author Sam Lantinga
Sat, 10 Oct 2009 09:02:17 +0000
changeset 4299 0ca47eaff9c9
parent 4280 e1826b24ee8d
child 4318 34a0a589b9c4
permissions -rw-r--r--
Changed environment variable to match Debian patch 205_lock_keys.diff
     2 This is a list of API changes in SDL's version history.
     4 Version 1.0:
     6 1.2.14:
     7 	Added cast macros for correct usage with C++:
     8 		SDL_reinterpret_cast(type, expression)
     9 		SDL_static_cast(type, expression)
    11 	Added SDL_DISABLE_LOCK_KEYS environment variable to enable normal
    12 	up/down events for Caps-Lock and Num-Lock keys.
    14 1.2.13:
    15 	Added SDL_BUTTON_X1 and SDL_BUTTON_X2 constants.
    17 1.2.12:
    18 	Added SDL_VIDEO_ALLOW_SCREENSAVER to override SDL's disabling
    19 	of the screensaver on Mac OS X and X11.
    21 1.2.10:
    22 	If SDL_OpenAudio() is passed zero for the desired format
    23 	fields, the following environment variables will be used
    24 	to fill them in:
    29 	If an environment variable is not specified, it will be set
    30 	to a reasonable default value.
    32 	Added support for the SDL_VIDEO_FULLSCREEN_HEAD environment
    33 	variable, currently supported on X11 Xinerama configurations.
    35 	Added SDL_GL_SWAP_CONTROL to wait for vsync in OpenGL applications.
    37 	Added SDL_GL_ACCELERATED_VISUAL to guarantee hardware acceleration.
    39 	Added current_w and current_h to the SDL_VideoInfo structure,
    40 	which is set to the desktop resolution during video intialization,
    41 	and then set to the current resolution when a video mode is set.
    43 	SDL_SetVideoMode() now accepts 0 for width or height and will use
    44 	the current video mode (or the desktop mode if no mode has been set.)
    46 	Added SDL_GetKeyRepeat()
    48 	Added SDL_config.h, with defaults for various build environments.
    50 1.2.7:
    51 	Added CPU feature detection functions to SDL_cpuinfo.h:
    52 		SDL_HasRDTSC(), SDL_HasMMX(), SDL_Has3DNow(), SDL_HasSSE(),
    53 		SDL_HasAltiVec()
    54 	Added function to create RWops from const memory: SDL_RWFromConstMem()
    56 1.2.6:
    57 	Added SDL_LoadObject(), SDL_LoadFunction(), and SDL_UnloadObject()
    61 1.2.5:
    64 	Added SDL_GL_STEREO for stereoscopic OpenGL contexts
    66 1.2.0:
    67 	Added SDL_VIDEOEXPOSE event to signal that the screen needs to
    68 	be redrawn.  This is currently only delivered to OpenGL windows
    69 	on X11, though it may be delivered in the future when the video
    70 	memory is lost under DirectX.
    72 1.1.8:
    73 	You can pass SDL_NOFRAME to SDL_VideoMode() to create a window
    74 	that has no title bar or frame decoration.  Fullscreen video
    75 	modes automatically have this flag set.
    77 	Added a function to query the clipping rectangle for a surface:
    78 		void SDL_GetClipRect(SDL_Surface *surface, SDL_Rect *rect)
    80 	Added a function to query the current event filter:
    81 		SDL_EventFilter SDL_GetEventFilter(void)
    83 	If you pass -1 to SDL_ShowCursor(), it won't change the current
    84 	cursor visibility state, but will still return it.
    86 	SDL_LockSurface() and SDL_UnlockSurface() are recursive, meaning
    87 	you can nest them as deep as you want, as long as each lock call
    88 	has a matching unlock call.  The surface remains locked until the
    89 	last matching unlock call.
    91 	Note that you may not blit to or from a locked surface.
    93 1.1.7:
    94 	The SDL_SetGammaRamp() and SDL_GetGammaRamp() functions now take
    95 	arrays of Uint16 values instead of Uint8 values.  For the most part,
    96 	you can just take your old values and shift them up 8 bits to get
    97 	new correct values for your gamma ramps.
    99 	You can pass SDL_RLEACCEL in flags passed to SDL_ConvertSurface()
   100         and SDL will try to RLE accelerate colorkey and alpha blits in the
   101 	resulting surface.
   103 1.1.6:
   104 	Added a function to return the thread ID of a specific thread:
   105 		Uint32 SDL_GetThreadID(SDL_Thread *thread)
   106 	If 'thread' is NULL, this function returns the id for this thread.
   108 1.1.5:
   109 	The YUV overlay structure has been changed to use an array of
   110 	pitches and pixels representing the planes of a YUV image, to
   111 	better enable hardware acceleration.  The YV12 and IYUV formats
   112 	each have three planes, corresponding to the Y, U, and V portions
   113 	of the image, while packed pixel YUV formats just have one plane.
   115 	For palettized mode (8bpp), the screen colormap is now split in
   116 	a physical and a logical palette. The physical palette determines
   117 	what colours the screen pixels will get when displayed, and the
   118 	logical palette controls the mapping from blits to/from the screen.
   119 	A new function, SDL_SetPalette() has been added to change
   120 	logical and physical palettes separately. SDL_SetColors() works
   121 	just as before, and is equivalent to calling SDL_SetPalette() with
   122 	a flag argument of (SDL_LOGPAL|SDL_PHYSPAL).
   124 	SDL_BlitSurface() no longer modifies the source rectangle, only the
   125 	destination rectangle. The width/height members of the destination
   126 	rectangle are ignored, only the position is used.
   128 	The old source clipping function SDL_SetClipping() has been replaced
   129 	with a more useful function to set the destination clipping rectangle:
   130 		SDL_bool SDL_SetClipRect(SDL_Surface *surface, SDL_Rect *rect)
   132 	Added a function to see what subsystems have been initialized:
   133 		Uint32 SDL_WasInit(Uint32 flags)
   135 	The Big Alpha Flip: SDL now treats alpha as opacity like everybody
   136 	else, and not as transparency:
   138 	A new cpp symbol: SDL_ALPHA_OPAQUE is defined as 255
   139 	A new cpp symbol: SDL_ALPHA_TRANSPARENT is defined as 0
   140 	Values between 0 and 255 vary from fully transparent to fully opaque.
   142 	New functions:
   143 	SDL_DisplayFormatAlpha()
   144 	    Returns a surface converted to a format with alpha-channel
   145 	    that can be blit efficiently to the screen. (In other words,
   146 	    like SDL_DisplayFormat() but the resulting surface has
   147 	    an alpha channel.)  This is useful for surfaces with alpha.
   148 	SDL_MapRGBA()
   149 	    Works as SDL_MapRGB() but takes an additional alpha parameter.
   150 	SDL_GetRGBA()
   151 	    Works as SDL_GetRGB() but also returns the alpha value
   152 	    (SDL_ALPHA_OPAQUE for formats without an alpha channel)
   154 	Both SDL_GetRGB() and SDL_GetRGBA() now always return values in
   155 	the [0..255] interval. Previously, SDL_GetRGB() would return
   156 	(0xf8, 0xfc, 0xf8) for a completely white pixel in RGB565 format.
   157 	(N.B.: This is broken for bit fields < 3 bits.)
   159 	SDL_MapRGB() returns pixels in which the alpha channel is set opaque.
   161 	SDL_SetAlpha() can now be used for both setting the per-surface
   162 	alpha, using the new way of thinking of alpha, and also to enable
   163 	and disable per-pixel alpha blending for surfaces with an alpha
   164 	channel:
   165 		To disable alpha blending:
   166 			SDL_SetAlpha(surface, 0, 0);
   167 		To re-enable alpha blending:
   168 			SDL_SetAlpha(surface, SDL_SRCALPHA, 0);
   169 	Surfaces with an alpha channel have blending enabled by default.
   171 	SDL_SetAlpha() now accepts SDL_RLEACCEL as a flag, which requests
   172 	RLE acceleration of blits, just as like with SDL_SetColorKey().
   173 	This flag can be set for both surfaces with an alpha channel
   174 	and surfaces with an alpha value set by SDL_SetAlpha().
   175 	As always, RLE surfaces must be locked before pixel access is
   176 	allowed, and unlocked before any other SDL operations are done
   177 	on it.
   179 	The blit semantics for surfaces with and without alpha and colorkey
   180 	have now been defined:
   182 	RGBA->RGB:
   183 	    SDL_SRCALPHA set:
   184 		alpha-blend (using alpha-channel).
   185 		SDL_SRCCOLORKEY ignored.
   186 	    SDL_SRCALPHA not set:
   187 		copy RGB.
   188 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   189 		RGB values of the source colour key, ignoring alpha in the
   190 		comparison.
   192 	RGB->RGBA:
   193 	    SDL_SRCALPHA set:
   194 		alpha-blend (using the source per-surface alpha value);
   195 		set destination alpha to opaque.
   196 	    SDL_SRCALPHA not set:
   197 		copy RGB, set destination alpha to opaque.
   198 	    both:
   199 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   200 		source colour key.
   202 	RGBA->RGBA:
   203 	    SDL_SRCALPHA set:
   204 		alpha-blend (using the source alpha channel) the RGB values;
   205 		leave destination alpha untouched. [Note: is this correct?]
   206 		SDL_SRCCOLORKEY ignored.
   207 	    SDL_SRCALPHA not set:
   208 		copy all of RGBA to the destination.
   209 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   210 		RGB values of the source colour key, ignoring alpha in the
   211 		comparison.
   213 	RGB->RGB: 
   214 	    SDL_SRCALPHA set:
   215 		alpha-blend (using the source per-surface alpha value).
   216 	    SDL_SRCALPHA not set:
   217 		copy RGB.
   218 	    both:
   219 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   220 		source colour key.
   222 	As a special case, blits from surfaces with per-surface alpha
   223 	value of 128 (50% transparency) are optimised and much faster
   224 	than other alpha values. This does not apply to surfaces with
   225 	alpha channels (per-pixel alpha).
   227 	New functions for manipulating the gamma of the display have
   228 	been added:
   229 		int SDL_SetGamma(float red, float green, float blue);
   230 		int SDL_SetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   231 		int SDL_GetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   232 	Gamma ramps are tables with 256 entries which map the screen color
   233 	components into actually displayed colors.  For an example of
   234 	implementing gamma correction and gamma fades, see test/testgamma.c
   235 	Gamma control is not supported on all hardware.
   237 1.1.4:
   238 	The size of the SDL_CDtrack structure changed from 8 to 12 bytes
   239 	as the size of the length member was extended to 32 bits.
   241         You can now use SDL for 2D blitting with a GL mode by passing the
   242 	SDL_OPENGLBLIT flag to SDL_SetVideoMode().  You can specify 16 or
   243 	32 bpp, and the data in the framebuffer is put into the GL scene
   244 	when you call SDL_UpdateRects(), and the scene will be visible
   245 	when you call SDL_GL_SwapBuffers().
   247 	Run the "testgl" test program with the -logo command line option
   248 	to see an example of this blending of 2D and 3D in SDL.
   250 1.1.3:
   251 	Added SDL_FreeRW() to the API, to complement SDL_AllocRW()
   253 	Added resizable window support - just add SDL_RESIZABLE to the
   254 	SDL_SetVideoMode() flags, and then wait for SDL_VIDEORESIZE events.
   255 	See SDL_events.h for details on the new SDL_ResizeEvent structure.
   257 	Added condition variable support, based on mutexes and semaphores.
   258 		SDL_CreateCond()
   259 		SDL_DestroyCond()
   260 		SDL_CondSignal()
   261 		SDL_CondBroadcast()
   262 		SDL_CondWait()
   263 		SDL_CondTimedWait()
   264 	The new function prototypes are in SDL_mutex.h
   266 	Added counting semaphore support, based on the mutex primitive.
   267 		SDL_CreateSemaphore()
   268 		SDL_DestroySemaphore()
   269 		SDL_SemWait()
   270 		SDL_SemTryWait()
   271 		SDL_SemWaitTimeout()
   272 		SDL_SemPost()
   273 		SDL_SemValue()
   274 	The new function prototypes are in SDL_mutex.h
   276 	Added support for asynchronous blitting.  To take advantage of this,
   277 	you must set the SDL_ASYNCBLIT flag when setting the video mode and
   278 	creating surfaces that you want accelerated in this way.  You must
   279 	lock surfaces that have this flag set, and the lock will block until
   280 	any queued blits have completed.
   282 	Added YUV video overlay support.
   283 	The supported YUV formats are: YV12, IYUV, YUY2, UYVY, and YVYU.
   284 	This function creates an overlay surface:
   285 		SDL_CreateYUVOverlay()
   286 	You must lock and unlock the overlay to get access to the data:
   287 		SDL_LockYUVOverlay() SDL_UnlockYUVOverlay()
   288 	You can then display the overlay:
   289 		SDL_DisplayYUVOverlay()
   290 	You must free the overlay when you are done using it:
   291 		SDL_FreeYUVOverlay()
   292 	See SDL_video.h for the full function prototypes.
   294 	The joystick hat position constants have been changed:
   295 	Old constant            New constant
   296 	------------            ------------
   297 	     0                  SDL_HAT_CENTERED
   298 	     1                  SDL_HAT_UP
   299 	     2                  SDL_HAT_RIGHTUP
   300 	     3                  SDL_HAT_RIGHT
   301 	     4                  SDL_HAT_RIGHTDOWN
   302 	     5                  SDL_HAT_DOWN
   303 	     6                  SDL_HAT_LEFTDOWN
   304 	     7                  SDL_HAT_LEFT
   305 	     8                  SDL_HAT_LEFTUP
   306 	The new constants are bitmasks, so you can check for the
   307 	individual axes like this:
   308 		if ( hat_position & SDL_HAT_UP ) {
   309 		}
   310 	and you'll catch left-up, up, and right-up.
   312 1.1.2:
   313 	Added multiple timer support:
   314 		SDL_AddTimer() and SDL_RemoveTimer()
   316 	SDL_WM_SetIcon() now respects the icon colorkey if mask is NULL.
   318 1.1.0:
   319 	Added initial OpenGL support.
   320 	First set GL attributes (such as RGB depth, alpha depth, etc.)
   321 		SDL_GL_SetAttribute()
   322 	Then call SDL_SetVideoMode() with the SDL_OPENGL flag.
   323 	Perform all of your normal GL drawing.
   324 	Finally swap the buffers with the new SDL function:
   325 		SDL_GL_SwapBuffers()
   326 	See the new 'testgl' test program for an example of using GL with SDL.
   328 	You can load GL extension functions by using the function:
   329 		SDL_GL_LoadProcAddress()
   331 	Added functions to initialize and cleanup specific SDL subsystems:
   332 		SDL_InitSubSystem() and SDL_QuitSubSystem()
   334 	Added user-defined event type:
   335 		typedef struct {
   336         		Uint8 type;
   337         		int code;
   338         		void *data1;
   339         		void *data2;
   340 		} SDL_UserEvent;
   341 	This structure is in the "user" member of an SDL_Event.
   343 	Added a function to push events into the event queue:
   344 		SDL_PushEvent()
   346 	Example of using the new SDL user-defined events:
   347 	{
   348 		SDL_Event event;
   350 		event.type = SDL_USEREVENT;
   351 		event.user.code = my_event_code;
   352 		event.user.data1 = significant_data;
   353 		event.user.data2 = 0;
   354 		SDL_PushEvent(&event);
   355 	}
   357 	Added a function to get mouse deltas since last query:
   358 		SDL_GetRelativeMouseState()
   360 	Added a boolean datatype to SDL_types.h:
   361 		SDL_bool = { SDL_TRUE, SDL_FALSE }
   363 	Added a function to get the current audio status:
   364 		SDL_GetAudioState();
   365 	It returns one of:
   370 	Added an AAlib driver (ASCII Art) - by Stephane Peter.
   372 1.0.6:
   373 	The input grab state is reset after each call to SDL_SetVideoMode().
   374 	The input is grabbed by default in fullscreen mode, and ungrabbed in
   375 	windowed mode.  If you want to set input grab to a particular value,
   376 	you should set it after each call to SDL_SetVideoMode().
   378 1.0.5:
   379 	Exposed SDL_AudioInit(), SDL_VideoInit()
   380 	Added SDL_AudioDriverName() and SDL_VideoDriverName()
   382 	Added new window manager function:
   383 		SDL_WM_ToggleFullScreen()
   384 	This is currently implemented only on Linux
   386 	The ALT-ENTER code has been removed - it's not appropriate for a
   387 	lib to bind keys when they aren't even emergency escape sequences.
   389 	ALT-ENTER functionality can be implemented with the following code:
   391 	int Handle_AltEnter(const SDL_Event *event)
   392 	{
   393 	    if ( event->type == SDL_KEYDOWN ) {
   394 	        if ( (event->key.keysym.sym == SDLK_RETURN) &&
   395 	             (event->key.keysym.mod & KMOD_ALT) ) {   
   396 	                SDL_WM_ToggleFullScreen(SDL_GetVideoSurface());
   397 	                return(0);
   398 	        }
   399 	    }
   400 	    return(1);
   401 	}
   402 	SDL_SetEventFilter(Handle_AltEnter);
   404 1.0.3:
   405 	Under X11, if you grab the input and hide the mouse cursor,
   406 	the mouse will go into a "relative motion" mode where you
   407 	will always get relative motion events no matter how far in
   408 	each direction you move the mouse - relative motion is not
   409 	bounded by the edges of the window (though the absolute values
   410 	of the mouse positions are clamped by the size of the window).
   411 	The SVGAlib, framebuffer console, and DirectInput drivers all
   412 	have this behavior naturally, and the GDI and BWindow drivers
   413 	never go into "relative motion" mode.
   415 1.0.2:
   416 	Added a function to enable keyboard repeat:
   417 		SDL_EnableKeyRepeat()
   419 	Added a function to grab the mouse and keyboard input
   420 		SDL_WM_GrabInput()
   422 	Added a function to iconify the window.
   423 		SDL_WM_IconifyWindow()
   424 	If this function succeeds, the application will receive an event
   425 	signaling SDL_APPACTIVE event 
   427 1.0.1:
   428 	Added constants to SDL_audio.h for 16-bit native byte ordering:
   431 1.0.0:
   432 	New public release
   434 Version 0.11:
   436 0.11.5:
   437 	A new function SDL_GetVideoSurface() has been added, and returns
   438 	a pointer to the current display surface.
   440 	SDL_AllocSurface() has been renamed SDL_CreateRGBSurface(), and
   441 	a new function SDL_CreateRGBSurfaceFrom() has been added to allow
   442 	creating an SDL surface from an existing pixel data buffer.
   444 	Added SDL_GetRGB() to the headers and documentation.
   446 0.11.4:
   447 	SDL_SetLibraryPath() is no longer meaningful, and has been removed.
   449 0.11.3:
   450 	A new flag for SDL_Init(), SDL_INIT_NOPARACHUTE, prevents SDL from
   451 	installing fatal signal handlers on operating systems that support
   452 	them.
   454 Version 0.9:
   456 0.9.15:
   457 	SDL_CreateColorCursor() has been removed.  Color cursors should
   458 	be implemented as sprites, blitted by the application when the
   459 	cursor moves.  To get smooth color cursor updates when the app
   460 	is busy, pass the SDL_INIT_EVENTTHREAD flag to SDL_Init().  This
   461 	allows you to handle the mouse motion in another thread from an
   462 	event filter function, but is currently only supported by Linux
   463 	and BeOS.  Note that you'll have to protect the display surface
   464 	from multi-threaded access by using mutexes if you do this.
   466 	Thread-safe surface support has been removed from SDL.
   467 	This makes blitting somewhat faster, by removing SDL_MiddleBlit().
   468 	Code that used SDL_MiddleBlit() should use SDL_LowerBlit() instead.
   469 	You can make your surfaces thread-safe by allocating your own
   470 	mutex and making lock/unlock calls around accesses to your surface.
   472 0.9.14:
   473 	SDL_GetMouseState() now takes pointers to int rather than Uint16.
   475 	If you set the SDL_WINDOWID environment variable under UNIX X11,
   476 	SDL will use that as the main window instead of creating it's own.
   477 	This is an unsupported extension to SDL, and not portable at all.
   479 0.9.13:
   480 	Added a function SDL_SetLibraryPath() which can be used to specify
   481 	the directory containing the SDL dynamic libraries.  This is useful
   482 	for commercial applications which ship with particular versions
   483 	of the libraries, and for security on multi-user systems.
   484 	If this function is not used, the default system directories are 
   485 	searched using the native dynamic object loading mechanism.
   487 	In order to support C linkage under Visual C++, you must declare
   488 	main() without any return type:
   489 		main(int argc, char *argv[]) {
   490 			/* Do the program... */
   491 			return(0);
   492 		}
   493 	C++ programs should also return a value if compiled under VC++.
   495 	The blit_endian member of the SDL_VideoInfo struct has been removed.
   497 	SDL_SymToASCII() has been replaced with SDL_GetKeyName(), so there
   498 	is now no longer any function to translate a keysym to a character.
   500 	The SDL_keysym structure has been extended with a 'scancode' and
   501 	'unicode' member.  The 'scancode' is a hardware specific scancode
   502 	for the key that was pressed, and may be 0.  The 'unicode' member
   503 	is a 16-bit UNICODE translation of the key that was pressed along
   504 	with any modifiers or compose keys that have been pressed.
   505 	If no UNICODE translation exists for the key, 'unicode' will be 0.
   507 	Added a function SDL_EnableUNICODE() to enable/disable UNICODE
   508 	translation of character keypresses.  Translation defaults off.
   510 	To convert existing code to use the new API, change code which
   511 	uses SDL_SymToASCII() to get the keyname to use SDL_GetKeyName(),
   512 	and change code which uses it to get the ASCII value of a sym to
   513 	use the 'unicode' member of the event keysym.
   515 0.9.12:
   516 	There is partial support for 64-bit datatypes.  I don't recommend 
   517 	you use this if you have a choice, because 64-bit datatypes are not
   518 	supported on many platforms.  On platforms for which it is supported,
   519 	the SDL_HAS_64BIT_TYPE C preprocessor define will be enabled, and
   520 	you can use the Uint64 and Sint64 datatypes.
   522 	Added functions to SDL_endian.h to support 64-bit datatypes:
   523 	    SDL_SwapLE64(), SDL_SwapBE64(),
   524 	    SDL_ReadLE64(), SDL_ReadBE64(), SDL_WriteLE64(), SDL_WriteBE64()
   526 	A new member "len_ratio" has been added to the SDL_AudioCVT structure,
   527 	and allows you to determine either the original buffer length or the
   528 	converted buffer length, given the other.
   530 	A new function SDL_FreeWAV() has been added to the API to free data
   531 	allocated by SDL_LoadWAV_RW().  This is necessary under Win32 since
   532 	the gcc compiled DLL uses a different heap than VC++ compiled apps.
   534 	SDL now has initial support for international keyboards using the
   535 	Latin character set.
   536 	If a particular mapping is desired, you can set the DEFAULT_KEYBOARD
   537 	compile-time variable, or you can set the environment variable 
   538 	"SDL_KEYBOARD" to a string identifying the keyboard mapping you desire.
   539 	The valid values for these variables can be found in SDL_keyboard.c
   541 	Full support for German and French keyboards under X11 is implemented.
   543 0.9.11:
   544 	The THREADED_EVENTS compile-time define has been replaced with the
   545 	SDL_INIT_EVENTTHREAD flag.  If this flag is passed to SDL_Init(),
   546 	SDL will create a separate thread to perform input event handling.
   547 	If this flag is passed to SDL_Init(), and the OS doesn't support 
   548 	event handling in a separate thread, SDL_Init() will fail.
   549 	Be sure to add calls to SDL_Delay() in your main thread to allow
   550 	the OS to schedule your event thread, or it may starve, leading
   551 	to slow event delivery and/or dropped events.
   552 	Currently MacOS and Win32 do not support this flag, while BeOS 
   553 	and Linux do support it.  I recommend that your application only
   554 	use this flag if absolutely necessary.
   556 	The SDL thread function passed to SDL_CreateThread() now returns a
   557 	status.  This status can be retrieved by passing a non-NULL pointer
   558 	as the 'status' argument to SDL_WaitThread().
   560 	The volume parameter to SDL_MixAudio() has been increased in range
   561 	from (0-8) to (0-128)
   563 	SDL now has a data source abstraction which can encompass a file,
   564 	an area of memory, or any custom object you can envision.  It uses
   565 	these abstractions, SDL_RWops, in the endian read/write functions,
   566 	and the built-in WAV and BMP file loaders.  This means you can load
   567 	WAV chunks from memory mapped files, compressed archives, network
   568 	pipes, or anything else that has a data read abstraction.
   570 	There are three built-in data source abstractions:
   571 	    SDL_RWFromFile(), SDL_RWFromFP(), SDL_RWFromMem()
   572 	along with a generic data source allocation function:
   573 	    SDL_AllocRW()
   574 	These data sources can be used like stdio file pointers with the
   575 	following convenience functions:
   576 	    SDL_RWseek(), SDL_RWread(), SDL_RWwrite(), SDL_RWclose()
   577 	These functions are defined in the new header file "SDL_rwops.h"
   579 	The endian swapping functions have been turned into macros for speed
   580 	and SDL_CalculateEndian() has been removed.  SDL_endian.h now defines
   581 	SDL_BYTEORDER as either SDL_BIG_ENDIAN or SDL_LIL_ENDIAN depending on
   582 	the endianness of the host system.
   584 	The endian read/write functions now take an SDL_RWops pointer
   585 	instead of a stdio FILE pointer, to support the new data source
   586 	abstraction.
   588 	The SDL_*LoadWAV() functions have been replaced with a single
   589 	SDL_LoadWAV_RW() function that takes a SDL_RWops pointer as it's
   590 	first parameter, and a flag whether or not to automatically 
   591 	free it as the second parameter.  SDL_LoadWAV() is a macro for
   592 	backward compatibility and convenience:
   593 	    SDL_LoadWAV_RW(SDL_RWFromFile("sample.wav", "rb"), 1, ...);
   595 	The SDL_*LoadBMP()/SDL_*SaveBMP() functions have each been replaced
   596 	with a single function that takes a SDL_RWops pointer as it's
   597 	first parameter, and a flag whether or not to automatically 
   598 	free it as the second parameter.  SDL_LoadBMP() and SDL_SaveBMP()
   599 	are macros for backward compatibility and convenience:
   600 	    SDL_LoadBMP_RW(SDL_RWFromFile("sample.bmp", "rb"), 1, ...);
   601 	    SDL_SaveBMP_RW(SDL_RWFromFile("sample.bmp", "wb"), 1, ...);
   602 	Note that these functions use SDL_RWseek() extensively, and should
   603 	not be used on pipes or other non-seekable data sources.
   605 0.9.10:
   606 	The Linux SDL_SysWMInfo and SDL_SysWMMsg structures have been 
   607 	extended to support multiple types of display drivers, as well as
   608         safe access to the X11 display when THREADED_EVENTS is enabled.
   609         The new structures are documented in the SDL_syswm.h header file.
   611 	Thanks to John Elliott <jce@seasip.demon.co.uk>, the UK keyboard
   612 	should now work properly, as well as the "Windows" keys on US
   613 	keyboards.
   615 	The Linux CD-ROM code now reads the CD-ROM devices from /etc/fstab
   616 	instead of trying to open each block device on the system.
   617 	The CD must be listed in /etc/fstab as using the iso9660 filesystem.
   619 	On Linux, if you define THREADED_EVENTS at compile time, a separate
   620 	thread will be spawned to gather X events asynchronously from the
   621 	graphics updates.  This hasn't been extensively tested, but it does
   622 	provide a means of handling keyboard and mouse input in a separate
   623 	thread from the graphics thread.  (This is now enabled by default.)
   625 	A special access function SDL_PeepEvents() allows you to manipulate
   626 	the event queue in a thread-safe manner, including peeking at events,
   627 	removing events of a specified type, and adding new events of arbitrary
   628 	type to the queue (use the new 'user' member of the SDL_Event type).
   630 	If you use SDL_PeepEvents() to gather events, then the main graphics
   631 	thread needs to call SDL_PumpEvents() periodically to drive the event
   632 	loop and generate input events.  This is not necessary if SDL has been 
   633 	compiled with THREADED_EVENTS defined, but doesn't hurt.
   635 	A new function SDL_ThreadID() returns the identifier associated with
   636 	the current thread.
   638 0.9.9:
   639 	The AUDIO_STEREO format flag has been replaced with a new 'channels'
   640 	member of the SDL_AudioSpec structure.  The channels are 1 for mono
   641 	audio, and 2 for stereo audio.  In the future more channels may be
   642 	supported for 3D surround sound.
   644 	The SDL_MixAudio() function now takes an additional volume parameter,
   645 	which should be set to SDL_MIX_MAXVOLUME for compatibility with the
   646 	original function.
   648 	The CD-ROM functions which take a 'cdrom' parameter can now be
   649 	passed NULL, and will act on the last successfully opened CD-ROM.
   651 0.9.8:
   652 	No changes, bugfixes only.
   654 0.9.7:
   655 	No changes, bugfixes only.
   657 0.9.6:
   658 	Added a fast rectangle fill function: SDL_FillRect()
   660 	Addition of a useful function for getting info on the video hardware:
   661 	    const SDL_VideoInfo *SDL_GetVideoInfo(void)
   662         This function replaces SDL_GetDisplayFormat().
   664 	Initial support for double-buffering:
   665 	  Use the SDL_DOUBLEBUF flag in SDL_SetVideoMode()
   666 	  Update the screen with a new function: SDL_Flip()
   668 	SDL_AllocSurface() takes two new flags:
   669 	SDL_SRCCOLORKEY means that the surface will be used for colorkey blits
   670 	  and if the hardware supports hardware acceleration of colorkey blits
   671 	  between two surfaces in video memory, to place the surface in video
   672 	  memory if possible, otherwise it will be placed in system memory.
   673 	SDL_SRCALPHA means that the surface will be used for alpha blits and
   674 	  if the hardware supports hardware acceleration of alpha blits between
   675 	  two surfaces in video memory, to place the surface in video memory
   676 	  if possible, otherwise it will be placed in system memory.
   677 	SDL_HWSURFACE now means that the surface will be created with the 
   678 	  same format as the display surface, since having surfaces in video
   679 	  memory is only useful for fast blitting to the screen, and you can't
   680 	  blit surfaces with different surface formats in video memory.
   682 0.9.5:
   683 	You can now pass a NULL mask to SDL_WM_SetIcon(), and it will assume
   684 	that the icon consists of the entire image.
   686 	SDL_LowerBlit() is back -- but don't use it on the display surface.
   687 	It is exactly the same as SDL_MiddleBlit(), but doesn't check for
   688 	thread safety.
   690 	Added SDL_FPLoadBMP(), SDL_FPSaveBMP(), SDL_FPLoadWAV(), which take
   691 	a FILE pointer instead of a file name.
   693 	Added CD-ROM audio control API:
   694 	    SDL_CDNumDrives()
   695 	    SDL_CDName()
   696 	    SDL_CDOpen()
   697 	    SDL_CDStatus()
   698 	    SDL_CDPlayTracks()
   699 	    SDL_CDPlay()
   700 	    SDL_CDPause()
   701 	    SDL_CDResume()
   702 	    SDL_CDStop()
   703 	    SDL_CDEject()
   704 	    SDL_CDClose()
   706 0.9.4:
   707 	No changes, bugfixes only.
   709 0.9.3:
   710 	Mouse motion event now includes relative motion information:
   711 	    Sint16 event->motion.xrel, Sint16 event->motion.yrel
   713 	X11 keyrepeat handling can be disabled by defining IGNORE_X_KEYREPEAT
   714 	    (Add -DIGNORE_X_KEYREPEAT to CFLAGS line in obj/x11Makefile)
   716 0.9.2:
   717 	No changes, bugfixes only.
   719 0.9.1:
   720 	Removed SDL_MapSurface() and SDL_UnmapSurface() -- surfaces are now
   721 	automatically mapped on blit.
   723 0.8.0:
   724 	SDL stable release