WhatsNew
author Sam Lantinga <slouken@libsdl.org>
Tue, 18 Nov 2003 01:27:06 +0000
changeset 739 22dbf364c017
parent 656 864e2d2a9a55
child 751 6e9505e0647f
permissions -rw-r--r--
Added SDL_HasMMX(), SDL_Has3DNow(), SDL_HasSSE() in SDL_cpuinfo.h
     1 
     2 This is a list of API changes in SDL's version history.
     3 
     4 Version 1.0:
     5 
     6 1.2.7:
     7 	Added SDL_HasMMX(), SDL_Has3DNow(), SDL_HasSSE()
     8 
     9 1.2.6:
    10 	Added SDL_LoadObject(), SDL_LoadFunction(), and SDL_UnloadObject()
    11 
    12 	Added SDL_GL_MULTISAMPLEBUFFERS and SDL_GL_MULTISAMPLESAMPLES for FSAA
    13 
    14 1.2.5:
    15 	Added SDL_BUTTON_WHEELUP (4) and SDL_BUTTON_WHEELDOWN (5)
    16 
    17 	Added SDL_GL_STEREO for stereoscopic OpenGL contexts
    18 
    19 1.2.0:
    20 	Added SDL_VIDEOEXPOSE event to signal that the screen needs to
    21 	be redrawn.  This is currently only delivered to OpenGL windows
    22 	on X11, though it may be delivered in the future when the video
    23 	memory is lost under DirectX.
    24 
    25 1.1.8:
    26 	You can pass SDL_NOFRAME to SDL_VideoMode() to create a window
    27 	that has no title bar or frame decoration.  Fullscreen video
    28 	modes automatically have this flag set.
    29 
    30 	Added a function to query the clipping rectangle for a surface:
    31 		void SDL_GetClipRect(SDL_Surface *surface, SDL_Rect *rect)
    32 
    33 	Added a function to query the current event filter:
    34 		SDL_EventFilter SDL_GetEventFilter(void)
    35 
    36 	If you pass -1 to SDL_ShowCursor(), it won't change the current
    37 	cursor visibility state, but will still return it.
    38 
    39 	SDL_LockSurface() and SDL_UnlockSurface() are recursive, meaning
    40 	you can nest them as deep as you want, as long as each lock call
    41 	has a matching unlock call.  The surface remains locked until the
    42 	last matching unlock call.
    43 
    44 	Note that you may not blit to or from a locked surface.
    45 
    46 1.1.7:
    47 	The SDL_SetGammaRamp() and SDL_GetGammaRamp() functions now take
    48 	arrays of Uint16 values instead of Uint8 values.  For the most part,
    49 	you can just take your old values and shift them up 8 bits to get
    50 	new correct values for your gamma ramps.
    51 
    52 	You can pass SDL_RLEACCEL in flags passed to SDL_ConvertSurface()
    53         and SDL will try to RLE accelerate colorkey and alpha blits in the
    54 	resulting surface.
    55 
    56 1.1.6:
    57 	Added a function to return the thread ID of a specific thread:
    58 		Uint32 SDL_GetThreadID(SDL_Thread *thread)
    59 	If 'thread' is NULL, this function returns the id for this thread.
    60 
    61 1.1.5:
    62 	The YUV overlay structure has been changed to use an array of
    63 	pitches and pixels representing the planes of a YUV image, to
    64 	better enable hardware acceleration.  The YV12 and IYUV formats
    65 	each have three planes, corresponding to the Y, U, and V portions
    66 	of the image, while packed pixel YUV formats just have one plane.
    67 
    68 	For palettized mode (8bpp), the screen colormap is now split in
    69 	a physical and a logical palette. The physical palette determines
    70 	what colours the screen pixels will get when displayed, and the
    71 	logical palette controls the mapping from blits to/from the screen.
    72 	A new function, SDL_SetPalette() has been added to change
    73 	logical and physical palettes separately. SDL_SetColors() works
    74 	just as before, and is equivalent to calling SDL_SetPalette() with
    75 	a flag argument of (SDL_LOGPAL|SDL_PHYSPAL).
    76 
    77 	SDL_BlitSurface() no longer modifies the source rectangle, only the
    78 	destination rectangle. The width/height members of the destination
    79 	rectangle are ignored, only the position is used.
    80 
    81 	The old source clipping function SDL_SetClipping() has been replaced
    82 	with a more useful function to set the destination clipping rectangle:
    83 		SDL_bool SDL_SetClipRect(SDL_Surface *surface, SDL_Rect *rect)
    84 		
    85 	Added a function to see what subsystems have been initialized:
    86 		Uint32 SDL_WasInit(Uint32 flags)
    87 
    88 	The Big Alpha Flip: SDL now treats alpha as opacity like everybody
    89 	else, and not as transparency:
    90 
    91 	A new cpp symbol: SDL_ALPHA_OPAQUE is defined as 255
    92 	A new cpp symbol: SDL_ALPHA_TRANSPARENT is defined as 0
    93 	Values between 0 and 255 vary from fully transparent to fully opaque.
    94 
    95 	New functions:
    96 	SDL_DisplayFormatAlpha()
    97 	    Returns a surface converted to a format with alpha-channel
    98 	    that can be blit efficiently to the screen. (In other words,
    99 	    like SDL_DisplayFormat() but the resulting surface has
   100 	    an alpha channel.)  This is useful for surfaces with alpha.
   101 	SDL_MapRGBA()
   102 	    Works as SDL_MapRGB() but takes an additional alpha parameter.
   103 	SDL_GetRGBA()
   104 	    Works as SDL_GetRGB() but also returns the alpha value
   105 	    (SDL_ALPHA_OPAQUE for formats without an alpha channel)
   106 
   107 	Both SDL_GetRGB() and SDL_GetRGBA() now always return values in
   108 	the [0..255] interval. Previously, SDL_GetRGB() would return
   109 	(0xf8, 0xfc, 0xf8) for a completely white pixel in RGB565 format.
   110 	(N.B.: This is broken for bit fields < 3 bits.)
   111 
   112 	SDL_MapRGB() returns pixels in which the alpha channel is set opaque.
   113 
   114 	SDL_SetAlpha() can now be used for both setting the per-surface
   115 	alpha, using the new way of thinking of alpha, and also to enable
   116 	and disable per-pixel alpha blending for surfaces with an alpha
   117 	channel:
   118 		To disable alpha blending:
   119 			SDL_SetAlpha(surface, 0, 0);
   120 		To re-enable alpha blending:
   121 			SDL_SetAlpha(surface, SDL_SRCALPHA, 0);
   122 	Surfaces with an alpha channel have blending enabled by default.
   123 
   124 	SDL_SetAlpha() now accepts SDL_RLEACCEL as a flag, which requests
   125 	RLE acceleration of blits, just as like with SDL_SetColorKey().
   126 	This flag can be set for both surfaces with an alpha channel
   127 	and surfaces with an alpha value set by SDL_SetAlpha().
   128 	As always, RLE surfaces must be locked before pixel access is
   129 	allowed, and unlocked before any other SDL operations are done
   130 	on it.
   131 
   132 	The blit semantics for surfaces with and without alpha and colorkey
   133 	have now been defined:
   134 
   135 	RGBA->RGB:
   136 	    SDL_SRCALPHA set:
   137 		alpha-blend (using alpha-channel).
   138 		SDL_SRCCOLORKEY ignored.
   139 	    SDL_SRCALPHA not set:
   140 		copy RGB.
   141 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   142 		RGB values of the source colour key, ignoring alpha in the
   143 		comparison.
   144 
   145 	RGB->RGBA:
   146 	    SDL_SRCALPHA set:
   147 		alpha-blend (using the source per-surface alpha value);
   148 		set destination alpha to opaque.
   149 	    SDL_SRCALPHA not set:
   150 		copy RGB, set destination alpha to opaque.
   151 	    both:
   152 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   153 		source colour key.
   154 
   155 	RGBA->RGBA:
   156 	    SDL_SRCALPHA set:
   157 		alpha-blend (using the source alpha channel) the RGB values;
   158 		leave destination alpha untouched. [Note: is this correct?]
   159 		SDL_SRCCOLORKEY ignored.
   160 	    SDL_SRCALPHA not set:
   161 		copy all of RGBA to the destination.
   162 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   163 		RGB values of the source colour key, ignoring alpha in the
   164 		comparison.
   165 
   166 	RGB->RGB: 
   167 	    SDL_SRCALPHA set:
   168 		alpha-blend (using the source per-surface alpha value).
   169 	    SDL_SRCALPHA not set:
   170 		copy RGB.
   171 	    both:
   172 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   173 		source colour key.
   174 
   175 	As a special case, blits from surfaces with per-surface alpha
   176 	value of 128 (50% transparency) are optimised and much faster
   177 	than other alpha values. This does not apply to surfaces with
   178 	alpha channels (per-pixel alpha).
   179 
   180 	New functions for manipulating the gamma of the display have
   181 	been added:
   182 		int SDL_SetGamma(float red, float green, float blue);
   183 		int SDL_SetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   184 		int SDL_GetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   185 	Gamma ramps are tables with 256 entries which map the screen color
   186 	components into actually displayed colors.  For an example of
   187 	implementing gamma correction and gamma fades, see test/testgamma.c
   188 	Gamma control is not supported on all hardware.
   189 
   190 1.1.4:
   191 	The size of the SDL_CDtrack structure changed from 8 to 12 bytes
   192 	as the size of the length member was extended to 32 bits.
   193 
   194         You can now use SDL for 2D blitting with a GL mode by passing the
   195 	SDL_OPENGLBLIT flag to SDL_SetVideoMode().  You can specify 16 or
   196 	32 bpp, and the data in the framebuffer is put into the GL scene
   197 	when you call SDL_UpdateRects(), and the scene will be visible
   198 	when you call SDL_GL_SwapBuffers().
   199 
   200 	Run the "testgl" test program with the -logo command line option
   201 	to see an example of this blending of 2D and 3D in SDL.
   202 
   203 1.1.3:
   204 	Added SDL_FreeRW() to the API, to complement SDL_AllocRW()
   205 
   206 	Added resizable window support - just add SDL_RESIZABLE to the
   207 	SDL_SetVideoMode() flags, and then wait for SDL_VIDEORESIZE events.
   208 	See SDL_events.h for details on the new SDL_ResizeEvent structure.
   209 
   210 	Added condition variable support, based on mutexes and semaphores.
   211 		SDL_CreateCond()
   212 		SDL_DestroyCond()
   213 		SDL_CondSignal()
   214 		SDL_CondBroadcast()
   215 		SDL_CondWait()
   216 		SDL_CondTimedWait()
   217 	The new function prototypes are in SDL_mutex.h
   218 
   219 	Added counting semaphore support, based on the mutex primitive.
   220 		SDL_CreateSemaphore()
   221 		SDL_DestroySemaphore()
   222 		SDL_SemWait()
   223 		SDL_SemTryWait()
   224 		SDL_SemWaitTimeout()
   225 		SDL_SemPost()
   226 		SDL_SemValue()
   227 	The new function prototypes are in SDL_mutex.h
   228 
   229 	Added support for asynchronous blitting.  To take advantage of this,
   230 	you must set the SDL_ASYNCBLIT flag when setting the video mode and
   231 	creating surfaces that you want accelerated in this way.  You must
   232 	lock surfaces that have this flag set, and the lock will block until
   233 	any queued blits have completed.
   234 
   235 	Added YUV video overlay support.
   236 	The supported YUV formats are: YV12, IYUV, YUY2, UYVY, and YVYU.
   237 	This function creates an overlay surface:
   238 		SDL_CreateYUVOverlay()
   239 	You must lock and unlock the overlay to get access to the data:
   240 		SDL_LockYUVOverlay() SDL_UnlockYUVOverlay()
   241 	You can then display the overlay:
   242 		SDL_DisplayYUVOverlay()
   243 	You must free the overlay when you are done using it:
   244 		SDL_FreeYUVOverlay()
   245 	See SDL_video.h for the full function prototypes.
   246 
   247 	The joystick hat position constants have been changed:
   248 	Old constant            New constant
   249 	------------            ------------
   250 	     0                  SDL_HAT_CENTERED
   251 	     1                  SDL_HAT_UP
   252 	     2                  SDL_HAT_RIGHTUP
   253 	     3                  SDL_HAT_RIGHT
   254 	     4                  SDL_HAT_RIGHTDOWN
   255 	     5                  SDL_HAT_DOWN
   256 	     6                  SDL_HAT_LEFTDOWN
   257 	     7                  SDL_HAT_LEFT
   258 	     8                  SDL_HAT_LEFTUP
   259 	The new constants are bitmasks, so you can check for the
   260 	individual axes like this:
   261 		if ( hat_position & SDL_HAT_UP ) {
   262 		}
   263 	and you'll catch left-up, up, and right-up.
   264 
   265 1.1.2:
   266 	Added multiple timer support:
   267 		SDL_AddTimer() and SDL_RemoveTimer()
   268 
   269 	SDL_WM_SetIcon() now respects the icon colorkey if mask is NULL.
   270 
   271 1.1.0:
   272 	Added initial OpenGL support.
   273 	First set GL attributes (such as RGB depth, alpha depth, etc.)
   274 		SDL_GL_SetAttribute()
   275 	Then call SDL_SetVideoMode() with the SDL_OPENGL flag.
   276 	Perform all of your normal GL drawing.
   277 	Finally swap the buffers with the new SDL function:
   278 		SDL_GL_SwapBuffers()
   279 	See the new 'testgl' test program for an example of using GL with SDL.
   280 
   281 	You can load GL extension functions by using the function:
   282 		SDL_GL_LoadProcAddress()
   283 
   284 	Added functions to initialize and cleanup specific SDL subsystems:
   285 		SDL_InitSubSystem() and SDL_QuitSubSystem()
   286 
   287 	Added user-defined event type:
   288 		typedef struct {
   289         		Uint8 type;
   290         		int code;
   291         		void *data1;
   292         		void *data2;
   293 		} SDL_UserEvent;
   294 	This structure is in the "user" member of an SDL_Event.
   295 
   296 	Added a function to push events into the event queue:
   297 		SDL_PushEvent()
   298 
   299 	Example of using the new SDL user-defined events:
   300 	{
   301 		SDL_Event event;
   302 
   303 		event.type = SDL_USEREVENT;
   304 		event.user.code = my_event_code;
   305 		event.user.data1 = significant_data;
   306 		event.user.data2 = 0;
   307 		SDL_PushEvent(&event);
   308 	}
   309 
   310 	Added a function to get mouse deltas since last query:
   311 		SDL_GetRelativeMouseState()
   312 
   313 	Added a boolean datatype to SDL_types.h:
   314 		SDL_bool = { SDL_TRUE, SDL_FALSE }
   315 
   316 	Added a function to get the current audio status:
   317 		SDL_GetAudioState();
   318 	It returns one of:
   319 		SDL_AUDIO_STOPPED,
   320 		SDL_AUDIO_PLAYING,
   321 		SDL_AUDIO_PAUSED
   322 
   323 	Added an AAlib driver (ASCII Art) - by Stephane Peter.
   324 
   325 1.0.6:
   326 	The input grab state is reset after each call to SDL_SetVideoMode().
   327 	The input is grabbed by default in fullscreen mode, and ungrabbed in
   328 	windowed mode.  If you want to set input grab to a particular value,
   329 	you should set it after each call to SDL_SetVideoMode().
   330 
   331 1.0.5:
   332 	Exposed SDL_AudioInit(), SDL_VideoInit()
   333 	Added SDL_AudioDriverName() and SDL_VideoDriverName()
   334 
   335 	Added new window manager function:
   336 		SDL_WM_ToggleFullScreen()
   337 	This is currently implemented only on Linux
   338 
   339 	The ALT-ENTER code has been removed - it's not appropriate for a
   340 	lib to bind keys when they aren't even emergency escape sequences.
   341 
   342 	ALT-ENTER functionality can be implemented with the following code:
   343 
   344 	int Handle_AltEnter(const SDL_Event *event)
   345 	{
   346 	    if ( event->type == SDL_KEYDOWN ) {
   347 	        if ( (event->key.keysym.sym == SDLK_RETURN) &&
   348 	             (event->key.keysym.mod & KMOD_ALT) ) {   
   349 	                SDL_WM_ToggleFullScreen(SDL_GetVideoSurface());
   350 	                return(0);
   351 	        }
   352 	    }
   353 	    return(1);
   354 	}
   355 	SDL_SetEventFilter(Handle_AltEnter);
   356 
   357 1.0.3:
   358 	Under X11, if you grab the input and hide the mouse cursor,
   359 	the mouse will go into a "relative motion" mode where you
   360 	will always get relative motion events no matter how far in
   361 	each direction you move the mouse - relative motion is not
   362 	bounded by the edges of the window (though the absolute values
   363 	of the mouse positions are clamped by the size of the window).
   364 	The SVGAlib, framebuffer console, and DirectInput drivers all
   365 	have this behavior naturally, and the GDI and BWindow drivers
   366 	never go into "relative motion" mode.
   367 
   368 1.0.2:
   369 	Added a function to enable keyboard repeat:
   370 		SDL_EnableKeyRepeat()
   371 
   372 	Added a function to grab the mouse and keyboard input
   373 		SDL_WM_GrabInput()
   374 
   375 	Added a function to iconify the window.
   376 		SDL_WM_IconifyWindow()
   377 	If this function succeeds, the application will receive an event
   378 	signaling SDL_APPACTIVE event 
   379 
   380 1.0.1:
   381 	Added constants to SDL_audio.h for 16-bit native byte ordering:
   382 		AUDIO_U16SYS, AUDIO_S16SYS
   383 
   384 1.0.0:
   385 	New public release
   386 
   387 Version 0.11:
   388 
   389 0.11.5:
   390 	A new function SDL_GetVideoSurface() has been added, and returns
   391 	a pointer to the current display surface.
   392 
   393 	SDL_AllocSurface() has been renamed SDL_CreateRGBSurface(), and
   394 	a new function SDL_CreateRGBSurfaceFrom() has been added to allow
   395 	creating an SDL surface from an existing pixel data buffer.
   396 
   397 	Added SDL_GetRGB() to the headers and documentation.
   398 
   399 0.11.4:
   400 	SDL_SetLibraryPath() is no longer meaningful, and has been removed.
   401 
   402 0.11.3:
   403 	A new flag for SDL_Init(), SDL_INIT_NOPARACHUTE, prevents SDL from
   404 	installing fatal signal handlers on operating systems that support
   405 	them.
   406 
   407 Version 0.9:
   408 
   409 0.9.15:
   410 	SDL_CreateColorCursor() has been removed.  Color cursors should
   411 	be implemented as sprites, blitted by the application when the
   412 	cursor moves.  To get smooth color cursor updates when the app
   413 	is busy, pass the SDL_INIT_EVENTTHREAD flag to SDL_Init().  This
   414 	allows you to handle the mouse motion in another thread from an
   415 	event filter function, but is currently only supported by Linux
   416 	and BeOS.  Note that you'll have to protect the display surface
   417 	from multi-threaded access by using mutexes if you do this.
   418 
   419 	Thread-safe surface support has been removed from SDL.
   420 	This makes blitting somewhat faster, by removing SDL_MiddleBlit().
   421 	Code that used SDL_MiddleBlit() should use SDL_LowerBlit() instead.
   422 	You can make your surfaces thread-safe by allocating your own
   423 	mutex and making lock/unlock calls around accesses to your surface.
   424 
   425 0.9.14:
   426 	SDL_GetMouseState() now takes pointers to int rather than Uint16.
   427 
   428 	If you set the SDL_WINDOWID environment variable under UNIX X11,
   429 	SDL will use that as the main window instead of creating it's own.
   430 	This is an unsupported extension to SDL, and not portable at all.
   431 
   432 0.9.13:
   433 	Added a function SDL_SetLibraryPath() which can be used to specify
   434 	the directory containing the SDL dynamic libraries.  This is useful
   435 	for commercial applications which ship with particular versions
   436 	of the libraries, and for security on multi-user systems.
   437 	If this function is not used, the default system directories are 
   438 	searched using the native dynamic object loading mechanism.
   439 
   440 	In order to support C linkage under Visual C++, you must declare
   441 	main() without any return type:
   442 		main(int argc, char *argv[]) {
   443 			/* Do the program... */
   444 			return(0);
   445 		}
   446 	C++ programs should also return a value if compiled under VC++.
   447 
   448 	The blit_endian member of the SDL_VideoInfo struct has been removed.
   449 
   450 	SDL_SymToASCII() has been replaced with SDL_GetKeyName(), so there
   451 	is now no longer any function to translate a keysym to a character.
   452 
   453 	The SDL_keysym structure has been extended with a 'scancode' and
   454 	'unicode' member.  The 'scancode' is a hardware specific scancode
   455 	for the key that was pressed, and may be 0.  The 'unicode' member
   456 	is a 16-bit UNICODE translation of the key that was pressed along
   457 	with any modifiers or compose keys that have been pressed.
   458 	If no UNICODE translation exists for the key, 'unicode' will be 0.
   459 
   460 	Added a function SDL_EnableUNICODE() to enable/disable UNICODE
   461 	translation of character keypresses.  Translation defaults off.
   462 
   463 	To convert existing code to use the new API, change code which
   464 	uses SDL_SymToASCII() to get the keyname to use SDL_GetKeyName(),
   465 	and change code which uses it to get the ASCII value of a sym to
   466 	use the 'unicode' member of the event keysym.
   467 
   468 0.9.12:
   469 	There is partial support for 64-bit datatypes.  I don't recommend 
   470 	you use this if you have a choice, because 64-bit datatypes are not
   471 	supported on many platforms.  On platforms for which it is supported,
   472 	the SDL_HAS_64BIT_TYPE C preprocessor define will be enabled, and
   473 	you can use the Uint64 and Sint64 datatypes.
   474 
   475 	Added functions to SDL_endian.h to support 64-bit datatypes:
   476 	    SDL_SwapLE64(), SDL_SwapBE64(),
   477 	    SDL_ReadLE64(), SDL_ReadBE64(), SDL_WriteLE64(), SDL_WriteBE64()
   478 
   479 	A new member "len_ratio" has been added to the SDL_AudioCVT structure,
   480 	and allows you to determine either the original buffer length or the
   481 	converted buffer length, given the other.
   482 
   483 	A new function SDL_FreeWAV() has been added to the API to free data
   484 	allocated by SDL_LoadWAV_RW().  This is necessary under Win32 since
   485 	the gcc compiled DLL uses a different heap than VC++ compiled apps.
   486 
   487 	SDL now has initial support for international keyboards using the
   488 	Latin character set.
   489 	If a particular mapping is desired, you can set the DEFAULT_KEYBOARD
   490 	compile-time variable, or you can set the environment variable 
   491 	"SDL_KEYBOARD" to a string identifying the keyboard mapping you desire.
   492 	The valid values for these variables can be found in SDL_keyboard.c
   493 
   494 	Full support for German and French keyboards under X11 is implemented.
   495 
   496 0.9.11:
   497 	The THREADED_EVENTS compile-time define has been replaced with the
   498 	SDL_INIT_EVENTTHREAD flag.  If this flag is passed to SDL_Init(),
   499 	SDL will create a separate thread to perform input event handling.
   500 	If this flag is passed to SDL_Init(), and the OS doesn't support 
   501 	event handling in a separate thread, SDL_Init() will fail.
   502 	Be sure to add calls to SDL_Delay() in your main thread to allow
   503 	the OS to schedule your event thread, or it may starve, leading
   504 	to slow event delivery and/or dropped events.
   505 	Currently MacOS and Win32 do not support this flag, while BeOS 
   506 	and Linux do support it.  I recommend that your application only
   507 	use this flag if absolutely necessary.
   508 
   509 	The SDL thread function passed to SDL_CreateThread() now returns a
   510 	status.  This status can be retrieved by passing a non-NULL pointer
   511 	as the 'status' argument to SDL_WaitThread().
   512 
   513 	The volume parameter to SDL_MixAudio() has been increased in range
   514 	from (0-8) to (0-128)
   515 
   516 	SDL now has a data source abstraction which can encompass a file,
   517 	an area of memory, or any custom object you can envision.  It uses
   518 	these abstractions, SDL_RWops, in the endian read/write functions,
   519 	and the built-in WAV and BMP file loaders.  This means you can load
   520 	WAV chunks from memory mapped files, compressed archives, network
   521 	pipes, or anything else that has a data read abstraction.
   522 
   523 	There are three built-in data source abstractions:
   524 	    SDL_RWFromFile(), SDL_RWFromFP(), SDL_RWFromMem()
   525 	along with a generic data source allocation function:
   526 	    SDL_AllocRW()
   527 	These data sources can be used like stdio file pointers with the
   528 	following convenience functions:
   529 	    SDL_RWseek(), SDL_RWread(), SDL_RWwrite(), SDL_RWclose()
   530 	These functions are defined in the new header file "SDL_rwops.h"
   531 
   532 	The endian swapping functions have been turned into macros for speed
   533 	and SDL_CalculateEndian() has been removed.  SDL_endian.h now defines
   534 	SDL_BYTEORDER as either SDL_BIG_ENDIAN or SDL_LIL_ENDIAN depending on
   535 	the endianness of the host system.
   536 
   537 	The endian read/write functions now take an SDL_RWops pointer
   538 	instead of a stdio FILE pointer, to support the new data source
   539 	abstraction.
   540 
   541 	The SDL_*LoadWAV() functions have been replaced with a single
   542 	SDL_LoadWAV_RW() function that takes a SDL_RWops pointer as it's
   543 	first parameter, and a flag whether or not to automatically 
   544 	free it as the second parameter.  SDL_LoadWAV() is a macro for
   545 	backward compatibility and convenience:
   546 	    SDL_LoadWAV_RW(SDL_RWFromFile("sample.wav", "rb"), 1, ...);
   547 
   548 	The SDL_*LoadBMP()/SDL_*SaveBMP() functions have each been replaced
   549 	with a single function that takes a SDL_RWops pointer as it's
   550 	first parameter, and a flag whether or not to automatically 
   551 	free it as the second parameter.  SDL_LoadBMP() and SDL_SaveBMP()
   552 	are macros for backward compatibility and convenience:
   553 	    SDL_LoadBMP_RW(SDL_RWFromFile("sample.bmp", "rb"), 1, ...);
   554 	    SDL_SaveBMP_RW(SDL_RWFromFile("sample.bmp", "wb"), 1, ...);
   555 	Note that these functions use SDL_RWseek() extensively, and should
   556 	not be used on pipes or other non-seekable data sources.
   557 
   558 0.9.10:
   559 	The Linux SDL_SysWMInfo and SDL_SysWMMsg structures have been 
   560 	extended to support multiple types of display drivers, as well as
   561         safe access to the X11 display when THREADED_EVENTS is enabled.
   562         The new structures are documented in the SDL_syswm.h header file.
   563 
   564 	Thanks to John Elliott <jce@seasip.demon.co.uk>, the UK keyboard
   565 	should now work properly, as well as the "Windows" keys on US
   566 	keyboards.
   567 
   568 	The Linux CD-ROM code now reads the CD-ROM devices from /etc/fstab
   569 	instead of trying to open each block device on the system.
   570 	The CD must be listed in /etc/fstab as using the iso9660 filesystem.
   571 
   572 	On Linux, if you define THREADED_EVENTS at compile time, a separate
   573 	thread will be spawned to gather X events asynchronously from the
   574 	graphics updates.  This hasn't been extensively tested, but it does
   575 	provide a means of handling keyboard and mouse input in a separate
   576 	thread from the graphics thread.  (This is now enabled by default.)
   577 
   578 	A special access function SDL_PeepEvents() allows you to manipulate
   579 	the event queue in a thread-safe manner, including peeking at events,
   580 	removing events of a specified type, and adding new events of arbitrary
   581 	type to the queue (use the new 'user' member of the SDL_Event type).
   582 
   583 	If you use SDL_PeepEvents() to gather events, then the main graphics
   584 	thread needs to call SDL_PumpEvents() periodically to drive the event
   585 	loop and generate input events.  This is not necessary if SDL has been 
   586 	compiled with THREADED_EVENTS defined, but doesn't hurt.
   587 
   588 	A new function SDL_ThreadID() returns the identifier associated with
   589 	the current thread.
   590 
   591 0.9.9:
   592 	The AUDIO_STEREO format flag has been replaced with a new 'channels'
   593 	member of the SDL_AudioSpec structure.  The channels are 1 for mono
   594 	audio, and 2 for stereo audio.  In the future more channels may be
   595 	supported for 3D surround sound.
   596 
   597 	The SDL_MixAudio() function now takes an additional volume parameter,
   598 	which should be set to SDL_MIX_MAXVOLUME for compatibility with the
   599 	original function.
   600 
   601 	The CD-ROM functions which take a 'cdrom' parameter can now be
   602 	passed NULL, and will act on the last successfully opened CD-ROM.
   603 
   604 0.9.8:
   605 	No changes, bugfixes only.
   606 	
   607 0.9.7:
   608 	No changes, bugfixes only.
   609 	
   610 0.9.6:
   611 	Added a fast rectangle fill function: SDL_FillRect()
   612 
   613 	Addition of a useful function for getting info on the video hardware:
   614 	    const SDL_VideoInfo *SDL_GetVideoInfo(void)
   615         This function replaces SDL_GetDisplayFormat().
   616 
   617 	Initial support for double-buffering:
   618 	  Use the SDL_DOUBLEBUF flag in SDL_SetVideoMode()
   619 	  Update the screen with a new function: SDL_Flip()
   620 
   621 	SDL_AllocSurface() takes two new flags:
   622 	SDL_SRCCOLORKEY means that the surface will be used for colorkey blits
   623 	  and if the hardware supports hardware acceleration of colorkey blits
   624 	  between two surfaces in video memory, to place the surface in video
   625 	  memory if possible, otherwise it will be placed in system memory.
   626 	SDL_SRCALPHA means that the surface will be used for alpha blits and
   627 	  if the hardware supports hardware acceleration of alpha blits between
   628 	  two surfaces in video memory, to place the surface in video memory
   629 	  if possible, otherwise it will be placed in system memory.
   630 	SDL_HWSURFACE now means that the surface will be created with the 
   631 	  same format as the display surface, since having surfaces in video
   632 	  memory is only useful for fast blitting to the screen, and you can't
   633 	  blit surfaces with different surface formats in video memory.
   634 
   635 0.9.5:
   636 	You can now pass a NULL mask to SDL_WM_SetIcon(), and it will assume
   637 	that the icon consists of the entire image.
   638 
   639 	SDL_LowerBlit() is back -- but don't use it on the display surface.
   640 	It is exactly the same as SDL_MiddleBlit(), but doesn't check for
   641 	thread safety.
   642 
   643 	Added SDL_FPLoadBMP(), SDL_FPSaveBMP(), SDL_FPLoadWAV(), which take
   644 	a FILE pointer instead of a file name.
   645 
   646 	Added CD-ROM audio control API:
   647 	    SDL_CDNumDrives()
   648 	    SDL_CDName()
   649 	    SDL_CDOpen()
   650 	    SDL_CDStatus()
   651 	    SDL_CDPlayTracks()
   652 	    SDL_CDPlay()
   653 	    SDL_CDPause()
   654 	    SDL_CDResume()
   655 	    SDL_CDStop()
   656 	    SDL_CDEject()
   657 	    SDL_CDClose()
   658 
   659 0.9.4:
   660 	No changes, bugfixes only.
   661 
   662 0.9.3:
   663 	Mouse motion event now includes relative motion information:
   664 	    Sint16 event->motion.xrel, Sint16 event->motion.yrel
   665 
   666 	X11 keyrepeat handling can be disabled by defining IGNORE_X_KEYREPEAT
   667 	    (Add -DIGNORE_X_KEYREPEAT to CFLAGS line in obj/x11Makefile)
   668 
   669 0.9.2:
   670 	No changes, bugfixes only.
   671 
   672 0.9.1:
   673 	Removed SDL_MapSurface() and SDL_UnmapSurface() -- surfaces are now
   674 	automatically mapped on blit.
   675 
   676 0.8.0:
   677 	SDL stable release