WhatsNew
author Sam Lantinga <slouken@libsdl.org>
Thu, 04 May 2006 16:51:07 +0000
changeset 1765 c2c6ff414ef5
parent 1737 eacc5bc01d1c
child 1794 5605a9820134
permissions -rw-r--r--
Fixed bug #45

Improved Xinerama support.
Added support for the SDL_VIDEO_FULLSCREEN_HEAD environment variable, currently supported on X11 Xinerama configurations.
Only use the VidMode extension on the primary head.
     1 
     2 This is a list of API changes in SDL's version history.
     3 
     4 Version 1.0:
     5 
     6 1.2.10:
     7 	Added support for the SDL_VIDEO_FULLSCREEN_HEAD environment
     8 	variable, currently supported on X11 Xinerama configurations.
     9 
    10 	Added SDL_GL_SWAP_CONTROL to wait for vsync in OpenGL applications.
    11 
    12 	Added SDL_GL_ACCELERATED_VISUAL to guarantee hardware acceleration.
    13 
    14 	Added current_w and current_h to the SDL_VideoInfo structure,
    15 	which is set to the desktop resolution during video intialization,
    16 	and then set to the current resolution when a video mode is set.
    17 
    18 	SDL_SetVideoMode() now accepts 0 for width or height and will use
    19 	the current video mode (or the desktop mode if no mode has been set.)
    20 
    21 	Added SDL_GetKeyRepeat()
    22 
    23 	Added SDL_config.h, with defaults for various build environments.
    24 
    25 1.2.7:
    26 	Added CPU feature detection functions to SDL_cpuinfo.h:
    27 		SDL_HasRDTSC(), SDL_HasMMX(), SDL_Has3DNow(), SDL_HasSSE(),
    28 		SDL_HasAltiVec()
    29 	Added function to create RWops from const memory: SDL_RWFromConstMem()
    30 
    31 1.2.6:
    32 	Added SDL_LoadObject(), SDL_LoadFunction(), and SDL_UnloadObject()
    33 
    34 	Added SDL_GL_MULTISAMPLEBUFFERS and SDL_GL_MULTISAMPLESAMPLES for FSAA
    35 
    36 1.2.5:
    37 	Added SDL_BUTTON_WHEELUP (4) and SDL_BUTTON_WHEELDOWN (5)
    38 
    39 	Added SDL_GL_STEREO for stereoscopic OpenGL contexts
    40 
    41 1.2.0:
    42 	Added SDL_VIDEOEXPOSE event to signal that the screen needs to
    43 	be redrawn.  This is currently only delivered to OpenGL windows
    44 	on X11, though it may be delivered in the future when the video
    45 	memory is lost under DirectX.
    46 
    47 1.1.8:
    48 	You can pass SDL_NOFRAME to SDL_VideoMode() to create a window
    49 	that has no title bar or frame decoration.  Fullscreen video
    50 	modes automatically have this flag set.
    51 
    52 	Added a function to query the clipping rectangle for a surface:
    53 		void SDL_GetClipRect(SDL_Surface *surface, SDL_Rect *rect)
    54 
    55 	Added a function to query the current event filter:
    56 		SDL_EventFilter SDL_GetEventFilter(void)
    57 
    58 	If you pass -1 to SDL_ShowCursor(), it won't change the current
    59 	cursor visibility state, but will still return it.
    60 
    61 	SDL_LockSurface() and SDL_UnlockSurface() are recursive, meaning
    62 	you can nest them as deep as you want, as long as each lock call
    63 	has a matching unlock call.  The surface remains locked until the
    64 	last matching unlock call.
    65 
    66 	Note that you may not blit to or from a locked surface.
    67 
    68 1.1.7:
    69 	The SDL_SetGammaRamp() and SDL_GetGammaRamp() functions now take
    70 	arrays of Uint16 values instead of Uint8 values.  For the most part,
    71 	you can just take your old values and shift them up 8 bits to get
    72 	new correct values for your gamma ramps.
    73 
    74 	You can pass SDL_RLEACCEL in flags passed to SDL_ConvertSurface()
    75         and SDL will try to RLE accelerate colorkey and alpha blits in the
    76 	resulting surface.
    77 
    78 1.1.6:
    79 	Added a function to return the thread ID of a specific thread:
    80 		Uint32 SDL_GetThreadID(SDL_Thread *thread)
    81 	If 'thread' is NULL, this function returns the id for this thread.
    82 
    83 1.1.5:
    84 	The YUV overlay structure has been changed to use an array of
    85 	pitches and pixels representing the planes of a YUV image, to
    86 	better enable hardware acceleration.  The YV12 and IYUV formats
    87 	each have three planes, corresponding to the Y, U, and V portions
    88 	of the image, while packed pixel YUV formats just have one plane.
    89 
    90 	For palettized mode (8bpp), the screen colormap is now split in
    91 	a physical and a logical palette. The physical palette determines
    92 	what colours the screen pixels will get when displayed, and the
    93 	logical palette controls the mapping from blits to/from the screen.
    94 	A new function, SDL_SetPalette() has been added to change
    95 	logical and physical palettes separately. SDL_SetColors() works
    96 	just as before, and is equivalent to calling SDL_SetPalette() with
    97 	a flag argument of (SDL_LOGPAL|SDL_PHYSPAL).
    98 
    99 	SDL_BlitSurface() no longer modifies the source rectangle, only the
   100 	destination rectangle. The width/height members of the destination
   101 	rectangle are ignored, only the position is used.
   102 
   103 	The old source clipping function SDL_SetClipping() has been replaced
   104 	with a more useful function to set the destination clipping rectangle:
   105 		SDL_bool SDL_SetClipRect(SDL_Surface *surface, SDL_Rect *rect)
   106 		
   107 	Added a function to see what subsystems have been initialized:
   108 		Uint32 SDL_WasInit(Uint32 flags)
   109 
   110 	The Big Alpha Flip: SDL now treats alpha as opacity like everybody
   111 	else, and not as transparency:
   112 
   113 	A new cpp symbol: SDL_ALPHA_OPAQUE is defined as 255
   114 	A new cpp symbol: SDL_ALPHA_TRANSPARENT is defined as 0
   115 	Values between 0 and 255 vary from fully transparent to fully opaque.
   116 
   117 	New functions:
   118 	SDL_DisplayFormatAlpha()
   119 	    Returns a surface converted to a format with alpha-channel
   120 	    that can be blit efficiently to the screen. (In other words,
   121 	    like SDL_DisplayFormat() but the resulting surface has
   122 	    an alpha channel.)  This is useful for surfaces with alpha.
   123 	SDL_MapRGBA()
   124 	    Works as SDL_MapRGB() but takes an additional alpha parameter.
   125 	SDL_GetRGBA()
   126 	    Works as SDL_GetRGB() but also returns the alpha value
   127 	    (SDL_ALPHA_OPAQUE for formats without an alpha channel)
   128 
   129 	Both SDL_GetRGB() and SDL_GetRGBA() now always return values in
   130 	the [0..255] interval. Previously, SDL_GetRGB() would return
   131 	(0xf8, 0xfc, 0xf8) for a completely white pixel in RGB565 format.
   132 	(N.B.: This is broken for bit fields < 3 bits.)
   133 
   134 	SDL_MapRGB() returns pixels in which the alpha channel is set opaque.
   135 
   136 	SDL_SetAlpha() can now be used for both setting the per-surface
   137 	alpha, using the new way of thinking of alpha, and also to enable
   138 	and disable per-pixel alpha blending for surfaces with an alpha
   139 	channel:
   140 		To disable alpha blending:
   141 			SDL_SetAlpha(surface, 0, 0);
   142 		To re-enable alpha blending:
   143 			SDL_SetAlpha(surface, SDL_SRCALPHA, 0);
   144 	Surfaces with an alpha channel have blending enabled by default.
   145 
   146 	SDL_SetAlpha() now accepts SDL_RLEACCEL as a flag, which requests
   147 	RLE acceleration of blits, just as like with SDL_SetColorKey().
   148 	This flag can be set for both surfaces with an alpha channel
   149 	and surfaces with an alpha value set by SDL_SetAlpha().
   150 	As always, RLE surfaces must be locked before pixel access is
   151 	allowed, and unlocked before any other SDL operations are done
   152 	on it.
   153 
   154 	The blit semantics for surfaces with and without alpha and colorkey
   155 	have now been defined:
   156 
   157 	RGBA->RGB:
   158 	    SDL_SRCALPHA set:
   159 		alpha-blend (using alpha-channel).
   160 		SDL_SRCCOLORKEY ignored.
   161 	    SDL_SRCALPHA not set:
   162 		copy RGB.
   163 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   164 		RGB values of the source colour key, ignoring alpha in the
   165 		comparison.
   166 
   167 	RGB->RGBA:
   168 	    SDL_SRCALPHA set:
   169 		alpha-blend (using the source per-surface alpha value);
   170 		set destination alpha to opaque.
   171 	    SDL_SRCALPHA not set:
   172 		copy RGB, set destination alpha to opaque.
   173 	    both:
   174 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   175 		source colour key.
   176 
   177 	RGBA->RGBA:
   178 	    SDL_SRCALPHA set:
   179 		alpha-blend (using the source alpha channel) the RGB values;
   180 		leave destination alpha untouched. [Note: is this correct?]
   181 		SDL_SRCCOLORKEY ignored.
   182 	    SDL_SRCALPHA not set:
   183 		copy all of RGBA to the destination.
   184 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   185 		RGB values of the source colour key, ignoring alpha in the
   186 		comparison.
   187 
   188 	RGB->RGB: 
   189 	    SDL_SRCALPHA set:
   190 		alpha-blend (using the source per-surface alpha value).
   191 	    SDL_SRCALPHA not set:
   192 		copy RGB.
   193 	    both:
   194 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   195 		source colour key.
   196 
   197 	As a special case, blits from surfaces with per-surface alpha
   198 	value of 128 (50% transparency) are optimised and much faster
   199 	than other alpha values. This does not apply to surfaces with
   200 	alpha channels (per-pixel alpha).
   201 
   202 	New functions for manipulating the gamma of the display have
   203 	been added:
   204 		int SDL_SetGamma(float red, float green, float blue);
   205 		int SDL_SetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   206 		int SDL_GetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   207 	Gamma ramps are tables with 256 entries which map the screen color
   208 	components into actually displayed colors.  For an example of
   209 	implementing gamma correction and gamma fades, see test/testgamma.c
   210 	Gamma control is not supported on all hardware.
   211 
   212 1.1.4:
   213 	The size of the SDL_CDtrack structure changed from 8 to 12 bytes
   214 	as the size of the length member was extended to 32 bits.
   215 
   216         You can now use SDL for 2D blitting with a GL mode by passing the
   217 	SDL_OPENGLBLIT flag to SDL_SetVideoMode().  You can specify 16 or
   218 	32 bpp, and the data in the framebuffer is put into the GL scene
   219 	when you call SDL_UpdateRects(), and the scene will be visible
   220 	when you call SDL_GL_SwapBuffers().
   221 
   222 	Run the "testgl" test program with the -logo command line option
   223 	to see an example of this blending of 2D and 3D in SDL.
   224 
   225 1.1.3:
   226 	Added SDL_FreeRW() to the API, to complement SDL_AllocRW()
   227 
   228 	Added resizable window support - just add SDL_RESIZABLE to the
   229 	SDL_SetVideoMode() flags, and then wait for SDL_VIDEORESIZE events.
   230 	See SDL_events.h for details on the new SDL_ResizeEvent structure.
   231 
   232 	Added condition variable support, based on mutexes and semaphores.
   233 		SDL_CreateCond()
   234 		SDL_DestroyCond()
   235 		SDL_CondSignal()
   236 		SDL_CondBroadcast()
   237 		SDL_CondWait()
   238 		SDL_CondTimedWait()
   239 	The new function prototypes are in SDL_mutex.h
   240 
   241 	Added counting semaphore support, based on the mutex primitive.
   242 		SDL_CreateSemaphore()
   243 		SDL_DestroySemaphore()
   244 		SDL_SemWait()
   245 		SDL_SemTryWait()
   246 		SDL_SemWaitTimeout()
   247 		SDL_SemPost()
   248 		SDL_SemValue()
   249 	The new function prototypes are in SDL_mutex.h
   250 
   251 	Added support for asynchronous blitting.  To take advantage of this,
   252 	you must set the SDL_ASYNCBLIT flag when setting the video mode and
   253 	creating surfaces that you want accelerated in this way.  You must
   254 	lock surfaces that have this flag set, and the lock will block until
   255 	any queued blits have completed.
   256 
   257 	Added YUV video overlay support.
   258 	The supported YUV formats are: YV12, IYUV, YUY2, UYVY, and YVYU.
   259 	This function creates an overlay surface:
   260 		SDL_CreateYUVOverlay()
   261 	You must lock and unlock the overlay to get access to the data:
   262 		SDL_LockYUVOverlay() SDL_UnlockYUVOverlay()
   263 	You can then display the overlay:
   264 		SDL_DisplayYUVOverlay()
   265 	You must free the overlay when you are done using it:
   266 		SDL_FreeYUVOverlay()
   267 	See SDL_video.h for the full function prototypes.
   268 
   269 	The joystick hat position constants have been changed:
   270 	Old constant            New constant
   271 	------------            ------------
   272 	     0                  SDL_HAT_CENTERED
   273 	     1                  SDL_HAT_UP
   274 	     2                  SDL_HAT_RIGHTUP
   275 	     3                  SDL_HAT_RIGHT
   276 	     4                  SDL_HAT_RIGHTDOWN
   277 	     5                  SDL_HAT_DOWN
   278 	     6                  SDL_HAT_LEFTDOWN
   279 	     7                  SDL_HAT_LEFT
   280 	     8                  SDL_HAT_LEFTUP
   281 	The new constants are bitmasks, so you can check for the
   282 	individual axes like this:
   283 		if ( hat_position & SDL_HAT_UP ) {
   284 		}
   285 	and you'll catch left-up, up, and right-up.
   286 
   287 1.1.2:
   288 	Added multiple timer support:
   289 		SDL_AddTimer() and SDL_RemoveTimer()
   290 
   291 	SDL_WM_SetIcon() now respects the icon colorkey if mask is NULL.
   292 
   293 1.1.0:
   294 	Added initial OpenGL support.
   295 	First set GL attributes (such as RGB depth, alpha depth, etc.)
   296 		SDL_GL_SetAttribute()
   297 	Then call SDL_SetVideoMode() with the SDL_OPENGL flag.
   298 	Perform all of your normal GL drawing.
   299 	Finally swap the buffers with the new SDL function:
   300 		SDL_GL_SwapBuffers()
   301 	See the new 'testgl' test program for an example of using GL with SDL.
   302 
   303 	You can load GL extension functions by using the function:
   304 		SDL_GL_LoadProcAddress()
   305 
   306 	Added functions to initialize and cleanup specific SDL subsystems:
   307 		SDL_InitSubSystem() and SDL_QuitSubSystem()
   308 
   309 	Added user-defined event type:
   310 		typedef struct {
   311         		Uint8 type;
   312         		int code;
   313         		void *data1;
   314         		void *data2;
   315 		} SDL_UserEvent;
   316 	This structure is in the "user" member of an SDL_Event.
   317 
   318 	Added a function to push events into the event queue:
   319 		SDL_PushEvent()
   320 
   321 	Example of using the new SDL user-defined events:
   322 	{
   323 		SDL_Event event;
   324 
   325 		event.type = SDL_USEREVENT;
   326 		event.user.code = my_event_code;
   327 		event.user.data1 = significant_data;
   328 		event.user.data2 = 0;
   329 		SDL_PushEvent(&event);
   330 	}
   331 
   332 	Added a function to get mouse deltas since last query:
   333 		SDL_GetRelativeMouseState()
   334 
   335 	Added a boolean datatype to SDL_types.h:
   336 		SDL_bool = { SDL_TRUE, SDL_FALSE }
   337 
   338 	Added a function to get the current audio status:
   339 		SDL_GetAudioState();
   340 	It returns one of:
   341 		SDL_AUDIO_STOPPED,
   342 		SDL_AUDIO_PLAYING,
   343 		SDL_AUDIO_PAUSED
   344 
   345 	Added an AAlib driver (ASCII Art) - by Stephane Peter.
   346 
   347 1.0.6:
   348 	The input grab state is reset after each call to SDL_SetVideoMode().
   349 	The input is grabbed by default in fullscreen mode, and ungrabbed in
   350 	windowed mode.  If you want to set input grab to a particular value,
   351 	you should set it after each call to SDL_SetVideoMode().
   352 
   353 1.0.5:
   354 	Exposed SDL_AudioInit(), SDL_VideoInit()
   355 	Added SDL_AudioDriverName() and SDL_VideoDriverName()
   356 
   357 	Added new window manager function:
   358 		SDL_WM_ToggleFullScreen()
   359 	This is currently implemented only on Linux
   360 
   361 	The ALT-ENTER code has been removed - it's not appropriate for a
   362 	lib to bind keys when they aren't even emergency escape sequences.
   363 
   364 	ALT-ENTER functionality can be implemented with the following code:
   365 
   366 	int Handle_AltEnter(const SDL_Event *event)
   367 	{
   368 	    if ( event->type == SDL_KEYDOWN ) {
   369 	        if ( (event->key.keysym.sym == SDLK_RETURN) &&
   370 	             (event->key.keysym.mod & KMOD_ALT) ) {   
   371 	                SDL_WM_ToggleFullScreen(SDL_GetVideoSurface());
   372 	                return(0);
   373 	        }
   374 	    }
   375 	    return(1);
   376 	}
   377 	SDL_SetEventFilter(Handle_AltEnter);
   378 
   379 1.0.3:
   380 	Under X11, if you grab the input and hide the mouse cursor,
   381 	the mouse will go into a "relative motion" mode where you
   382 	will always get relative motion events no matter how far in
   383 	each direction you move the mouse - relative motion is not
   384 	bounded by the edges of the window (though the absolute values
   385 	of the mouse positions are clamped by the size of the window).
   386 	The SVGAlib, framebuffer console, and DirectInput drivers all
   387 	have this behavior naturally, and the GDI and BWindow drivers
   388 	never go into "relative motion" mode.
   389 
   390 1.0.2:
   391 	Added a function to enable keyboard repeat:
   392 		SDL_EnableKeyRepeat()
   393 
   394 	Added a function to grab the mouse and keyboard input
   395 		SDL_WM_GrabInput()
   396 
   397 	Added a function to iconify the window.
   398 		SDL_WM_IconifyWindow()
   399 	If this function succeeds, the application will receive an event
   400 	signaling SDL_APPACTIVE event 
   401 
   402 1.0.1:
   403 	Added constants to SDL_audio.h for 16-bit native byte ordering:
   404 		AUDIO_U16SYS, AUDIO_S16SYS
   405 
   406 1.0.0:
   407 	New public release
   408 
   409 Version 0.11:
   410 
   411 0.11.5:
   412 	A new function SDL_GetVideoSurface() has been added, and returns
   413 	a pointer to the current display surface.
   414 
   415 	SDL_AllocSurface() has been renamed SDL_CreateRGBSurface(), and
   416 	a new function SDL_CreateRGBSurfaceFrom() has been added to allow
   417 	creating an SDL surface from an existing pixel data buffer.
   418 
   419 	Added SDL_GetRGB() to the headers and documentation.
   420 
   421 0.11.4:
   422 	SDL_SetLibraryPath() is no longer meaningful, and has been removed.
   423 
   424 0.11.3:
   425 	A new flag for SDL_Init(), SDL_INIT_NOPARACHUTE, prevents SDL from
   426 	installing fatal signal handlers on operating systems that support
   427 	them.
   428 
   429 Version 0.9:
   430 
   431 0.9.15:
   432 	SDL_CreateColorCursor() has been removed.  Color cursors should
   433 	be implemented as sprites, blitted by the application when the
   434 	cursor moves.  To get smooth color cursor updates when the app
   435 	is busy, pass the SDL_INIT_EVENTTHREAD flag to SDL_Init().  This
   436 	allows you to handle the mouse motion in another thread from an
   437 	event filter function, but is currently only supported by Linux
   438 	and BeOS.  Note that you'll have to protect the display surface
   439 	from multi-threaded access by using mutexes if you do this.
   440 
   441 	Thread-safe surface support has been removed from SDL.
   442 	This makes blitting somewhat faster, by removing SDL_MiddleBlit().
   443 	Code that used SDL_MiddleBlit() should use SDL_LowerBlit() instead.
   444 	You can make your surfaces thread-safe by allocating your own
   445 	mutex and making lock/unlock calls around accesses to your surface.
   446 
   447 0.9.14:
   448 	SDL_GetMouseState() now takes pointers to int rather than Uint16.
   449 
   450 	If you set the SDL_WINDOWID environment variable under UNIX X11,
   451 	SDL will use that as the main window instead of creating it's own.
   452 	This is an unsupported extension to SDL, and not portable at all.
   453 
   454 0.9.13:
   455 	Added a function SDL_SetLibraryPath() which can be used to specify
   456 	the directory containing the SDL dynamic libraries.  This is useful
   457 	for commercial applications which ship with particular versions
   458 	of the libraries, and for security on multi-user systems.
   459 	If this function is not used, the default system directories are 
   460 	searched using the native dynamic object loading mechanism.
   461 
   462 	In order to support C linkage under Visual C++, you must declare
   463 	main() without any return type:
   464 		main(int argc, char *argv[]) {
   465 			/* Do the program... */
   466 			return(0);
   467 		}
   468 	C++ programs should also return a value if compiled under VC++.
   469 
   470 	The blit_endian member of the SDL_VideoInfo struct has been removed.
   471 
   472 	SDL_SymToASCII() has been replaced with SDL_GetKeyName(), so there
   473 	is now no longer any function to translate a keysym to a character.
   474 
   475 	The SDL_keysym structure has been extended with a 'scancode' and
   476 	'unicode' member.  The 'scancode' is a hardware specific scancode
   477 	for the key that was pressed, and may be 0.  The 'unicode' member
   478 	is a 16-bit UNICODE translation of the key that was pressed along
   479 	with any modifiers or compose keys that have been pressed.
   480 	If no UNICODE translation exists for the key, 'unicode' will be 0.
   481 
   482 	Added a function SDL_EnableUNICODE() to enable/disable UNICODE
   483 	translation of character keypresses.  Translation defaults off.
   484 
   485 	To convert existing code to use the new API, change code which
   486 	uses SDL_SymToASCII() to get the keyname to use SDL_GetKeyName(),
   487 	and change code which uses it to get the ASCII value of a sym to
   488 	use the 'unicode' member of the event keysym.
   489 
   490 0.9.12:
   491 	There is partial support for 64-bit datatypes.  I don't recommend 
   492 	you use this if you have a choice, because 64-bit datatypes are not
   493 	supported on many platforms.  On platforms for which it is supported,
   494 	the SDL_HAS_64BIT_TYPE C preprocessor define will be enabled, and
   495 	you can use the Uint64 and Sint64 datatypes.
   496 
   497 	Added functions to SDL_endian.h to support 64-bit datatypes:
   498 	    SDL_SwapLE64(), SDL_SwapBE64(),
   499 	    SDL_ReadLE64(), SDL_ReadBE64(), SDL_WriteLE64(), SDL_WriteBE64()
   500 
   501 	A new member "len_ratio" has been added to the SDL_AudioCVT structure,
   502 	and allows you to determine either the original buffer length or the
   503 	converted buffer length, given the other.
   504 
   505 	A new function SDL_FreeWAV() has been added to the API to free data
   506 	allocated by SDL_LoadWAV_RW().  This is necessary under Win32 since
   507 	the gcc compiled DLL uses a different heap than VC++ compiled apps.
   508 
   509 	SDL now has initial support for international keyboards using the
   510 	Latin character set.
   511 	If a particular mapping is desired, you can set the DEFAULT_KEYBOARD
   512 	compile-time variable, or you can set the environment variable 
   513 	"SDL_KEYBOARD" to a string identifying the keyboard mapping you desire.
   514 	The valid values for these variables can be found in SDL_keyboard.c
   515 
   516 	Full support for German and French keyboards under X11 is implemented.
   517 
   518 0.9.11:
   519 	The THREADED_EVENTS compile-time define has been replaced with the
   520 	SDL_INIT_EVENTTHREAD flag.  If this flag is passed to SDL_Init(),
   521 	SDL will create a separate thread to perform input event handling.
   522 	If this flag is passed to SDL_Init(), and the OS doesn't support 
   523 	event handling in a separate thread, SDL_Init() will fail.
   524 	Be sure to add calls to SDL_Delay() in your main thread to allow
   525 	the OS to schedule your event thread, or it may starve, leading
   526 	to slow event delivery and/or dropped events.
   527 	Currently MacOS and Win32 do not support this flag, while BeOS 
   528 	and Linux do support it.  I recommend that your application only
   529 	use this flag if absolutely necessary.
   530 
   531 	The SDL thread function passed to SDL_CreateThread() now returns a
   532 	status.  This status can be retrieved by passing a non-NULL pointer
   533 	as the 'status' argument to SDL_WaitThread().
   534 
   535 	The volume parameter to SDL_MixAudio() has been increased in range
   536 	from (0-8) to (0-128)
   537 
   538 	SDL now has a data source abstraction which can encompass a file,
   539 	an area of memory, or any custom object you can envision.  It uses
   540 	these abstractions, SDL_RWops, in the endian read/write functions,
   541 	and the built-in WAV and BMP file loaders.  This means you can load
   542 	WAV chunks from memory mapped files, compressed archives, network
   543 	pipes, or anything else that has a data read abstraction.
   544 
   545 	There are three built-in data source abstractions:
   546 	    SDL_RWFromFile(), SDL_RWFromFP(), SDL_RWFromMem()
   547 	along with a generic data source allocation function:
   548 	    SDL_AllocRW()
   549 	These data sources can be used like stdio file pointers with the
   550 	following convenience functions:
   551 	    SDL_RWseek(), SDL_RWread(), SDL_RWwrite(), SDL_RWclose()
   552 	These functions are defined in the new header file "SDL_rwops.h"
   553 
   554 	The endian swapping functions have been turned into macros for speed
   555 	and SDL_CalculateEndian() has been removed.  SDL_endian.h now defines
   556 	SDL_BYTEORDER as either SDL_BIG_ENDIAN or SDL_LIL_ENDIAN depending on
   557 	the endianness of the host system.
   558 
   559 	The endian read/write functions now take an SDL_RWops pointer
   560 	instead of a stdio FILE pointer, to support the new data source
   561 	abstraction.
   562 
   563 	The SDL_*LoadWAV() functions have been replaced with a single
   564 	SDL_LoadWAV_RW() function that takes a SDL_RWops pointer as it's
   565 	first parameter, and a flag whether or not to automatically 
   566 	free it as the second parameter.  SDL_LoadWAV() is a macro for
   567 	backward compatibility and convenience:
   568 	    SDL_LoadWAV_RW(SDL_RWFromFile("sample.wav", "rb"), 1, ...);
   569 
   570 	The SDL_*LoadBMP()/SDL_*SaveBMP() functions have each been replaced
   571 	with a single function that takes a SDL_RWops pointer as it's
   572 	first parameter, and a flag whether or not to automatically 
   573 	free it as the second parameter.  SDL_LoadBMP() and SDL_SaveBMP()
   574 	are macros for backward compatibility and convenience:
   575 	    SDL_LoadBMP_RW(SDL_RWFromFile("sample.bmp", "rb"), 1, ...);
   576 	    SDL_SaveBMP_RW(SDL_RWFromFile("sample.bmp", "wb"), 1, ...);
   577 	Note that these functions use SDL_RWseek() extensively, and should
   578 	not be used on pipes or other non-seekable data sources.
   579 
   580 0.9.10:
   581 	The Linux SDL_SysWMInfo and SDL_SysWMMsg structures have been 
   582 	extended to support multiple types of display drivers, as well as
   583         safe access to the X11 display when THREADED_EVENTS is enabled.
   584         The new structures are documented in the SDL_syswm.h header file.
   585 
   586 	Thanks to John Elliott <jce@seasip.demon.co.uk>, the UK keyboard
   587 	should now work properly, as well as the "Windows" keys on US
   588 	keyboards.
   589 
   590 	The Linux CD-ROM code now reads the CD-ROM devices from /etc/fstab
   591 	instead of trying to open each block device on the system.
   592 	The CD must be listed in /etc/fstab as using the iso9660 filesystem.
   593 
   594 	On Linux, if you define THREADED_EVENTS at compile time, a separate
   595 	thread will be spawned to gather X events asynchronously from the
   596 	graphics updates.  This hasn't been extensively tested, but it does
   597 	provide a means of handling keyboard and mouse input in a separate
   598 	thread from the graphics thread.  (This is now enabled by default.)
   599 
   600 	A special access function SDL_PeepEvents() allows you to manipulate
   601 	the event queue in a thread-safe manner, including peeking at events,
   602 	removing events of a specified type, and adding new events of arbitrary
   603 	type to the queue (use the new 'user' member of the SDL_Event type).
   604 
   605 	If you use SDL_PeepEvents() to gather events, then the main graphics
   606 	thread needs to call SDL_PumpEvents() periodically to drive the event
   607 	loop and generate input events.  This is not necessary if SDL has been 
   608 	compiled with THREADED_EVENTS defined, but doesn't hurt.
   609 
   610 	A new function SDL_ThreadID() returns the identifier associated with
   611 	the current thread.
   612 
   613 0.9.9:
   614 	The AUDIO_STEREO format flag has been replaced with a new 'channels'
   615 	member of the SDL_AudioSpec structure.  The channels are 1 for mono
   616 	audio, and 2 for stereo audio.  In the future more channels may be
   617 	supported for 3D surround sound.
   618 
   619 	The SDL_MixAudio() function now takes an additional volume parameter,
   620 	which should be set to SDL_MIX_MAXVOLUME for compatibility with the
   621 	original function.
   622 
   623 	The CD-ROM functions which take a 'cdrom' parameter can now be
   624 	passed NULL, and will act on the last successfully opened CD-ROM.
   625 
   626 0.9.8:
   627 	No changes, bugfixes only.
   628 	
   629 0.9.7:
   630 	No changes, bugfixes only.
   631 	
   632 0.9.6:
   633 	Added a fast rectangle fill function: SDL_FillRect()
   634 
   635 	Addition of a useful function for getting info on the video hardware:
   636 	    const SDL_VideoInfo *SDL_GetVideoInfo(void)
   637         This function replaces SDL_GetDisplayFormat().
   638 
   639 	Initial support for double-buffering:
   640 	  Use the SDL_DOUBLEBUF flag in SDL_SetVideoMode()
   641 	  Update the screen with a new function: SDL_Flip()
   642 
   643 	SDL_AllocSurface() takes two new flags:
   644 	SDL_SRCCOLORKEY means that the surface will be used for colorkey blits
   645 	  and if the hardware supports hardware acceleration of colorkey blits
   646 	  between two surfaces in video memory, to place the surface in video
   647 	  memory if possible, otherwise it will be placed in system memory.
   648 	SDL_SRCALPHA means that the surface will be used for alpha blits and
   649 	  if the hardware supports hardware acceleration of alpha blits between
   650 	  two surfaces in video memory, to place the surface in video memory
   651 	  if possible, otherwise it will be placed in system memory.
   652 	SDL_HWSURFACE now means that the surface will be created with the 
   653 	  same format as the display surface, since having surfaces in video
   654 	  memory is only useful for fast blitting to the screen, and you can't
   655 	  blit surfaces with different surface formats in video memory.
   656 
   657 0.9.5:
   658 	You can now pass a NULL mask to SDL_WM_SetIcon(), and it will assume
   659 	that the icon consists of the entire image.
   660 
   661 	SDL_LowerBlit() is back -- but don't use it on the display surface.
   662 	It is exactly the same as SDL_MiddleBlit(), but doesn't check for
   663 	thread safety.
   664 
   665 	Added SDL_FPLoadBMP(), SDL_FPSaveBMP(), SDL_FPLoadWAV(), which take
   666 	a FILE pointer instead of a file name.
   667 
   668 	Added CD-ROM audio control API:
   669 	    SDL_CDNumDrives()
   670 	    SDL_CDName()
   671 	    SDL_CDOpen()
   672 	    SDL_CDStatus()
   673 	    SDL_CDPlayTracks()
   674 	    SDL_CDPlay()
   675 	    SDL_CDPause()
   676 	    SDL_CDResume()
   677 	    SDL_CDStop()
   678 	    SDL_CDEject()
   679 	    SDL_CDClose()
   680 
   681 0.9.4:
   682 	No changes, bugfixes only.
   683 
   684 0.9.3:
   685 	Mouse motion event now includes relative motion information:
   686 	    Sint16 event->motion.xrel, Sint16 event->motion.yrel
   687 
   688 	X11 keyrepeat handling can be disabled by defining IGNORE_X_KEYREPEAT
   689 	    (Add -DIGNORE_X_KEYREPEAT to CFLAGS line in obj/x11Makefile)
   690 
   691 0.9.2:
   692 	No changes, bugfixes only.
   693 
   694 0.9.1:
   695 	Removed SDL_MapSurface() and SDL_UnmapSurface() -- surfaces are now
   696 	automatically mapped on blit.
   697 
   698 0.8.0:
   699 	SDL stable release