WhatsNew
author Sam Lantinga
Tue, 05 Mar 2002 19:55:32 +0000
changeset 292 eadc0746dfaf
parent 0 74212992fb08
child 294 d2d48e10f370
permissions -rw-r--r--
Added SDL_LockRect() and SDL_UnlockRect()
Incorporated XFree86 extension libraries into the source
     1 
     2 This is a list of API changes in SDL's version history.
     3 
     4 Version 1.0:
     5 
     6 1.2.4:
     7 	Added SDL_LockRect() and SDL_UnlockRect() to lock a portion of a
     8 	surface.  This may be more efficient than a full lock if you are
     9 	using a hardware surface and plan to make a few changes to small
    10 	areas in the surface.
    11 
    12 1.2.0:
    13 	Added SDL_VIDEOEXPOSE event to signal that the screen needs to
    14 	be redrawn.  This is currently only delivered to OpenGL windows
    15 	on X11, though it may be delivered in the future when the video
    16 	memory is lost under DirectX.
    17 
    18 1.1.8:
    19 	You can pass SDL_NOFRAME to SDL_VideoMode() to create a window
    20 	that has no title bar or frame decoration.  Fullscreen video
    21 	modes automatically have this flag set.
    22 
    23 	Added a function to query the clipping rectangle for a surface:
    24 		void SDL_GetClipRect(SDL_Surface *surface, SDL_Rect *rect)
    25 
    26 	Added a function to query the current event filter:
    27 		SDL_EventFilter SDL_GetEventFilter(void)
    28 
    29 	If you pass -1 to SDL_ShowCursor(), it won't change the current
    30 	cursor visibility state, but will still return it.
    31 
    32 	SDL_LockSurface() and SDL_UnlockSurface() are recursive, meaning
    33 	you can nest them as deep as you want, as long as each lock call
    34 	has a matching unlock call.  The surface remains locked until the
    35 	last matching unlock call.
    36 
    37 	Note that you may not blit to or from a locked surface.
    38 
    39 1.1.7:
    40 	The SDL_SetGammaRamp() and SDL_GetGammaRamp() functions now take
    41 	arrays of Uint16 values instead of Uint8 values.  For the most part,
    42 	you can just take your old values and shift them up 8 bits to get
    43 	new correct values for your gamma ramps.
    44 
    45 	You can pass SDL_RLEACCEL in flags passed to SDL_ConvertSurface()
    46         and SDL will try to RLE accelerate colorkey and alpha blits in the
    47 	resulting surface.
    48 
    49 1.1.6:
    50 	Added a function to return the thread ID of a specific thread:
    51 		Uint32 SDL_GetThreadID(SDL_Thread *thread)
    52 	If 'thread' is NULL, this function returns the id for this thread.
    53 
    54 1.1.5:
    55 	The YUV overlay structure has been changed to use an array of
    56 	pitches and pixels representing the planes of a YUV image, to
    57 	better enable hardware acceleration.  The YV12 and IYUV formats
    58 	each have three planes, corresponding to the Y, U, and V portions
    59 	of the image, while packed pixel YUV formats just have one plane.
    60 
    61 	For palettized mode (8bpp), the screen colormap is now split in
    62 	a physical and a logical palette. The physical palette determines
    63 	what colours the screen pixels will get when displayed, and the
    64 	logical palette controls the mapping from blits to/from the screen.
    65 	A new function, SDL_SetPalette() has been added to change
    66 	logical and physical palettes separately. SDL_SetColors() works
    67 	just as before, and is equivalent to calling SDL_SetPalette() with
    68 	a flag argument of (SDL_LOGPAL|SDL_PHYSPAL).
    69 
    70 	SDL_BlitSurface() no longer modifies the source rectangle, only the
    71 	destination rectangle. The width/height members of the destination
    72 	rectangle are ignored, only the position is used.
    73 
    74 	The old source clipping function SDL_SetClipping() has been replaced
    75 	with a more useful function to set the destination clipping rectangle:
    76 		SDL_bool SDL_SetClipRect(SDL_Surface *surface, SDL_Rect *rect)
    77 		
    78 	Added a function to see what subsystems have been initialized:
    79 		Uint32 SDL_WasInit(Uint32 flags)
    80 
    81 	The Big Alpha Flip: SDL now treats alpha as opacity like everybody
    82 	else, and not as transparency:
    83 
    84 	A new cpp symbol: SDL_ALPHA_OPAQUE is defined as 255
    85 	A new cpp symbol: SDL_ALPHA_TRANSPARENT is defined as 0
    86 	Values between 0 and 255 vary from fully transparent to fully opaque.
    87 
    88 	New functions:
    89 	SDL_DisplayFormatAlpha()
    90 	    Returns a surface converted to a format with alpha-channel
    91 	    that can be blit efficiently to the screen. (In other words,
    92 	    like SDL_DisplayFormat() but the resulting surface has
    93 	    an alpha channel.)  This is useful for surfaces with alpha.
    94 	SDL_MapRGBA()
    95 	    Works as SDL_MapRGB() but takes an additional alpha parameter.
    96 	SDL_GetRGBA()
    97 	    Works as SDL_GetRGB() but also returns the alpha value
    98 	    (SDL_ALPHA_OPAQUE for formats without an alpha channel)
    99 
   100 	Both SDL_GetRGB() and SDL_GetRGBA() now always return values in
   101 	the [0..255] interval. Previously, SDL_GetRGB() would return
   102 	(0xf8, 0xfc, 0xf8) for a completely white pixel in RGB565 format.
   103 	(N.B.: This is broken for bit fields < 3 bits.)
   104 
   105 	SDL_MapRGB() returns pixels in which the alpha channel is set opaque.
   106 
   107 	SDL_SetAlpha() can now be used for both setting the per-surface
   108 	alpha, using the new way of thinking of alpha, and also to enable
   109 	and disable per-pixel alpha blending for surfaces with an alpha
   110 	channel:
   111 		To disable alpha blending:
   112 			SDL_SetAlpha(surface, 0, 0);
   113 		To re-enable alpha blending:
   114 			SDL_SetAlpha(surface, SDL_SRCALPHA, 0);
   115 	Surfaces with an alpha channel have blending enabled by default.
   116 
   117 	SDL_SetAlpha() now accepts SDL_RLEACCEL as a flag, which requests
   118 	RLE acceleration of blits, just as like with SDL_SetColorKey().
   119 	This flag can be set for both surfaces with an alpha channel
   120 	and surfaces with an alpha value set by SDL_SetAlpha().
   121 	As always, RLE surfaces must be locked before pixel access is
   122 	allowed, and unlocked before any other SDL operations are done
   123 	on it.
   124 
   125 	The blit semantics for surfaces with and without alpha and colorkey
   126 	have now been defined:
   127 
   128 	RGBA->RGB:
   129 	    SDL_SRCALPHA set:
   130 		alpha-blend (using alpha-channel).
   131 		SDL_SRCCOLORKEY ignored.
   132 	    SDL_SRCALPHA not set:
   133 		copy RGB.
   134 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   135 		RGB values of the source colour key, ignoring alpha in the
   136 		comparison.
   137 
   138 	RGB->RGBA:
   139 	    SDL_SRCALPHA set:
   140 		alpha-blend (using the source per-surface alpha value);
   141 		set destination alpha to opaque.
   142 	    SDL_SRCALPHA not set:
   143 		copy RGB, set destination alpha to opaque.
   144 	    both:
   145 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   146 		source colour key.
   147 
   148 	RGBA->RGBA:
   149 	    SDL_SRCALPHA set:
   150 		alpha-blend (using the source alpha channel) the RGB values;
   151 		leave destination alpha untouched. [Note: is this correct?]
   152 		SDL_SRCCOLORKEY ignored.
   153 	    SDL_SRCALPHA not set:
   154 		copy all of RGBA to the destination.
   155 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   156 		RGB values of the source colour key, ignoring alpha in the
   157 		comparison.
   158 
   159 	RGB->RGB: 
   160 	    SDL_SRCALPHA set:
   161 		alpha-blend (using the source per-surface alpha value).
   162 	    SDL_SRCALPHA not set:
   163 		copy RGB.
   164 	    both:
   165 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   166 		source colour key.
   167 
   168 	As a special case, blits from surfaces with per-surface alpha
   169 	value of 128 (50% transparency) are optimised and much faster
   170 	than other alpha values. This does not apply to surfaces with
   171 	alpha channels (per-pixel alpha).
   172 
   173 	New functions for manipulating the gamma of the display have
   174 	been added:
   175 		int SDL_SetGamma(float red, float green, float blue);
   176 		int SDL_SetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   177 		int SDL_GetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   178 	Gamma ramps are tables with 256 entries which map the screen color
   179 	components into actually displayed colors.  For an example of
   180 	implementing gamma correction and gamma fades, see test/testgamma.c
   181 	Gamma control is not supported on all hardware.
   182 
   183 1.1.4:
   184 	The size of the SDL_CDtrack structure changed from 8 to 12 bytes
   185 	as the size of the length member was extended to 32 bits.
   186 
   187         You can now use SDL for 2D blitting with a GL mode by passing the
   188 	SDL_OPENGLBLIT flag to SDL_SetVideoMode().  You can specify 16 or
   189 	32 bpp, and the data in the framebuffer is put into the GL scene
   190 	when you call SDL_UpdateRects(), and the scene will be visible
   191 	when you call SDL_GL_SwapBuffers().
   192 
   193 	Run the "testgl" test program with the -logo command line option
   194 	to see an example of this blending of 2D and 3D in SDL.
   195 
   196 1.1.3:
   197 	Added SDL_FreeRW() to the API, to complement SDL_AllocRW()
   198 
   199 	Added resizable window support - just add SDL_RESIZABLE to the
   200 	SDL_SetVideoMode() flags, and then wait for SDL_VIDEORESIZE events.
   201 	See SDL_events.h for details on the new SDL_ResizeEvent structure.
   202 
   203 	Added condition variable support, based on mutexes and semaphores.
   204 		SDL_CreateCond()
   205 		SDL_DestroyCond()
   206 		SDL_CondSignal()
   207 		SDL_CondBroadcast()
   208 		SDL_CondWait()
   209 		SDL_CondTimedWait()
   210 	The new function prototypes are in SDL_mutex.h
   211 
   212 	Added counting semaphore support, based on the mutex primitive.
   213 		SDL_CreateSemaphore()
   214 		SDL_DestroySemaphore()
   215 		SDL_SemWait()
   216 		SDL_SemTryWait()
   217 		SDL_SemWaitTimeout()
   218 		SDL_SemPost()
   219 		SDL_SemValue()
   220 	The new function prototypes are in SDL_mutex.h
   221 
   222 	Added support for asynchronous blitting.  To take advantage of this,
   223 	you must set the SDL_ASYNCBLIT flag when setting the video mode and
   224 	creating surfaces that you want accelerated in this way.  You must
   225 	lock surfaces that have this flag set, and the lock will block until
   226 	any queued blits have completed.
   227 
   228 	Added YUV video overlay support.
   229 	The supported YUV formats are: YV12, IYUV, YUY2, UYVY, and YVYU.
   230 	This function creates an overlay surface:
   231 		SDL_CreateYUVOverlay()
   232 	You must lock and unlock the overlay to get access to the data:
   233 		SDL_LockYUVOverlay() SDL_UnlockYUVOverlay()
   234 	You can then display the overlay:
   235 		SDL_DisplayYUVOverlay()
   236 	You must free the overlay when you are done using it:
   237 		SDL_FreeYUVOverlay()
   238 	See SDL_video.h for the full function prototypes.
   239 
   240 	The joystick hat position constants have been changed:
   241 	Old constant            New constant
   242 	------------            ------------
   243 	     0                  SDL_HAT_CENTERED
   244 	     1                  SDL_HAT_UP
   245 	     2                  SDL_HAT_RIGHTUP
   246 	     3                  SDL_HAT_RIGHT
   247 	     4                  SDL_HAT_RIGHTDOWN
   248 	     5                  SDL_HAT_DOWN
   249 	     6                  SDL_HAT_LEFTDOWN
   250 	     7                  SDL_HAT_LEFT
   251 	     8                  SDL_HAT_LEFTUP
   252 	The new constants are bitmasks, so you can check for the
   253 	individual axes like this:
   254 		if ( hat_position & SDL_HAT_UP ) {
   255 		}
   256 	and you'll catch left-up, up, and right-up.
   257 
   258 1.1.2:
   259 	Added multiple timer support:
   260 		SDL_AddTimer() and SDL_RemoveTimer()
   261 
   262 	SDL_WM_SetIcon() now respects the icon colorkey if mask is NULL.
   263 
   264 1.1.0:
   265 	Added initial OpenGL support.
   266 	First set GL attributes (such as RGB depth, alpha depth, etc.)
   267 		SDL_GL_SetAttribute()
   268 	Then call SDL_SetVideoMode() with the SDL_OPENGL flag.
   269 	Perform all of your normal GL drawing.
   270 	Finally swap the buffers with the new SDL function:
   271 		SDL_GL_SwapBuffers()
   272 	See the new 'testgl' test program for an example of using GL with SDL.
   273 
   274 	You can load GL extension functions by using the function:
   275 		SDL_GL_LoadProcAddress()
   276 
   277 	Added functions to initialize and cleanup specific SDL subsystems:
   278 		SDL_InitSubSystem() and SDL_QuitSubSystem()
   279 
   280 	Added user-defined event type:
   281 		typedef struct {
   282         		Uint8 type;
   283         		int code;
   284         		void *data1;
   285         		void *data2;
   286 		} SDL_UserEvent;
   287 	This structure is in the "user" member of an SDL_Event.
   288 
   289 	Added a function to push events into the event queue:
   290 		SDL_PushEvent()
   291 
   292 	Example of using the new SDL user-defined events:
   293 	{
   294 		SDL_Event event;
   295 
   296 		event.type = SDL_USEREVENT;
   297 		event.user.code = my_event_code;
   298 		event.user.data1 = significant_data;
   299 		event.user.data2 = 0;
   300 		SDL_PushEvent(&event);
   301 	}
   302 
   303 	Added a function to get mouse deltas since last query:
   304 		SDL_GetRelativeMouseState()
   305 
   306 	Added a boolean datatype to SDL_types.h:
   307 		SDL_bool = { SDL_TRUE, SDL_FALSE }
   308 
   309 	Added a function to get the current audio status:
   310 		SDL_GetAudioState();
   311 	It returns one of:
   312 		SDL_AUDIO_STOPPED,
   313 		SDL_AUDIO_PLAYING,
   314 		SDL_AUDIO_PAUSED
   315 
   316 	Added an AAlib driver (ASCII Art) - by Stephane Peter.
   317 
   318 1.0.6:
   319 	The input grab state is reset after each call to SDL_SetVideoMode().
   320 	The input is grabbed by default in fullscreen mode, and ungrabbed in
   321 	windowed mode.  If you want to set input grab to a particular value,
   322 	you should set it after each call to SDL_SetVideoMode().
   323 
   324 1.0.5:
   325 	Exposed SDL_AudioInit(), SDL_VideoInit()
   326 	Added SDL_AudioDriverName() and SDL_VideoDriverName()
   327 
   328 	Added new window manager function:
   329 		SDL_WM_ToggleFullScreen()
   330 	This is currently implemented only on Linux
   331 
   332 	The ALT-ENTER code has been removed - it's not appropriate for a
   333 	lib to bind keys when they aren't even emergency escape sequences.
   334 
   335 	ALT-ENTER functionality can be implemented with the following code:
   336 
   337 	int Handle_AltEnter(const SDL_Event *event)
   338 	{
   339 	    if ( event->type == SDL_KEYDOWN ) {
   340 	        if ( (event->key.keysym.sym == SDLK_RETURN) &&
   341 	             (event->key.keysym.mod & KMOD_ALT) ) {   
   342 	                SDL_WM_ToggleFullScreen(SDL_GetVideoSurface());
   343 	                return(0);
   344 	        }
   345 	    }
   346 	    return(1);
   347 	}
   348 	SDL_SetEventFilter(Handle_AltEnter);
   349 
   350 1.0.3:
   351 	Under X11, if you grab the input and hide the mouse cursor,
   352 	the mouse will go into a "relative motion" mode where you
   353 	will always get relative motion events no matter how far in
   354 	each direction you move the mouse - relative motion is not
   355 	bounded by the edges of the window (though the absolute values
   356 	of the mouse positions are clamped by the size of the window).
   357 	The SVGAlib, framebuffer console, and DirectInput drivers all
   358 	have this behavior naturally, and the GDI and BWindow drivers
   359 	never go into "relative motion" mode.
   360 
   361 1.0.2:
   362 	Added a function to enable keyboard repeat:
   363 		SDL_EnableKeyRepeat()
   364 
   365 	Added a function to grab the mouse and keyboard input
   366 		SDL_WM_GrabInput()
   367 
   368 	Added a function to iconify the window.
   369 		SDL_WM_IconifyWindow()
   370 	If this function succeeds, the application will receive an event
   371 	signaling SDL_APPACTIVE event 
   372 
   373 1.0.1:
   374 	Added constants to SDL_audio.h for 16-bit native byte ordering:
   375 		AUDIO_U16SYS, AUDIO_S16SYS
   376 
   377 1.0.0:
   378 	New public release
   379 
   380 Version 0.11:
   381 
   382 0.11.5:
   383 	A new function SDL_GetVideoSurface() has been added, and returns
   384 	a pointer to the current display surface.
   385 
   386 	SDL_AllocSurface() has been renamed SDL_CreateRGBSurface(), and
   387 	a new function SDL_CreateRGBSurfaceFrom() has been added to allow
   388 	creating an SDL surface from an existing pixel data buffer.
   389 
   390 	Added SDL_GetRGB() to the headers and documentation.
   391 
   392 0.11.4:
   393 	SDL_SetLibraryPath() is no longer meaningful, and has been removed.
   394 
   395 0.11.3:
   396 	A new flag for SDL_Init(), SDL_INIT_NOPARACHUTE, prevents SDL from
   397 	installing fatal signal handlers on operating systems that support
   398 	them.
   399 
   400 Version 0.9:
   401 
   402 0.9.15:
   403 	SDL_CreateColorCursor() has been removed.  Color cursors should
   404 	be implemented as sprites, blitted by the application when the
   405 	cursor moves.  To get smooth color cursor updates when the app
   406 	is busy, pass the SDL_INIT_EVENTTHREAD flag to SDL_Init().  This
   407 	allows you to handle the mouse motion in another thread from an
   408 	event filter function, but is currently only supported by Linux
   409 	and BeOS.  Note that you'll have to protect the display surface
   410 	from multi-threaded access by using mutexes if you do this.
   411 
   412 	Thread-safe surface support has been removed from SDL.
   413 	This makes blitting somewhat faster, by removing SDL_MiddleBlit().
   414 	Code that used SDL_MiddleBlit() should use SDL_LowerBlit() instead.
   415 	You can make your surfaces thread-safe by allocating your own
   416 	mutex and making lock/unlock calls around accesses to your surface.
   417 
   418 0.9.14:
   419 	SDL_GetMouseState() now takes pointers to int rather than Uint16.
   420 
   421 	If you set the SDL_WINDOWID environment variable under UNIX X11,
   422 	SDL will use that as the main window instead of creating it's own.
   423 	This is an unsupported extension to SDL, and not portable at all.
   424 
   425 0.9.13:
   426 	Added a function SDL_SetLibraryPath() which can be used to specify
   427 	the directory containing the SDL dynamic libraries.  This is useful
   428 	for commercial applications which ship with particular versions
   429 	of the libraries, and for security on multi-user systems.
   430 	If this function is not used, the default system directories are 
   431 	searched using the native dynamic object loading mechanism.
   432 
   433 	In order to support C linkage under Visual C++, you must declare
   434 	main() without any return type:
   435 		main(int argc, char *argv[]) {
   436 			/* Do the program... */
   437 			return(0);
   438 		}
   439 	C++ programs should also return a value if compiled under VC++.
   440 
   441 	The blit_endian member of the SDL_VideoInfo struct has been removed.
   442 
   443 	SDL_SymToASCII() has been replaced with SDL_GetKeyName(), so there
   444 	is now no longer any function to translate a keysym to a character.
   445 
   446 	The SDL_keysym structure has been extended with a 'scancode' and
   447 	'unicode' member.  The 'scancode' is a hardware specific scancode
   448 	for the key that was pressed, and may be 0.  The 'unicode' member
   449 	is a 16-bit UNICODE translation of the key that was pressed along
   450 	with any modifiers or compose keys that have been pressed.
   451 	If no UNICODE translation exists for the key, 'unicode' will be 0.
   452 
   453 	Added a function SDL_EnableUNICODE() to enable/disable UNICODE
   454 	translation of character keypresses.  Translation defaults off.
   455 
   456 	To convert existing code to use the new API, change code which
   457 	uses SDL_SymToASCII() to get the keyname to use SDL_GetKeyName(),
   458 	and change code which uses it to get the ASCII value of a sym to
   459 	use the 'unicode' member of the event keysym.
   460 
   461 0.9.12:
   462 	There is partial support for 64-bit datatypes.  I don't recommend 
   463 	you use this if you have a choice, because 64-bit datatypes are not
   464 	supported on many platforms.  On platforms for which it is supported,
   465 	the SDL_HAS_64BIT_TYPE C preprocessor define will be enabled, and
   466 	you can use the Uint64 and Sint64 datatypes.
   467 
   468 	Added functions to SDL_endian.h to support 64-bit datatypes:
   469 	    SDL_SwapLE64(), SDL_SwapBE64(),
   470 	    SDL_ReadLE64(), SDL_ReadBE64(), SDL_WriteLE64(), SDL_WriteBE64()
   471 
   472 	A new member "len_ratio" has been added to the SDL_AudioCVT structure,
   473 	and allows you to determine either the original buffer length or the
   474 	converted buffer length, given the other.
   475 
   476 	A new function SDL_FreeWAV() has been added to the API to free data
   477 	allocated by SDL_LoadWAV_RW().  This is necessary under Win32 since
   478 	the gcc compiled DLL uses a different heap than VC++ compiled apps.
   479 
   480 	SDL now has initial support for international keyboards using the
   481 	Latin character set.
   482 	If a particular mapping is desired, you can set the DEFAULT_KEYBOARD
   483 	compile-time variable, or you can set the environment variable 
   484 	"SDL_KEYBOARD" to a string identifying the keyboard mapping you desire.
   485 	The valid values for these variables can be found in SDL_keyboard.c
   486 
   487 	Full support for German and French keyboards under X11 is implemented.
   488 
   489 0.9.11:
   490 	The THREADED_EVENTS compile-time define has been replaced with the
   491 	SDL_INIT_EVENTTHREAD flag.  If this flag is passed to SDL_Init(),
   492 	SDL will create a separate thread to perform input event handling.
   493 	If this flag is passed to SDL_Init(), and the OS doesn't support 
   494 	event handling in a separate thread, SDL_Init() will fail.
   495 	Be sure to add calls to SDL_Delay() in your main thread to allow
   496 	the OS to schedule your event thread, or it may starve, leading
   497 	to slow event delivery and/or dropped events.
   498 	Currently MacOS and Win32 do not support this flag, while BeOS 
   499 	and Linux do support it.  I recommend that your application only
   500 	use this flag if absolutely necessary.
   501 
   502 	The SDL thread function passed to SDL_CreateThread() now returns a
   503 	status.  This status can be retrieved by passing a non-NULL pointer
   504 	as the 'status' argument to SDL_WaitThread().
   505 
   506 	The volume parameter to SDL_MixAudio() has been increased in range
   507 	from (0-8) to (0-128)
   508 
   509 	SDL now has a data source abstraction which can encompass a file,
   510 	an area of memory, or any custom object you can envision.  It uses
   511 	these abstractions, SDL_RWops, in the endian read/write functions,
   512 	and the built-in WAV and BMP file loaders.  This means you can load
   513 	WAV chunks from memory mapped files, compressed archives, network
   514 	pipes, or anything else that has a data read abstraction.
   515 
   516 	There are three built-in data source abstractions:
   517 	    SDL_RWFromFile(), SDL_RWFromFP(), SDL_RWFromMem()
   518 	along with a generic data source allocation function:
   519 	    SDL_AllocRW()
   520 	These data sources can be used like stdio file pointers with the
   521 	following convenience functions:
   522 	    SDL_RWseek(), SDL_RWread(), SDL_RWwrite(), SDL_RWclose()
   523 	These functions are defined in the new header file "SDL_rwops.h"
   524 
   525 	The endian swapping functions have been turned into macros for speed
   526 	and SDL_CalculateEndian() has been removed.  SDL_endian.h now defines
   527 	SDL_BYTEORDER as either SDL_BIG_ENDIAN or SDL_LIL_ENDIAN depending on
   528 	the endianness of the host system.
   529 
   530 	The endian read/write functions now take an SDL_RWops pointer
   531 	instead of a stdio FILE pointer, to support the new data source
   532 	abstraction.
   533 
   534 	The SDL_*LoadWAV() functions have been replaced with a single
   535 	SDL_LoadWAV_RW() function that takes a SDL_RWops pointer as it's
   536 	first parameter, and a flag whether or not to automatically 
   537 	free it as the second parameter.  SDL_LoadWAV() is a macro for
   538 	backward compatibility and convenience:
   539 	    SDL_LoadWAV_RW(SDL_RWFromFile("sample.wav", "rb"), 1, ...);
   540 
   541 	The SDL_*LoadBMP()/SDL_*SaveBMP() functions have each been replaced
   542 	with a single function that takes a SDL_RWops pointer as it's
   543 	first parameter, and a flag whether or not to automatically 
   544 	free it as the second parameter.  SDL_LoadBMP() and SDL_SaveBMP()
   545 	are macros for backward compatibility and convenience:
   546 	    SDL_LoadBMP_RW(SDL_RWFromFile("sample.bmp", "rb"), 1, ...);
   547 	    SDL_SaveBMP_RW(SDL_RWFromFile("sample.bmp", "wb"), 1, ...);
   548 	Note that these functions use SDL_RWseek() extensively, and should
   549 	not be used on pipes or other non-seekable data sources.
   550 
   551 0.9.10:
   552 	The Linux SDL_SysWMInfo and SDL_SysWMMsg structures have been 
   553 	extended to support multiple types of display drivers, as well as
   554         safe access to the X11 display when THREADED_EVENTS is enabled.
   555         The new structures are documented in the SDL_syswm.h header file.
   556 
   557 	Thanks to John Elliott <jce@seasip.demon.co.uk>, the UK keyboard
   558 	should now work properly, as well as the "Windows" keys on US
   559 	keyboards.
   560 
   561 	The Linux CD-ROM code now reads the CD-ROM devices from /etc/fstab
   562 	instead of trying to open each block device on the system.
   563 	The CD must be listed in /etc/fstab as using the iso9660 filesystem.
   564 
   565 	On Linux, if you define THREADED_EVENTS at compile time, a separate
   566 	thread will be spawned to gather X events asynchronously from the
   567 	graphics updates.  This hasn't been extensively tested, but it does
   568 	provide a means of handling keyboard and mouse input in a separate
   569 	thread from the graphics thread.  (This is now enabled by default.)
   570 
   571 	A special access function SDL_PeepEvents() allows you to manipulate
   572 	the event queue in a thread-safe manner, including peeking at events,
   573 	removing events of a specified type, and adding new events of arbitrary
   574 	type to the queue (use the new 'user' member of the SDL_Event type).
   575 
   576 	If you use SDL_PeepEvents() to gather events, then the main graphics
   577 	thread needs to call SDL_PumpEvents() periodically to drive the event
   578 	loop and generate input events.  This is not necessary if SDL has been 
   579 	compiled with THREADED_EVENTS defined, but doesn't hurt.
   580 
   581 	A new function SDL_ThreadID() returns the identifier associated with
   582 	the current thread.
   583 
   584 0.9.9:
   585 	The AUDIO_STEREO format flag has been replaced with a new 'channels'
   586 	member of the SDL_AudioSpec structure.  The channels are 1 for mono
   587 	audio, and 2 for stereo audio.  In the future more channels may be
   588 	supported for 3D surround sound.
   589 
   590 	The SDL_MixAudio() function now takes an additional volume parameter,
   591 	which should be set to SDL_MIX_MAXVOLUME for compatibility with the
   592 	original function.
   593 
   594 	The CD-ROM functions which take a 'cdrom' parameter can now be
   595 	passed NULL, and will act on the last successfully opened CD-ROM.
   596 
   597 0.9.8:
   598 	No changes, bugfixes only.
   599 	
   600 0.9.7:
   601 	No changes, bugfixes only.
   602 	
   603 0.9.6:
   604 	Added a fast rectangle fill function: SDL_FillRect()
   605 
   606 	Addition of a useful function for getting info on the video hardware:
   607 	    const SDL_VideoInfo *SDL_GetVideoInfo(void)
   608         This function replaces SDL_GetDisplayFormat().
   609 
   610 	Initial support for double-buffering:
   611 	  Use the SDL_DOUBLEBUF flag in SDL_SetVideoMode()
   612 	  Update the screen with a new function: SDL_Flip()
   613 
   614 	SDL_AllocSurface() takes two new flags:
   615 	SDL_SRCCOLORKEY means that the surface will be used for colorkey blits
   616 	  and if the hardware supports hardware acceleration of colorkey blits
   617 	  between two surfaces in video memory, to place the surface in video
   618 	  memory if possible, otherwise it will be placed in system memory.
   619 	SDL_SRCALPHA means that the surface will be used for alpha blits and
   620 	  if the hardware supports hardware acceleration of alpha blits between
   621 	  two surfaces in video memory, to place the surface in video memory
   622 	  if possible, otherwise it will be placed in system memory.
   623 	SDL_HWSURFACE now means that the surface will be created with the 
   624 	  same format as the display surface, since having surfaces in video
   625 	  memory is only useful for fast blitting to the screen, and you can't
   626 	  blit surfaces with different surface formats in video memory.
   627 
   628 0.9.5:
   629 	You can now pass a NULL mask to SDL_WM_SetIcon(), and it will assume
   630 	that the icon consists of the entire image.
   631 
   632 	SDL_LowerBlit() is back -- but don't use it on the display surface.
   633 	It is exactly the same as SDL_MiddleBlit(), but doesn't check for
   634 	thread safety.
   635 
   636 	Added SDL_FPLoadBMP(), SDL_FPSaveBMP(), SDL_FPLoadWAV(), which take
   637 	a FILE pointer instead of a file name.
   638 
   639 	Added CD-ROM audio control API:
   640 	    SDL_CDNumDrives()
   641 	    SDL_CDName()
   642 	    SDL_CDOpen()
   643 	    SDL_CDStatus()
   644 	    SDL_CDPlayTracks()
   645 	    SDL_CDPlay()
   646 	    SDL_CDPause()
   647 	    SDL_CDResume()
   648 	    SDL_CDStop()
   649 	    SDL_CDEject()
   650 	    SDL_CDClose()
   651 
   652 0.9.4:
   653 	No changes, bugfixes only.
   654 
   655 0.9.3:
   656 	Mouse motion event now includes relative motion information:
   657 	    Sint16 event->motion.xrel, Sint16 event->motion.yrel
   658 
   659 	X11 keyrepeat handling can be disabled by defining IGNORE_X_KEYREPEAT
   660 	    (Add -DIGNORE_X_KEYREPEAT to CFLAGS line in obj/x11Makefile)
   661 
   662 0.9.2:
   663 	No changes, bugfixes only.
   664 
   665 0.9.1:
   666 	Removed SDL_MapSurface() and SDL_UnmapSurface() -- surfaces are now
   667 	automatically mapped on blit.
   668 
   669 0.8.0:
   670 	SDL stable release