WhatsNew
author Sam Lantinga <slouken@libsdl.org>
Wed, 15 Mar 2006 17:46:41 +0000
changeset 1545 8d9bb0cf2c2a
parent 1507 1ff64ad478b2
child 1656 96c2f89cc7e1
child 1736 3b2a92126f4d
permissions -rw-r--r--
Added current_w and current_h to the SDL_VideoInfo structure, which is set to the desktop resolution during video intialization, and then set to the current resolution when a video mode is set.

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