WhatsNew
author Sam Lantinga <slouken@libsdl.org>
Mon, 24 Nov 2003 22:52:28 +0000
changeset 751 6e9505e0647f
parent 739 22dbf364c017
child 764 974c0fb74bf8
permissions -rw-r--r--
*** empty log message ***
     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 CPU feature detection functions to SDL_cpuinfo.h:
     8 		SDL_HasRDTSC(), SDL_HasMMX(), SDL_Has3DNow(), SDL_HasSSE()
     9 
    10 1.2.6:
    11 	Added SDL_LoadObject(), SDL_LoadFunction(), and SDL_UnloadObject()
    12 
    13 	Added SDL_GL_MULTISAMPLEBUFFERS and SDL_GL_MULTISAMPLESAMPLES for FSAA
    14 
    15 1.2.5:
    16 	Added SDL_BUTTON_WHEELUP (4) and SDL_BUTTON_WHEELDOWN (5)
    17 
    18 	Added SDL_GL_STEREO for stereoscopic OpenGL contexts
    19 
    20 1.2.0:
    21 	Added SDL_VIDEOEXPOSE event to signal that the screen needs to
    22 	be redrawn.  This is currently only delivered to OpenGL windows
    23 	on X11, though it may be delivered in the future when the video
    24 	memory is lost under DirectX.
    25 
    26 1.1.8:
    27 	You can pass SDL_NOFRAME to SDL_VideoMode() to create a window
    28 	that has no title bar or frame decoration.  Fullscreen video
    29 	modes automatically have this flag set.
    30 
    31 	Added a function to query the clipping rectangle for a surface:
    32 		void SDL_GetClipRect(SDL_Surface *surface, SDL_Rect *rect)
    33 
    34 	Added a function to query the current event filter:
    35 		SDL_EventFilter SDL_GetEventFilter(void)
    36 
    37 	If you pass -1 to SDL_ShowCursor(), it won't change the current
    38 	cursor visibility state, but will still return it.
    39 
    40 	SDL_LockSurface() and SDL_UnlockSurface() are recursive, meaning
    41 	you can nest them as deep as you want, as long as each lock call
    42 	has a matching unlock call.  The surface remains locked until the
    43 	last matching unlock call.
    44 
    45 	Note that you may not blit to or from a locked surface.
    46 
    47 1.1.7:
    48 	The SDL_SetGammaRamp() and SDL_GetGammaRamp() functions now take
    49 	arrays of Uint16 values instead of Uint8 values.  For the most part,
    50 	you can just take your old values and shift them up 8 bits to get
    51 	new correct values for your gamma ramps.
    52 
    53 	You can pass SDL_RLEACCEL in flags passed to SDL_ConvertSurface()
    54         and SDL will try to RLE accelerate colorkey and alpha blits in the
    55 	resulting surface.
    56 
    57 1.1.6:
    58 	Added a function to return the thread ID of a specific thread:
    59 		Uint32 SDL_GetThreadID(SDL_Thread *thread)
    60 	If 'thread' is NULL, this function returns the id for this thread.
    61 
    62 1.1.5:
    63 	The YUV overlay structure has been changed to use an array of
    64 	pitches and pixels representing the planes of a YUV image, to
    65 	better enable hardware acceleration.  The YV12 and IYUV formats
    66 	each have three planes, corresponding to the Y, U, and V portions
    67 	of the image, while packed pixel YUV formats just have one plane.
    68 
    69 	For palettized mode (8bpp), the screen colormap is now split in
    70 	a physical and a logical palette. The physical palette determines
    71 	what colours the screen pixels will get when displayed, and the
    72 	logical palette controls the mapping from blits to/from the screen.
    73 	A new function, SDL_SetPalette() has been added to change
    74 	logical and physical palettes separately. SDL_SetColors() works
    75 	just as before, and is equivalent to calling SDL_SetPalette() with
    76 	a flag argument of (SDL_LOGPAL|SDL_PHYSPAL).
    77 
    78 	SDL_BlitSurface() no longer modifies the source rectangle, only the
    79 	destination rectangle. The width/height members of the destination
    80 	rectangle are ignored, only the position is used.
    81 
    82 	The old source clipping function SDL_SetClipping() has been replaced
    83 	with a more useful function to set the destination clipping rectangle:
    84 		SDL_bool SDL_SetClipRect(SDL_Surface *surface, SDL_Rect *rect)
    85 		
    86 	Added a function to see what subsystems have been initialized:
    87 		Uint32 SDL_WasInit(Uint32 flags)
    88 
    89 	The Big Alpha Flip: SDL now treats alpha as opacity like everybody
    90 	else, and not as transparency:
    91 
    92 	A new cpp symbol: SDL_ALPHA_OPAQUE is defined as 255
    93 	A new cpp symbol: SDL_ALPHA_TRANSPARENT is defined as 0
    94 	Values between 0 and 255 vary from fully transparent to fully opaque.
    95 
    96 	New functions:
    97 	SDL_DisplayFormatAlpha()
    98 	    Returns a surface converted to a format with alpha-channel
    99 	    that can be blit efficiently to the screen. (In other words,
   100 	    like SDL_DisplayFormat() but the resulting surface has
   101 	    an alpha channel.)  This is useful for surfaces with alpha.
   102 	SDL_MapRGBA()
   103 	    Works as SDL_MapRGB() but takes an additional alpha parameter.
   104 	SDL_GetRGBA()
   105 	    Works as SDL_GetRGB() but also returns the alpha value
   106 	    (SDL_ALPHA_OPAQUE for formats without an alpha channel)
   107 
   108 	Both SDL_GetRGB() and SDL_GetRGBA() now always return values in
   109 	the [0..255] interval. Previously, SDL_GetRGB() would return
   110 	(0xf8, 0xfc, 0xf8) for a completely white pixel in RGB565 format.
   111 	(N.B.: This is broken for bit fields < 3 bits.)
   112 
   113 	SDL_MapRGB() returns pixels in which the alpha channel is set opaque.
   114 
   115 	SDL_SetAlpha() can now be used for both setting the per-surface
   116 	alpha, using the new way of thinking of alpha, and also to enable
   117 	and disable per-pixel alpha blending for surfaces with an alpha
   118 	channel:
   119 		To disable alpha blending:
   120 			SDL_SetAlpha(surface, 0, 0);
   121 		To re-enable alpha blending:
   122 			SDL_SetAlpha(surface, SDL_SRCALPHA, 0);
   123 	Surfaces with an alpha channel have blending enabled by default.
   124 
   125 	SDL_SetAlpha() now accepts SDL_RLEACCEL as a flag, which requests
   126 	RLE acceleration of blits, just as like with SDL_SetColorKey().
   127 	This flag can be set for both surfaces with an alpha channel
   128 	and surfaces with an alpha value set by SDL_SetAlpha().
   129 	As always, RLE surfaces must be locked before pixel access is
   130 	allowed, and unlocked before any other SDL operations are done
   131 	on it.
   132 
   133 	The blit semantics for surfaces with and without alpha and colorkey
   134 	have now been defined:
   135 
   136 	RGBA->RGB:
   137 	    SDL_SRCALPHA set:
   138 		alpha-blend (using alpha-channel).
   139 		SDL_SRCCOLORKEY ignored.
   140 	    SDL_SRCALPHA not set:
   141 		copy RGB.
   142 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   143 		RGB values of the source colour key, ignoring alpha in the
   144 		comparison.
   145 
   146 	RGB->RGBA:
   147 	    SDL_SRCALPHA set:
   148 		alpha-blend (using the source per-surface alpha value);
   149 		set destination alpha to opaque.
   150 	    SDL_SRCALPHA not set:
   151 		copy RGB, set destination alpha to opaque.
   152 	    both:
   153 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   154 		source colour key.
   155 
   156 	RGBA->RGBA:
   157 	    SDL_SRCALPHA set:
   158 		alpha-blend (using the source alpha channel) the RGB values;
   159 		leave destination alpha untouched. [Note: is this correct?]
   160 		SDL_SRCCOLORKEY ignored.
   161 	    SDL_SRCALPHA not set:
   162 		copy all of RGBA to the destination.
   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->RGB: 
   168 	    SDL_SRCALPHA set:
   169 		alpha-blend (using the source per-surface alpha value).
   170 	    SDL_SRCALPHA not set:
   171 		copy RGB.
   172 	    both:
   173 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   174 		source colour key.
   175 
   176 	As a special case, blits from surfaces with per-surface alpha
   177 	value of 128 (50% transparency) are optimised and much faster
   178 	than other alpha values. This does not apply to surfaces with
   179 	alpha channels (per-pixel alpha).
   180 
   181 	New functions for manipulating the gamma of the display have
   182 	been added:
   183 		int SDL_SetGamma(float red, float green, float blue);
   184 		int SDL_SetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   185 		int SDL_GetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   186 	Gamma ramps are tables with 256 entries which map the screen color
   187 	components into actually displayed colors.  For an example of
   188 	implementing gamma correction and gamma fades, see test/testgamma.c
   189 	Gamma control is not supported on all hardware.
   190 
   191 1.1.4:
   192 	The size of the SDL_CDtrack structure changed from 8 to 12 bytes
   193 	as the size of the length member was extended to 32 bits.
   194 
   195         You can now use SDL for 2D blitting with a GL mode by passing the
   196 	SDL_OPENGLBLIT flag to SDL_SetVideoMode().  You can specify 16 or
   197 	32 bpp, and the data in the framebuffer is put into the GL scene
   198 	when you call SDL_UpdateRects(), and the scene will be visible
   199 	when you call SDL_GL_SwapBuffers().
   200 
   201 	Run the "testgl" test program with the -logo command line option
   202 	to see an example of this blending of 2D and 3D in SDL.
   203 
   204 1.1.3:
   205 	Added SDL_FreeRW() to the API, to complement SDL_AllocRW()
   206 
   207 	Added resizable window support - just add SDL_RESIZABLE to the
   208 	SDL_SetVideoMode() flags, and then wait for SDL_VIDEORESIZE events.
   209 	See SDL_events.h for details on the new SDL_ResizeEvent structure.
   210 
   211 	Added condition variable support, based on mutexes and semaphores.
   212 		SDL_CreateCond()
   213 		SDL_DestroyCond()
   214 		SDL_CondSignal()
   215 		SDL_CondBroadcast()
   216 		SDL_CondWait()
   217 		SDL_CondTimedWait()
   218 	The new function prototypes are in SDL_mutex.h
   219 
   220 	Added counting semaphore support, based on the mutex primitive.
   221 		SDL_CreateSemaphore()
   222 		SDL_DestroySemaphore()
   223 		SDL_SemWait()
   224 		SDL_SemTryWait()
   225 		SDL_SemWaitTimeout()
   226 		SDL_SemPost()
   227 		SDL_SemValue()
   228 	The new function prototypes are in SDL_mutex.h
   229 
   230 	Added support for asynchronous blitting.  To take advantage of this,
   231 	you must set the SDL_ASYNCBLIT flag when setting the video mode and
   232 	creating surfaces that you want accelerated in this way.  You must
   233 	lock surfaces that have this flag set, and the lock will block until
   234 	any queued blits have completed.
   235 
   236 	Added YUV video overlay support.
   237 	The supported YUV formats are: YV12, IYUV, YUY2, UYVY, and YVYU.
   238 	This function creates an overlay surface:
   239 		SDL_CreateYUVOverlay()
   240 	You must lock and unlock the overlay to get access to the data:
   241 		SDL_LockYUVOverlay() SDL_UnlockYUVOverlay()
   242 	You can then display the overlay:
   243 		SDL_DisplayYUVOverlay()
   244 	You must free the overlay when you are done using it:
   245 		SDL_FreeYUVOverlay()
   246 	See SDL_video.h for the full function prototypes.
   247 
   248 	The joystick hat position constants have been changed:
   249 	Old constant            New constant
   250 	------------            ------------
   251 	     0                  SDL_HAT_CENTERED
   252 	     1                  SDL_HAT_UP
   253 	     2                  SDL_HAT_RIGHTUP
   254 	     3                  SDL_HAT_RIGHT
   255 	     4                  SDL_HAT_RIGHTDOWN
   256 	     5                  SDL_HAT_DOWN
   257 	     6                  SDL_HAT_LEFTDOWN
   258 	     7                  SDL_HAT_LEFT
   259 	     8                  SDL_HAT_LEFTUP
   260 	The new constants are bitmasks, so you can check for the
   261 	individual axes like this:
   262 		if ( hat_position & SDL_HAT_UP ) {
   263 		}
   264 	and you'll catch left-up, up, and right-up.
   265 
   266 1.1.2:
   267 	Added multiple timer support:
   268 		SDL_AddTimer() and SDL_RemoveTimer()
   269 
   270 	SDL_WM_SetIcon() now respects the icon colorkey if mask is NULL.
   271 
   272 1.1.0:
   273 	Added initial OpenGL support.
   274 	First set GL attributes (such as RGB depth, alpha depth, etc.)
   275 		SDL_GL_SetAttribute()
   276 	Then call SDL_SetVideoMode() with the SDL_OPENGL flag.
   277 	Perform all of your normal GL drawing.
   278 	Finally swap the buffers with the new SDL function:
   279 		SDL_GL_SwapBuffers()
   280 	See the new 'testgl' test program for an example of using GL with SDL.
   281 
   282 	You can load GL extension functions by using the function:
   283 		SDL_GL_LoadProcAddress()
   284 
   285 	Added functions to initialize and cleanup specific SDL subsystems:
   286 		SDL_InitSubSystem() and SDL_QuitSubSystem()
   287 
   288 	Added user-defined event type:
   289 		typedef struct {
   290         		Uint8 type;
   291         		int code;
   292         		void *data1;
   293         		void *data2;
   294 		} SDL_UserEvent;
   295 	This structure is in the "user" member of an SDL_Event.
   296 
   297 	Added a function to push events into the event queue:
   298 		SDL_PushEvent()
   299 
   300 	Example of using the new SDL user-defined events:
   301 	{
   302 		SDL_Event event;
   303 
   304 		event.type = SDL_USEREVENT;
   305 		event.user.code = my_event_code;
   306 		event.user.data1 = significant_data;
   307 		event.user.data2 = 0;
   308 		SDL_PushEvent(&event);
   309 	}
   310 
   311 	Added a function to get mouse deltas since last query:
   312 		SDL_GetRelativeMouseState()
   313 
   314 	Added a boolean datatype to SDL_types.h:
   315 		SDL_bool = { SDL_TRUE, SDL_FALSE }
   316 
   317 	Added a function to get the current audio status:
   318 		SDL_GetAudioState();
   319 	It returns one of:
   320 		SDL_AUDIO_STOPPED,
   321 		SDL_AUDIO_PLAYING,
   322 		SDL_AUDIO_PAUSED
   323 
   324 	Added an AAlib driver (ASCII Art) - by Stephane Peter.
   325 
   326 1.0.6:
   327 	The input grab state is reset after each call to SDL_SetVideoMode().
   328 	The input is grabbed by default in fullscreen mode, and ungrabbed in
   329 	windowed mode.  If you want to set input grab to a particular value,
   330 	you should set it after each call to SDL_SetVideoMode().
   331 
   332 1.0.5:
   333 	Exposed SDL_AudioInit(), SDL_VideoInit()
   334 	Added SDL_AudioDriverName() and SDL_VideoDriverName()
   335 
   336 	Added new window manager function:
   337 		SDL_WM_ToggleFullScreen()
   338 	This is currently implemented only on Linux
   339 
   340 	The ALT-ENTER code has been removed - it's not appropriate for a
   341 	lib to bind keys when they aren't even emergency escape sequences.
   342 
   343 	ALT-ENTER functionality can be implemented with the following code:
   344 
   345 	int Handle_AltEnter(const SDL_Event *event)
   346 	{
   347 	    if ( event->type == SDL_KEYDOWN ) {
   348 	        if ( (event->key.keysym.sym == SDLK_RETURN) &&
   349 	             (event->key.keysym.mod & KMOD_ALT) ) {   
   350 	                SDL_WM_ToggleFullScreen(SDL_GetVideoSurface());
   351 	                return(0);
   352 	        }
   353 	    }
   354 	    return(1);
   355 	}
   356 	SDL_SetEventFilter(Handle_AltEnter);
   357 
   358 1.0.3:
   359 	Under X11, if you grab the input and hide the mouse cursor,
   360 	the mouse will go into a "relative motion" mode where you
   361 	will always get relative motion events no matter how far in
   362 	each direction you move the mouse - relative motion is not
   363 	bounded by the edges of the window (though the absolute values
   364 	of the mouse positions are clamped by the size of the window).
   365 	The SVGAlib, framebuffer console, and DirectInput drivers all
   366 	have this behavior naturally, and the GDI and BWindow drivers
   367 	never go into "relative motion" mode.
   368 
   369 1.0.2:
   370 	Added a function to enable keyboard repeat:
   371 		SDL_EnableKeyRepeat()
   372 
   373 	Added a function to grab the mouse and keyboard input
   374 		SDL_WM_GrabInput()
   375 
   376 	Added a function to iconify the window.
   377 		SDL_WM_IconifyWindow()
   378 	If this function succeeds, the application will receive an event
   379 	signaling SDL_APPACTIVE event 
   380 
   381 1.0.1:
   382 	Added constants to SDL_audio.h for 16-bit native byte ordering:
   383 		AUDIO_U16SYS, AUDIO_S16SYS
   384 
   385 1.0.0:
   386 	New public release
   387 
   388 Version 0.11:
   389 
   390 0.11.5:
   391 	A new function SDL_GetVideoSurface() has been added, and returns
   392 	a pointer to the current display surface.
   393 
   394 	SDL_AllocSurface() has been renamed SDL_CreateRGBSurface(), and
   395 	a new function SDL_CreateRGBSurfaceFrom() has been added to allow
   396 	creating an SDL surface from an existing pixel data buffer.
   397 
   398 	Added SDL_GetRGB() to the headers and documentation.
   399 
   400 0.11.4:
   401 	SDL_SetLibraryPath() is no longer meaningful, and has been removed.
   402 
   403 0.11.3:
   404 	A new flag for SDL_Init(), SDL_INIT_NOPARACHUTE, prevents SDL from
   405 	installing fatal signal handlers on operating systems that support
   406 	them.
   407 
   408 Version 0.9:
   409 
   410 0.9.15:
   411 	SDL_CreateColorCursor() has been removed.  Color cursors should
   412 	be implemented as sprites, blitted by the application when the
   413 	cursor moves.  To get smooth color cursor updates when the app
   414 	is busy, pass the SDL_INIT_EVENTTHREAD flag to SDL_Init().  This
   415 	allows you to handle the mouse motion in another thread from an
   416 	event filter function, but is currently only supported by Linux
   417 	and BeOS.  Note that you'll have to protect the display surface
   418 	from multi-threaded access by using mutexes if you do this.
   419 
   420 	Thread-safe surface support has been removed from SDL.
   421 	This makes blitting somewhat faster, by removing SDL_MiddleBlit().
   422 	Code that used SDL_MiddleBlit() should use SDL_LowerBlit() instead.
   423 	You can make your surfaces thread-safe by allocating your own
   424 	mutex and making lock/unlock calls around accesses to your surface.
   425 
   426 0.9.14:
   427 	SDL_GetMouseState() now takes pointers to int rather than Uint16.
   428 
   429 	If you set the SDL_WINDOWID environment variable under UNIX X11,
   430 	SDL will use that as the main window instead of creating it's own.
   431 	This is an unsupported extension to SDL, and not portable at all.
   432 
   433 0.9.13:
   434 	Added a function SDL_SetLibraryPath() which can be used to specify
   435 	the directory containing the SDL dynamic libraries.  This is useful
   436 	for commercial applications which ship with particular versions
   437 	of the libraries, and for security on multi-user systems.
   438 	If this function is not used, the default system directories are 
   439 	searched using the native dynamic object loading mechanism.
   440 
   441 	In order to support C linkage under Visual C++, you must declare
   442 	main() without any return type:
   443 		main(int argc, char *argv[]) {
   444 			/* Do the program... */
   445 			return(0);
   446 		}
   447 	C++ programs should also return a value if compiled under VC++.
   448 
   449 	The blit_endian member of the SDL_VideoInfo struct has been removed.
   450 
   451 	SDL_SymToASCII() has been replaced with SDL_GetKeyName(), so there
   452 	is now no longer any function to translate a keysym to a character.
   453 
   454 	The SDL_keysym structure has been extended with a 'scancode' and
   455 	'unicode' member.  The 'scancode' is a hardware specific scancode
   456 	for the key that was pressed, and may be 0.  The 'unicode' member
   457 	is a 16-bit UNICODE translation of the key that was pressed along
   458 	with any modifiers or compose keys that have been pressed.
   459 	If no UNICODE translation exists for the key, 'unicode' will be 0.
   460 
   461 	Added a function SDL_EnableUNICODE() to enable/disable UNICODE
   462 	translation of character keypresses.  Translation defaults off.
   463 
   464 	To convert existing code to use the new API, change code which
   465 	uses SDL_SymToASCII() to get the keyname to use SDL_GetKeyName(),
   466 	and change code which uses it to get the ASCII value of a sym to
   467 	use the 'unicode' member of the event keysym.
   468 
   469 0.9.12:
   470 	There is partial support for 64-bit datatypes.  I don't recommend 
   471 	you use this if you have a choice, because 64-bit datatypes are not
   472 	supported on many platforms.  On platforms for which it is supported,
   473 	the SDL_HAS_64BIT_TYPE C preprocessor define will be enabled, and
   474 	you can use the Uint64 and Sint64 datatypes.
   475 
   476 	Added functions to SDL_endian.h to support 64-bit datatypes:
   477 	    SDL_SwapLE64(), SDL_SwapBE64(),
   478 	    SDL_ReadLE64(), SDL_ReadBE64(), SDL_WriteLE64(), SDL_WriteBE64()
   479 
   480 	A new member "len_ratio" has been added to the SDL_AudioCVT structure,
   481 	and allows you to determine either the original buffer length or the
   482 	converted buffer length, given the other.
   483 
   484 	A new function SDL_FreeWAV() has been added to the API to free data
   485 	allocated by SDL_LoadWAV_RW().  This is necessary under Win32 since
   486 	the gcc compiled DLL uses a different heap than VC++ compiled apps.
   487 
   488 	SDL now has initial support for international keyboards using the
   489 	Latin character set.
   490 	If a particular mapping is desired, you can set the DEFAULT_KEYBOARD
   491 	compile-time variable, or you can set the environment variable 
   492 	"SDL_KEYBOARD" to a string identifying the keyboard mapping you desire.
   493 	The valid values for these variables can be found in SDL_keyboard.c
   494 
   495 	Full support for German and French keyboards under X11 is implemented.
   496 
   497 0.9.11:
   498 	The THREADED_EVENTS compile-time define has been replaced with the
   499 	SDL_INIT_EVENTTHREAD flag.  If this flag is passed to SDL_Init(),
   500 	SDL will create a separate thread to perform input event handling.
   501 	If this flag is passed to SDL_Init(), and the OS doesn't support 
   502 	event handling in a separate thread, SDL_Init() will fail.
   503 	Be sure to add calls to SDL_Delay() in your main thread to allow
   504 	the OS to schedule your event thread, or it may starve, leading
   505 	to slow event delivery and/or dropped events.
   506 	Currently MacOS and Win32 do not support this flag, while BeOS 
   507 	and Linux do support it.  I recommend that your application only
   508 	use this flag if absolutely necessary.
   509 
   510 	The SDL thread function passed to SDL_CreateThread() now returns a
   511 	status.  This status can be retrieved by passing a non-NULL pointer
   512 	as the 'status' argument to SDL_WaitThread().
   513 
   514 	The volume parameter to SDL_MixAudio() has been increased in range
   515 	from (0-8) to (0-128)
   516 
   517 	SDL now has a data source abstraction which can encompass a file,
   518 	an area of memory, or any custom object you can envision.  It uses
   519 	these abstractions, SDL_RWops, in the endian read/write functions,
   520 	and the built-in WAV and BMP file loaders.  This means you can load
   521 	WAV chunks from memory mapped files, compressed archives, network
   522 	pipes, or anything else that has a data read abstraction.
   523 
   524 	There are three built-in data source abstractions:
   525 	    SDL_RWFromFile(), SDL_RWFromFP(), SDL_RWFromMem()
   526 	along with a generic data source allocation function:
   527 	    SDL_AllocRW()
   528 	These data sources can be used like stdio file pointers with the
   529 	following convenience functions:
   530 	    SDL_RWseek(), SDL_RWread(), SDL_RWwrite(), SDL_RWclose()
   531 	These functions are defined in the new header file "SDL_rwops.h"
   532 
   533 	The endian swapping functions have been turned into macros for speed
   534 	and SDL_CalculateEndian() has been removed.  SDL_endian.h now defines
   535 	SDL_BYTEORDER as either SDL_BIG_ENDIAN or SDL_LIL_ENDIAN depending on
   536 	the endianness of the host system.
   537 
   538 	The endian read/write functions now take an SDL_RWops pointer
   539 	instead of a stdio FILE pointer, to support the new data source
   540 	abstraction.
   541 
   542 	The SDL_*LoadWAV() functions have been replaced with a single
   543 	SDL_LoadWAV_RW() function that takes a SDL_RWops pointer as it's
   544 	first parameter, and a flag whether or not to automatically 
   545 	free it as the second parameter.  SDL_LoadWAV() is a macro for
   546 	backward compatibility and convenience:
   547 	    SDL_LoadWAV_RW(SDL_RWFromFile("sample.wav", "rb"), 1, ...);
   548 
   549 	The SDL_*LoadBMP()/SDL_*SaveBMP() functions have each been replaced
   550 	with a single function that takes a SDL_RWops pointer as it's
   551 	first parameter, and a flag whether or not to automatically 
   552 	free it as the second parameter.  SDL_LoadBMP() and SDL_SaveBMP()
   553 	are macros for backward compatibility and convenience:
   554 	    SDL_LoadBMP_RW(SDL_RWFromFile("sample.bmp", "rb"), 1, ...);
   555 	    SDL_SaveBMP_RW(SDL_RWFromFile("sample.bmp", "wb"), 1, ...);
   556 	Note that these functions use SDL_RWseek() extensively, and should
   557 	not be used on pipes or other non-seekable data sources.
   558 
   559 0.9.10:
   560 	The Linux SDL_SysWMInfo and SDL_SysWMMsg structures have been 
   561 	extended to support multiple types of display drivers, as well as
   562         safe access to the X11 display when THREADED_EVENTS is enabled.
   563         The new structures are documented in the SDL_syswm.h header file.
   564 
   565 	Thanks to John Elliott <jce@seasip.demon.co.uk>, the UK keyboard
   566 	should now work properly, as well as the "Windows" keys on US
   567 	keyboards.
   568 
   569 	The Linux CD-ROM code now reads the CD-ROM devices from /etc/fstab
   570 	instead of trying to open each block device on the system.
   571 	The CD must be listed in /etc/fstab as using the iso9660 filesystem.
   572 
   573 	On Linux, if you define THREADED_EVENTS at compile time, a separate
   574 	thread will be spawned to gather X events asynchronously from the
   575 	graphics updates.  This hasn't been extensively tested, but it does
   576 	provide a means of handling keyboard and mouse input in a separate
   577 	thread from the graphics thread.  (This is now enabled by default.)
   578 
   579 	A special access function SDL_PeepEvents() allows you to manipulate
   580 	the event queue in a thread-safe manner, including peeking at events,
   581 	removing events of a specified type, and adding new events of arbitrary
   582 	type to the queue (use the new 'user' member of the SDL_Event type).
   583 
   584 	If you use SDL_PeepEvents() to gather events, then the main graphics
   585 	thread needs to call SDL_PumpEvents() periodically to drive the event
   586 	loop and generate input events.  This is not necessary if SDL has been 
   587 	compiled with THREADED_EVENTS defined, but doesn't hurt.
   588 
   589 	A new function SDL_ThreadID() returns the identifier associated with
   590 	the current thread.
   591 
   592 0.9.9:
   593 	The AUDIO_STEREO format flag has been replaced with a new 'channels'
   594 	member of the SDL_AudioSpec structure.  The channels are 1 for mono
   595 	audio, and 2 for stereo audio.  In the future more channels may be
   596 	supported for 3D surround sound.
   597 
   598 	The SDL_MixAudio() function now takes an additional volume parameter,
   599 	which should be set to SDL_MIX_MAXVOLUME for compatibility with the
   600 	original function.
   601 
   602 	The CD-ROM functions which take a 'cdrom' parameter can now be
   603 	passed NULL, and will act on the last successfully opened CD-ROM.
   604 
   605 0.9.8:
   606 	No changes, bugfixes only.
   607 	
   608 0.9.7:
   609 	No changes, bugfixes only.
   610 	
   611 0.9.6:
   612 	Added a fast rectangle fill function: SDL_FillRect()
   613 
   614 	Addition of a useful function for getting info on the video hardware:
   615 	    const SDL_VideoInfo *SDL_GetVideoInfo(void)
   616         This function replaces SDL_GetDisplayFormat().
   617 
   618 	Initial support for double-buffering:
   619 	  Use the SDL_DOUBLEBUF flag in SDL_SetVideoMode()
   620 	  Update the screen with a new function: SDL_Flip()
   621 
   622 	SDL_AllocSurface() takes two new flags:
   623 	SDL_SRCCOLORKEY means that the surface will be used for colorkey blits
   624 	  and if the hardware supports hardware acceleration of colorkey blits
   625 	  between two surfaces in video memory, to place the surface in video
   626 	  memory if possible, otherwise it will be placed in system memory.
   627 	SDL_SRCALPHA means that the surface will be used for alpha blits and
   628 	  if the hardware supports hardware acceleration of alpha blits between
   629 	  two surfaces in video memory, to place the surface in video memory
   630 	  if possible, otherwise it will be placed in system memory.
   631 	SDL_HWSURFACE now means that the surface will be created with the 
   632 	  same format as the display surface, since having surfaces in video
   633 	  memory is only useful for fast blitting to the screen, and you can't
   634 	  blit surfaces with different surface formats in video memory.
   635 
   636 0.9.5:
   637 	You can now pass a NULL mask to SDL_WM_SetIcon(), and it will assume
   638 	that the icon consists of the entire image.
   639 
   640 	SDL_LowerBlit() is back -- but don't use it on the display surface.
   641 	It is exactly the same as SDL_MiddleBlit(), but doesn't check for
   642 	thread safety.
   643 
   644 	Added SDL_FPLoadBMP(), SDL_FPSaveBMP(), SDL_FPLoadWAV(), which take
   645 	a FILE pointer instead of a file name.
   646 
   647 	Added CD-ROM audio control API:
   648 	    SDL_CDNumDrives()
   649 	    SDL_CDName()
   650 	    SDL_CDOpen()
   651 	    SDL_CDStatus()
   652 	    SDL_CDPlayTracks()
   653 	    SDL_CDPlay()
   654 	    SDL_CDPause()
   655 	    SDL_CDResume()
   656 	    SDL_CDStop()
   657 	    SDL_CDEject()
   658 	    SDL_CDClose()
   659 
   660 0.9.4:
   661 	No changes, bugfixes only.
   662 
   663 0.9.3:
   664 	Mouse motion event now includes relative motion information:
   665 	    Sint16 event->motion.xrel, Sint16 event->motion.yrel
   666 
   667 	X11 keyrepeat handling can be disabled by defining IGNORE_X_KEYREPEAT
   668 	    (Add -DIGNORE_X_KEYREPEAT to CFLAGS line in obj/x11Makefile)
   669 
   670 0.9.2:
   671 	No changes, bugfixes only.
   672 
   673 0.9.1:
   674 	Removed SDL_MapSurface() and SDL_UnmapSurface() -- surfaces are now
   675 	automatically mapped on blit.
   676 
   677 0.8.0:
   678 	SDL stable release