WhatsNew
author Ozkan Sezer <sezeroz@gmail.com>
Sat, 24 Mar 2018 22:29:42 +0300
branchSDL-1.2
changeset 11967 e2982541c99c
parent 4318 34a0a589b9c4
permissions -rw-r--r--
SDL_audio.c: do the pulseaudio name dance only if SDL_AUDIO_DRIVER_PULSE is defined.
     1 
     2 This is a list of API changes in SDL's version history.
     3 
     4 Version 1.0:
     5 
     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)
    10 
    11 	Added SDL_VIDEO_FULLSCREEN_DISPLAY as a preferred synonym for 
    12 	SDL_VIDEO_FULLSCREEN_HEAD on X11.
    13 
    14 	Added SDL_DISABLE_LOCK_KEYS environment variable to enable normal
    15 	up/down events for Caps-Lock and Num-Lock keys.
    16 
    17 1.2.13:
    18 	Added SDL_BUTTON_X1 and SDL_BUTTON_X2 constants.
    19 
    20 1.2.12:
    21 	Added SDL_VIDEO_ALLOW_SCREENSAVER to override SDL's disabling
    22 	of the screensaver on Mac OS X and X11.
    23 
    24 1.2.10:
    25 	If SDL_OpenAudio() is passed zero for the desired format
    26 	fields, the following environment variables will be used
    27 	to fill them in:
    28 		SDL_AUDIO_FREQUENCY
    29 		SDL_AUDIO_FORMAT
    30 		SDL_AUDIO_CHANNELS
    31 		SDL_AUDIO_SAMPLES
    32 	If an environment variable is not specified, it will be set
    33 	to a reasonable default value.
    34 
    35 	Added support for the SDL_VIDEO_FULLSCREEN_HEAD environment
    36 	variable, currently supported on X11 Xinerama configurations.
    37 
    38 	Added SDL_GL_SWAP_CONTROL to wait for vsync in OpenGL applications.
    39 
    40 	Added SDL_GL_ACCELERATED_VISUAL to guarantee hardware acceleration.
    41 
    42 	Added current_w and current_h to the SDL_VideoInfo structure,
    43 	which is set to the desktop resolution during video intialization,
    44 	and then set to the current resolution when a video mode is set.
    45 
    46 	SDL_SetVideoMode() now accepts 0 for width or height and will use
    47 	the current video mode (or the desktop mode if no mode has been set.)
    48 
    49 	Added SDL_GetKeyRepeat()
    50 
    51 	Added SDL_config.h, with defaults for various build environments.
    52 
    53 1.2.7:
    54 	Added CPU feature detection functions to SDL_cpuinfo.h:
    55 		SDL_HasRDTSC(), SDL_HasMMX(), SDL_Has3DNow(), SDL_HasSSE(),
    56 		SDL_HasAltiVec()
    57 	Added function to create RWops from const memory: SDL_RWFromConstMem()
    58 
    59 1.2.6:
    60 	Added SDL_LoadObject(), SDL_LoadFunction(), and SDL_UnloadObject()
    61 
    62 	Added SDL_GL_MULTISAMPLEBUFFERS and SDL_GL_MULTISAMPLESAMPLES for FSAA
    63 
    64 1.2.5:
    65 	Added SDL_BUTTON_WHEELUP (4) and SDL_BUTTON_WHEELDOWN (5)
    66 
    67 	Added SDL_GL_STEREO for stereoscopic OpenGL contexts
    68 
    69 1.2.0:
    70 	Added SDL_VIDEOEXPOSE event to signal that the screen needs to
    71 	be redrawn.  This is currently only delivered to OpenGL windows
    72 	on X11, though it may be delivered in the future when the video
    73 	memory is lost under DirectX.
    74 
    75 1.1.8:
    76 	You can pass SDL_NOFRAME to SDL_VideoMode() to create a window
    77 	that has no title bar or frame decoration.  Fullscreen video
    78 	modes automatically have this flag set.
    79 
    80 	Added a function to query the clipping rectangle for a surface:
    81 		void SDL_GetClipRect(SDL_Surface *surface, SDL_Rect *rect)
    82 
    83 	Added a function to query the current event filter:
    84 		SDL_EventFilter SDL_GetEventFilter(void)
    85 
    86 	If you pass -1 to SDL_ShowCursor(), it won't change the current
    87 	cursor visibility state, but will still return it.
    88 
    89 	SDL_LockSurface() and SDL_UnlockSurface() are recursive, meaning
    90 	you can nest them as deep as you want, as long as each lock call
    91 	has a matching unlock call.  The surface remains locked until the
    92 	last matching unlock call.
    93 
    94 	Note that you may not blit to or from a locked surface.
    95 
    96 1.1.7:
    97 	The SDL_SetGammaRamp() and SDL_GetGammaRamp() functions now take
    98 	arrays of Uint16 values instead of Uint8 values.  For the most part,
    99 	you can just take your old values and shift them up 8 bits to get
   100 	new correct values for your gamma ramps.
   101 
   102 	You can pass SDL_RLEACCEL in flags passed to SDL_ConvertSurface()
   103         and SDL will try to RLE accelerate colorkey and alpha blits in the
   104 	resulting surface.
   105 
   106 1.1.6:
   107 	Added a function to return the thread ID of a specific thread:
   108 		Uint32 SDL_GetThreadID(SDL_Thread *thread)
   109 	If 'thread' is NULL, this function returns the id for this thread.
   110 
   111 1.1.5:
   112 	The YUV overlay structure has been changed to use an array of
   113 	pitches and pixels representing the planes of a YUV image, to
   114 	better enable hardware acceleration.  The YV12 and IYUV formats
   115 	each have three planes, corresponding to the Y, U, and V portions
   116 	of the image, while packed pixel YUV formats just have one plane.
   117 
   118 	For palettized mode (8bpp), the screen colormap is now split in
   119 	a physical and a logical palette. The physical palette determines
   120 	what colours the screen pixels will get when displayed, and the
   121 	logical palette controls the mapping from blits to/from the screen.
   122 	A new function, SDL_SetPalette() has been added to change
   123 	logical and physical palettes separately. SDL_SetColors() works
   124 	just as before, and is equivalent to calling SDL_SetPalette() with
   125 	a flag argument of (SDL_LOGPAL|SDL_PHYSPAL).
   126 
   127 	SDL_BlitSurface() no longer modifies the source rectangle, only the
   128 	destination rectangle. The width/height members of the destination
   129 	rectangle are ignored, only the position is used.
   130 
   131 	The old source clipping function SDL_SetClipping() has been replaced
   132 	with a more useful function to set the destination clipping rectangle:
   133 		SDL_bool SDL_SetClipRect(SDL_Surface *surface, SDL_Rect *rect)
   134 		
   135 	Added a function to see what subsystems have been initialized:
   136 		Uint32 SDL_WasInit(Uint32 flags)
   137 
   138 	The Big Alpha Flip: SDL now treats alpha as opacity like everybody
   139 	else, and not as transparency:
   140 
   141 	A new cpp symbol: SDL_ALPHA_OPAQUE is defined as 255
   142 	A new cpp symbol: SDL_ALPHA_TRANSPARENT is defined as 0
   143 	Values between 0 and 255 vary from fully transparent to fully opaque.
   144 
   145 	New functions:
   146 	SDL_DisplayFormatAlpha()
   147 	    Returns a surface converted to a format with alpha-channel
   148 	    that can be blit efficiently to the screen. (In other words,
   149 	    like SDL_DisplayFormat() but the resulting surface has
   150 	    an alpha channel.)  This is useful for surfaces with alpha.
   151 	SDL_MapRGBA()
   152 	    Works as SDL_MapRGB() but takes an additional alpha parameter.
   153 	SDL_GetRGBA()
   154 	    Works as SDL_GetRGB() but also returns the alpha value
   155 	    (SDL_ALPHA_OPAQUE for formats without an alpha channel)
   156 
   157 	Both SDL_GetRGB() and SDL_GetRGBA() now always return values in
   158 	the [0..255] interval. Previously, SDL_GetRGB() would return
   159 	(0xf8, 0xfc, 0xf8) for a completely white pixel in RGB565 format.
   160 	(N.B.: This is broken for bit fields < 3 bits.)
   161 
   162 	SDL_MapRGB() returns pixels in which the alpha channel is set opaque.
   163 
   164 	SDL_SetAlpha() can now be used for both setting the per-surface
   165 	alpha, using the new way of thinking of alpha, and also to enable
   166 	and disable per-pixel alpha blending for surfaces with an alpha
   167 	channel:
   168 		To disable alpha blending:
   169 			SDL_SetAlpha(surface, 0, 0);
   170 		To re-enable alpha blending:
   171 			SDL_SetAlpha(surface, SDL_SRCALPHA, 0);
   172 	Surfaces with an alpha channel have blending enabled by default.
   173 
   174 	SDL_SetAlpha() now accepts SDL_RLEACCEL as a flag, which requests
   175 	RLE acceleration of blits, just as like with SDL_SetColorKey().
   176 	This flag can be set for both surfaces with an alpha channel
   177 	and surfaces with an alpha value set by SDL_SetAlpha().
   178 	As always, RLE surfaces must be locked before pixel access is
   179 	allowed, and unlocked before any other SDL operations are done
   180 	on it.
   181 
   182 	The blit semantics for surfaces with and without alpha and colorkey
   183 	have now been defined:
   184 
   185 	RGBA->RGB:
   186 	    SDL_SRCALPHA set:
   187 		alpha-blend (using alpha-channel).
   188 		SDL_SRCCOLORKEY ignored.
   189 	    SDL_SRCALPHA not set:
   190 		copy RGB.
   191 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   192 		RGB values of the source colour key, ignoring alpha in the
   193 		comparison.
   194 
   195 	RGB->RGBA:
   196 	    SDL_SRCALPHA set:
   197 		alpha-blend (using the source per-surface alpha value);
   198 		set destination alpha to opaque.
   199 	    SDL_SRCALPHA not set:
   200 		copy RGB, set destination alpha to opaque.
   201 	    both:
   202 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   203 		source colour key.
   204 
   205 	RGBA->RGBA:
   206 	    SDL_SRCALPHA set:
   207 		alpha-blend (using the source alpha channel) the RGB values;
   208 		leave destination alpha untouched. [Note: is this correct?]
   209 		SDL_SRCCOLORKEY ignored.
   210 	    SDL_SRCALPHA not set:
   211 		copy all of RGBA to the destination.
   212 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   213 		RGB values of the source colour key, ignoring alpha in the
   214 		comparison.
   215 
   216 	RGB->RGB: 
   217 	    SDL_SRCALPHA set:
   218 		alpha-blend (using the source per-surface alpha value).
   219 	    SDL_SRCALPHA not set:
   220 		copy RGB.
   221 	    both:
   222 		if SDL_SRCCOLORKEY set, only copy the pixels matching the
   223 		source colour key.
   224 
   225 	As a special case, blits from surfaces with per-surface alpha
   226 	value of 128 (50% transparency) are optimised and much faster
   227 	than other alpha values. This does not apply to surfaces with
   228 	alpha channels (per-pixel alpha).
   229 
   230 	New functions for manipulating the gamma of the display have
   231 	been added:
   232 		int SDL_SetGamma(float red, float green, float blue);
   233 		int SDL_SetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   234 		int SDL_GetGammaRamp(Uint8 *red, Uint8 *green, Uint8 *blue);
   235 	Gamma ramps are tables with 256 entries which map the screen color
   236 	components into actually displayed colors.  For an example of
   237 	implementing gamma correction and gamma fades, see test/testgamma.c
   238 	Gamma control is not supported on all hardware.
   239 
   240 1.1.4:
   241 	The size of the SDL_CDtrack structure changed from 8 to 12 bytes
   242 	as the size of the length member was extended to 32 bits.
   243 
   244         You can now use SDL for 2D blitting with a GL mode by passing the
   245 	SDL_OPENGLBLIT flag to SDL_SetVideoMode().  You can specify 16 or
   246 	32 bpp, and the data in the framebuffer is put into the GL scene
   247 	when you call SDL_UpdateRects(), and the scene will be visible
   248 	when you call SDL_GL_SwapBuffers().
   249 
   250 	Run the "testgl" test program with the -logo command line option
   251 	to see an example of this blending of 2D and 3D in SDL.
   252 
   253 1.1.3:
   254 	Added SDL_FreeRW() to the API, to complement SDL_AllocRW()
   255 
   256 	Added resizable window support - just add SDL_RESIZABLE to the
   257 	SDL_SetVideoMode() flags, and then wait for SDL_VIDEORESIZE events.
   258 	See SDL_events.h for details on the new SDL_ResizeEvent structure.
   259 
   260 	Added condition variable support, based on mutexes and semaphores.
   261 		SDL_CreateCond()
   262 		SDL_DestroyCond()
   263 		SDL_CondSignal()
   264 		SDL_CondBroadcast()
   265 		SDL_CondWait()
   266 		SDL_CondTimedWait()
   267 	The new function prototypes are in SDL_mutex.h
   268 
   269 	Added counting semaphore support, based on the mutex primitive.
   270 		SDL_CreateSemaphore()
   271 		SDL_DestroySemaphore()
   272 		SDL_SemWait()
   273 		SDL_SemTryWait()
   274 		SDL_SemWaitTimeout()
   275 		SDL_SemPost()
   276 		SDL_SemValue()
   277 	The new function prototypes are in SDL_mutex.h
   278 
   279 	Added support for asynchronous blitting.  To take advantage of this,
   280 	you must set the SDL_ASYNCBLIT flag when setting the video mode and
   281 	creating surfaces that you want accelerated in this way.  You must
   282 	lock surfaces that have this flag set, and the lock will block until
   283 	any queued blits have completed.
   284 
   285 	Added YUV video overlay support.
   286 	The supported YUV formats are: YV12, IYUV, YUY2, UYVY, and YVYU.
   287 	This function creates an overlay surface:
   288 		SDL_CreateYUVOverlay()
   289 	You must lock and unlock the overlay to get access to the data:
   290 		SDL_LockYUVOverlay() SDL_UnlockYUVOverlay()
   291 	You can then display the overlay:
   292 		SDL_DisplayYUVOverlay()
   293 	You must free the overlay when you are done using it:
   294 		SDL_FreeYUVOverlay()
   295 	See SDL_video.h for the full function prototypes.
   296 
   297 	The joystick hat position constants have been changed:
   298 	Old constant            New constant
   299 	------------            ------------
   300 	     0                  SDL_HAT_CENTERED
   301 	     1                  SDL_HAT_UP
   302 	     2                  SDL_HAT_RIGHTUP
   303 	     3                  SDL_HAT_RIGHT
   304 	     4                  SDL_HAT_RIGHTDOWN
   305 	     5                  SDL_HAT_DOWN
   306 	     6                  SDL_HAT_LEFTDOWN
   307 	     7                  SDL_HAT_LEFT
   308 	     8                  SDL_HAT_LEFTUP
   309 	The new constants are bitmasks, so you can check for the
   310 	individual axes like this:
   311 		if ( hat_position & SDL_HAT_UP ) {
   312 		}
   313 	and you'll catch left-up, up, and right-up.
   314 
   315 1.1.2:
   316 	Added multiple timer support:
   317 		SDL_AddTimer() and SDL_RemoveTimer()
   318 
   319 	SDL_WM_SetIcon() now respects the icon colorkey if mask is NULL.
   320 
   321 1.1.0:
   322 	Added initial OpenGL support.
   323 	First set GL attributes (such as RGB depth, alpha depth, etc.)
   324 		SDL_GL_SetAttribute()
   325 	Then call SDL_SetVideoMode() with the SDL_OPENGL flag.
   326 	Perform all of your normal GL drawing.
   327 	Finally swap the buffers with the new SDL function:
   328 		SDL_GL_SwapBuffers()
   329 	See the new 'testgl' test program for an example of using GL with SDL.
   330 
   331 	You can load GL extension functions by using the function:
   332 		SDL_GL_LoadProcAddress()
   333 
   334 	Added functions to initialize and cleanup specific SDL subsystems:
   335 		SDL_InitSubSystem() and SDL_QuitSubSystem()
   336 
   337 	Added user-defined event type:
   338 		typedef struct {
   339         		Uint8 type;
   340         		int code;
   341         		void *data1;
   342         		void *data2;
   343 		} SDL_UserEvent;
   344 	This structure is in the "user" member of an SDL_Event.
   345 
   346 	Added a function to push events into the event queue:
   347 		SDL_PushEvent()
   348 
   349 	Example of using the new SDL user-defined events:
   350 	{
   351 		SDL_Event event;
   352 
   353 		event.type = SDL_USEREVENT;
   354 		event.user.code = my_event_code;
   355 		event.user.data1 = significant_data;
   356 		event.user.data2 = 0;
   357 		SDL_PushEvent(&event);
   358 	}
   359 
   360 	Added a function to get mouse deltas since last query:
   361 		SDL_GetRelativeMouseState()
   362 
   363 	Added a boolean datatype to SDL_types.h:
   364 		SDL_bool = { SDL_TRUE, SDL_FALSE }
   365 
   366 	Added a function to get the current audio status:
   367 		SDL_GetAudioState();
   368 	It returns one of:
   369 		SDL_AUDIO_STOPPED,
   370 		SDL_AUDIO_PLAYING,
   371 		SDL_AUDIO_PAUSED
   372 
   373 	Added an AAlib driver (ASCII Art) - by Stephane Peter.
   374 
   375 1.0.6:
   376 	The input grab state is reset after each call to SDL_SetVideoMode().
   377 	The input is grabbed by default in fullscreen mode, and ungrabbed in
   378 	windowed mode.  If you want to set input grab to a particular value,
   379 	you should set it after each call to SDL_SetVideoMode().
   380 
   381 1.0.5:
   382 	Exposed SDL_AudioInit(), SDL_VideoInit()
   383 	Added SDL_AudioDriverName() and SDL_VideoDriverName()
   384 
   385 	Added new window manager function:
   386 		SDL_WM_ToggleFullScreen()
   387 	This is currently implemented only on Linux
   388 
   389 	The ALT-ENTER code has been removed - it's not appropriate for a
   390 	lib to bind keys when they aren't even emergency escape sequences.
   391 
   392 	ALT-ENTER functionality can be implemented with the following code:
   393 
   394 	int Handle_AltEnter(const SDL_Event *event)
   395 	{
   396 	    if ( event->type == SDL_KEYDOWN ) {
   397 	        if ( (event->key.keysym.sym == SDLK_RETURN) &&
   398 	             (event->key.keysym.mod & KMOD_ALT) ) {   
   399 	                SDL_WM_ToggleFullScreen(SDL_GetVideoSurface());
   400 	                return(0);
   401 	        }
   402 	    }
   403 	    return(1);
   404 	}
   405 	SDL_SetEventFilter(Handle_AltEnter);
   406 
   407 1.0.3:
   408 	Under X11, if you grab the input and hide the mouse cursor,
   409 	the mouse will go into a "relative motion" mode where you
   410 	will always get relative motion events no matter how far in
   411 	each direction you move the mouse - relative motion is not
   412 	bounded by the edges of the window (though the absolute values
   413 	of the mouse positions are clamped by the size of the window).
   414 	The SVGAlib, framebuffer console, and DirectInput drivers all
   415 	have this behavior naturally, and the GDI and BWindow drivers
   416 	never go into "relative motion" mode.
   417 
   418 1.0.2:
   419 	Added a function to enable keyboard repeat:
   420 		SDL_EnableKeyRepeat()
   421 
   422 	Added a function to grab the mouse and keyboard input
   423 		SDL_WM_GrabInput()
   424 
   425 	Added a function to iconify the window.
   426 		SDL_WM_IconifyWindow()
   427 	If this function succeeds, the application will receive an event
   428 	signaling SDL_APPACTIVE event 
   429 
   430 1.0.1:
   431 	Added constants to SDL_audio.h for 16-bit native byte ordering:
   432 		AUDIO_U16SYS, AUDIO_S16SYS
   433 
   434 1.0.0:
   435 	New public release
   436 
   437 Version 0.11:
   438 
   439 0.11.5:
   440 	A new function SDL_GetVideoSurface() has been added, and returns
   441 	a pointer to the current display surface.
   442 
   443 	SDL_AllocSurface() has been renamed SDL_CreateRGBSurface(), and
   444 	a new function SDL_CreateRGBSurfaceFrom() has been added to allow
   445 	creating an SDL surface from an existing pixel data buffer.
   446 
   447 	Added SDL_GetRGB() to the headers and documentation.
   448 
   449 0.11.4:
   450 	SDL_SetLibraryPath() is no longer meaningful, and has been removed.
   451 
   452 0.11.3:
   453 	A new flag for SDL_Init(), SDL_INIT_NOPARACHUTE, prevents SDL from
   454 	installing fatal signal handlers on operating systems that support
   455 	them.
   456 
   457 Version 0.9:
   458 
   459 0.9.15:
   460 	SDL_CreateColorCursor() has been removed.  Color cursors should
   461 	be implemented as sprites, blitted by the application when the
   462 	cursor moves.  To get smooth color cursor updates when the app
   463 	is busy, pass the SDL_INIT_EVENTTHREAD flag to SDL_Init().  This
   464 	allows you to handle the mouse motion in another thread from an
   465 	event filter function, but is currently only supported by Linux
   466 	and BeOS.  Note that you'll have to protect the display surface
   467 	from multi-threaded access by using mutexes if you do this.
   468 
   469 	Thread-safe surface support has been removed from SDL.
   470 	This makes blitting somewhat faster, by removing SDL_MiddleBlit().
   471 	Code that used SDL_MiddleBlit() should use SDL_LowerBlit() instead.
   472 	You can make your surfaces thread-safe by allocating your own
   473 	mutex and making lock/unlock calls around accesses to your surface.
   474 
   475 0.9.14:
   476 	SDL_GetMouseState() now takes pointers to int rather than Uint16.
   477 
   478 	If you set the SDL_WINDOWID environment variable under UNIX X11,
   479 	SDL will use that as the main window instead of creating it's own.
   480 	This is an unsupported extension to SDL, and not portable at all.
   481 
   482 0.9.13:
   483 	Added a function SDL_SetLibraryPath() which can be used to specify
   484 	the directory containing the SDL dynamic libraries.  This is useful
   485 	for commercial applications which ship with particular versions
   486 	of the libraries, and for security on multi-user systems.
   487 	If this function is not used, the default system directories are 
   488 	searched using the native dynamic object loading mechanism.
   489 
   490 	In order to support C linkage under Visual C++, you must declare
   491 	main() without any return type:
   492 		main(int argc, char *argv[]) {
   493 			/* Do the program... */
   494 			return(0);
   495 		}
   496 	C++ programs should also return a value if compiled under VC++.
   497 
   498 	The blit_endian member of the SDL_VideoInfo struct has been removed.
   499 
   500 	SDL_SymToASCII() has been replaced with SDL_GetKeyName(), so there
   501 	is now no longer any function to translate a keysym to a character.
   502 
   503 	The SDL_keysym structure has been extended with a 'scancode' and
   504 	'unicode' member.  The 'scancode' is a hardware specific scancode
   505 	for the key that was pressed, and may be 0.  The 'unicode' member
   506 	is a 16-bit UNICODE translation of the key that was pressed along
   507 	with any modifiers or compose keys that have been pressed.
   508 	If no UNICODE translation exists for the key, 'unicode' will be 0.
   509 
   510 	Added a function SDL_EnableUNICODE() to enable/disable UNICODE
   511 	translation of character keypresses.  Translation defaults off.
   512 
   513 	To convert existing code to use the new API, change code which
   514 	uses SDL_SymToASCII() to get the keyname to use SDL_GetKeyName(),
   515 	and change code which uses it to get the ASCII value of a sym to
   516 	use the 'unicode' member of the event keysym.
   517 
   518 0.9.12:
   519 	There is partial support for 64-bit datatypes.  I don't recommend 
   520 	you use this if you have a choice, because 64-bit datatypes are not
   521 	supported on many platforms.  On platforms for which it is supported,
   522 	the SDL_HAS_64BIT_TYPE C preprocessor define will be enabled, and
   523 	you can use the Uint64 and Sint64 datatypes.
   524 
   525 	Added functions to SDL_endian.h to support 64-bit datatypes:
   526 	    SDL_SwapLE64(), SDL_SwapBE64(),
   527 	    SDL_ReadLE64(), SDL_ReadBE64(), SDL_WriteLE64(), SDL_WriteBE64()
   528 
   529 	A new member "len_ratio" has been added to the SDL_AudioCVT structure,
   530 	and allows you to determine either the original buffer length or the
   531 	converted buffer length, given the other.
   532 
   533 	A new function SDL_FreeWAV() has been added to the API to free data
   534 	allocated by SDL_LoadWAV_RW().  This is necessary under Win32 since
   535 	the gcc compiled DLL uses a different heap than VC++ compiled apps.
   536 
   537 	SDL now has initial support for international keyboards using the
   538 	Latin character set.
   539 	If a particular mapping is desired, you can set the DEFAULT_KEYBOARD
   540 	compile-time variable, or you can set the environment variable 
   541 	"SDL_KEYBOARD" to a string identifying the keyboard mapping you desire.
   542 	The valid values for these variables can be found in SDL_keyboard.c
   543 
   544 	Full support for German and French keyboards under X11 is implemented.
   545 
   546 0.9.11:
   547 	The THREADED_EVENTS compile-time define has been replaced with the
   548 	SDL_INIT_EVENTTHREAD flag.  If this flag is passed to SDL_Init(),
   549 	SDL will create a separate thread to perform input event handling.
   550 	If this flag is passed to SDL_Init(), and the OS doesn't support 
   551 	event handling in a separate thread, SDL_Init() will fail.
   552 	Be sure to add calls to SDL_Delay() in your main thread to allow
   553 	the OS to schedule your event thread, or it may starve, leading
   554 	to slow event delivery and/or dropped events.
   555 	Currently MacOS and Win32 do not support this flag, while BeOS 
   556 	and Linux do support it.  I recommend that your application only
   557 	use this flag if absolutely necessary.
   558 
   559 	The SDL thread function passed to SDL_CreateThread() now returns a
   560 	status.  This status can be retrieved by passing a non-NULL pointer
   561 	as the 'status' argument to SDL_WaitThread().
   562 
   563 	The volume parameter to SDL_MixAudio() has been increased in range
   564 	from (0-8) to (0-128)
   565 
   566 	SDL now has a data source abstraction which can encompass a file,
   567 	an area of memory, or any custom object you can envision.  It uses
   568 	these abstractions, SDL_RWops, in the endian read/write functions,
   569 	and the built-in WAV and BMP file loaders.  This means you can load
   570 	WAV chunks from memory mapped files, compressed archives, network
   571 	pipes, or anything else that has a data read abstraction.
   572 
   573 	There are three built-in data source abstractions:
   574 	    SDL_RWFromFile(), SDL_RWFromFP(), SDL_RWFromMem()
   575 	along with a generic data source allocation function:
   576 	    SDL_AllocRW()
   577 	These data sources can be used like stdio file pointers with the
   578 	following convenience functions:
   579 	    SDL_RWseek(), SDL_RWread(), SDL_RWwrite(), SDL_RWclose()
   580 	These functions are defined in the new header file "SDL_rwops.h"
   581 
   582 	The endian swapping functions have been turned into macros for speed
   583 	and SDL_CalculateEndian() has been removed.  SDL_endian.h now defines
   584 	SDL_BYTEORDER as either SDL_BIG_ENDIAN or SDL_LIL_ENDIAN depending on
   585 	the endianness of the host system.
   586 
   587 	The endian read/write functions now take an SDL_RWops pointer
   588 	instead of a stdio FILE pointer, to support the new data source
   589 	abstraction.
   590 
   591 	The SDL_*LoadWAV() functions have been replaced with a single
   592 	SDL_LoadWAV_RW() function that takes a SDL_RWops pointer as it's
   593 	first parameter, and a flag whether or not to automatically 
   594 	free it as the second parameter.  SDL_LoadWAV() is a macro for
   595 	backward compatibility and convenience:
   596 	    SDL_LoadWAV_RW(SDL_RWFromFile("sample.wav", "rb"), 1, ...);
   597 
   598 	The SDL_*LoadBMP()/SDL_*SaveBMP() functions have each been replaced
   599 	with a single function that takes a SDL_RWops pointer as it's
   600 	first parameter, and a flag whether or not to automatically 
   601 	free it as the second parameter.  SDL_LoadBMP() and SDL_SaveBMP()
   602 	are macros for backward compatibility and convenience:
   603 	    SDL_LoadBMP_RW(SDL_RWFromFile("sample.bmp", "rb"), 1, ...);
   604 	    SDL_SaveBMP_RW(SDL_RWFromFile("sample.bmp", "wb"), 1, ...);
   605 	Note that these functions use SDL_RWseek() extensively, and should
   606 	not be used on pipes or other non-seekable data sources.
   607 
   608 0.9.10:
   609 	The Linux SDL_SysWMInfo and SDL_SysWMMsg structures have been 
   610 	extended to support multiple types of display drivers, as well as
   611         safe access to the X11 display when THREADED_EVENTS is enabled.
   612         The new structures are documented in the SDL_syswm.h header file.
   613 
   614 	Thanks to John Elliott <jce@seasip.demon.co.uk>, the UK keyboard
   615 	should now work properly, as well as the "Windows" keys on US
   616 	keyboards.
   617 
   618 	The Linux CD-ROM code now reads the CD-ROM devices from /etc/fstab
   619 	instead of trying to open each block device on the system.
   620 	The CD must be listed in /etc/fstab as using the iso9660 filesystem.
   621 
   622 	On Linux, if you define THREADED_EVENTS at compile time, a separate
   623 	thread will be spawned to gather X events asynchronously from the
   624 	graphics updates.  This hasn't been extensively tested, but it does
   625 	provide a means of handling keyboard and mouse input in a separate
   626 	thread from the graphics thread.  (This is now enabled by default.)
   627 
   628 	A special access function SDL_PeepEvents() allows you to manipulate
   629 	the event queue in a thread-safe manner, including peeking at events,
   630 	removing events of a specified type, and adding new events of arbitrary
   631 	type to the queue (use the new 'user' member of the SDL_Event type).
   632 
   633 	If you use SDL_PeepEvents() to gather events, then the main graphics
   634 	thread needs to call SDL_PumpEvents() periodically to drive the event
   635 	loop and generate input events.  This is not necessary if SDL has been 
   636 	compiled with THREADED_EVENTS defined, but doesn't hurt.
   637 
   638 	A new function SDL_ThreadID() returns the identifier associated with
   639 	the current thread.
   640 
   641 0.9.9:
   642 	The AUDIO_STEREO format flag has been replaced with a new 'channels'
   643 	member of the SDL_AudioSpec structure.  The channels are 1 for mono
   644 	audio, and 2 for stereo audio.  In the future more channels may be
   645 	supported for 3D surround sound.
   646 
   647 	The SDL_MixAudio() function now takes an additional volume parameter,
   648 	which should be set to SDL_MIX_MAXVOLUME for compatibility with the
   649 	original function.
   650 
   651 	The CD-ROM functions which take a 'cdrom' parameter can now be
   652 	passed NULL, and will act on the last successfully opened CD-ROM.
   653 
   654 0.9.8:
   655 	No changes, bugfixes only.
   656 	
   657 0.9.7:
   658 	No changes, bugfixes only.
   659 	
   660 0.9.6:
   661 	Added a fast rectangle fill function: SDL_FillRect()
   662 
   663 	Addition of a useful function for getting info on the video hardware:
   664 	    const SDL_VideoInfo *SDL_GetVideoInfo(void)
   665         This function replaces SDL_GetDisplayFormat().
   666 
   667 	Initial support for double-buffering:
   668 	  Use the SDL_DOUBLEBUF flag in SDL_SetVideoMode()
   669 	  Update the screen with a new function: SDL_Flip()
   670 
   671 	SDL_AllocSurface() takes two new flags:
   672 	SDL_SRCCOLORKEY means that the surface will be used for colorkey blits
   673 	  and if the hardware supports hardware acceleration of colorkey blits
   674 	  between two surfaces in video memory, to place the surface in video
   675 	  memory if possible, otherwise it will be placed in system memory.
   676 	SDL_SRCALPHA means that the surface will be used for alpha blits and
   677 	  if the hardware supports hardware acceleration of alpha blits between
   678 	  two surfaces in video memory, to place the surface in video memory
   679 	  if possible, otherwise it will be placed in system memory.
   680 	SDL_HWSURFACE now means that the surface will be created with the 
   681 	  same format as the display surface, since having surfaces in video
   682 	  memory is only useful for fast blitting to the screen, and you can't
   683 	  blit surfaces with different surface formats in video memory.
   684 
   685 0.9.5:
   686 	You can now pass a NULL mask to SDL_WM_SetIcon(), and it will assume
   687 	that the icon consists of the entire image.
   688 
   689 	SDL_LowerBlit() is back -- but don't use it on the display surface.
   690 	It is exactly the same as SDL_MiddleBlit(), but doesn't check for
   691 	thread safety.
   692 
   693 	Added SDL_FPLoadBMP(), SDL_FPSaveBMP(), SDL_FPLoadWAV(), which take
   694 	a FILE pointer instead of a file name.
   695 
   696 	Added CD-ROM audio control API:
   697 	    SDL_CDNumDrives()
   698 	    SDL_CDName()
   699 	    SDL_CDOpen()
   700 	    SDL_CDStatus()
   701 	    SDL_CDPlayTracks()
   702 	    SDL_CDPlay()
   703 	    SDL_CDPause()
   704 	    SDL_CDResume()
   705 	    SDL_CDStop()
   706 	    SDL_CDEject()
   707 	    SDL_CDClose()
   708 
   709 0.9.4:
   710 	No changes, bugfixes only.
   711 
   712 0.9.3:
   713 	Mouse motion event now includes relative motion information:
   714 	    Sint16 event->motion.xrel, Sint16 event->motion.yrel
   715 
   716 	X11 keyrepeat handling can be disabled by defining IGNORE_X_KEYREPEAT
   717 	    (Add -DIGNORE_X_KEYREPEAT to CFLAGS line in obj/x11Makefile)
   718 
   719 0.9.2:
   720 	No changes, bugfixes only.
   721 
   722 0.9.1:
   723 	Removed SDL_MapSurface() and SDL_UnmapSurface() -- surfaces are now
   724 	automatically mapped on blit.
   725 
   726 0.8.0:
   727 	SDL stable release