WhatsNew
author Sam Lantinga <slouken@libsdl.org>
Mon, 13 Mar 2006 01:41:32 +0000
changeset 1507 1ff64ad478b2
parent 781 67176351a1b8
child 1545 8d9bb0cf2c2a
permissions -rw-r--r--
Fixed bug #112
Added SDL_GetKeyRepeat()
     1 
     2 This is a list of API changes in SDL's version history.
     3 
     4 Version 1.0:
     5 
     6 1.2.10:
     7 	Added SDL_GetKeyRepeat()
     8 	Added SDL_config.h, with defaults for various build environments.
     9 
    10 1.2.7:
    11 	Added CPU feature detection functions to SDL_cpuinfo.h:
    12 		SDL_HasRDTSC(), SDL_HasMMX(), SDL_Has3DNow(), SDL_HasSSE(),
    13 		SDL_HasAltiVec()
    14 	Added function to create RWops from const memory: SDL_RWFromConstMem()
    15 
    16 1.2.6:
    17 	Added SDL_LoadObject(), SDL_LoadFunction(), and SDL_UnloadObject()
    18 
    19 	Added SDL_GL_MULTISAMPLEBUFFERS and SDL_GL_MULTISAMPLESAMPLES for FSAA
    20 
    21 1.2.5:
    22 	Added SDL_BUTTON_WHEELUP (4) and SDL_BUTTON_WHEELDOWN (5)
    23 
    24 	Added SDL_GL_STEREO for stereoscopic OpenGL contexts
    25 
    26 1.2.0:
    27 	Added SDL_VIDEOEXPOSE event to signal that the screen needs to
    28 	be redrawn.  This is currently only delivered to OpenGL windows
    29 	on X11, though it may be delivered in the future when the video
    30 	memory is lost under DirectX.
    31 
    32 1.1.8:
    33 	You can pass SDL_NOFRAME to SDL_VideoMode() to create a window
    34 	that has no title bar or frame decoration.  Fullscreen video
    35 	modes automatically have this flag set.
    36 
    37 	Added a function to query the clipping rectangle for a surface:
    38 		void SDL_GetClipRect(SDL_Surface *surface, SDL_Rect *rect)
    39 
    40 	Added a function to query the current event filter:
    41 		SDL_EventFilter SDL_GetEventFilter(void)
    42 
    43 	If you pass -1 to SDL_ShowCursor(), it won't change the current
    44 	cursor visibility state, but will still return it.
    45 
    46 	SDL_LockSurface() and SDL_UnlockSurface() are recursive, meaning
    47 	you can nest them as deep as you want, as long as each lock call
    48 	has a matching unlock call.  The surface remains locked until the
    49 	last matching unlock call.
    50 
    51 	Note that you may not blit to or from a locked surface.
    52 
    53 1.1.7:
    54 	The SDL_SetGammaRamp() and SDL_GetGammaRamp() functions now take
    55 	arrays of Uint16 values instead of Uint8 values.  For the most part,
    56 	you can just take your old values and shift them up 8 bits to get
    57 	new correct values for your gamma ramps.
    58 
    59 	You can pass SDL_RLEACCEL in flags passed to SDL_ConvertSurface()
    60         and SDL will try to RLE accelerate colorkey and alpha blits in the
    61 	resulting surface.
    62 
    63 1.1.6:
    64 	Added a function to return the thread ID of a specific thread:
    65 		Uint32 SDL_GetThreadID(SDL_Thread *thread)
    66 	If 'thread' is NULL, this function returns the id for this thread.
    67 
    68 1.1.5:
    69 	The YUV overlay structure has been changed to use an array of
    70 	pitches and pixels representing the planes of a YUV image, to
    71 	better enable hardware acceleration.  The YV12 and IYUV formats
    72 	each have three planes, corresponding to the Y, U, and V portions
    73 	of the image, while packed pixel YUV formats just have one plane.
    74 
    75 	For palettized mode (8bpp), the screen colormap is now split in
    76 	a physical and a logical palette. The physical palette determines
    77 	what colours the screen pixels will get when displayed, and the
    78 	logical palette controls the mapping from blits to/from the screen.
    79 	A new function, SDL_SetPalette() has been added to change
    80 	logical and physical palettes separately. SDL_SetColors() works
    81 	just as before, and is equivalent to calling SDL_SetPalette() with
    82 	a flag argument of (SDL_LOGPAL|SDL_PHYSPAL).
    83 
    84 	SDL_BlitSurface() no longer modifies the source rectangle, only the
    85 	destination rectangle. The width/height members of the destination
    86 	rectangle are ignored, only the position is used.
    87 
    88 	The old source clipping function SDL_SetClipping() has been replaced
    89 	with a more useful function to set the destination clipping rectangle:
    90 		SDL_bool SDL_SetClipRect(SDL_Surface *surface, SDL_Rect *rect)
    91 		
    92 	Added a function to see what subsystems have been initialized:
    93 		Uint32 SDL_WasInit(Uint32 flags)
    94 
    95 	The Big Alpha Flip: SDL now treats alpha as opacity like everybody
    96 	else, and not as transparency:
    97 
    98 	A new cpp symbol: SDL_ALPHA_OPAQUE is defined as 255
    99 	A new cpp symbol: SDL_ALPHA_TRANSPARENT is defined as 0
   100 	Values between 0 and 255 vary from fully transparent to fully opaque.
   101 
   102 	New functions:
   103 	SDL_DisplayFormatAlpha()
   104 	    Returns a surface converted to a format with alpha-channel
   105 	    that can be blit efficiently to the screen. (In other words,
   106 	    like SDL_DisplayFormat() but the resulting surface has
   107 	    an alpha channel.)  This is useful for surfaces with alpha.
   108 	SDL_MapRGBA()
   109 	    Works as SDL_MapRGB() but takes an additional alpha parameter.
   110 	SDL_GetRGBA()
   111 	    Works as SDL_GetRGB() but also returns the alpha value
   112 	    (SDL_ALPHA_OPAQUE for formats without an alpha channel)
   113 
   114 	Both SDL_GetRGB() and SDL_GetRGBA() now always return values in
   115 	the [0..255] interval. Previously, SDL_GetRGB() would return
   116 	(0xf8, 0xfc, 0xf8) for a completely white pixel in RGB565 format.
   117 	(N.B.: This is broken for bit fields < 3 bits.)
   118 
   119 	SDL_MapRGB() returns pixels in which the alpha channel is set opaque.
   120 
   121 	SDL_SetAlpha() can now be used for both setting the per-surface
   122 	alpha, using the new way of thinking of alpha, and also to enable
   123 	and disable per-pixel alpha blending for surfaces with an alpha
   124 	channel:
   125 		To disable alpha blending:
   126 			SDL_SetAlpha(surface, 0, 0);
   127 		To re-enable alpha blending:
   128 			SDL_SetAlpha(surface, SDL_SRCALPHA, 0);
   129 	Surfaces with an alpha channel have blending enabled by default.
   130 
   131 	SDL_SetAlpha() now accepts SDL_RLEACCEL as a flag, which requests
   132 	RLE acceleration of blits, just as like with SDL_SetColorKey().
   133 	This flag can be set for both surfaces with an alpha channel
   134 	and surfaces with an alpha value set by SDL_SetAlpha().
   135 	As always, RLE surfaces must be locked before pixel access is
   136 	allowed, and unlocked before any other SDL operations are done
   137 	on it.
   138 
   139 	The blit semantics for surfaces with and without alpha and colorkey
   140 	have now been defined:
   141 
   142 	RGBA->RGB:
   143 	    SDL_SRCALPHA set:
   144 		alpha-blend (using alpha-channel).
   145 		SDL_SRCCOLORKEY ignored.
   146 	    SDL_SRCALPHA not set:
   147 		copy RGB.
   148 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   149 		RGB values of the source colour key, ignoring alpha in the
   150 		comparison.
   151 
   152 	RGB->RGBA:
   153 	    SDL_SRCALPHA set:
   154 		alpha-blend (using the source per-surface alpha value);
   155 		set destination alpha to opaque.
   156 	    SDL_SRCALPHA not set:
   157 		copy RGB, set destination alpha to opaque.
   158 	    both:
   159 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   160 		source colour key.
   161 
   162 	RGBA->RGBA:
   163 	    SDL_SRCALPHA set:
   164 		alpha-blend (using the source alpha channel) the RGB values;
   165 		leave destination alpha untouched. [Note: is this correct?]
   166 		SDL_SRCCOLORKEY ignored.
   167 	    SDL_SRCALPHA not set:
   168 		copy all of RGBA to the destination.
   169 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   170 		RGB values of the source colour key, ignoring alpha in the
   171 		comparison.
   172 
   173 	RGB->RGB: 
   174 	    SDL_SRCALPHA set:
   175 		alpha-blend (using the source per-surface alpha value).
   176 	    SDL_SRCALPHA not set:
   177 		copy RGB.
   178 	    both:
   179 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   180 		source colour key.
   181 
   182 	As a special case, blits from surfaces with per-surface alpha
   183 	value of 128 (50% transparency) are optimised and much faster
   184 	than other alpha values. This does not apply to surfaces with
   185 	alpha channels (per-pixel alpha).
   186 
   187 	New functions for manipulating the gamma of the display have
   188 	been added:
   189 		int SDL_SetGamma(float red, float green, float blue);
   190 		int SDL_SetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   191 		int SDL_GetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   192 	Gamma ramps are tables with 256 entries which map the screen color
   193 	components into actually displayed colors.  For an example of
   194 	implementing gamma correction and gamma fades, see test/testgamma.c
   195 	Gamma control is not supported on all hardware.
   196 
   197 1.1.4:
   198 	The size of the SDL_CDtrack structure changed from 8 to 12 bytes
   199 	as the size of the length member was extended to 32 bits.
   200 
   201         You can now use SDL for 2D blitting with a GL mode by passing the
   202 	SDL_OPENGLBLIT flag to SDL_SetVideoMode().  You can specify 16 or
   203 	32 bpp, and the data in the framebuffer is put into the GL scene
   204 	when you call SDL_UpdateRects(), and the scene will be visible
   205 	when you call SDL_GL_SwapBuffers().
   206 
   207 	Run the "testgl" test program with the -logo command line option
   208 	to see an example of this blending of 2D and 3D in SDL.
   209 
   210 1.1.3:
   211 	Added SDL_FreeRW() to the API, to complement SDL_AllocRW()
   212 
   213 	Added resizable window support - just add SDL_RESIZABLE to the
   214 	SDL_SetVideoMode() flags, and then wait for SDL_VIDEORESIZE events.
   215 	See SDL_events.h for details on the new SDL_ResizeEvent structure.
   216 
   217 	Added condition variable support, based on mutexes and semaphores.
   218 		SDL_CreateCond()
   219 		SDL_DestroyCond()
   220 		SDL_CondSignal()
   221 		SDL_CondBroadcast()
   222 		SDL_CondWait()
   223 		SDL_CondTimedWait()
   224 	The new function prototypes are in SDL_mutex.h
   225 
   226 	Added counting semaphore support, based on the mutex primitive.
   227 		SDL_CreateSemaphore()
   228 		SDL_DestroySemaphore()
   229 		SDL_SemWait()
   230 		SDL_SemTryWait()
   231 		SDL_SemWaitTimeout()
   232 		SDL_SemPost()
   233 		SDL_SemValue()
   234 	The new function prototypes are in SDL_mutex.h
   235 
   236 	Added support for asynchronous blitting.  To take advantage of this,
   237 	you must set the SDL_ASYNCBLIT flag when setting the video mode and
   238 	creating surfaces that you want accelerated in this way.  You must
   239 	lock surfaces that have this flag set, and the lock will block until
   240 	any queued blits have completed.
   241 
   242 	Added YUV video overlay support.
   243 	The supported YUV formats are: YV12, IYUV, YUY2, UYVY, and YVYU.
   244 	This function creates an overlay surface:
   245 		SDL_CreateYUVOverlay()
   246 	You must lock and unlock the overlay to get access to the data:
   247 		SDL_LockYUVOverlay() SDL_UnlockYUVOverlay()
   248 	You can then display the overlay:
   249 		SDL_DisplayYUVOverlay()
   250 	You must free the overlay when you are done using it:
   251 		SDL_FreeYUVOverlay()
   252 	See SDL_video.h for the full function prototypes.
   253 
   254 	The joystick hat position constants have been changed:
   255 	Old constant            New constant
   256 	------------            ------------
   257 	     0                  SDL_HAT_CENTERED
   258 	     1                  SDL_HAT_UP
   259 	     2                  SDL_HAT_RIGHTUP
   260 	     3                  SDL_HAT_RIGHT
   261 	     4                  SDL_HAT_RIGHTDOWN
   262 	     5                  SDL_HAT_DOWN
   263 	     6                  SDL_HAT_LEFTDOWN
   264 	     7                  SDL_HAT_LEFT
   265 	     8                  SDL_HAT_LEFTUP
   266 	The new constants are bitmasks, so you can check for the
   267 	individual axes like this:
   268 		if ( hat_position & SDL_HAT_UP ) {
   269 		}
   270 	and you'll catch left-up, up, and right-up.
   271 
   272 1.1.2:
   273 	Added multiple timer support:
   274 		SDL_AddTimer() and SDL_RemoveTimer()
   275 
   276 	SDL_WM_SetIcon() now respects the icon colorkey if mask is NULL.
   277 
   278 1.1.0:
   279 	Added initial OpenGL support.
   280 	First set GL attributes (such as RGB depth, alpha depth, etc.)
   281 		SDL_GL_SetAttribute()
   282 	Then call SDL_SetVideoMode() with the SDL_OPENGL flag.
   283 	Perform all of your normal GL drawing.
   284 	Finally swap the buffers with the new SDL function:
   285 		SDL_GL_SwapBuffers()
   286 	See the new 'testgl' test program for an example of using GL with SDL.
   287 
   288 	You can load GL extension functions by using the function:
   289 		SDL_GL_LoadProcAddress()
   290 
   291 	Added functions to initialize and cleanup specific SDL subsystems:
   292 		SDL_InitSubSystem() and SDL_QuitSubSystem()
   293 
   294 	Added user-defined event type:
   295 		typedef struct {
   296         		Uint8 type;
   297         		int code;
   298         		void *data1;
   299         		void *data2;
   300 		} SDL_UserEvent;
   301 	This structure is in the "user" member of an SDL_Event.
   302 
   303 	Added a function to push events into the event queue:
   304 		SDL_PushEvent()
   305 
   306 	Example of using the new SDL user-defined events:
   307 	{
   308 		SDL_Event event;
   309 
   310 		event.type = SDL_USEREVENT;
   311 		event.user.code = my_event_code;
   312 		event.user.data1 = significant_data;
   313 		event.user.data2 = 0;
   314 		SDL_PushEvent(&event);
   315 	}
   316 
   317 	Added a function to get mouse deltas since last query:
   318 		SDL_GetRelativeMouseState()
   319 
   320 	Added a boolean datatype to SDL_types.h:
   321 		SDL_bool = { SDL_TRUE, SDL_FALSE }
   322 
   323 	Added a function to get the current audio status:
   324 		SDL_GetAudioState();
   325 	It returns one of:
   326 		SDL_AUDIO_STOPPED,
   327 		SDL_AUDIO_PLAYING,
   328 		SDL_AUDIO_PAUSED
   329 
   330 	Added an AAlib driver (ASCII Art) - by Stephane Peter.
   331 
   332 1.0.6:
   333 	The input grab state is reset after each call to SDL_SetVideoMode().
   334 	The input is grabbed by default in fullscreen mode, and ungrabbed in
   335 	windowed mode.  If you want to set input grab to a particular value,
   336 	you should set it after each call to SDL_SetVideoMode().
   337 
   338 1.0.5:
   339 	Exposed SDL_AudioInit(), SDL_VideoInit()
   340 	Added SDL_AudioDriverName() and SDL_VideoDriverName()
   341 
   342 	Added new window manager function:
   343 		SDL_WM_ToggleFullScreen()
   344 	This is currently implemented only on Linux
   345 
   346 	The ALT-ENTER code has been removed - it's not appropriate for a
   347 	lib to bind keys when they aren't even emergency escape sequences.
   348 
   349 	ALT-ENTER functionality can be implemented with the following code:
   350 
   351 	int Handle_AltEnter(const SDL_Event *event)
   352 	{
   353 	    if ( event->type == SDL_KEYDOWN ) {
   354 	        if ( (event->key.keysym.sym == SDLK_RETURN) &&
   355 	             (event->key.keysym.mod & KMOD_ALT) ) {   
   356 	                SDL_WM_ToggleFullScreen(SDL_GetVideoSurface());
   357 	                return(0);
   358 	        }
   359 	    }
   360 	    return(1);
   361 	}
   362 	SDL_SetEventFilter(Handle_AltEnter);
   363 
   364 1.0.3:
   365 	Under X11, if you grab the input and hide the mouse cursor,
   366 	the mouse will go into a "relative motion" mode where you
   367 	will always get relative motion events no matter how far in
   368 	each direction you move the mouse - relative motion is not
   369 	bounded by the edges of the window (though the absolute values
   370 	of the mouse positions are clamped by the size of the window).
   371 	The SVGAlib, framebuffer console, and DirectInput drivers all
   372 	have this behavior naturally, and the GDI and BWindow drivers
   373 	never go into "relative motion" mode.
   374 
   375 1.0.2:
   376 	Added a function to enable keyboard repeat:
   377 		SDL_EnableKeyRepeat()
   378 
   379 	Added a function to grab the mouse and keyboard input
   380 		SDL_WM_GrabInput()
   381 
   382 	Added a function to iconify the window.
   383 		SDL_WM_IconifyWindow()
   384 	If this function succeeds, the application will receive an event
   385 	signaling SDL_APPACTIVE event 
   386 
   387 1.0.1:
   388 	Added constants to SDL_audio.h for 16-bit native byte ordering:
   389 		AUDIO_U16SYS, AUDIO_S16SYS
   390 
   391 1.0.0:
   392 	New public release
   393 
   394 Version 0.11:
   395 
   396 0.11.5:
   397 	A new function SDL_GetVideoSurface() has been added, and returns
   398 	a pointer to the current display surface.
   399 
   400 	SDL_AllocSurface() has been renamed SDL_CreateRGBSurface(), and
   401 	a new function SDL_CreateRGBSurfaceFrom() has been added to allow
   402 	creating an SDL surface from an existing pixel data buffer.
   403 
   404 	Added SDL_GetRGB() to the headers and documentation.
   405 
   406 0.11.4:
   407 	SDL_SetLibraryPath() is no longer meaningful, and has been removed.
   408 
   409 0.11.3:
   410 	A new flag for SDL_Init(), SDL_INIT_NOPARACHUTE, prevents SDL from
   411 	installing fatal signal handlers on operating systems that support
   412 	them.
   413 
   414 Version 0.9:
   415 
   416 0.9.15:
   417 	SDL_CreateColorCursor() has been removed.  Color cursors should
   418 	be implemented as sprites, blitted by the application when the
   419 	cursor moves.  To get smooth color cursor updates when the app
   420 	is busy, pass the SDL_INIT_EVENTTHREAD flag to SDL_Init().  This
   421 	allows you to handle the mouse motion in another thread from an
   422 	event filter function, but is currently only supported by Linux
   423 	and BeOS.  Note that you'll have to protect the display surface
   424 	from multi-threaded access by using mutexes if you do this.
   425 
   426 	Thread-safe surface support has been removed from SDL.
   427 	This makes blitting somewhat faster, by removing SDL_MiddleBlit().
   428 	Code that used SDL_MiddleBlit() should use SDL_LowerBlit() instead.
   429 	You can make your surfaces thread-safe by allocating your own
   430 	mutex and making lock/unlock calls around accesses to your surface.
   431 
   432 0.9.14:
   433 	SDL_GetMouseState() now takes pointers to int rather than Uint16.
   434 
   435 	If you set the SDL_WINDOWID environment variable under UNIX X11,
   436 	SDL will use that as the main window instead of creating it's own.
   437 	This is an unsupported extension to SDL, and not portable at all.
   438 
   439 0.9.13:
   440 	Added a function SDL_SetLibraryPath() which can be used to specify
   441 	the directory containing the SDL dynamic libraries.  This is useful
   442 	for commercial applications which ship with particular versions
   443 	of the libraries, and for security on multi-user systems.
   444 	If this function is not used, the default system directories are 
   445 	searched using the native dynamic object loading mechanism.
   446 
   447 	In order to support C linkage under Visual C++, you must declare
   448 	main() without any return type:
   449 		main(int argc, char *argv[]) {
   450 			/* Do the program... */
   451 			return(0);
   452 		}
   453 	C++ programs should also return a value if compiled under VC++.
   454 
   455 	The blit_endian member of the SDL_VideoInfo struct has been removed.
   456 
   457 	SDL_SymToASCII() has been replaced with SDL_GetKeyName(), so there
   458 	is now no longer any function to translate a keysym to a character.
   459 
   460 	The SDL_keysym structure has been extended with a 'scancode' and
   461 	'unicode' member.  The 'scancode' is a hardware specific scancode
   462 	for the key that was pressed, and may be 0.  The 'unicode' member
   463 	is a 16-bit UNICODE translation of the key that was pressed along
   464 	with any modifiers or compose keys that have been pressed.
   465 	If no UNICODE translation exists for the key, 'unicode' will be 0.
   466 
   467 	Added a function SDL_EnableUNICODE() to enable/disable UNICODE
   468 	translation of character keypresses.  Translation defaults off.
   469 
   470 	To convert existing code to use the new API, change code which
   471 	uses SDL_SymToASCII() to get the keyname to use SDL_GetKeyName(),
   472 	and change code which uses it to get the ASCII value of a sym to
   473 	use the 'unicode' member of the event keysym.
   474 
   475 0.9.12:
   476 	There is partial support for 64-bit datatypes.  I don't recommend 
   477 	you use this if you have a choice, because 64-bit datatypes are not
   478 	supported on many platforms.  On platforms for which it is supported,
   479 	the SDL_HAS_64BIT_TYPE C preprocessor define will be enabled, and
   480 	you can use the Uint64 and Sint64 datatypes.
   481 
   482 	Added functions to SDL_endian.h to support 64-bit datatypes:
   483 	    SDL_SwapLE64(), SDL_SwapBE64(),
   484 	    SDL_ReadLE64(), SDL_ReadBE64(), SDL_WriteLE64(), SDL_WriteBE64()
   485 
   486 	A new member "len_ratio" has been added to the SDL_AudioCVT structure,
   487 	and allows you to determine either the original buffer length or the
   488 	converted buffer length, given the other.
   489 
   490 	A new function SDL_FreeWAV() has been added to the API to free data
   491 	allocated by SDL_LoadWAV_RW().  This is necessary under Win32 since
   492 	the gcc compiled DLL uses a different heap than VC++ compiled apps.
   493 
   494 	SDL now has initial support for international keyboards using the
   495 	Latin character set.
   496 	If a particular mapping is desired, you can set the DEFAULT_KEYBOARD
   497 	compile-time variable, or you can set the environment variable 
   498 	"SDL_KEYBOARD" to a string identifying the keyboard mapping you desire.
   499 	The valid values for these variables can be found in SDL_keyboard.c
   500 
   501 	Full support for German and French keyboards under X11 is implemented.
   502 
   503 0.9.11:
   504 	The THREADED_EVENTS compile-time define has been replaced with the
   505 	SDL_INIT_EVENTTHREAD flag.  If this flag is passed to SDL_Init(),
   506 	SDL will create a separate thread to perform input event handling.
   507 	If this flag is passed to SDL_Init(), and the OS doesn't support 
   508 	event handling in a separate thread, SDL_Init() will fail.
   509 	Be sure to add calls to SDL_Delay() in your main thread to allow
   510 	the OS to schedule your event thread, or it may starve, leading
   511 	to slow event delivery and/or dropped events.
   512 	Currently MacOS and Win32 do not support this flag, while BeOS 
   513 	and Linux do support it.  I recommend that your application only
   514 	use this flag if absolutely necessary.
   515 
   516 	The SDL thread function passed to SDL_CreateThread() now returns a
   517 	status.  This status can be retrieved by passing a non-NULL pointer
   518 	as the 'status' argument to SDL_WaitThread().
   519 
   520 	The volume parameter to SDL_MixAudio() has been increased in range
   521 	from (0-8) to (0-128)
   522 
   523 	SDL now has a data source abstraction which can encompass a file,
   524 	an area of memory, or any custom object you can envision.  It uses
   525 	these abstractions, SDL_RWops, in the endian read/write functions,
   526 	and the built-in WAV and BMP file loaders.  This means you can load
   527 	WAV chunks from memory mapped files, compressed archives, network
   528 	pipes, or anything else that has a data read abstraction.
   529 
   530 	There are three built-in data source abstractions:
   531 	    SDL_RWFromFile(), SDL_RWFromFP(), SDL_RWFromMem()
   532 	along with a generic data source allocation function:
   533 	    SDL_AllocRW()
   534 	These data sources can be used like stdio file pointers with the
   535 	following convenience functions:
   536 	    SDL_RWseek(), SDL_RWread(), SDL_RWwrite(), SDL_RWclose()
   537 	These functions are defined in the new header file "SDL_rwops.h"
   538 
   539 	The endian swapping functions have been turned into macros for speed
   540 	and SDL_CalculateEndian() has been removed.  SDL_endian.h now defines
   541 	SDL_BYTEORDER as either SDL_BIG_ENDIAN or SDL_LIL_ENDIAN depending on
   542 	the endianness of the host system.
   543 
   544 	The endian read/write functions now take an SDL_RWops pointer
   545 	instead of a stdio FILE pointer, to support the new data source
   546 	abstraction.
   547 
   548 	The SDL_*LoadWAV() functions have been replaced with a single
   549 	SDL_LoadWAV_RW() 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_LoadWAV() is a macro for
   552 	backward compatibility and convenience:
   553 	    SDL_LoadWAV_RW(SDL_RWFromFile("sample.wav", "rb"), 1, ...);
   554 
   555 	The SDL_*LoadBMP()/SDL_*SaveBMP() functions have each been replaced
   556 	with a single function that takes a SDL_RWops pointer as it's
   557 	first parameter, and a flag whether or not to automatically 
   558 	free it as the second parameter.  SDL_LoadBMP() and SDL_SaveBMP()
   559 	are macros for backward compatibility and convenience:
   560 	    SDL_LoadBMP_RW(SDL_RWFromFile("sample.bmp", "rb"), 1, ...);
   561 	    SDL_SaveBMP_RW(SDL_RWFromFile("sample.bmp", "wb"), 1, ...);
   562 	Note that these functions use SDL_RWseek() extensively, and should
   563 	not be used on pipes or other non-seekable data sources.
   564 
   565 0.9.10:
   566 	The Linux SDL_SysWMInfo and SDL_SysWMMsg structures have been 
   567 	extended to support multiple types of display drivers, as well as
   568         safe access to the X11 display when THREADED_EVENTS is enabled.
   569         The new structures are documented in the SDL_syswm.h header file.
   570 
   571 	Thanks to John Elliott <jce@seasip.demon.co.uk>, the UK keyboard
   572 	should now work properly, as well as the "Windows" keys on US
   573 	keyboards.
   574 
   575 	The Linux CD-ROM code now reads the CD-ROM devices from /etc/fstab
   576 	instead of trying to open each block device on the system.
   577 	The CD must be listed in /etc/fstab as using the iso9660 filesystem.
   578 
   579 	On Linux, if you define THREADED_EVENTS at compile time, a separate
   580 	thread will be spawned to gather X events asynchronously from the
   581 	graphics updates.  This hasn't been extensively tested, but it does
   582 	provide a means of handling keyboard and mouse input in a separate
   583 	thread from the graphics thread.  (This is now enabled by default.)
   584 
   585 	A special access function SDL_PeepEvents() allows you to manipulate
   586 	the event queue in a thread-safe manner, including peeking at events,
   587 	removing events of a specified type, and adding new events of arbitrary
   588 	type to the queue (use the new 'user' member of the SDL_Event type).
   589 
   590 	If you use SDL_PeepEvents() to gather events, then the main graphics
   591 	thread needs to call SDL_PumpEvents() periodically to drive the event
   592 	loop and generate input events.  This is not necessary if SDL has been 
   593 	compiled with THREADED_EVENTS defined, but doesn't hurt.
   594 
   595 	A new function SDL_ThreadID() returns the identifier associated with
   596 	the current thread.
   597 
   598 0.9.9:
   599 	The AUDIO_STEREO format flag has been replaced with a new 'channels'
   600 	member of the SDL_AudioSpec structure.  The channels are 1 for mono
   601 	audio, and 2 for stereo audio.  In the future more channels may be
   602 	supported for 3D surround sound.
   603 
   604 	The SDL_MixAudio() function now takes an additional volume parameter,
   605 	which should be set to SDL_MIX_MAXVOLUME for compatibility with the
   606 	original function.
   607 
   608 	The CD-ROM functions which take a 'cdrom' parameter can now be
   609 	passed NULL, and will act on the last successfully opened CD-ROM.
   610 
   611 0.9.8:
   612 	No changes, bugfixes only.
   613 	
   614 0.9.7:
   615 	No changes, bugfixes only.
   616 	
   617 0.9.6:
   618 	Added a fast rectangle fill function: SDL_FillRect()
   619 
   620 	Addition of a useful function for getting info on the video hardware:
   621 	    const SDL_VideoInfo *SDL_GetVideoInfo(void)
   622         This function replaces SDL_GetDisplayFormat().
   623 
   624 	Initial support for double-buffering:
   625 	  Use the SDL_DOUBLEBUF flag in SDL_SetVideoMode()
   626 	  Update the screen with a new function: SDL_Flip()
   627 
   628 	SDL_AllocSurface() takes two new flags:
   629 	SDL_SRCCOLORKEY means that the surface will be used for colorkey blits
   630 	  and if the hardware supports hardware acceleration of colorkey blits
   631 	  between two surfaces in video memory, to place the surface in video
   632 	  memory if possible, otherwise it will be placed in system memory.
   633 	SDL_SRCALPHA means that the surface will be used for alpha blits and
   634 	  if the hardware supports hardware acceleration of alpha blits between
   635 	  two surfaces in video memory, to place the surface in video memory
   636 	  if possible, otherwise it will be placed in system memory.
   637 	SDL_HWSURFACE now means that the surface will be created with the 
   638 	  same format as the display surface, since having surfaces in video
   639 	  memory is only useful for fast blitting to the screen, and you can't
   640 	  blit surfaces with different surface formats in video memory.
   641 
   642 0.9.5:
   643 	You can now pass a NULL mask to SDL_WM_SetIcon(), and it will assume
   644 	that the icon consists of the entire image.
   645 
   646 	SDL_LowerBlit() is back -- but don't use it on the display surface.
   647 	It is exactly the same as SDL_MiddleBlit(), but doesn't check for
   648 	thread safety.
   649 
   650 	Added SDL_FPLoadBMP(), SDL_FPSaveBMP(), SDL_FPLoadWAV(), which take
   651 	a FILE pointer instead of a file name.
   652 
   653 	Added CD-ROM audio control API:
   654 	    SDL_CDNumDrives()
   655 	    SDL_CDName()
   656 	    SDL_CDOpen()
   657 	    SDL_CDStatus()
   658 	    SDL_CDPlayTracks()
   659 	    SDL_CDPlay()
   660 	    SDL_CDPause()
   661 	    SDL_CDResume()
   662 	    SDL_CDStop()
   663 	    SDL_CDEject()
   664 	    SDL_CDClose()
   665 
   666 0.9.4:
   667 	No changes, bugfixes only.
   668 
   669 0.9.3:
   670 	Mouse motion event now includes relative motion information:
   671 	    Sint16 event->motion.xrel, Sint16 event->motion.yrel
   672 
   673 	X11 keyrepeat handling can be disabled by defining IGNORE_X_KEYREPEAT
   674 	    (Add -DIGNORE_X_KEYREPEAT to CFLAGS line in obj/x11Makefile)
   675 
   676 0.9.2:
   677 	No changes, bugfixes only.
   678 
   679 0.9.1:
   680 	Removed SDL_MapSurface() and SDL_UnmapSurface() -- surfaces are now
   681 	automatically mapped on blit.
   682 
   683 0.8.0:
   684 	SDL stable release