events.h for details on the new SDL_ResizeEvent structure.
   204 
   205 	Added condition variable support, based on mutexes and semaphores.
   206 		SDL_CreateCond()
   207 		SDL_DestroyCond()
   208 		SDL_CondSignal()
   209 		SDL_CondBroadcast()
   210 		SDL_CondWait()
   211 		SDL_CondTimedWait()
   212 	The new function prototypes are in SDL_mutex.h
   213 
   214 	Added counting semaphore support, based on the mutex primitive.
   215 		SDL_CreateSemaphore()
   216 		SDL_DestroySemaphore()
   217 		SDL_SemWait()
   218 		SDL_SemTryWait()
   219 		SDL_SemWaitTimeout()
   220 		SDL_SemPost()
   221 		SDL_SemValue()
   222 	The new function prototypes are in SDL_mutex.h
   223 
   224 	Added support for asynchronous blitting.  To take advantage of this,
   225 	you must set the SDL_ASYNCBLIT flag when setting the video mode and
   226 	creating surfaces that you want accelerated in this way.  You must
   227 	lock surfaces that have this flag set, and the lock will block until
   228 	any queued blits have completed.
   229 
   230 	Added YUV video overlay support.
   231 	The supported YUV formats are: YV12, IYUV, YUY2, UYVY, and YVYU.
   232 	This function creates an overlay surface:
   233 		SDL_CreateYUVOverlay()
   234 	You must lock and unlock the overlay to get access to the data:
   235 		SDL_LockYUVOverlay() SDL_UnlockYUVOverlay()
   236 	You can then display the overlay:
   237 		SDL_DisplayYUVOverlay()
   238 	You must free the overlay when you are done using it:
   239 		SDL_FreeYUVOverlay()
   240 	See SDL_video.h for the full function prototypes.
   241 
   242 	The joystick hat position constants have been changed:
   243 	Old constant            New constant
   244 	------------            ------------
   245 	     0                  SDL_HAT_CENTERED
   246 	     1                  SDL_HAT_UP
   247 	     2                  SDL_HAT_RIGHTUP
   248 	     3                  SDL_HAT_RIGHT
   249 	     4                  SDL_HAT_RIGHTDOWN
   250 	     5                  SDL_HAT_DOWN
   251 	     6                  SDL_HAT_LEFTDOWN
   252 	     7                  SDL_HAT_LEFT
   253 	     8                  SDL_HAT_LEFTUP
   254 	The new constants are bitmasks, so you can check for the
   255 	individual axes like this:
   256 		if ( hat_position & SDL_HAT_UP ) {
   257 		}
   258 	and you'll catch left-up, up, and right-up.
   259 
   260 1.1.2:
   261 	Added multiple timer support:
   262 		SDL_AddTimer() and SDL_RemoveTimer()
   263 
   264 	SDL_WM_SetIcon() now respects the icon colorkey if mask is NULL.
   265 
   266 1.1.0:
   267 	Added initial OpenGL support.
   268 	First set GL attributes (such as RGB depth, alpha depth, etc.)
   269 		SDL_GL_SetAttribute()
   270 	Then call SDL_SetVideoMode() with the SDL_OPENGL flag.
   271 	Perform all of your normal GL drawing.
   272 	Finally swap the buffers with the new SDL function:
   273 		SDL_GL_SwapBuffers()
   274 	See the new 'testgl' test program for an example of using GL with SDL.
   275 
   276 	You can load GL extension functions by using the function:
   277 		SDL_GL_LoadProcAddress()
   278 
   279 	Added functions to initialize and cleanup specific SDL subsystems:
   280 		SDL_InitSubSystem() and SDL_QuitSubSystem()
   281 
   282 	Added user-defined event type:
   283 		typedef struct {
   284         		Uint8 type;
   285         		int code;
   286         		void *data1;
   287         		void *data2;
   288 		} SDL_UserEvent;
   289 	This structure is in the "user" member of an SDL_Event.
   290 
   291 	Added a function to push events into the event queue:
   292 		SDL_PushEvent()
   293 
   294 	Example of using the new SDL user-defined events:
   295 	{
   296 		SDL_Event event;
   297 
   298 		event.type = SDL_USEREVENT;
   299 		event.user.code = my_event_code;
   300 		event.user.data1 = significant_data;
   301 		event.user.data2 = 0;
   302 		SDL_PushEvent(&event);
   303 	}
   304 
   305 	Added a function to get mouse deltas since last query:
   306 		SDL_GetRelativeMouseState()
   307 
   308 	Added a boolean datatype to SDL_types.h:
   309 		SDL_bool = { SDL_TRUE, SDL_FALSE }
   310 
   311 	Added a function to get the current audio status:
   312 		SDL_GetAudioState();
   313 	It returns one of:
   314 		SDL_AUDIO_STOPPED,
   315 		SDL_AUDIO_PLAYING,
   316 		SDL_AUDIO_PAUSED
   317 
   318 	Added an AAlib driver (ASCII Art) - by Stephane Peter.
   319 
   320 1.0.6:
   321 	The input grab state is reset after each call to SDL_SetVideoMode().
   322 	The input is grabbed by default in fullscreen mode, and ungrabbed in
   323 	windowed mode.  If you want to set input grab to a particular value,
   324 	you should set it after each call to SDL_SetVideoMode().
   325 
   326 1.0.5:
   327 	Exposed SDL_AudioInit(), SDL_VideoInit()
   328 	Added SDL_AudioDriverName() and SDL_VideoDriverName()
   329 
   330 	Added new window manager function:
   331 		SDL_WM_ToggleFullScreen()
   332 	This is currently implemented only on Linux
   333 
   334 	The ALT-ENTER code has been removed - it's not appropriate for a
   335 	lib to bind keys when they aren't even emergency escape sequences.
   336 
   337 	ALT-ENTER functionality can be implemented with the following code:
   338 
   339 	int Handle_AltEnter(const SDL_Event *event)
   340 	{
   341 	    if ( event->type == SDL_KEYDOWN ) {
   342 	        if ( (event->key.keysym.sym == SDLK_RETURN) &&
   343 	             (event->key.keysym.mod & KMOD_ALT) ) {   
   344 	                SDL_WM_ToggleFullScreen(SDL_GetVideoSurface());
   345 	                return(0);
   346 	        }
   347 	    }
   348 	    return(1);
   349 	}
   350 	SDL_SetEventFilter(Handle_AltEnter);
   351 
   352 1.0.3:
   353 	Under X11, if you grab the input and hide the mouse cursor,
   354 	the mouse will go into a "relative motion" mode where you
   355 	will always get relative motion events no matter how far in
   356 	each direction you move the mouse - relative motion is not
   357 	bounded by the edges of the window (though the absolute values
   358 	of the mouse positions are clamped by the size of the window).
   359 	The SVGAlib, framebuffer console, and DirectInput drivers all
   360 	have this behavior naturally, and the GDI and BWindow drivers
   361 	never go into "relative motion" mode.
   362 
   363 1.0.2:
   364 	Added a function to enable keyboard repeat:
   365 		SDL_EnableKeyRepeat()
   366 
   367 	Added a function to grab the mouse and keyboard input
   368 		SDL_WM_GrabInput()
   369 
   370 	Added a function to iconify the window.
   371 		SDL_WM_IconifyWindow()
   372 	If this function succeeds, the application will receive an event
   373 	signaling SDL_APPACTIVE event 
   374 
   375 1.0.1:
   376 	Added constants to SDL_audio.h for 16-bit native byte ordering:
   377 		AUDIO_U16SYS, AUDIO_S16SYS
   378 
   379 1.0.0:
   380 	New public release
   381 
   382 Version 0.11:
   383 
   384 0.11.5:
   385 	A new function SDL_GetVideoSurface() has been added, and returns
   386 	a pointer to the current display surface.
   387 
   388 	SDL_AllocSurface() has been renamed SDL_CreateRGBSurface(), and
   389 	a new function SDL_CreateRGBSurfaceFrom() has been added to allow
   390 	creating an SDL surface from an existing pixel data buffer.
   391 
   392 	Added SDL_GetRGB() to the headers and documentation.
   393 
   394 0.11.4:
   395 	SDL_SetLibraryPath() is no longer meaningful, and has been removed.
   396 
   397 0.11.3:
   398 	A new flag for SDL_Init(), SDL_INIT_NOPARACHUTE, prevents SDL from
   399 	installing fatal signal handlers on operating systems that support
   400 	them.
   401 
   402 Version 0.9:
   403 
   404 0.9.15:
   405 	SDL_CreateColorCursor() has been removed.  Color cursors should
   406 	be implemented as sprites, blitted by the application when the
   407 	cursor moves.  To get smooth color cursor updates when the app
   408 	is busy, pass the SDL_INIT_EVENTTHREAD flag to SDL_Init().  This
   409 	allows you to handle the mouse motion in another thread from an
   410 	event filter function, but is currently only supported by Linux
   411 	and BeOS.  Note that you'll have to protect the display surface
   412 	from multi-threaded access by using mutexes if you do this.
   413 
   414 	Thread-safe surface support has been removed from SDL.
   415 	This makes blitting somewhat faster, by removing SDL_MiddleBlit().
   416 	Code that used SDL_MiddleBlit() should use SDL_LowerBlit() instead.
   417 	You can make your surfaces thread-safe by allocating your own
   418 	mutex and making lock/unlock calls around accesses to your surface.
   419 
   420 0.9.14:
   421 	SDL_GetMouseState() now takes pointers to int rather than Uint16.
   422 
   423 	If you set the SDL_WINDOWID environment variable under UNIX X11,
   424 	SDL will use that as the main window instead of creating it's own.
   425 	This is an unsupported extension to SDL, and not portable at all.
   426 
   427 0.9.13:
   428 	Added a function SDL_SetLibraryPath() which can be used to specify
   429 	the directory containing the SDL dynamic libraries.  This is useful
   430 	for commercial applications which ship with particular versions
   431 	of the libraries, and for security on multi-user systems.
   432 	If this function is not used, the default system directories are 
   433 	searched using the native dynamic object loading mechanism.
   434 
   435 	In order to support C linkage under Visual C++, you must declare
   436 	main() without any return type:
   437 		main(int argc, char *argv[]) {
   438 			/* Do the program... */
   439 			return(0);
   440 		}
   441 	C++ programs should also return a value if compiled under VC++.
   442 
   443 	The blit_endian member of the SDL_VideoInfo struct has been removed.
   444 
   445 	SDL_SymToASCII() has been replaced with SDL_GetKeyName(), so there
   446 	is now no longer any function to translate a keysym to a character.
   447 
   448 	The SDL_keysym structure has been extended with a 'scancode' and
   449 	'unicode' member.  The 'scancode' is a hardware specific scancode
   450 	for the key that was pressed, and may be 0.  The 'unicode' member
   451 	is a 16-bit UNICODE translation of the key that was pressed along
   452 	with any modifiers or compose keys that have been pressed.
   453 	If no UNICODE translation exists for the key, 'unicode' will be 0.
   454 
   455 	Added a function SDL_EnableUNICODE() to enable/disable UNICODE
   456 	translation of character keypresses.  Translation defaults off.
   457 
   458 	To convert existing code to use the new API, change code which
   459 	uses SDL_SymToASCII() to get the keyname to use SDL_GetKeyName(),
   460 	and change code which uses it to get the ASCII value of a sym to
   461 	use the 'unicode' member of the event keysym.
   462 
   463 0.9.12:
   464 	There is partial support for 64-bit datatypes.  I don't recommend 
   465 	you use this if you have a choice, because 64-bit datatypes are not
   466 	supported on many platforms.  On platforms for which it is supported,
   467 	the SDL_HAS_64BIT_TYPE C preprocessor define will be enabled, and
   468 	you can use the Uint64 and Sint64 datatypes.
   469 
   470 	Added functions to SDL_endian.h to support 64-bit datatypes:
   471 	    SDL_SwapLE64(), SDL_SwapBE64(),
   472 	    SDL_ReadLE64(), SDL_ReadBE64(), SDL_WriteLE64(), SDL_WriteBE64()
   473 
   474 	A new member "len_ratio" has been added to the SDL_AudioCVT structure,
   475 	and allows you to determine either the original buffer length or the
   476 	converted buffer length, given the other.
   477 
   478 	A new function SDL_FreeWAV() has been added to the API to free data
   479 	allocated by SDL_LoadWAV_RW().  This is necessary under Win32 since
   480 	the gcc compiled DLL uses a different heap than VC++ compiled apps.
   481 
   482 	SDL now has initial support for international keyboards using the
   483 	Latin character set.
   484 	If a particular mapping is desired, you can set the DEFAULT_KEYBOARD
   485 	compile-time variable, or you can set the environment variable 
   486 	"SDL_KEYBOARD" to a string identifying the keyboard mapping you desire.
   487 	The valid values for these variables can be found in SDL_keyboard.c
   488 
   489 	Full support for German and French keyboards under X11 is implemented.
   490 
   491 0.9.11:
   492 	The THREADED_EVENTS compile-time define has been replaced with the
   493 	SDL_INIT_EVENTTHREAD flag.  If this flag is passed to SDL_Init(),
   494 	SDL will create a separate thread to perform input event handling.
   495 	If this flag is passed to SDL_Init(), and the OS doesn't support 
   496 	event handling in a separate thread, SDL_Init() will fail.
   497 	Be sure to add calls to SDL_Delay() in your main thread to allow
   498 	the OS to schedule your event thread, or it may starve, leading
   499 	to slow event delivery and/or dropped events.
   500 	Currently MacOS and Win32 do not support this flag, while BeOS 
   501 	and Linux do support it.  I recommend that your application only
   502 	use this flag if absolutely necessary.
   503 
   504 	The SDL thread function passed to SDL_CreateThread() now returns a
   505 	status.  This status can be retrieved by passing a non-NULL pointer
   506 	as the 'status' argument to SDL_WaitThread().
   507 
   508 	The volume parameter to SDL_MixAudio() has been increased in range
   509 	from (0-8) to (0-128)
   510 
   511 	SDL now has a data source abstraction which can encompass a file,
   512 	an area of memory, or any custom object you can envision.  It uses
   513 	these abstractions, SDL_RWops, in the endian read/write functions,
   514 	and the built-in WAV and BMP file loaders.  This means you can load
   515 	WAV chunks from memory mapped files, compressed archives, network
   516 	pipes, or anything else that has a data read abstraction.
   517 
   518 	There are three built-in data source abstractions:
   519 	    SDL_RWFromFile(), SDL_RWFromFP(), SDL_RWFromMem()
   520 	along with a generic data source allocation function:
   521 	    SDL_AllocRW()
   522 	These data sources can be used like stdio file pointers with the
   523 	following convenience functions:
   524 	    SDL_RWseek(), SDL_RWread(), SDL_RWwrite(), SDL_RWclose()
   525 	These functions are defined in the new header file "SDL_rwops.h"
   526 
   527 	The endian swapping functions have been turned into macros for speed
   528 	and SDL_CalculateEndian() has been removed.  SDL_endian.h now defines
   529 	SDL_BYTEORDER as either SDL_BIG_ENDIAN or SDL_LIL_ENDIAN depending on
   530 	the endianness of the host system.
   531 
   532 	The endian read/write functions now take an SDL_RWops pointer
   533 	instead of a stdio FILE pointer, to support the new data source
   534 	abstraction.
   535 
   536 	The SDL_*LoadWAV() functions have been replaced with a single
   537 	SDL_LoadWAV_RW() function that takes a SDL_RWops pointer as it's
   538 	first parameter, and a flag whether or not to automatically 
   539 	free it as the second parameter.  SDL_LoadWAV() is a macro for
   540 	backward compatibility and convenience:
   541 	    SDL_LoadWAV_RW(SDL_RWFromFile("sample.wav", "rb"), 1, ...);
   542 
   543 	The SDL_*LoadBMP()/SDL_*SaveBMP() functions have each been replaced
   544 	with a single function that takes a SDL_RWops pointer as it's
   545 	first parameter, and a flag whether or not to automatically 
   546 	free it as the second parameter.  SDL_LoadBMP() and SDL_SaveBMP()
   547 	are macros for backward compatibility and convenience:
   548 	    SDL_LoadBMP_RW(SDL_RWFromFile("sample.bmp", "rb"), 1, ...);
   549 	    SDL_SaveBMP_RW(SDL_RWFromFile("sample.bmp", "wb"), 1, ...);
   550 	Note that these functions use SDL_RWseek() extensively, and should
   551 	not be used on pipes or other non-seekable data sources.
   552 
   553 0.9.10:
   554 	The Linux SDL_SysWMInfo and SDL_SysWMMsg structures have been 
   555 	extended to support multiple types of display drivers, as well as
   556         safe access to the X11 display when THREADED_EVENTS is enabled.
   557         The new structures are documented in the SDL_syswm.h header file.
   558 
   559 	Thanks to John Elliott <jce@seasip.demon.co.uk>, the UK keyboard
   560 	should now work properly, as well as the "Windows" keys on US
   561 	keyboards.
   562 
   563 	The Linux CD-ROM code now reads the CD-ROM devices from /etc/fstab
   564 	instead of trying to open each block device on the system.
   565 	The CD must be listed in /etc/fstab as using the iso9660 filesystem.
   566 
   567 	On Linux, if you define THREADED_EVENTS at compile time, a separate
   568 	thread will be spawned to gather X events asynchronously from the
   569 	graphics updates.  This hasn't been extensively tested, but it does
   570 	provide a means of handling keyboard and mouse input in a separate
   571 	thread from the graphics thread.  (This is now enabled by default.)
   572 
   573 	A special access function SDL_PeepEvents() allows you to manipulate
   574 	the event queue in a thread-safe manner, including peeking at events,
   575 	removing events of a specified type, and adding new events of arbitrary
   576 	type to the queue (use the new 'user' member of the SDL_Event type).
   577 
   578 	If you use SDL_PeepEvents() to gather events, then the main graphics
   579 	thread needs to call SDL_PumpEvents() periodically to drive the event
   580 	loop and generate input events.  This is not necessary if SDL has been 
   581 	compiled with THREADED_EVENTS defined, but doesn't hurt.
   582 
   583 	A new function SDL_ThreadID() returns the identifier associated with
   584 	the current thread.
   585 
   586 0.9.9:
   587 	The AUDIO_STEREO format flag has been replaced with a new 'channels'
   588 	member of the SDL_AudioSpec structure.  The channels are 1 for mono
   589 	audio, and 2 for stereo audio.  In the future more channels may be
   590 	supported for 3D surround sound.
   591 
   592 	The SDL_MixAudio() function now takes an additional volume parameter,
   593 	which should be set to SDL_MIX_MAXVOLUME for compatibility with the
   594 	original function.
   595 
   596 	The CD-ROM functions which take a 'cdrom' parameter can now be
   597 	passed NULL, and will act on the last successfully opened CD-ROM.
   598 
   599 0.9.8:
   600 	No changes, bugfixes only.
   601 	
   602 0.9.7:
   603 	No changes, bugfixes only.
   604 	
   605 0.9.6:
   606 	Added a fast rectangle fill function: SDL_FillRect()
   607 
   608 	Addition of a useful function for getting info on the video hardware:
   609 	    const SDL_VideoInfo *SDL_GetVideoInfo(void)
   610         This function replaces SDL_GetDisplayFormat().
   611 
   612 	Initial support for double-buffering:
   613 	  Use the SDL_DOUBLEBUF flag in SDL_SetVideoMode()
   614 	  Update the screen with a new function: SDL_Flip()
   615 
   616 	SDL_AllocSurface() takes two new flags:
   617 	SDL_SRCCOLORKEY means that the surface will be used for colorkey blits
   618 	  and if the hardware supports hardware acceleration of colorkey blits
   619 	  between two surfaces in video memory, to place the surface in video
   620 	  memory if possible, otherwise it will be placed in system memory.
   621 	SDL_SRCALPHA means that the surface will be used for alpha blits and
   622 	  if the hardware supports hardware acceleration of alpha blits between
   623 	  two surfaces in video memory, to place the surface in video memory
   624 	  if possible, otherwise it will be placed in system memory.
   625 	SDL_HWSURFACE now means that the surface will be created with the 
   626 	  same format as the display surface, since having surfaces in video
   627 	  memory is only useful for fast blitting to the screen, and you can't
   628 	  blit surfaces with different surface formats in video memory.
   629 
   630 0.9.5:
   631 	You can now pass a NULL mask to SDL_WM_SetIcon(), and it will assume
   632 	that the icon consists of the entire image.
   633 
   634 	SDL_LowerBlit() is back -- but don't use it on the display surface.
   635 	It is exactly the same as SDL_MiddleBlit(), but doesn't check for
   636 	thread safety.
   637 
   638 	Added SDL_FPLoadBMP(), SDL_FPSaveBMP(), SDL_FPLoadWAV(), which take
   639 	a FILE pointer instead of a file name.
   640 
   641 	Added CD-ROM audio control API:
   642 	    SDL_CDNumDrives()
   643 	    SDL_CDName()
   644 	    SDL_CDOpen()
   645 	    SDL_CDStatus()
   646 	    SDL_CDPlayTracks()
   647 	    SDL_CDPlay()
   648 	    SDL_CDPause()
   649 	    SDL_CDResume()
   650 	    SDL_CDStop()
   651 	    SDL_CDEject()
   652 	    SDL_CDClose()
   653 
   654 0.9.4:
   655 	No changes, bugfixes only.
   656 
   657 0.9.3:
   658 	Mouse motion event now includes relative motion information:
   659 	    Sint16 event->motion.xrel, Sint16 event->motion.yrel
   660 
   661 	X11 keyrepeat handling can be disabled by defining IGNORE_X_KEYREPEAT
   662 	    (Add -DIGNORE_X_KEYREPEAT to CFLAGS line in obj/x11Makefile)
   663 
   664 0.9.2:
   665 	No changes, bugfixes only.
   666 
   667 0.9.1:
   668 	Removed SDL_MapSurface() and SDL_UnmapSurface() -- surfaces are now
   669 	automatically mapped on blit.
   670 
   671 0.8.0:
   672 	SDL stable release