WhatsNew
author Sam Lantinga <slouken@libsdl.org>
Sat, 29 Dec 2007 06:08:17 +0000
branchSDL-1.2
changeset 4113 82dab719502e
parent 4011 f5794774970d
child 4280 e1826b24ee8d
permissions -rw-r--r--
Fixed bug #464
Added X1/X2 button constants
     1 
     2 This is a list of API changes in SDL's version history.
     3 
     4 Version 1.0:
     5 
     6 1.2.13:
     7 	Added SDL_BUTTON_X1 and SDL_BUTTON_X2 constants.
     8 
     9 1.2.12:
    10 	Added SDL_VIDEO_ALLOW_SCREENSAVER to override SDL's disabling
    11 	of the screensaver on Mac OS X and X11.
    12 
    13 1.2.10:
    14 	If SDL_OpenAudio() is passed zero for the desired format
    15 	fields, the following environment variables will be used
    16 	to fill them in:
    17 		SDL_AUDIO_FREQUENCY
    18 		SDL_AUDIO_FORMAT
    19 		SDL_AUDIO_CHANNELS
    20 		SDL_AUDIO_SAMPLES
    21 	If an environment variable is not specified, it will be set
    22 	to a reasonable default value.
    23 
    24 	Added support for the SDL_VIDEO_FULLSCREEN_HEAD environment
    25 	variable, currently supported on X11 Xinerama configurations.
    26 
    27 	Added SDL_GL_SWAP_CONTROL to wait for vsync in OpenGL applications.
    28 
    29 	Added SDL_GL_ACCELERATED_VISUAL to guarantee hardware acceleration.
    30 
    31 	Added current_w and current_h to the SDL_VideoInfo structure,
    32 	which is set to the desktop resolution during video intialization,
    33 	and then set to the current resolution when a video mode is set.
    34 
    35 	SDL_SetVideoMode() now accepts 0 for width or height and will use
    36 	the current video mode (or the desktop mode if no mode has been set.)
    37 
    38 	Added SDL_GetKeyRepeat()
    39 
    40 	Added SDL_config.h, with defaults for various build environments.
    41 
    42 1.2.7:
    43 	Added CPU feature detection functions to SDL_cpuinfo.h:
    44 		SDL_HasRDTSC(), SDL_HasMMX(), SDL_Has3DNow(), SDL_HasSSE(),
    45 		SDL_HasAltiVec()
    46 	Added function to create RWops from const memory: SDL_RWFromConstMem()
    47 
    48 1.2.6:
    49 	Added SDL_LoadObject(), SDL_LoadFunction(), and SDL_UnloadObject()
    50 
    51 	Added SDL_GL_MULTISAMPLEBUFFERS and SDL_GL_MULTISAMPLESAMPLES for FSAA
    52 
    53 1.2.5:
    54 	Added SDL_BUTTON_WHEELUP (4) and SDL_BUTTON_WHEELDOWN (5)
    55 
    56 	Added SDL_GL_STEREO for stereoscopic OpenGL contexts
    57 
    58 1.2.0:
    59 	Added SDL_VIDEOEXPOSE event to signal that the screen needs to
    60 	be redrawn.  This is currently only delivered to OpenGL windows
    61 	on X11, though it may be delivered in the future when the video
    62 	memory is lost under DirectX.
    63 
    64 1.1.8:
    65 	You can pass SDL_NOFRAME to SDL_VideoMode() to create a window
    66 	that has no title bar or frame decoration.  Fullscreen video
    67 	modes automatically have this flag set.
    68 
    69 	Added a function to query the clipping rectangle for a surface:
    70 		void SDL_GetClipRect(SDL_Surface *surface, SDL_Rect *rect)
    71 
    72 	Added a function to query the current event filter:
    73 		SDL_EventFilter SDL_GetEventFilter(void)
    74 
    75 	If you pass -1 to SDL_ShowCursor(), it won't change the current
    76 	cursor visibility state, but will still return it.
    77 
    78 	SDL_LockSurface() and SDL_UnlockSurface() are recursive, meaning
    79 	you can nest them as deep as you want, as long as each lock call
    80 	has a matching unlock call.  The surface remains locked until the
    81 	last matching unlock call.
    82 
    83 	Note that you may not blit to or from a locked surface.
    84 
    85 1.1.7:
    86 	The SDL_SetGammaRamp() and SDL_GetGammaRamp() functions now take
    87 	arrays of Uint16 values instead of Uint8 values.  For the most part,
    88 	you can just take your old values and shift them up 8 bits to get
    89 	new correct values for your gamma ramps.
    90 
    91 	You can pass SDL_RLEACCEL in flags passed to SDL_ConvertSurface()
    92         and SDL will try to RLE accelerate colorkey and alpha blits in the
    93 	resulting surface.
    94 
    95 1.1.6:
    96 	Added a function to return the thread ID of a specific thread:
    97 		Uint32 SDL_GetThreadID(SDL_Thread *thread)
    98 	If 'thread' is NULL, this function returns the id for this thread.
    99 
   100 1.1.5:
   101 	The YUV overlay structure has been changed to use an array of
   102 	pitches and pixels representing the planes of a YUV image, to
   103 	better enable hardware acceleration.  The YV12 and IYUV formats
   104 	each have three planes, corresponding to the Y, U, and V portions
   105 	of the image, while packed pixel YUV formats just have one plane.
   106 
   107 	For palettized mode (8bpp), the screen colormap is now split in
   108 	a physical and a logical palette. The physical palette determines
   109 	what colours the screen pixels will get when displayed, and the
   110 	logical palette controls the mapping from blits to/from the screen.
   111 	A new function, SDL_SetPalette() has been added to change
   112 	logical and physical palettes separately. SDL_SetColors() works
   113 	just as before, and is equivalent to calling SDL_SetPalette() with
   114 	a flag argument of (SDL_LOGPAL|SDL_PHYSPAL).
   115 
   116 	SDL_BlitSurface() no longer modifies the source rectangle, only the
   117 	destination rectangle. The width/height members of the destination
   118 	rectangle are ignored, only the position is used.
   119 
   120 	The old source clipping function SDL_SetClipping() has been replaced
   121 	with a more useful function to set the destination clipping rectangle:
   122 		SDL_bool SDL_SetClipRect(SDL_Surface *surface, SDL_Rect *rect)
   123 		
   124 	Added a function to see what subsystems have been initialized:
   125 		Uint32 SDL_WasInit(Uint32 flags)
   126 
   127 	The Big Alpha Flip: SDL now treats alpha as opacity like everybody
   128 	else, and not as transparency:
   129 
   130 	A new cpp symbol: SDL_ALPHA_OPAQUE is defined as 255
   131 	A new cpp symbol: SDL_ALPHA_TRANSPARENT is defined as 0
   132 	Values between 0 and 255 vary from fully transparent to fully opaque.
   133 
   134 	New functions:
   135 	SDL_DisplayFormatAlpha()
   136 	    Returns a surface converted to a format with alpha-channel
   137 	    that can be blit efficiently to the screen. (In other words,
   138 	    like SDL_DisplayFormat() but the resulting surface has
   139 	    an alpha channel.)  This is useful for surfaces with alpha.
   140 	SDL_MapRGBA()
   141 	    Works as SDL_MapRGB() but takes an additional alpha parameter.
   142 	SDL_GetRGBA()
   143 	    Works as SDL_GetRGB() but also returns the alpha value
   144 	    (SDL_ALPHA_OPAQUE for formats without an alpha channel)
   145 
   146 	Both SDL_GetRGB() and SDL_GetRGBA() now always return values in
   147 	the [0..255] interval. Previously, SDL_GetRGB() would return
   148 	(0xf8, 0xfc, 0xf8) for a completely white pixel in RGB565 format.
   149 	(N.B.: This is broken for bit fields < 3 bits.)
   150 
   151 	SDL_MapRGB() returns pixels in which the alpha channel is set opaque.
   152 
   153 	SDL_SetAlpha() can now be used for both setting the per-surface
   154 	alpha, using the new way of thinking of alpha, and also to enable
   155 	and disable per-pixel alpha blending for surfaces with an alpha
   156 	channel:
   157 		To disable alpha blending:
   158 			SDL_SetAlpha(surface, 0, 0);
   159 		To re-enable alpha blending:
   160 			SDL_SetAlpha(surface, SDL_SRCALPHA, 0);
   161 	Surfaces with an alpha channel have blending enabled by default.
   162 
   163 	SDL_SetAlpha() now accepts SDL_RLEACCEL as a flag, which requests
   164 	RLE acceleration of blits, just as like with SDL_SetColorKey().
   165 	This flag can be set for both surfaces with an alpha channel
   166 	and surfaces with an alpha value set by SDL_SetAlpha().
   167 	As always, RLE surfaces must be locked before pixel access is
   168 	allowed, and unlocked before any other SDL operations are done
   169 	on it.
   170 
   171 	The blit semantics for surfaces with and without alpha and colorkey
   172 	have now been defined:
   173 
   174 	RGBA->RGB:
   175 	    SDL_SRCALPHA set:
   176 		alpha-blend (using alpha-channel).
   177 		SDL_SRCCOLORKEY ignored.
   178 	    SDL_SRCALPHA not set:
   179 		copy RGB.
   180 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   181 		RGB values of the source colour key, ignoring alpha in the
   182 		comparison.
   183 
   184 	RGB->RGBA:
   185 	    SDL_SRCALPHA set:
   186 		alpha-blend (using the source per-surface alpha value);
   187 		set destination alpha to opaque.
   188 	    SDL_SRCALPHA not set:
   189 		copy RGB, set destination alpha to opaque.
   190 	    both:
   191 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   192 		source colour key.
   193 
   194 	RGBA->RGBA:
   195 	    SDL_SRCALPHA set:
   196 		alpha-blend (using the source alpha channel) the RGB values;
   197 		leave destination alpha untouched. [Note: is this correct?]
   198 		SDL_SRCCOLORKEY ignored.
   199 	    SDL_SRCALPHA not set:
   200 		copy all of RGBA to the destination.
   201 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   202 		RGB values of the source colour key, ignoring alpha in the
   203 		comparison.
   204 
   205 	RGB->RGB: 
   206 	    SDL_SRCALPHA set:
   207 		alpha-blend (using the source per-surface alpha value).
   208 	    SDL_SRCALPHA not set:
   209 		copy RGB.
   210 	    both:
   211 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   212 		source colour key.
   213 
   214 	As a special case, blits from surfaces with per-surface alpha
   215 	value of 128 (50% transparency) are optimised and much faster
   216 	than other alpha values. This does not apply to surfaces with
   217 	alpha channels (per-pixel alpha).
   218 
   219 	New functions for manipulating the gamma of the display have
   220 	been added:
   221 		int SDL_SetGamma(float red, float green, float blue);
   222 		int SDL_SetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   223 		int SDL_GetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   224 	Gamma ramps are tables with 256 entries which map the screen color
   225 	components into actually displayed colors.  For an example of
   226 	implementing gamma correction and gamma fades, see test/testgamma.c
   227 	Gamma control is not supported on all hardware.
   228 
   229 1.1.4:
   230 	The size of the SDL_CDtrack structure changed from 8 to 12 bytes
   231 	as the size of the length member was extended to 32 bits.
   232 
   233         You can now use SDL for 2D blitting with a GL mode by passing the
   234 	SDL_OPENGLBLIT flag to SDL_SetVideoMode().  You can specify 16 or
   235 	32 bpp, and the data in the framebuffer is put into the GL scene
   236 	when you call SDL_UpdateRects(), and the scene will be visible
   237 	when you call SDL_GL_SwapBuffers().
   238 
   239 	Run the "testgl" test program with the -logo command line option
   240 	to see an example of this blending of 2D and 3D in SDL.
   241 
   242 1.1.3:
   243 	Added SDL_FreeRW() to the API, to complement SDL_AllocRW()
   244 
   245 	Added resizable window support - just add SDL_RESIZABLE to the
   246 	SDL_SetVideoMode() flags, and then wait for SDL_VIDEORESIZE events.
   247 	See SDL_events.h for details on the new SDL_ResizeEvent structure.
   248 
   249 	Added condition variable support, based on mutexes and semaphores.
   250 		SDL_CreateCond()
   251 		SDL_DestroyCond()
   252 		SDL_CondSignal()
   253 		SDL_CondBroadcast()
   254 		SDL_CondWait()
   255 		SDL_CondTimedWait()
   256 	The new function prototypes are in SDL_mutex.h
   257 
   258 	Added counting semaphore support, based on the mutex primitive.
   259 		SDL_CreateSemaphore()
   260 		SDL_DestroySemaphore()
   261 		SDL_SemWait()
   262 		SDL_SemTryWait()
   263 		SDL_SemWaitTimeout()
   264 		SDL_SemPost()
   265 		SDL_SemValue()
   266 	The new function prototypes are in SDL_mutex.h
   267 
   268 	Added support for asynchronous blitting.  To take advantage of this,
   269 	you must set the SDL_ASYNCBLIT flag when setting the video mode and
   270 	creating surfaces that you want accelerated in this way.  You must
   271 	lock surfaces that have this flag set, and the lock will block until
   272 	any queued blits have completed.
   273 
   274 	Added YUV video overlay support.
   275 	The supported YUV formats are: YV12, IYUV, YUY2, UYVY, and YVYU.
   276 	This function creates an overlay surface:
   277 		SDL_CreateYUVOverlay()
   278 	You must lock and unlock the overlay to get access to the data:
   279 		SDL_LockYUVOverlay() SDL_UnlockYUVOverlay()
   280 	You can then display the overlay:
   281 		SDL_DisplayYUVOverlay()
   282 	You must free the overlay when you are done using it:
   283 		SDL_FreeYUVOverlay()
   284 	See SDL_video.h for the full function prototypes.
   285 
   286 	The joystick hat position constants have been changed:
   287 	Old constant            New constant
   288 	------------            ------------
   289 	     0                  SDL_HAT_CENTERED
   290 	     1                  SDL_HAT_UP
   291 	     2                  SDL_HAT_RIGHTUP
   292 	     3                  SDL_HAT_RIGHT
   293 	     4                  SDL_HAT_RIGHTDOWN
   294 	     5                  SDL_HAT_DOWN
   295 	     6                  SDL_HAT_LEFTDOWN
   296 	     7                  SDL_HAT_LEFT
   297 	     8                  SDL_HAT_LEFTUP
   298 	The new constants are bitmasks, so you can check for the
   299 	individual axes like this:
   300 		if ( hat_position & SDL_HAT_UP ) {
   301 		}
   302 	and you'll catch left-up, up, and right-up.
   303 
   304 1.1.2:
   305 	Added multiple timer support:
   306 		SDL_AddTimer() and SDL_RemoveTimer()
   307 
   308 	SDL_WM_SetIcon() now respects the icon colorkey if mask is NULL.
   309 
   310 1.1.0:
   311 	Added initial OpenGL support.
   312 	First set GL attributes (such as RGB depth, alpha depth, etc.)
   313 		SDL_GL_SetAttribute()
   314 	Then call SDL_SetVideoMode() with the SDL_OPENGL flag.
   315 	Perform all of your normal GL drawing.
   316 	Finally swap the buffers with the new SDL function:
   317 		SDL_GL_SwapBuffers()
   318 	See the new 'testgl' test program for an example of using GL with SDL.
   319 
   320 	You can load GL extension functions by using the function:
   321 		SDL_GL_LoadProcAddress()
   322 
   323 	Added functions to initialize and cleanup specific SDL subsystems:
   324 		SDL_InitSubSystem() and SDL_QuitSubSystem()
   325 
   326 	Added user-defined event type:
   327 		typedef struct {
   328         		Uint8 type;
   329         		int code;
   330         		void *data1;
   331         		void *data2;
   332 		} SDL_UserEvent;
   333 	This structure is in the "user" member of an SDL_Event.
   334 
   335 	Added a function to push events into the event queue:
   336 		SDL_PushEvent()
   337 
   338 	Example of using the new SDL user-defined events:
   339 	{
   340 		SDL_Event event;
   341 
   342 		event.type = SDL_USEREVENT;
   343 		event.user.code = my_event_code;
   344 		event.user.data1 = significant_data;
   345 		event.user.data2 = 0;
   346 		SDL_PushEvent(&event);
   347 	}
   348 
   349 	Added a function to get mouse deltas since last query:
   350 		SDL_GetRelativeMouseState()
   351 
   352 	Added a boolean datatype to SDL_types.h:
   353 		SDL_bool = { SDL_TRUE, SDL_FALSE }
   354 
   355 	Added a function to get the current audio status:
   356 		SDL_GetAudioState();
   357 	It returns one of:
   358 		SDL_AUDIO_STOPPED,
   359 		SDL_AUDIO_PLAYING,
   360 		SDL_AUDIO_PAUSED
   361 
   362 	Added an AAlib driver (ASCII Art) - by Stephane Peter.
   363 
   364 1.0.6:
   365 	The input grab state is reset after each call to SDL_SetVideoMode().
   366 	The input is grabbed by default in fullscreen mode, and ungrabbed in
   367 	windowed mode.  If you want to set input grab to a particular value,
   368 	you should set it after each call to SDL_SetVideoMode().
   369 
   370 1.0.5:
   371 	Exposed SDL_AudioInit(), SDL_VideoInit()
   372 	Added SDL_AudioDriverName() and SDL_VideoDriverName()
   373 
   374 	Added new window manager function:
   375 		SDL_WM_ToggleFullScreen()
   376 	This is currently implemented only on Linux
   377 
   378 	The ALT-ENTER code has been removed - it's not appropriate for a
   379 	lib to bind keys when they aren't even emergency escape sequences.
   380 
   381 	ALT-ENTER functionality can be implemented with the following code:
   382 
   383 	int Handle_AltEnter(const SDL_Event *event)
   384 	{
   385 	    if ( event->type == SDL_KEYDOWN ) {
   386 	        if ( (event->key.keysym.sym == SDLK_RETURN) &&
   387 	             (event->key.keysym.mod & KMOD_ALT) ) {   
   388 	                SDL_WM_ToggleFullScreen(SDL_GetVideoSurface());
   389 	                return(0);
   390 	        }
   391 	    }
   392 	    return(1);
   393 	}
   394 	SDL_SetEventFilter(Handle_AltEnter);
   395 
   396 1.0.3:
   397 	Under X11, if you grab the input and hide the mouse cursor,
   398 	the mouse will go into a "relative motion" mode where you
   399 	will always get relative motion events no matter how far in
   400 	each direction you move the mouse - relative motion is not
   401 	bounded by the edges of the window (though the absolute values
   402 	of the mouse positions are clamped by the size of the window).
   403 	The SVGAlib, framebuffer console, and DirectInput drivers all
   404 	have this behavior naturally, and the GDI and BWindow drivers
   405 	never go into "relative motion" mode.
   406 
   407 1.0.2:
   408 	Added a function to enable keyboard repeat:
   409 		SDL_EnableKeyRepeat()
   410 
   411 	Added a function to grab the mouse and keyboard input
   412 		SDL_WM_GrabInput()
   413 
   414 	Added a function to iconify the window.
   415 		SDL_WM_IconifyWindow()
   416 	If this function succeeds, the application will receive an event
   417 	signaling SDL_APPACTIVE event 
   418 
   419 1.0.1:
   420 	Added constants to SDL_audio.h for 16-bit native byte ordering:
   421 		AUDIO_U16SYS, AUDIO_S16SYS
   422 
   423 1.0.0:
   424 	New public release
   425 
   426 Version 0.11:
   427 
   428 0.11.5:
   429 	A new function SDL_GetVideoSurface() has been added, and returns
   430 	a pointer to the current display surface.
   431 
   432 	SDL_AllocSurface() has been renamed SDL_CreateRGBSurface(), and
   433 	a new function SDL_CreateRGBSurfaceFrom() has been added to allow
   434 	creating an SDL surface from an existing pixel data buffer.
   435 
   436 	Added SDL_GetRGB() to the headers and documentation.
   437 
   438 0.11.4:
   439 	SDL_SetLibraryPath() is no longer meaningful, and has been removed.
   440 
   441 0.11.3:
   442 	A new flag for SDL_Init(), SDL_INIT_NOPARACHUTE, prevents SDL from
   443 	installing fatal signal handlers on operating systems that support
   444 	them.
   445 
   446 Version 0.9:
   447 
   448 0.9.15:
   449 	SDL_CreateColorCursor() has been removed.  Color cursors should
   450 	be implemented as sprites, blitted by the application when the
   451 	cursor moves.  To get smooth color cursor updates when the app
   452 	is busy, pass the SDL_INIT_EVENTTHREAD flag to SDL_Init().  This
   453 	allows you to handle the mouse motion in another thread from an
   454 	event filter function, but is currently only supported by Linux
   455 	and BeOS.  Note that you'll have to protect the display surface
   456 	from multi-threaded access by using mutexes if you do this.
   457 
   458 	Thread-safe surface support has been removed from SDL.
   459 	This makes blitting somewhat faster, by removing SDL_MiddleBlit().
   460 	Code that used SDL_MiddleBlit() should use SDL_LowerBlit() instead.
   461 	You can make your surfaces thread-safe by allocating your own
   462 	mutex and making lock/unlock calls around accesses to your surface.
   463 
   464 0.9.14:
   465 	SDL_GetMouseState() now takes pointers to int rather than Uint16.
   466 
   467 	If you set the SDL_WINDOWID environment variable under UNIX X11,
   468 	SDL will use that as the main window instead of creating it's own.
   469 	This is an unsupported extension to SDL, and not portable at all.
   470 
   471 0.9.13:
   472 	Added a function SDL_SetLibraryPath() which can be used to specify
   473 	the directory containing the SDL dynamic libraries.  This is useful
   474 	for commercial applications which ship with particular versions
   475 	of the libraries, and for security on multi-user systems.
   476 	If this function is not used, the default system directories are 
   477 	searched using the native dynamic object loading mechanism.
   478 
   479 	In order to support C linkage under Visual C++, you must declare
   480 	main() without any return type:
   481 		main(int argc, char *argv[]) {
   482 			/* Do the program... */
   483 			return(0);
   484 		}
   485 	C++ programs should also return a value if compiled under VC++.
   486 
   487 	The blit_endian member of the SDL_VideoInfo struct has been removed.
   488 
   489 	SDL_SymToASCII() has been replaced with SDL_GetKeyName(), so there
   490 	is now no longer any function to translate a keysym to a character.
   491 
   492 	The SDL_keysym structure has been extended with a 'scancode' and
   493 	'unicode' member.  The 'scancode' is a hardware specific scancode
   494 	for the key that was pressed, and may be 0.  The 'unicode' member
   495 	is a 16-bit UNICODE translation of the key that was pressed along
   496 	with any modifiers or compose keys that have been pressed.
   497 	If no UNICODE translation exists for the key, 'unicode' will be 0.
   498 
   499 	Added a function SDL_EnableUNICODE() to enable/disable UNICODE
   500 	translation of character keypresses.  Translation defaults off.
   501 
   502 	To convert existing code to use the new API, change code which
   503 	uses SDL_SymToASCII() to get the keyname to use SDL_GetKeyName(),
   504 	and change code which uses it to get the ASCII value of a sym to
   505 	use the 'unicode' member of the event keysym.
   506 
   507 0.9.12:
   508 	There is partial support for 64-bit datatypes.  I don't recommend 
   509 	you use this if you have a choice, because 64-bit datatypes are not
   510 	supported on many platforms.  On platforms for which it is supported,
   511 	the SDL_HAS_64BIT_TYPE C preprocessor define will be enabled, and
   512 	you can use the Uint64 and Sint64 datatypes.
   513 
   514 	Added functions to SDL_endian.h to support 64-bit datatypes:
   515 	    SDL_SwapLE64(), SDL_SwapBE64(),
   516 	    SDL_ReadLE64(), SDL_ReadBE64(), SDL_WriteLE64(), SDL_WriteBE64()
   517 
   518 	A new member "len_ratio" has been added to the SDL_AudioCVT structure,
   519 	and allows you to determine either the original buffer length or the
   520 	converted buffer length, given the other.
   521 
   522 	A new function SDL_FreeWAV() has been added to the API to free data
   523 	allocated by SDL_LoadWAV_RW().  This is necessary under Win32 since
   524 	the gcc compiled DLL uses a different heap than VC++ compiled apps.
   525 
   526 	SDL now has initial support for international keyboards using the
   527 	Latin character set.
   528 	If a particular mapping is desired, you can set the DEFAULT_KEYBOARD
   529 	compile-time variable, or you can set the environment variable 
   530 	"SDL_KEYBOARD" to a string identifying the keyboard mapping you desire.
   531 	The valid values for these variables can be found in SDL_keyboard.c
   532 
   533 	Full support for German and French keyboards under X11 is implemented.
   534 
   535 0.9.11:
   536 	The THREADED_EVENTS compile-time define has been replaced with the
   537 	SDL_INIT_EVENTTHREAD flag.  If this flag is passed to SDL_Init(),
   538 	SDL will create a separate thread to perform input event handling.
   539 	If this flag is passed to SDL_Init(), and the OS doesn't support 
   540 	event handling in a separate thread, SDL_Init() will fail.
   541 	Be sure to add calls to SDL_Delay() in your main thread to allow
   542 	the OS to schedule your event thread, or it may starve, leading
   543 	to slow event delivery and/or dropped events.
   544 	Currently MacOS and Win32 do not support this flag, while BeOS 
   545 	and Linux do support it.  I recommend that your application only
   546 	use this flag if absolutely necessary.
   547 
   548 	The SDL thread function passed to SDL_CreateThread() now returns a
   549 	status.  This status can be retrieved by passing a non-NULL pointer
   550 	as the 'status' argument to SDL_WaitThread().
   551 
   552 	The volume parameter to SDL_MixAudio() has been increased in range
   553 	from (0-8) to (0-128)
   554 
   555 	SDL now has a data source abstraction which can encompass a file,
   556 	an area of memory, or any custom object you can envision.  It uses
   557 	these abstractions, SDL_RWops, in the endian read/write functions,
   558 	and the built-in WAV and BMP file loaders.  This means you can load
   559 	WAV chunks from memory mapped files, compressed archives, network
   560 	pipes, or anything else that has a data read abstraction.
   561 
   562 	There are three built-in data source abstractions:
   563 	    SDL_RWFromFile(), SDL_RWFromFP(), SDL_RWFromMem()
   564 	along with a generic data source allocation function:
   565 	    SDL_AllocRW()
   566 	These data sources can be used like stdio file pointers with the
   567 	following convenience functions:
   568 	    SDL_RWseek(), SDL_RWread(), SDL_RWwrite(), SDL_RWclose()
   569 	These functions are defined in the new header file "SDL_rwops.h"
   570 
   571 	The endian swapping functions have been turned into macros for speed
   572 	and SDL_CalculateEndian() has been removed.  SDL_endian.h now defines
   573 	SDL_BYTEORDER as either SDL_BIG_ENDIAN or SDL_LIL_ENDIAN depending on
   574 	the endianness of the host system.
   575 
   576 	The endian read/write functions now take an SDL_RWops pointer
   577 	instead of a stdio FILE pointer, to support the new data source
   578 	abstraction.
   579 
   580 	The SDL_*LoadWAV() functions have been replaced with a single
   581 	SDL_LoadWAV_RW() function that takes a SDL_RWops pointer as it's
   582 	first parameter, and a flag whether or not to automatically 
   583 	free it as the second parameter.  SDL_LoadWAV() is a macro for
   584 	backward compatibility and convenience:
   585 	    SDL_LoadWAV_RW(SDL_RWFromFile("sample.wav", "rb"), 1, ...);
   586 
   587 	The SDL_*LoadBMP()/SDL_*SaveBMP() functions have each been replaced
   588 	with a single function that takes a SDL_RWops pointer as it's
   589 	first parameter, and a flag whether or not to automatically 
   590 	free it as the second parameter.  SDL_LoadBMP() and SDL_SaveBMP()
   591 	are macros for backward compatibility and convenience:
   592 	    SDL_LoadBMP_RW(SDL_RWFromFile("sample.bmp", "rb"), 1, ...);
   593 	    SDL_SaveBMP_RW(SDL_RWFromFile("sample.bmp", "wb"), 1, ...);
   594 	Note that these functions use SDL_RWseek() extensively, and should
   595 	not be used on pipes or other non-seekable data sources.
   596 
   597 0.9.10:
   598 	The Linux SDL_SysWMInfo and SDL_SysWMMsg structures have been 
   599 	extended to support multiple types of display drivers, as well as
   600         safe access to the X11 display when THREADED_EVENTS is enabled.
   601         The new structures are documented in the SDL_syswm.h header file.
   602 
   603 	Thanks to John Elliott <jce@seasip.demon.co.uk>, the UK keyboard
   604 	should now work properly, as well as the "Windows" keys on US
   605 	keyboards.
   606 
   607 	The Linux CD-ROM code now reads the CD-ROM devices from /etc/fstab
   608 	instead of trying to open each block device on the system.
   609 	The CD must be listed in /etc/fstab as using the iso9660 filesystem.
   610 
   611 	On Linux, if you define THREADED_EVENTS at compile time, a separate
   612 	thread will be spawned to gather X events asynchronously from the
   613 	graphics updates.  This hasn't been extensively tested, but it does
   614 	provide a means of handling keyboard and mouse input in a separate
   615 	thread from the graphics thread.  (This is now enabled by default.)
   616 
   617 	A special access function SDL_PeepEvents() allows you to manipulate
   618 	the event queue in a thread-safe manner, including peeking at events,
   619 	removing events of a specified type, and adding new events of arbitrary
   620 	type to the queue (use the new 'user' member of the SDL_Event type).
   621 
   622 	If you use SDL_PeepEvents() to gather events, then the main graphics
   623 	thread needs to call SDL_PumpEvents() periodically to drive the event
   624 	loop and generate input events.  This is not necessary if SDL has been 
   625 	compiled with THREADED_EVENTS defined, but doesn't hurt.
   626 
   627 	A new function SDL_ThreadID() returns the identifier associated with
   628 	the current thread.
   629 
   630 0.9.9:
   631 	The AUDIO_STEREO format flag has been replaced with a new 'channels'
   632 	member of the SDL_AudioSpec structure.  The channels are 1 for mono
   633 	audio, and 2 for stereo audio.  In the future more channels may be
   634 	supported for 3D surround sound.
   635 
   636 	The SDL_MixAudio() function now takes an additional volume parameter,
   637 	which should be set to SDL_MIX_MAXVOLUME for compatibility with the
   638 	original function.
   639 
   640 	The CD-ROM functions which take a 'cdrom' parameter can now be
   641 	passed NULL, and will act on the last successfully opened CD-ROM.
   642 
   643 0.9.8:
   644 	No changes, bugfixes only.
   645 	
   646 0.9.7:
   647 	No changes, bugfixes only.
   648 	
   649 0.9.6:
   650 	Added a fast rectangle fill function: SDL_FillRect()
   651 
   652 	Addition of a useful function for getting info on the video hardware:
   653 	    const SDL_VideoInfo *SDL_GetVideoInfo(void)
   654         This function replaces SDL_GetDisplayFormat().
   655 
   656 	Initial support for double-buffering:
   657 	  Use the SDL_DOUBLEBUF flag in SDL_SetVideoMode()
   658 	  Update the screen with a new function: SDL_Flip()
   659 
   660 	SDL_AllocSurface() takes two new flags:
   661 	SDL_SRCCOLORKEY means that the surface will be used for colorkey blits
   662 	  and if the hardware supports hardware acceleration of colorkey blits
   663 	  between two surfaces in video memory, to place the surface in video
   664 	  memory if possible, otherwise it will be placed in system memory.
   665 	SDL_SRCALPHA means that the surface will be used for alpha blits and
   666 	  if the hardware supports hardware acceleration of alpha blits between
   667 	  two surfaces in video memory, to place the surface in video memory
   668 	  if possible, otherwise it will be placed in system memory.
   669 	SDL_HWSURFACE now means that the surface will be created with the 
   670 	  same format as the display surface, since having surfaces in video
   671 	  memory is only useful for fast blitting to the screen, and you can't
   672 	  blit surfaces with different surface formats in video memory.
   673 
   674 0.9.5:
   675 	You can now pass a NULL mask to SDL_WM_SetIcon(), and it will assume
   676 	that the icon consists of the entire image.
   677 
   678 	SDL_LowerBlit() is back -- but don't use it on the display surface.
   679 	It is exactly the same as SDL_MiddleBlit(), but doesn't check for
   680 	thread safety.
   681 
   682 	Added SDL_FPLoadBMP(), SDL_FPSaveBMP(), SDL_FPLoadWAV(), which take
   683 	a FILE pointer instead of a file name.
   684 
   685 	Added CD-ROM audio control API:
   686 	    SDL_CDNumDrives()
   687 	    SDL_CDName()
   688 	    SDL_CDOpen()
   689 	    SDL_CDStatus()
   690 	    SDL_CDPlayTracks()
   691 	    SDL_CDPlay()
   692 	    SDL_CDPause()
   693 	    SDL_CDResume()
   694 	    SDL_CDStop()
   695 	    SDL_CDEject()
   696 	    SDL_CDClose()
   697 
   698 0.9.4:
   699 	No changes, bugfixes only.
   700 
   701 0.9.3:
   702 	Mouse motion event now includes relative motion information:
   703 	    Sint16 event->motion.xrel, Sint16 event->motion.yrel
   704 
   705 	X11 keyrepeat handling can be disabled by defining IGNORE_X_KEYREPEAT
   706 	    (Add -DIGNORE_X_KEYREPEAT to CFLAGS line in obj/x11Makefile)
   707 
   708 0.9.2:
   709 	No changes, bugfixes only.
   710 
   711 0.9.1:
   712 	Removed SDL_MapSurface() and SDL_UnmapSurface() -- surfaces are now
   713 	automatically mapped on blit.
   714 
   715 0.8.0:
   716 	SDL stable release