WhatsNew
author Sam Lantinga <slouken@libsdl.org>
Sun, 14 Oct 2001 20:30:10 +0000
changeset 206 b69bb2a368a0
parent 0 74212992fb08
child 292 eadc0746dfaf
permissions -rw-r--r--
Fixed flashing the screen when creating a window on BeOS
     1 
     2 This is a list of API changes in SDL's version history.
     3 
     4 Version 1.0:
     5 
     6 1.2.0:
     7 	Added SDL_VIDEOEXPOSE event to signal that the screen needs to
     8 	be redrawn.  This is currently only delivered to OpenGL windows
     9 	on X11, though it may be delivered in the future when the video
    10 	memory is lost under DirectX.
    11 
    12 1.1.8:
    13 	You can pass SDL_NOFRAME to SDL_VideoMode() to create a window
    14 	that has no title bar or frame decoration.  Fullscreen video
    15 	modes automatically have this flag set.
    16 
    17 	Added a function to query the clipping rectangle for a surface:
    18 		void SDL_GetClipRect(SDL_Surface *surface, SDL_Rect *rect)
    19 
    20 	Added a function to query the current event filter:
    21 		SDL_EventFilter SDL_GetEventFilter(void)
    22 
    23 	If you pass -1 to SDL_ShowCursor(), it won't change the current
    24 	cursor visibility state, but will still return it.
    25 
    26 	SDL_LockSurface() and SDL_UnlockSurface() are recursive, meaning
    27 	you can nest them as deep as you want, as long as each lock call
    28 	has a matching unlock call.  The surface remains locked until the
    29 	last matching unlock call.
    30 
    31 	Note that you may not blit to or from a locked surface.
    32 
    33 1.1.7:
    34 	The SDL_SetGammaRamp() and SDL_GetGammaRamp() functions now take
    35 	arrays of Uint16 values instead of Uint8 values.  For the most part,
    36 	you can just take your old values and shift them up 8 bits to get
    37 	new correct values for your gamma ramps.
    38 
    39 	You can pass SDL_RLEACCEL in flags passed to SDL_ConvertSurface()
    40         and SDL will try to RLE accelerate colorkey and alpha blits in the
    41 	resulting surface.
    42 
    43 1.1.6:
    44 	Added a function to return the thread ID of a specific thread:
    45 		Uint32 SDL_GetThreadID(SDL_Thread *thread)
    46 	If 'thread' is NULL, this function returns the id for this thread.
    47 
    48 1.1.5:
    49 	The YUV overlay structure has been changed to use an array of
    50 	pitches and pixels representing the planes of a YUV image, to
    51 	better enable hardware acceleration.  The YV12 and IYUV formats
    52 	each have three planes, corresponding to the Y, U, and V portions
    53 	of the image, while packed pixel YUV formats just have one plane.
    54 
    55 	For palettized mode (8bpp), the screen colormap is now split in
    56 	a physical and a logical palette. The physical palette determines
    57 	what colours the screen pixels will get when displayed, and the
    58 	logical palette controls the mapping from blits to/from the screen.
    59 	A new function, SDL_SetPalette() has been added to change
    60 	logical and physical palettes separately. SDL_SetColors() works
    61 	just as before, and is equivalent to calling SDL_SetPalette() with
    62 	a flag argument of (SDL_LOGPAL|SDL_PHYSPAL).
    63 
    64 	SDL_BlitSurface() no longer modifies the source rectangle, only the
    65 	destination rectangle. The width/height members of the destination
    66 	rectangle are ignored, only the position is used.
    67 
    68 	The old source clipping function SDL_SetClipping() has been replaced
    69 	with a more useful function to set the destination clipping rectangle:
    70 		SDL_bool SDL_SetClipRect(SDL_Surface *surface, SDL_Rect *rect)
    71 		
    72 	Added a function to see what subsystems have been initialized:
    73 		Uint32 SDL_WasInit(Uint32 flags)
    74 
    75 	The Big Alpha Flip: SDL now treats alpha as opacity like everybody
    76 	else, and not as transparency:
    77 
    78 	A new cpp symbol: SDL_ALPHA_OPAQUE is defined as 255
    79 	A new cpp symbol: SDL_ALPHA_TRANSPARENT is defined as 0
    80 	Values between 0 and 255 vary from fully transparent to fully opaque.
    81 
    82 	New functions:
    83 	SDL_DisplayFormatAlpha()
    84 	    Returns a surface converted to a format with alpha-channel
    85 	    that can be blit efficiently to the screen. (In other words,
    86 	    like SDL_DisplayFormat() but the resulting surface has
    87 	    an alpha channel.)  This is useful for surfaces with alpha.
    88 	SDL_MapRGBA()
    89 	    Works as SDL_MapRGB() but takes an additional alpha parameter.
    90 	SDL_GetRGBA()
    91 	    Works as SDL_GetRGB() but also returns the alpha value
    92 	    (SDL_ALPHA_OPAQUE for formats without an alpha channel)
    93 
    94 	Both SDL_GetRGB() and SDL_GetRGBA() now always return values in
    95 	the [0..255] interval. Previously, SDL_GetRGB() would return
    96 	(0xf8, 0xfc, 0xf8) for a completely white pixel in RGB565 format.
    97 	(N.B.: This is broken for bit fields < 3 bits.)
    98 
    99 	SDL_MapRGB() returns pixels in which the alpha channel is set opaque.
   100 
   101 	SDL_SetAlpha() can now be used for both setting the per-surface
   102 	alpha, using the new way of thinking of alpha, and also to enable
   103 	and disable per-pixel alpha blending for surfaces with an alpha
   104 	channel:
   105 		To disable alpha blending:
   106 			SDL_SetAlpha(surface, 0, 0);
   107 		To re-enable alpha blending:
   108 			SDL_SetAlpha(surface, SDL_SRCALPHA, 0);
   109 	Surfaces with an alpha channel have blending enabled by default.
   110 
   111 	SDL_SetAlpha() now accepts SDL_RLEACCEL as a flag, which requests
   112 	RLE acceleration of blits, just as like with SDL_SetColorKey().
   113 	This flag can be set for both surfaces with an alpha channel
   114 	and surfaces with an alpha value set by SDL_SetAlpha().
   115 	As always, RLE surfaces must be locked before pixel access is
   116 	allowed, and unlocked before any other SDL operations are done
   117 	on it.
   118 
   119 	The blit semantics for surfaces with and without alpha and colorkey
   120 	have now been defined:
   121 
   122 	RGBA->RGB:
   123 	    SDL_SRCALPHA set:
   124 		alpha-blend (using alpha-channel).
   125 		SDL_SRCCOLORKEY ignored.
   126 	    SDL_SRCALPHA not set:
   127 		copy RGB.
   128 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   129 		RGB values of the source colour key, ignoring alpha in the
   130 		comparison.
   131 
   132 	RGB->RGBA:
   133 	    SDL_SRCALPHA set:
   134 		alpha-blend (using the source per-surface alpha value);
   135 		set destination alpha to opaque.
   136 	    SDL_SRCALPHA not set:
   137 		copy RGB, set destination alpha to opaque.
   138 	    both:
   139 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   140 		source colour key.
   141 
   142 	RGBA->RGBA:
   143 	    SDL_SRCALPHA set:
   144 		alpha-blend (using the source alpha channel) the RGB values;
   145 		leave destination alpha untouched. [Note: is this correct?]
   146 		SDL_SRCCOLORKEY ignored.
   147 	    SDL_SRCALPHA not set:
   148 		copy all of RGBA to the destination.
   149 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   150 		RGB values of the source colour key, ignoring alpha in the
   151 		comparison.
   152 
   153 	RGB->RGB: 
   154 	    SDL_SRCALPHA set:
   155 		alpha-blend (using the source per-surface alpha value).
   156 	    SDL_SRCALPHA not set:
   157 		copy RGB.
   158 	    both:
   159 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   160 		source colour key.
   161 
   162 	As a special case, blits from surfaces with per-surface alpha
   163 	value of 128 (50% transparency) are optimised and much faster
   164 	than other alpha values. This does not apply to surfaces with
   165 	alpha channels (per-pixel alpha).
   166 
   167 	New functions for manipulating the gamma of the display have
   168 	been added:
   169 		int SDL_SetGamma(float red, float green, float blue);
   170 		int SDL_SetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   171 		int SDL_GetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   172 	Gamma ramps are tables with 256 entries which map the screen color
   173 	components into actually displayed colors.  For an example of
   174 	implementing gamma correction and gamma fades, see test/testgamma.c
   175 	Gamma control is not supported on all hardware.
   176 
   177 1.1.4:
   178 	The size of the SDL_CDtrack structure changed from 8 to 12 bytes
   179 	as the size of the length member was extended to 32 bits.
   180 
   181         You can now use SDL for 2D blitting with a GL mode by passing the
   182 	SDL_OPENGLBLIT flag to SDL_SetVideoMode().  You can specify 16 or
   183 	32 bpp, and the data in the framebuffer is put into the GL scene
   184 	when you call SDL_UpdateRects(), and the scene will be visible
   185 	when you call SDL_GL_SwapBuffers().
   186 
   187 	Run the "testgl" test program with the -logo command line option
   188 	to see an example of this blending of 2D and 3D in SDL.
   189 
   190 1.1.3:
   191 	Added SDL_FreeRW() to the API, to complement SDL_AllocRW()
   192 
   193 	Added resizable window support - just add SDL_RESIZABLE to the
   194 	SDL_SetVideoMode() flags, and then wait for SDL_VIDEORESIZE events.
   195 	See SDL_events.h for details on the new SDL_ResizeEvent structure.
   196 
   197 	Added condition variable support, based on mutexes and semaphores.
   198 		SDL_CreateCond()
   199 		SDL_DestroyCond()
   200 		SDL_CondSignal()
   201 		SDL_CondBroadcast()
   202 		SDL_CondWait()
   203 		SDL_CondTimedWait()
   204 	The new function prototypes are in SDL_mutex.h
   205 
   206 	Added counting semaphore support, based on the mutex primitive.
   207 		SDL_CreateSemaphore()
   208 		SDL_DestroySemaphore()
   209 		SDL_SemWait()
   210 		SDL_SemTryWait()
   211 		SDL_SemWaitTimeout()
   212 		SDL_SemPost()
   213 		SDL_SemValue()
   214 	The new function prototypes are in SDL_mutex.h
   215 
   216 	Added support for asynchronous blitting.  To take advantage of this,
   217 	you must set the SDL_ASYNCBLIT flag when setting the video mode and
   218 	creating surfaces that you want accelerated in this way.  You must
   219 	lock surfaces that have this flag set, and the lock will block until
   220 	any queued blits have completed.
   221 
   222 	Added YUV video overlay support.
   223 	The supported YUV formats are: YV12, IYUV, YUY2, UYVY, and YVYU.
   224 	This function creates an overlay surface:
   225 		SDL_CreateYUVOverlay()
   226 	You must lock and unlock the overlay to get access to the data:
   227 		SDL_LockYUVOverlay() SDL_UnlockYUVOverlay()
   228 	You can then display the overlay:
   229 		SDL_DisplayYUVOverlay()
   230 	You must free the overlay when you are done using it:
   231 		SDL_FreeYUVOverlay()
   232 	See SDL_video.h for the full function prototypes.
   233 
   234 	The joystick hat position constants have been changed:
   235 	Old constant            New constant
   236 	------------            ------------
   237 	     0                  SDL_HAT_CENTERED
   238 	     1                  SDL_HAT_UP
   239 	     2                  SDL_HAT_RIGHTUP
   240 	     3                  SDL_HAT_RIGHT
   241 	     4                  SDL_HAT_RIGHTDOWN
   242 	     5                  SDL_HAT_DOWN
   243 	     6                  SDL_HAT_LEFTDOWN
   244 	     7                  SDL_HAT_LEFT
   245 	     8                  SDL_HAT_LEFTUP
   246 	The new constants are bitmasks, so you can check for the
   247 	individual axes like this:
   248 		if ( hat_position & SDL_HAT_UP ) {
   249 		}
   250 	and you'll catch left-up, up, and right-up.
   251 
   252 1.1.2:
   253 	Added multiple timer support:
   254 		SDL_AddTimer() and SDL_RemoveTimer()
   255 
   256 	SDL_WM_SetIcon() now respects the icon colorkey if mask is NULL.
   257 
   258 1.1.0:
   259 	Added initial OpenGL support.
   260 	First set GL attributes (such as RGB depth, alpha depth, etc.)
   261 		SDL_GL_SetAttribute()
   262 	Then call SDL_SetVideoMode() with the SDL_OPENGL flag.
   263 	Perform all of your normal GL drawing.
   264 	Finally swap the buffers with the new SDL function:
   265 		SDL_GL_SwapBuffers()
   266 	See the new 'testgl' test program for an example of using GL with SDL.
   267 
   268 	You can load GL extension functions by using the function:
   269 		SDL_GL_LoadProcAddress()
   270 
   271 	Added functions to initialize and cleanup specific SDL subsystems:
   272 		SDL_InitSubSystem() and SDL_QuitSubSystem()
   273 
   274 	Added user-defined event type:
   275 		typedef struct {
   276         		Uint8 type;
   277         		int code;
   278         		void *data1;
   279         		void *data2;
   280 		} SDL_UserEvent;
   281 	This structure is in the "user" member of an SDL_Event.
   282 
   283 	Added a function to push events into the event queue:
   284 		SDL_PushEvent()
   285 
   286 	Example of using the new SDL user-defined events:
   287 	{
   288 		SDL_Event event;
   289 
   290 		event.type = SDL_USEREVENT;
   291 		event.user.code = my_event_code;
   292 		event.user.data1 = significant_data;
   293 		event.user.data2 = 0;
   294 		SDL_PushEvent(&event);
   295 	}
   296 
   297 	Added a function to get mouse deltas since last query:
   298 		SDL_GetRelativeMouseState()
   299 
   300 	Added a boolean datatype to SDL_types.h:
   301 		SDL_bool = { SDL_TRUE, SDL_FALSE }
   302 
   303 	Added a function to get the current audio status:
   304 		SDL_GetAudioState();
   305 	It returns one of:
   306 		SDL_AUDIO_STOPPED,
   307 		SDL_AUDIO_PLAYING,
   308 		SDL_AUDIO_PAUSED
   309 
   310 	Added an AAlib driver (ASCII Art) - by Stephane Peter.
   311 
   312 1.0.6:
   313 	The input grab state is reset after each call to SDL_SetVideoMode().
   314 	The input is grabbed by default in fullscreen mode, and ungrabbed in
   315 	windowed mode.  If you want to set input grab to a particular value,
   316 	you should set it after each call to SDL_SetVideoMode().
   317 
   318 1.0.5:
   319 	Exposed SDL_AudioInit(), SDL_VideoInit()
   320 	Added SDL_AudioDriverName() and SDL_VideoDriverName()
   321 
   322 	Added new window manager function:
   323 		SDL_WM_ToggleFullScreen()
   324 	This is currently implemented only on Linux
   325 
   326 	The ALT-ENTER code has been removed - it's not appropriate for a
   327 	lib to bind keys when they aren't even emergency escape sequences.
   328 
   329 	ALT-ENTER functionality can be implemented with the following code:
   330 
   331 	int Handle_AltEnter(const SDL_Event *event)
   332 	{
   333 	    if ( event->type == SDL_KEYDOWN ) {
   334 	        if ( (event->key.keysym.sym == SDLK_RETURN) &&
   335 	             (event->key.keysym.mod & KMOD_ALT) ) {   
   336 	                SDL_WM_ToggleFullScreen(SDL_GetVideoSurface());
   337 	                return(0);
   338 	        }
   339 	    }
   340 	    return(1);
   341 	}
   342 	SDL_SetEventFilter(Handle_AltEnter);
   343 
   344 1.0.3:
   345 	Under X11, if you grab the input and hide the mouse cursor,
   346 	the mouse will go into a "relative motion" mode where you
   347 	will always get relative motion events no matter how far in
   348 	each direction you move the mouse - relative motion is not
   349 	bounded by the edges of the window (though the absolute values
   350 	of the mouse positions are clamped by the size of the window).
   351 	The SVGAlib, framebuffer console, and DirectInput drivers all
   352 	have this behavior naturally, and the GDI and BWindow drivers
   353 	never go into "relative motion" mode.
   354 
   355 1.0.2:
   356 	Added a function to enable keyboard repeat:
   357 		SDL_EnableKeyRepeat()
   358 
   359 	Added a function to grab the mouse and keyboard input
   360 		SDL_WM_GrabInput()
   361 
   362 	Added a function to iconify the window.
   363 		SDL_WM_IconifyWindow()
   364 	If this function succeeds, the application will receive an event
   365 	signaling SDL_APPACTIVE event 
   366 
   367 1.0.1:
   368 	Added constants to SDL_audio.h for 16-bit native byte ordering:
   369 		AUDIO_U16SYS, AUDIO_S16SYS
   370 
   371 1.0.0:
   372 	New public release
   373 
   374 Version 0.11:
   375 
   376 0.11.5:
   377 	A new function SDL_GetVideoSurface() has been added, and returns
   378 	a pointer to the current display surface.
   379 
   380 	SDL_AllocSurface() has been renamed SDL_CreateRGBSurface(), and
   381 	a new function SDL_CreateRGBSurfaceFrom() has been added to allow
   382 	creating an SDL surface from an existing pixel data buffer.
   383 
   384 	Added SDL_GetRGB() to the headers and documentation.
   385 
   386 0.11.4:
   387 	SDL_SetLibraryPath() is no longer meaningful, and has been removed.
   388 
   389 0.11.3:
   390 	A new flag for SDL_Init(), SDL_INIT_NOPARACHUTE, prevents SDL from
   391 	installing fatal signal handlers on operating systems that support
   392 	them.
   393 
   394 Version 0.9:
   395 
   396 0.9.15:
   397 	SDL_CreateColorCursor() has been removed.  Color cursors should
   398 	be implemented as sprites, blitted by the application when the
   399 	cursor moves.  To get smooth color cursor updates when the app
   400 	is busy, pass the SDL_INIT_EVENTTHREAD flag to SDL_Init().  This
   401 	allows you to handle the mouse motion in another thread from an
   402 	event filter function, but is currently only supported by Linux
   403 	and BeOS.  Note that you'll have to protect the display surface
   404 	from multi-threaded access by using mutexes if you do this.
   405 
   406 	Thread-safe surface support has been removed from SDL.
   407 	This makes blitting somewhat faster, by removing SDL_MiddleBlit().
   408 	Code that used SDL_MiddleBlit() should use SDL_LowerBlit() instead.
   409 	You can make your surfaces thread-safe by allocating your own
   410 	mutex and making lock/unlock calls around accesses to your surface.
   411 
   412 0.9.14:
   413 	SDL_GetMouseState() now takes pointers to int rather than Uint16.
   414 
   415 	If you set the SDL_WINDOWID environment variable under UNIX X11,
   416 	SDL will use that as the main window instead of creating it's own.
   417 	This is an unsupported extension to SDL, and not portable at all.
   418 
   419 0.9.13:
   420 	Added a function SDL_SetLibraryPath() which can be used to specify
   421 	the directory containing the SDL dynamic libraries.  This is useful
   422 	for commercial applications which ship with particular versions
   423 	of the libraries, and for security on multi-user systems.
   424 	If this function is not used, the default system directories are 
   425 	searched using the native dynamic object loading mechanism.
   426 
   427 	In order to support C linkage under Visual C++, you must declare
   428 	main() without any return type:
   429 		main(int argc, char *argv[]) {
   430 			/* Do the program... */
   431 			return(0);
   432 		}
   433 	C++ programs should also return a value if compiled under VC++.
   434 
   435 	The blit_endian member of the SDL_VideoInfo struct has been removed.
   436 
   437 	SDL_SymToASCII() has been replaced with SDL_GetKeyName(), so there
   438 	is now no longer any function to translate a keysym to a character.
   439 
   440 	The SDL_keysym structure has been extended with a 'scancode' and
   441 	'unicode' member.  The 'scancode' is a hardware specific scancode
   442 	for the key that was pressed, and may be 0.  The 'unicode' member
   443 	is a 16-bit UNICODE translation of the key that was pressed along
   444 	with any modifiers or compose keys that have been pressed.
   445 	If no UNICODE translation exists for the key, 'unicode' will be 0.
   446 
   447 	Added a function SDL_EnableUNICODE() to enable/disable UNICODE
   448 	translation of character keypresses.  Translation defaults off.
   449 
   450 	To convert existing code to use the new API, change code which
   451 	uses SDL_SymToASCII() to get the keyname to use SDL_GetKeyName(),
   452 	and change code which uses it to get the ASCII value of a sym to
   453 	use the 'unicode' member of the event keysym.
   454 
   455 0.9.12:
   456 	There is partial support for 64-bit datatypes.  I don't recommend 
   457 	you use this if you have a choice, because 64-bit datatypes are not
   458 	supported on many platforms.  On platforms for which it is supported,
   459 	the SDL_HAS_64BIT_TYPE C preprocessor define will be enabled, and
   460 	you can use the Uint64 and Sint64 datatypes.
   461 
   462 	Added functions to SDL_endian.h to support 64-bit datatypes:
   463 	    SDL_SwapLE64(), SDL_SwapBE64(),
   464 	    SDL_ReadLE64(), SDL_ReadBE64(), SDL_WriteLE64(), SDL_WriteBE64()
   465 
   466 	A new member "len_ratio" has been added to the SDL_AudioCVT structure,
   467 	and allows you to determine either the original buffer length or the
   468 	converted buffer length, given the other.
   469 
   470 	A new function SDL_FreeWAV() has been added to the API to free data
   471 	allocated by SDL_LoadWAV_RW().  This is necessary under Win32 since
   472 	the gcc compiled DLL uses a different heap than VC++ compiled apps.
   473 
   474 	SDL now has initial support for international keyboards using the
   475 	Latin character set.
   476 	If a particular mapping is desired, you can set the DEFAULT_KEYBOARD
   477 	compile-time variable, or you can set the environment variable 
   478 	"SDL_KEYBOARD" to a string identifying the keyboard mapping you desire.
   479 	The valid values for these variables can be found in SDL_keyboard.c
   480 
   481 	Full support for German and French keyboards under X11 is implemented.
   482 
   483 0.9.11:
   484 	The THREADED_EVENTS compile-time define has been replaced with the
   485 	SDL_INIT_EVENTTHREAD flag.  If this flag is passed to SDL_Init(),
   486 	SDL will create a separate thread to perform input event handling.
   487 	If this flag is passed to SDL_Init(), and the OS doesn't support 
   488 	event handling in a separate thread, SDL_Init() will fail.
   489 	Be sure to add calls to SDL_Delay() in your main thread to allow
   490 	the OS to schedule your event thread, or it may starve, leading
   491 	to slow event delivery and/or dropped events.
   492 	Currently MacOS and Win32 do not support this flag, while BeOS 
   493 	and Linux do support it.  I recommend that your application only
   494 	use this flag if absolutely necessary.
   495 
   496 	The SDL thread function passed to SDL_CreateThread() now returns a
   497 	status.  This status can be retrieved by passing a non-NULL pointer
   498 	as the 'status' argument to SDL_WaitThread().
   499 
   500 	The volume parameter to SDL_MixAudio() has been increased in range
   501 	from (0-8) to (0-128)
   502 
   503 	SDL now has a data source abstraction which can encompass a file,
   504 	an area of memory, or any custom object you can envision.  It uses
   505 	these abstractions, SDL_RWops, in the endian read/write functions,
   506 	and the built-in WAV and BMP file loaders.  This means you can load
   507 	WAV chunks from memory mapped files, compressed archives, network
   508 	pipes, or anything else that has a data read abstraction.
   509 
   510 	There are three built-in data source abstractions:
   511 	    SDL_RWFromFile(), SDL_RWFromFP(), SDL_RWFromMem()
   512 	along with a generic data source allocation function:
   513 	    SDL_AllocRW()
   514 	These data sources can be used like stdio file pointers with the
   515 	following convenience functions:
   516 	    SDL_RWseek(), SDL_RWread(), SDL_RWwrite(), SDL_RWclose()
   517 	These functions are defined in the new header file "SDL_rwops.h"
   518 
   519 	The endian swapping functions have been turned into macros for speed
   520 	and SDL_CalculateEndian() has been removed.  SDL_endian.h now defines
   521 	SDL_BYTEORDER as either SDL_BIG_ENDIAN or SDL_LIL_ENDIAN depending on
   522 	the endianness of the host system.
   523 
   524 	The endian read/write functions now take an SDL_RWops pointer
   525 	instead of a stdio FILE pointer, to support the new data source
   526 	abstraction.
   527 
   528 	The SDL_*LoadWAV() functions have been replaced with a single
   529 	SDL_LoadWAV_RW() function that takes a SDL_RWops pointer as it's
   530 	first parameter, and a flag whether or not to automatically 
   531 	free it as the second parameter.  SDL_LoadWAV() is a macro for
   532 	backward compatibility and convenience:
   533 	    SDL_LoadWAV_RW(SDL_RWFromFile("sample.wav", "rb"), 1, ...);
   534 
   535 	The SDL_*LoadBMP()/SDL_*SaveBMP() functions have each been replaced
   536 	with a single function that takes a SDL_RWops pointer as it's
   537 	first parameter, and a flag whether or not to automatically 
   538 	free it as the second parameter.  SDL_LoadBMP() and SDL_SaveBMP()
   539 	are macros for backward compatibility and convenience:
   540 	    SDL_LoadBMP_RW(SDL_RWFromFile("sample.bmp", "rb"), 1, ...);
   541 	    SDL_SaveBMP_RW(SDL_RWFromFile("sample.bmp", "wb"), 1, ...);
   542 	Note that these functions use SDL_RWseek() extensively, and should
   543 	not be used on pipes or other non-seekable data sources.
   544 
   545 0.9.10:
   546 	The Linux SDL_SysWMInfo and SDL_SysWMMsg structures have been 
   547 	extended to support multiple types of display drivers, as well as
   548         safe access to the X11 display when THREADED_EVENTS is enabled.
   549         The new structures are documented in the SDL_syswm.h header file.
   550 
   551 	Thanks to John Elliott <jce@seasip.demon.co.uk>, the UK keyboard
   552 	should now work properly, as well as the "Windows" keys on US
   553 	keyboards.
   554 
   555 	The Linux CD-ROM code now reads the CD-ROM devices from /etc/fstab
   556 	instead of trying to open each block device on the system.
   557 	The CD must be listed in /etc/fstab as using the iso9660 filesystem.
   558 
   559 	On Linux, if you define THREADED_EVENTS at compile time, a separate
   560 	thread will be spawned to gather X events asynchronously from the
   561 	graphics updates.  This hasn't been extensively tested, but it does
   562 	provide a means of handling keyboard and mouse input in a separate
   563 	thread from the graphics thread.  (This is now enabled by default.)
   564 
   565 	A special access function SDL_PeepEvents() allows you to manipulate
   566 	the event queue in a thread-safe manner, including peeking at events,
   567 	removing events of a specified type, and adding new events of arbitrary
   568 	type to the queue (use the new 'user' member of the SDL_Event type).
   569 
   570 	If you use SDL_PeepEvents() to gather events, then the main graphics
   571 	thread needs to call SDL_PumpEvents() periodically to drive the event
   572 	loop and generate input events.  This is not necessary if SDL has been 
   573 	compiled with THREADED_EVENTS defined, but doesn't hurt.
   574 
   575 	A new function SDL_ThreadID() returns the identifier associated with
   576 	the current thread.
   577 
   578 0.9.9:
   579 	The AUDIO_STEREO format flag has been replaced with a new 'channels'
   580 	member of the SDL_AudioSpec structure.  The channels are 1 for mono
   581 	audio, and 2 for stereo audio.  In the future more channels may be
   582 	supported for 3D surround sound.
   583 
   584 	The SDL_MixAudio() function now takes an additional volume parameter,
   585 	which should be set to SDL_MIX_MAXVOLUME for compatibility with the
   586 	original function.
   587 
   588 	The CD-ROM functions which take a 'cdrom' parameter can now be
   589 	passed NULL, and will act on the last successfully opened CD-ROM.
   590 
   591 0.9.8:
   592 	No changes, bugfixes only.
   593 	
   594 0.9.7:
   595 	No changes, bugfixes only.
   596 	
   597 0.9.6:
   598 	Added a fast rectangle fill function: SDL_FillRect()
   599 
   600 	Addition of a useful function for getting info on the video hardware:
   601 	    const SDL_VideoInfo *SDL_GetVideoInfo(void)
   602         This function replaces SDL_GetDisplayFormat().
   603 
   604 	Initial support for double-buffering:
   605 	  Use the SDL_DOUBLEBUF flag in SDL_SetVideoMode()
   606 	  Update the screen with a new function: SDL_Flip()
   607 
   608 	SDL_AllocSurface() takes two new flags:
   609 	SDL_SRCCOLORKEY means that the surface will be used for colorkey blits
   610 	  and if the hardware supports hardware acceleration of colorkey blits
   611 	  between two surfaces in video memory, to place the surface in video
   612 	  memory if possible, otherwise it will be placed in system memory.
   613 	SDL_SRCALPHA means that the surface will be used for alpha blits and
   614 	  if the hardware supports hardware acceleration of alpha blits between
   615 	  two surfaces in video memory, to place the surface in video memory
   616 	  if possible, otherwise it will be placed in system memory.
   617 	SDL_HWSURFACE now means that the surface will be created with the 
   618 	  same format as the display surface, since having surfaces in video
   619 	  memory is only useful for fast blitting to the screen, and you can't
   620 	  blit surfaces with different surface formats in video memory.
   621 
   622 0.9.5:
   623 	You can now pass a NULL mask to SDL_WM_SetIcon(), and it will assume
   624 	that the icon consists of the entire image.
   625 
   626 	SDL_LowerBlit() is back -- but don't use it on the display surface.
   627 	It is exactly the same as SDL_MiddleBlit(), but doesn't check for
   628 	thread safety.
   629 
   630 	Added SDL_FPLoadBMP(), SDL_FPSaveBMP(), SDL_FPLoadWAV(), which take
   631 	a FILE pointer instead of a file name.
   632 
   633 	Added CD-ROM audio control API:
   634 	    SDL_CDNumDrives()
   635 	    SDL_CDName()
   636 	    SDL_CDOpen()
   637 	    SDL_CDStatus()
   638 	    SDL_CDPlayTracks()
   639 	    SDL_CDPlay()
   640 	    SDL_CDPause()
   641 	    SDL_CDResume()
   642 	    SDL_CDStop()
   643 	    SDL_CDEject()
   644 	    SDL_CDClose()
   645 
   646 0.9.4:
   647 	No changes, bugfixes only.
   648 
   649 0.9.3:
   650 	Mouse motion event now includes relative motion information:
   651 	    Sint16 event->motion.xrel, Sint16 event->motion.yrel
   652 
   653 	X11 keyrepeat handling can be disabled by defining IGNORE_X_KEYREPEAT
   654 	    (Add -DIGNORE_X_KEYREPEAT to CFLAGS line in obj/x11Makefile)
   655 
   656 0.9.2:
   657 	No changes, bugfixes only.
   658 
   659 0.9.1:
   660 	Removed SDL_MapSurface() and SDL_UnmapSurface() -- surfaces are now
   661 	automatically mapped on blit.
   662 
   663 0.8.0:
   664 	SDL stable release