include/SDL_hints.h
author Ozkan Sezer <sezeroz@gmail.com>
Thu, 16 Aug 2018 11:01:02 +0300
changeset 12120 0131b11bd03f
parent 12119 648377d0e573
permissions -rw-r--r--
SDL_hidapi_ps4.c: define NTDDI_VISTA / _WIN32_WINNT_VISTA if not defined

it still needs a Vista or newer Platform SDK to build, though.
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
     4 
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     8 
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    12 
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    21 
    22 /**
    23  *  \file SDL_hints.h
    24  *
    25  *  Official documentation for SDL configuration variables
    26  *
    27  *  This file contains functions to set and get configuration hints,
    28  *  as well as listing each of them alphabetically.
    29  *
    30  *  The convention for naming hints is SDL_HINT_X, where "SDL_X" is
    31  *  the environment variable that can be used to override the default.
    32  *
    33  *  In general these hints are just that - they may or may not be
    34  *  supported or applicable on any given platform, but they provide
    35  *  a way for an application or user to give the library a hint as
    36  *  to how they would like the library to work.
    37  */
    38 
    39 #ifndef SDL_hints_h_
    40 #define SDL_hints_h_
    41 
    42 #include "SDL_stdinc.h"
    43 
    44 #include "begin_code.h"
    45 /* Set up for C function definitions, even when using C++ */
    46 #ifdef __cplusplus
    47 extern "C" {
    48 #endif
    49 
    50 /**
    51  *  \brief  A variable controlling how 3D acceleration is used to accelerate the SDL screen surface.
    52  *
    53  *  SDL can try to accelerate the SDL screen surface by using streaming
    54  *  textures with a 3D rendering engine.  This variable controls whether and
    55  *  how this is done.
    56  *
    57  *  This variable can be set to the following values:
    58  *    "0"       - Disable 3D acceleration
    59  *    "1"       - Enable 3D acceleration, using the default renderer.
    60  *    "X"       - Enable 3D acceleration, using X where X is one of the valid rendering drivers.  (e.g. "direct3d", "opengl", etc.)
    61  *
    62  *  By default SDL tries to make a best guess for each platform whether
    63  *  to use acceleration or not.
    64  */
    65 #define SDL_HINT_FRAMEBUFFER_ACCELERATION   "SDL_FRAMEBUFFER_ACCELERATION"
    66 
    67 /**
    68  *  \brief  A variable specifying which render driver to use.
    69  *
    70  *  If the application doesn't pick a specific renderer to use, this variable
    71  *  specifies the name of the preferred renderer.  If the preferred renderer
    72  *  can't be initialized, the normal default renderer is used.
    73  *
    74  *  This variable is case insensitive and can be set to the following values:
    75  *    "direct3d"
    76  *    "opengl"
    77  *    "opengles2"
    78  *    "opengles"
    79  *    "metal"
    80  *    "software"
    81  *
    82  *  The default varies by platform, but it's the first one in the list that
    83  *  is available on the current platform.
    84  */
    85 #define SDL_HINT_RENDER_DRIVER              "SDL_RENDER_DRIVER"
    86 
    87 /**
    88  *  \brief  A variable controlling whether the OpenGL render driver uses shaders if they are available.
    89  *
    90  *  This variable can be set to the following values:
    91  *    "0"       - Disable shaders
    92  *    "1"       - Enable shaders
    93  *
    94  *  By default shaders are used if OpenGL supports them.
    95  */
    96 #define SDL_HINT_RENDER_OPENGL_SHADERS      "SDL_RENDER_OPENGL_SHADERS"
    97 
    98 /**
    99  *  \brief  A variable controlling whether the Direct3D device is initialized for thread-safe operations.
   100  *
   101  *  This variable can be set to the following values:
   102  *    "0"       - Thread-safety is not enabled (faster)
   103  *    "1"       - Thread-safety is enabled
   104  *
   105  *  By default the Direct3D device is created with thread-safety disabled.
   106  */
   107 #define SDL_HINT_RENDER_DIRECT3D_THREADSAFE "SDL_RENDER_DIRECT3D_THREADSAFE"
   108 
   109 /**
   110  *  \brief  A variable controlling whether to enable Direct3D 11+'s Debug Layer.
   111  *
   112  *  This variable does not have any effect on the Direct3D 9 based renderer.
   113  *
   114  *  This variable can be set to the following values:
   115  *    "0"       - Disable Debug Layer use
   116  *    "1"       - Enable Debug Layer use
   117  *
   118  *  By default, SDL does not use Direct3D Debug Layer.
   119  */
   120 #define SDL_HINT_RENDER_DIRECT3D11_DEBUG    "SDL_RENDER_DIRECT3D11_DEBUG"
   121 
   122 /**
   123  *  \brief  A variable controlling the scaling policy for SDL_RenderSetLogicalSize.
   124  *
   125  *  This variable can be set to the following values:
   126  *    "0" or "letterbox" - Uses letterbox/sidebars to fit the entire rendering on screen
   127  *    "1" or "overscan"  - Will zoom the rendering so it fills the entire screen, allowing edges to be drawn offscreen
   128  *
   129  *  By default letterbox is used
   130  */
   131 #define SDL_HINT_RENDER_LOGICAL_SIZE_MODE       "SDL_RENDER_LOGICAL_SIZE_MODE"
   132 
   133 /**
   134  *  \brief  A variable controlling the scaling quality
   135  *
   136  *  This variable can be set to the following values:
   137  *    "0" or "nearest" - Nearest pixel sampling
   138  *    "1" or "linear"  - Linear filtering (supported by OpenGL and Direct3D)
   139  *    "2" or "best"    - Currently this is the same as "linear"
   140  *
   141  *  By default nearest pixel sampling is used
   142  */
   143 #define SDL_HINT_RENDER_SCALE_QUALITY       "SDL_RENDER_SCALE_QUALITY"
   144 
   145 /**
   146  *  \brief  A variable controlling whether updates to the SDL screen surface should be synchronized with the vertical refresh, to avoid tearing.
   147  *
   148  *  This variable can be set to the following values:
   149  *    "0"       - Disable vsync
   150  *    "1"       - Enable vsync
   151  *
   152  *  By default SDL does not sync screen surface updates with vertical refresh.
   153  */
   154 #define SDL_HINT_RENDER_VSYNC               "SDL_RENDER_VSYNC"
   155 
   156 /**
   157  *  \brief  A variable controlling whether the screensaver is enabled. 
   158  *
   159  *  This variable can be set to the following values:
   160  *    "0"       - Disable screensaver
   161  *    "1"       - Enable screensaver
   162  *
   163  *  By default SDL will disable the screensaver.
   164  */
   165 #define SDL_HINT_VIDEO_ALLOW_SCREENSAVER    "SDL_VIDEO_ALLOW_SCREENSAVER"
   166 
   167 /**
   168  *  \brief  A variable controlling whether the X11 VidMode extension should be used.
   169  *
   170  *  This variable can be set to the following values:
   171  *    "0"       - Disable XVidMode
   172  *    "1"       - Enable XVidMode
   173  *
   174  *  By default SDL will use XVidMode if it is available.
   175  */
   176 #define SDL_HINT_VIDEO_X11_XVIDMODE         "SDL_VIDEO_X11_XVIDMODE"
   177 
   178 /**
   179  *  \brief  A variable controlling whether the X11 Xinerama extension should be used.
   180  *
   181  *  This variable can be set to the following values:
   182  *    "0"       - Disable Xinerama
   183  *    "1"       - Enable Xinerama
   184  *
   185  *  By default SDL will use Xinerama if it is available.
   186  */
   187 #define SDL_HINT_VIDEO_X11_XINERAMA         "SDL_VIDEO_X11_XINERAMA"
   188 
   189 /**
   190  *  \brief  A variable controlling whether the X11 XRandR extension should be used.
   191  *
   192  *  This variable can be set to the following values:
   193  *    "0"       - Disable XRandR
   194  *    "1"       - Enable XRandR
   195  *
   196  *  By default SDL will not use XRandR because of window manager issues.
   197  */
   198 #define SDL_HINT_VIDEO_X11_XRANDR           "SDL_VIDEO_X11_XRANDR"
   199 
   200 /**
   201  *  \brief  A variable controlling whether the X11 _NET_WM_PING protocol should be supported.
   202  *
   203  *  This variable can be set to the following values:
   204  *    "0"       - Disable _NET_WM_PING
   205  *    "1"       - Enable _NET_WM_PING
   206  *
   207  *  By default SDL will use _NET_WM_PING, but for applications that know they
   208  *  will not always be able to respond to ping requests in a timely manner they can
   209  *  turn it off to avoid the window manager thinking the app is hung.
   210  *  The hint is checked in CreateWindow.
   211  */
   212 #define SDL_HINT_VIDEO_X11_NET_WM_PING      "SDL_VIDEO_X11_NET_WM_PING"
   213 
   214 /**
   215  * \brief A variable controlling whether the X11 _NET_WM_BYPASS_COMPOSITOR hint should be used.
   216  * 
   217  * This variable can be set to the following values:
   218  * "0" - Disable _NET_WM_BYPASS_COMPOSITOR
   219  * "1" - Enable _NET_WM_BYPASS_COMPOSITOR
   220  * 
   221  * By default SDL will use _NET_WM_BYPASS_COMPOSITOR
   222  * 
   223  */
   224 #define SDL_HINT_VIDEO_X11_NET_WM_BYPASS_COMPOSITOR "SDL_VIDEO_X11_NET_WM_BYPASS_COMPOSITOR"
   225 
   226 /**
   227  *  \brief  A variable controlling whether the window frame and title bar are interactive when the cursor is hidden 
   228  *
   229  *  This variable can be set to the following values:
   230  *    "0"       - The window frame is not interactive when the cursor is hidden (no move, resize, etc)
   231  *    "1"       - The window frame is interactive when the cursor is hidden
   232  *
   233  *  By default SDL will allow interaction with the window frame when the cursor is hidden
   234  */
   235 #define SDL_HINT_WINDOW_FRAME_USABLE_WHILE_CURSOR_HIDDEN    "SDL_WINDOW_FRAME_USABLE_WHILE_CURSOR_HIDDEN"
   236 
   237 /**
   238  * \brief A variable to specify custom icon resource id from RC file on Windows platform 
   239  */
   240 #define SDL_HINT_WINDOWS_INTRESOURCE_ICON       "SDL_WINDOWS_INTRESOURCE_ICON"
   241 #define SDL_HINT_WINDOWS_INTRESOURCE_ICON_SMALL "SDL_WINDOWS_INTRESOURCE_ICON_SMALL"
   242 
   243 /**
   244  *  \brief  A variable controlling whether the windows message loop is processed by SDL 
   245  *
   246  *  This variable can be set to the following values:
   247  *    "0"       - The window message loop is not run
   248  *    "1"       - The window message loop is processed in SDL_PumpEvents()
   249  *
   250  *  By default SDL will process the windows message loop
   251  */
   252 #define SDL_HINT_WINDOWS_ENABLE_MESSAGELOOP "SDL_WINDOWS_ENABLE_MESSAGELOOP"
   253 
   254 /**
   255  *  \brief  A variable controlling whether grabbing input grabs the keyboard
   256  *
   257  *  This variable can be set to the following values:
   258  *    "0"       - Grab will affect only the mouse
   259  *    "1"       - Grab will affect mouse and keyboard
   260  *
   261  *  By default SDL will not grab the keyboard so system shortcuts still work.
   262  */
   263 #define SDL_HINT_GRAB_KEYBOARD              "SDL_GRAB_KEYBOARD"
   264 
   265 /**
   266  *  \brief  A variable setting the speed scale for mouse motion, in floating point, when the mouse is not in relative mode
   267  */
   268 #define SDL_HINT_MOUSE_NORMAL_SPEED_SCALE    "SDL_MOUSE_NORMAL_SPEED_SCALE"
   269 
   270 /**
   271  *  \brief  A variable setting the scale for mouse motion, in floating point, when the mouse is in relative mode
   272  */
   273 #define SDL_HINT_MOUSE_RELATIVE_SPEED_SCALE    "SDL_MOUSE_RELATIVE_SPEED_SCALE"
   274 
   275 /**
   276  *  \brief  A variable controlling whether relative mouse mode is implemented using mouse warping
   277  *
   278  *  This variable can be set to the following values:
   279  *    "0"       - Relative mouse mode uses raw input
   280  *    "1"       - Relative mouse mode uses mouse warping
   281  *
   282  *  By default SDL will use raw input for relative mouse mode
   283  */
   284 #define SDL_HINT_MOUSE_RELATIVE_MODE_WARP    "SDL_MOUSE_RELATIVE_MODE_WARP"
   285 
   286 /**
   287  *  \brief Allow mouse click events when clicking to focus an SDL window
   288  *
   289  *  This variable can be set to the following values:
   290  *    "0"       - Ignore mouse clicks that activate a window
   291  *    "1"       - Generate events for mouse clicks that activate a window
   292  *
   293  *  By default SDL will ignore mouse clicks that activate a window
   294  */
   295 #define SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH "SDL_MOUSE_FOCUS_CLICKTHROUGH"
   296 
   297 /**
   298  *  \brief  A variable controlling whether touch events should generate synthetic mouse events
   299  *
   300  *  This variable can be set to the following values:
   301  *    "0"       - Touch events will not generate mouse events
   302  *    "1"       - Touch events will generate mouse events
   303  *
   304  *  By default SDL will generate mouse events for touch events
   305  */
   306 #define SDL_HINT_TOUCH_MOUSE_EVENTS    "SDL_TOUCH_MOUSE_EVENTS"
   307 
   308 /**
   309  *  \brief Minimize your SDL_Window if it loses key focus when in fullscreen mode. Defaults to true.
   310  *
   311  */
   312 #define SDL_HINT_VIDEO_MINIMIZE_ON_FOCUS_LOSS   "SDL_VIDEO_MINIMIZE_ON_FOCUS_LOSS"
   313 
   314 /**
   315  *  \brief  A variable controlling whether the idle timer is disabled on iOS.
   316  *
   317  *  When an iOS app does not receive touches for some time, the screen is
   318  *  dimmed automatically. For games where the accelerometer is the only input
   319  *  this is problematic. This functionality can be disabled by setting this
   320  *  hint.
   321  *
   322  *  As of SDL 2.0.4, SDL_EnableScreenSaver() and SDL_DisableScreenSaver()
   323  *  accomplish the same thing on iOS. They should be preferred over this hint.
   324  *
   325  *  This variable can be set to the following values:
   326  *    "0"       - Enable idle timer
   327  *    "1"       - Disable idle timer
   328  */
   329 #define SDL_HINT_IDLE_TIMER_DISABLED "SDL_IOS_IDLE_TIMER_DISABLED"
   330 
   331 /**
   332  *  \brief  A variable controlling which orientations are allowed on iOS.
   333  *
   334  *  In some circumstances it is necessary to be able to explicitly control
   335  *  which UI orientations are allowed.
   336  *
   337  *  This variable is a space delimited list of the following values:
   338  *    "LandscapeLeft", "LandscapeRight", "Portrait" "PortraitUpsideDown"
   339  */
   340 #define SDL_HINT_ORIENTATIONS "SDL_IOS_ORIENTATIONS"
   341 
   342 /**
   343  *  \brief  A variable controlling whether controllers used with the Apple TV
   344  *  generate UI events.
   345  *
   346  * When UI events are generated by controller input, the app will be
   347  * backgrounded when the Apple TV remote's menu button is pressed, and when the
   348  * pause or B buttons on gamepads are pressed.
   349  *
   350  * More information about properly making use of controllers for the Apple TV
   351  * can be found here:
   352  * https://developer.apple.com/tvos/human-interface-guidelines/remote-and-controllers/
   353  *
   354  *  This variable can be set to the following values:
   355  *    "0"       - Controller input does not generate UI events (the default).
   356  *    "1"       - Controller input generates UI events.
   357  */
   358 #define SDL_HINT_APPLE_TV_CONTROLLER_UI_EVENTS "SDL_APPLE_TV_CONTROLLER_UI_EVENTS"
   359 
   360 /**
   361  * \brief  A variable controlling whether the Apple TV remote's joystick axes
   362  *         will automatically match the rotation of the remote.
   363  *
   364  *  This variable can be set to the following values:
   365  *    "0"       - Remote orientation does not affect joystick axes (the default).
   366  *    "1"       - Joystick axes are based on the orientation of the remote.
   367  */
   368 #define SDL_HINT_APPLE_TV_REMOTE_ALLOW_ROTATION "SDL_APPLE_TV_REMOTE_ALLOW_ROTATION"
   369 
   370 /**
   371  * \brief  A variable controlling whether the home indicator bar on iPhone X
   372  *         should be hidden.
   373  *
   374  *  This variable can be set to the following values:
   375  *    "0"       - The indicator bar is not hidden (default for windowed applications)
   376  *    "1"       - The indicator bar is hidden and is shown when the screen is touched (useful for movie playback applications)
   377  *    "2"       - The indicator bar is dim and the first swipe makes it visible and the second swipe performs the "home" action (default for fullscreen applications)
   378  */
   379 #define SDL_HINT_IOS_HIDE_HOME_INDICATOR "SDL_IOS_HIDE_HOME_INDICATOR"
   380 
   381 /**
   382  *  \brief  A variable controlling whether the Android / iOS built-in
   383  *  accelerometer should be listed as a joystick device.
   384  *
   385  *  This variable can be set to the following values:
   386  *    "0"       - The accelerometer is not listed as a joystick
   387  *    "1"       - The accelerometer is available as a 3 axis joystick (the default).
   388  */
   389 #define SDL_HINT_ACCELEROMETER_AS_JOYSTICK "SDL_ACCELEROMETER_AS_JOYSTICK"
   390 
   391 /**
   392  *  \brief  A variable controlling whether the Android / tvOS remotes
   393  *  should be listed as joystick devices, instead of sending keyboard events.
   394  *
   395  *  This variable can be set to the following values:
   396  *    "0"       - Remotes send enter/escape/arrow key events
   397  *    "1"       - Remotes are available as 2 axis, 2 button joysticks (the default).
   398  */
   399 #define SDL_HINT_TV_REMOTE_AS_JOYSTICK "SDL_TV_REMOTE_AS_JOYSTICK"
   400 
   401 /**
   402  *  \brief  A variable that lets you disable the detection and use of Xinput gamepad devices
   403  *
   404  *  The variable can be set to the following values:
   405  *    "0"       - Disable XInput detection (only uses direct input)
   406  *    "1"       - Enable XInput detection (the default)
   407  */
   408 #define SDL_HINT_XINPUT_ENABLED "SDL_XINPUT_ENABLED"
   409 
   410 /**
   411  *  \brief  A variable that causes SDL to use the old axis and button mapping for XInput devices.
   412  *
   413  *  This hint is for backwards compatibility only and will be removed in SDL 2.1
   414  *
   415  *  The default value is "0".  This hint must be set before SDL_Init()
   416  */
   417 #define SDL_HINT_XINPUT_USE_OLD_JOYSTICK_MAPPING "SDL_XINPUT_USE_OLD_JOYSTICK_MAPPING"
   418 
   419 /**
   420  *  \brief  A variable that lets you manually hint extra gamecontroller db entries.
   421  *
   422  *  The variable should be newline delimited rows of gamecontroller config data, see SDL_gamecontroller.h
   423  *
   424  *  This hint must be set before calling SDL_Init(SDL_INIT_GAMECONTROLLER)
   425  *  You can update mappings after the system is initialized with SDL_GameControllerMappingForGUID() and SDL_GameControllerAddMapping()
   426  */
   427 #define SDL_HINT_GAMECONTROLLERCONFIG "SDL_GAMECONTROLLERCONFIG"
   428 
   429 /**
   430  *  \brief  A variable containing a list of devices to skip when scanning for game controllers.
   431  *
   432  *  The format of the string is a comma separated list of USB VID/PID pairs
   433  *  in hexadecimal form, e.g.
   434  *
   435  *      0xAAAA/0xBBBB,0xCCCC/0xDDDD
   436  *
   437  *  The variable can also take the form of @file, in which case the named
   438  *  file will be loaded and interpreted as the value of the variable.
   439  */
   440 #define SDL_HINT_GAMECONTROLLER_IGNORE_DEVICES "SDL_GAMECONTROLLER_IGNORE_DEVICES"
   441 
   442 /**
   443  *  \brief  If set, all devices will be skipped when scanning for game controllers except for the ones listed in this variable.
   444  *
   445  *  The format of the string is a comma separated list of USB VID/PID pairs
   446  *  in hexadecimal form, e.g.
   447  *
   448  *      0xAAAA/0xBBBB,0xCCCC/0xDDDD
   449  *
   450  *  The variable can also take the form of @file, in which case the named
   451  *  file will be loaded and interpreted as the value of the variable.
   452  */
   453 #define SDL_HINT_GAMECONTROLLER_IGNORE_DEVICES_EXCEPT "SDL_GAMECONTROLLER_IGNORE_DEVICES_EXCEPT"
   454 
   455 /**
   456  *  \brief  A variable that lets you enable joystick (and gamecontroller) events even when your app is in the background.
   457  *
   458  *  The variable can be set to the following values:
   459  *    "0"       - Disable joystick & gamecontroller input events when the
   460  *                application is in the background.
   461  *    "1"       - Enable joystick & gamecontroller input events when the
   462  *                application is in the background.
   463  *
   464  *  The default value is "0".  This hint may be set at any time.
   465  */
   466 #define SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS "SDL_JOYSTICK_ALLOW_BACKGROUND_EVENTS"
   467 
   468 /**
   469  *  \brief  A variable controlling whether the HIDAPI joystick drivers should be used.
   470  *
   471  *  This variable can be set to the following values:
   472  *    "0"       - HIDAPI drivers are not used
   473  *    "1"       - HIDAPI drivers are used (the default)
   474  *
   475  *  This variable is the default for all drivers, but can be overridden by the hints for specific drivers below.
   476  */
   477 #define SDL_HINT_JOYSTICK_HIDAPI "SDL_JOYSTICK_HIDAPI"
   478 
   479 /**
   480  *  \brief  A variable controlling whether the HIDAPI driver for PS4 controllers should be used.
   481  *
   482  *  This variable can be set to the following values:
   483  *    "0"       - HIDAPI driver is not used
   484  *    "1"       - HIDAPI driver is used
   485  *
   486  *  The default is the value of SDL_HINT_JOYSTICK_HIDAPI
   487  */
   488 #define SDL_HINT_JOYSTICK_HIDAPI_PS4 "SDL_JOYSTICK_HIDAPI_PS4"
   489 
   490 /**
   491  *  \brief  A variable controlling whether the HIDAPI driver for Steam Controllers should be used.
   492  *
   493  *  This variable can be set to the following values:
   494  *    "0"       - HIDAPI driver is not used
   495  *    "1"       - HIDAPI driver is used
   496  *
   497  *  The default is the value of SDL_HINT_JOYSTICK_HIDAPI
   498  */
   499 #define SDL_HINT_JOYSTICK_HIDAPI_STEAM "SDL_JOYSTICK_HIDAPI_STEAM"
   500 
   501 /**
   502  *  \brief  A variable controlling whether the HIDAPI driver for Nintendo Switch controllers should be used.
   503  *
   504  *  This variable can be set to the following values:
   505  *    "0"       - HIDAPI driver is not used
   506  *    "1"       - HIDAPI driver is used
   507  *
   508  *  The default is the value of SDL_HINT_JOYSTICK_HIDAPI
   509  */
   510 #define SDL_HINT_JOYSTICK_HIDAPI_SWITCH "SDL_JOYSTICK_HIDAPI_SWITCH"
   511 
   512 /**
   513  *  \brief  A variable controlling whether the HIDAPI driver for XBox controllers should be used.
   514  *
   515  *  This variable can be set to the following values:
   516  *    "0"       - HIDAPI driver is not used
   517  *    "1"       - HIDAPI driver is used
   518  *
   519  *  The default is the value of SDL_HINT_JOYSTICK_HIDAPI
   520  */
   521 #define SDL_HINT_JOYSTICK_HIDAPI_XBOX   "SDL_JOYSTICK_HIDAPI_XBOX"
   522 
   523 /**
   524  *  \brief  A variable that controls whether Steam Controllers should be exposed using the SDL joystick and game controller APIs
   525  *
   526  *  The variable can be set to the following values:
   527  *    "0"       - Do not scan for Steam Controllers
   528  *    "1"       - Scan for Steam Controllers (the default)
   529  *
   530  *  The default value is "1".  This hint must be set before initializing the joystick subsystem.
   531  */
   532 #define SDL_HINT_ENABLE_STEAM_CONTROLLERS "SDL_ENABLE_STEAM_CONTROLLERS"
   533 
   534 
   535 /**
   536  *  \brief If set to "0" then never set the top most bit on a SDL Window, even if the video mode expects it.
   537  *      This is a debugging aid for developers and not expected to be used by end users. The default is "1"
   538  *
   539  *  This variable can be set to the following values:
   540  *    "0"       - don't allow topmost
   541  *    "1"       - allow topmost
   542  */
   543 #define SDL_HINT_ALLOW_TOPMOST "SDL_ALLOW_TOPMOST"
   544 
   545 /**
   546  *  \brief A variable that controls the timer resolution, in milliseconds.
   547  *
   548  *  The higher resolution the timer, the more frequently the CPU services
   549  *  timer interrupts, and the more precise delays are, but this takes up
   550  *  power and CPU time.  This hint is only used on Windows 7 and earlier.
   551  *
   552  *  See this blog post for more information:
   553  *  http://randomascii.wordpress.com/2013/07/08/windows-timer-resolution-megawatts-wasted/
   554  *
   555  *  If this variable is set to "0", the system timer resolution is not set.
   556  *
   557  *  The default value is "1". This hint may be set at any time.
   558  */
   559 #define SDL_HINT_TIMER_RESOLUTION "SDL_TIMER_RESOLUTION"
   560 
   561 
   562 /**
   563  *  \brief  A variable describing the content orientation on QtWayland-based platforms.
   564  *
   565  *  On QtWayland platforms, windows are rotated client-side to allow for custom
   566  *  transitions. In order to correctly position overlays (e.g. volume bar) and
   567  *  gestures (e.g. events view, close/minimize gestures), the system needs to
   568  *  know in which orientation the application is currently drawing its contents.
   569  *
   570  *  This does not cause the window to be rotated or resized, the application
   571  *  needs to take care of drawing the content in the right orientation (the
   572  *  framebuffer is always in portrait mode).
   573  *
   574  *  This variable can be one of the following values:
   575  *    "primary" (default), "portrait", "landscape", "inverted-portrait", "inverted-landscape"
   576  */
   577 #define SDL_HINT_QTWAYLAND_CONTENT_ORIENTATION "SDL_QTWAYLAND_CONTENT_ORIENTATION"
   578 
   579 /**
   580  *  \brief  Flags to set on QtWayland windows to integrate with the native window manager.
   581  *
   582  *  On QtWayland platforms, this hint controls the flags to set on the windows.
   583  *  For example, on Sailfish OS "OverridesSystemGestures" disables swipe gestures.
   584  *
   585  *  This variable is a space-separated list of the following values (empty = no flags):
   586  *    "OverridesSystemGestures", "StaysOnTop", "BypassWindowManager"
   587  */
   588 #define SDL_HINT_QTWAYLAND_WINDOW_FLAGS "SDL_QTWAYLAND_WINDOW_FLAGS"
   589 
   590 /**
   591 *  \brief  A string specifying SDL's threads stack size in bytes or "0" for the backend's default size
   592 *
   593 *  Use this hint in case you need to set SDL's threads stack size to other than the default.
   594 *  This is specially useful if you build SDL against a non glibc libc library (such as musl) which
   595 *  provides a relatively small default thread stack size (a few kilobytes versus the default 8MB glibc uses).
   596 *  Support for this hint is currently available only in the pthread, Windows, and PSP backend.
   597 */
   598 #define SDL_HINT_THREAD_STACK_SIZE              "SDL_THREAD_STACK_SIZE"
   599 
   600 /**
   601  *  \brief If set to 1, then do not allow high-DPI windows. ("Retina" on Mac and iOS)
   602  */
   603 #define SDL_HINT_VIDEO_HIGHDPI_DISABLED "SDL_VIDEO_HIGHDPI_DISABLED"
   604 
   605 /**
   606  *  \brief A variable that determines whether ctrl+click should generate a right-click event on Mac
   607  *
   608  *  If present, holding ctrl while left clicking will generate a right click
   609  *  event when on Mac.
   610  */
   611 #define SDL_HINT_MAC_CTRL_CLICK_EMULATE_RIGHT_CLICK "SDL_MAC_CTRL_CLICK_EMULATE_RIGHT_CLICK"
   612 
   613 /**
   614 *  \brief  A variable specifying which shader compiler to preload when using the Chrome ANGLE binaries
   615 *
   616 *  SDL has EGL and OpenGL ES2 support on Windows via the ANGLE project. It
   617 *  can use two different sets of binaries, those compiled by the user from source
   618 *  or those provided by the Chrome browser. In the later case, these binaries require
   619 *  that SDL loads a DLL providing the shader compiler.
   620 *
   621 *  This variable can be set to the following values:
   622 *    "d3dcompiler_46.dll" - default, best for Vista or later.
   623 *    "d3dcompiler_43.dll" - for XP support.
   624 *    "none" - do not load any library, useful if you compiled ANGLE from source and included the compiler in your binaries.
   625 *
   626 */
   627 #define SDL_HINT_VIDEO_WIN_D3DCOMPILER              "SDL_VIDEO_WIN_D3DCOMPILER"
   628 
   629 /**
   630 *  \brief  A variable that is the address of another SDL_Window* (as a hex string formatted with "%p").
   631 *  
   632 *  If this hint is set before SDL_CreateWindowFrom() and the SDL_Window* it is set to has
   633 *  SDL_WINDOW_OPENGL set (and running on WGL only, currently), then two things will occur on the newly 
   634 *  created SDL_Window:
   635 *
   636 *  1. Its pixel format will be set to the same pixel format as this SDL_Window.  This is
   637 *  needed for example when sharing an OpenGL context across multiple windows.
   638 *
   639 *  2. The flag SDL_WINDOW_OPENGL will be set on the new window so it can be used for
   640 *  OpenGL rendering.
   641 *
   642 *  This variable can be set to the following values:
   643 *    The address (as a string "%p") of the SDL_Window* that new windows created with SDL_CreateWindowFrom() should
   644 *    share a pixel format with.
   645 */
   646 #define SDL_HINT_VIDEO_WINDOW_SHARE_PIXEL_FORMAT    "SDL_VIDEO_WINDOW_SHARE_PIXEL_FORMAT"
   647 
   648 /**
   649  *  \brief A URL to a WinRT app's privacy policy
   650  *
   651  *  All network-enabled WinRT apps must make a privacy policy available to its
   652  *  users.  On Windows 8, 8.1, and RT, Microsoft mandates that this policy be
   653  *  be available in the Windows Settings charm, as accessed from within the app.
   654  *  SDL provides code to add a URL-based link there, which can point to the app's
   655  *  privacy policy.
   656  *
   657  *  To setup a URL to an app's privacy policy, set SDL_HINT_WINRT_PRIVACY_POLICY_URL
   658  *  before calling any SDL_Init() functions.  The contents of the hint should
   659  *  be a valid URL.  For example, "http://www.example.com".
   660  *
   661  *  The default value is "", which will prevent SDL from adding a privacy policy
   662  *  link to the Settings charm.  This hint should only be set during app init.
   663  *
   664  *  The label text of an app's "Privacy Policy" link may be customized via another
   665  *  hint, SDL_HINT_WINRT_PRIVACY_POLICY_LABEL.
   666  *
   667  *  Please note that on Windows Phone, Microsoft does not provide standard UI
   668  *  for displaying a privacy policy link, and as such, SDL_HINT_WINRT_PRIVACY_POLICY_URL
   669  *  will not get used on that platform.  Network-enabled phone apps should display
   670  *  their privacy policy through some other, in-app means.
   671  */
   672 #define SDL_HINT_WINRT_PRIVACY_POLICY_URL "SDL_WINRT_PRIVACY_POLICY_URL"
   673 
   674 /** \brief Label text for a WinRT app's privacy policy link
   675  *
   676  *  Network-enabled WinRT apps must include a privacy policy.  On Windows 8, 8.1, and RT,
   677  *  Microsoft mandates that this policy be available via the Windows Settings charm.
   678  *  SDL provides code to add a link there, with its label text being set via the
   679  *  optional hint, SDL_HINT_WINRT_PRIVACY_POLICY_LABEL.
   680  *
   681  *  Please note that a privacy policy's contents are not set via this hint.  A separate
   682  *  hint, SDL_HINT_WINRT_PRIVACY_POLICY_URL, is used to link to the actual text of the
   683  *  policy.
   684  *
   685  *  The contents of this hint should be encoded as a UTF8 string.
   686  *
   687  *  The default value is "Privacy Policy".  This hint should only be set during app
   688  *  initialization, preferably before any calls to SDL_Init().
   689  *
   690  *  For additional information on linking to a privacy policy, see the documentation for
   691  *  SDL_HINT_WINRT_PRIVACY_POLICY_URL.
   692  */
   693 #define SDL_HINT_WINRT_PRIVACY_POLICY_LABEL "SDL_WINRT_PRIVACY_POLICY_LABEL"
   694 
   695 /** \brief Allows back-button-press events on Windows Phone to be marked as handled
   696  *
   697  *  Windows Phone devices typically feature a Back button.  When pressed,
   698  *  the OS will emit back-button-press events, which apps are expected to
   699  *  handle in an appropriate manner.  If apps do not explicitly mark these
   700  *  events as 'Handled', then the OS will invoke its default behavior for
   701  *  unhandled back-button-press events, which on Windows Phone 8 and 8.1 is to
   702  *  terminate the app (and attempt to switch to the previous app, or to the
   703  *  device's home screen).
   704  *
   705  *  Setting the SDL_HINT_WINRT_HANDLE_BACK_BUTTON hint to "1" will cause SDL
   706  *  to mark back-button-press events as Handled, if and when one is sent to
   707  *  the app.
   708  *
   709  *  Internally, Windows Phone sends back button events as parameters to
   710  *  special back-button-press callback functions.  Apps that need to respond
   711  *  to back-button-press events are expected to register one or more
   712  *  callback functions for such, shortly after being launched (during the
   713  *  app's initialization phase).  After the back button is pressed, the OS
   714  *  will invoke these callbacks.  If the app's callback(s) do not explicitly
   715  *  mark the event as handled by the time they return, or if the app never
   716  *  registers one of these callback, the OS will consider the event
   717  *  un-handled, and it will apply its default back button behavior (terminate
   718  *  the app).
   719  *
   720  *  SDL registers its own back-button-press callback with the Windows Phone
   721  *  OS.  This callback will emit a pair of SDL key-press events (SDL_KEYDOWN
   722  *  and SDL_KEYUP), each with a scancode of SDL_SCANCODE_AC_BACK, after which
   723  *  it will check the contents of the hint, SDL_HINT_WINRT_HANDLE_BACK_BUTTON.
   724  *  If the hint's value is set to "1", the back button event's Handled
   725  *  property will get set to 'true'.  If the hint's value is set to something
   726  *  else, or if it is unset, SDL will leave the event's Handled property
   727  *  alone.  (By default, the OS sets this property to 'false', to note.)
   728  *
   729  *  SDL apps can either set SDL_HINT_WINRT_HANDLE_BACK_BUTTON well before a
   730  *  back button is pressed, or can set it in direct-response to a back button
   731  *  being pressed.
   732  *
   733  *  In order to get notified when a back button is pressed, SDL apps should
   734  *  register a callback function with SDL_AddEventWatch(), and have it listen
   735  *  for SDL_KEYDOWN events that have a scancode of SDL_SCANCODE_AC_BACK.
   736  *  (Alternatively, SDL_KEYUP events can be listened-for.  Listening for
   737  *  either event type is suitable.)  Any value of SDL_HINT_WINRT_HANDLE_BACK_BUTTON
   738  *  set by such a callback, will be applied to the OS' current
   739  *  back-button-press event.
   740  *
   741  *  More details on back button behavior in Windows Phone apps can be found
   742  *  at the following page, on Microsoft's developer site:
   743  *  http://msdn.microsoft.com/en-us/library/windowsphone/develop/jj247550(v=vs.105).aspx
   744  */
   745 #define SDL_HINT_WINRT_HANDLE_BACK_BUTTON "SDL_WINRT_HANDLE_BACK_BUTTON"
   746 
   747 /**
   748  *  \brief  A variable that dictates policy for fullscreen Spaces on Mac OS X.
   749  *
   750  *  This hint only applies to Mac OS X.
   751  *
   752  *  The variable can be set to the following values:
   753  *    "0"       - Disable Spaces support (FULLSCREEN_DESKTOP won't use them and
   754  *                SDL_WINDOW_RESIZABLE windows won't offer the "fullscreen"
   755  *                button on their titlebars).
   756  *    "1"       - Enable Spaces support (FULLSCREEN_DESKTOP will use them and
   757  *                SDL_WINDOW_RESIZABLE windows will offer the "fullscreen"
   758  *                button on their titlebars).
   759  *
   760  *  The default value is "1". Spaces are disabled regardless of this hint if
   761  *   the OS isn't at least Mac OS X Lion (10.7). This hint must be set before
   762  *   any windows are created.
   763  */
   764 #define SDL_HINT_VIDEO_MAC_FULLSCREEN_SPACES    "SDL_VIDEO_MAC_FULLSCREEN_SPACES"
   765 
   766 /**
   767 *  \brief  When set don't force the SDL app to become a foreground process
   768 *
   769 *  This hint only applies to Mac OS X.
   770 *
   771 */
   772 #define SDL_HINT_MAC_BACKGROUND_APP    "SDL_MAC_BACKGROUND_APP"
   773 
   774 /**
   775  * \brief Android APK expansion main file version. Should be a string number like "1", "2" etc.
   776  *
   777  * Must be set together with SDL_HINT_ANDROID_APK_EXPANSION_PATCH_FILE_VERSION.
   778  *
   779  * If both hints were set then SDL_RWFromFile() will look into expansion files
   780  * after a given relative path was not found in the internal storage and assets.
   781  *
   782  * By default this hint is not set and the APK expansion files are not searched.
   783  */
   784 #define SDL_HINT_ANDROID_APK_EXPANSION_MAIN_FILE_VERSION "SDL_ANDROID_APK_EXPANSION_MAIN_FILE_VERSION"
   785  
   786 /**
   787  * \brief Android APK expansion patch file version. Should be a string number like "1", "2" etc.
   788  *
   789  * Must be set together with SDL_HINT_ANDROID_APK_EXPANSION_MAIN_FILE_VERSION.
   790  *
   791  * If both hints were set then SDL_RWFromFile() will look into expansion files
   792  * after a given relative path was not found in the internal storage and assets.
   793  *
   794  * By default this hint is not set and the APK expansion files are not searched.
   795  */
   796 #define SDL_HINT_ANDROID_APK_EXPANSION_PATCH_FILE_VERSION "SDL_ANDROID_APK_EXPANSION_PATCH_FILE_VERSION"
   797 
   798 /**
   799  * \brief A variable to control whether certain IMEs should handle text editing internally instead of sending SDL_TEXTEDITING events.
   800  *
   801  * The variable can be set to the following values:
   802  *   "0"       - SDL_TEXTEDITING events are sent, and it is the application's
   803  *               responsibility to render the text from these events and 
   804  *               differentiate it somehow from committed text. (default)
   805  *   "1"       - If supported by the IME then SDL_TEXTEDITING events are not sent, 
   806  *               and text that is being composed will be rendered in its own UI.
   807  */
   808 #define SDL_HINT_IME_INTERNAL_EDITING "SDL_IME_INTERNAL_EDITING"
   809 
   810  /**
   811  * \brief A variable to control whether mouse and touch events are to be treated together or separately
   812  *
   813  * The variable can be set to the following values:
   814  *   "0"       - Mouse events will be handled as touch events, and touch will raise fake mouse
   815  *               events. This is the behaviour of SDL <= 2.0.3. (default)
   816  *   "1"       - Mouse events will be handled separately from pure touch events.
   817  *
   818  * The value of this hint is used at runtime, so it can be changed at any time.
   819  */
   820 #define SDL_HINT_ANDROID_SEPARATE_MOUSE_AND_TOUCH "SDL_ANDROID_SEPARATE_MOUSE_AND_TOUCH"
   821 
   822  /**
   823  * \brief A variable to control whether we trap the Android back button to handle it manually.
   824  *        This is necessary for the right mouse button to work on some Android devices, or
   825  *        to be able to trap the back button for use in your code reliably.  If set to true,
   826  *        the back button will show up as an SDL_KEYDOWN / SDL_KEYUP pair with a keycode of 
   827  *        SDL_SCANCODE_AC_BACK.
   828  *
   829  * The variable can be set to the following values:
   830  *   "0"       - Back button will be handled as usual for system. (default)
   831  *   "1"       - Back button will be trapped, allowing you to handle the key press
   832  *               manually.  (This will also let right mouse click work on systems 
   833  *               where the right mouse button functions as back.)
   834  *
   835  * The value of this hint is used at runtime, so it can be changed at any time.
   836  */
   837 #define SDL_HINT_ANDROID_TRAP_BACK_BUTTON "SDL_ANDROID_TRAP_BACK_BUTTON"
   838 
   839  /**
   840  * \brief A variable to control whether the return key on the soft keyboard
   841  *        should hide the soft keyboard on Android and iOS.
   842  *
   843  * The variable can be set to the following values:
   844  *   "0"       - The return key will be handled as a key event. This is the behaviour of SDL <= 2.0.3. (default)
   845  *   "1"       - The return key will hide the keyboard.
   846  *
   847  * The value of this hint is used at runtime, so it can be changed at any time.
   848  */
   849 #define SDL_HINT_RETURN_KEY_HIDES_IME "SDL_RETURN_KEY_HIDES_IME"
   850 
   851 /**
   852  *  \brief override the binding element for keyboard inputs for Emscripten builds
   853  *
   854  * This hint only applies to the emscripten platform
   855  *
   856  * The variable can be one of
   857  *    "#window"      - The javascript window object (this is the default)
   858  *    "#document"    - The javascript document object
   859  *    "#screen"      - the javascript window.screen object
   860  *    "#canvas"      - the WebGL canvas element
   861  *    any other string without a leading # sign applies to the element on the page with that ID.
   862  */
   863 #define SDL_HINT_EMSCRIPTEN_KEYBOARD_ELEMENT   "SDL_EMSCRIPTEN_KEYBOARD_ELEMENT"
   864 
   865 /**
   866  *  \brief Tell SDL not to catch the SIGINT or SIGTERM signals.
   867  *
   868  * This hint only applies to Unix-like platforms.
   869  *
   870  * The variable can be set to the following values:
   871  *   "0"       - SDL will install a SIGINT and SIGTERM handler, and when it
   872  *               catches a signal, convert it into an SDL_QUIT event.
   873  *   "1"       - SDL will not install a signal handler at all.
   874  */
   875 #define SDL_HINT_NO_SIGNAL_HANDLERS   "SDL_NO_SIGNAL_HANDLERS"
   876 
   877 /**
   878  *  \brief Tell SDL not to generate window-close events for Alt+F4 on Windows.
   879  *
   880  * The variable can be set to the following values:
   881  *   "0"       - SDL will generate a window-close event when it sees Alt+F4.
   882  *   "1"       - SDL will only do normal key handling for Alt+F4.
   883  */
   884 #define SDL_HINT_WINDOWS_NO_CLOSE_ON_ALT_F4 "SDL_WINDOWS_NO_CLOSE_ON_ALT_F4"
   885 
   886 /**
   887  *  \brief Prevent SDL from using version 4 of the bitmap header when saving BMPs.
   888  *
   889  * The bitmap header version 4 is required for proper alpha channel support and
   890  * SDL will use it when required. Should this not be desired, this hint can
   891  * force the use of the 40 byte header version which is supported everywhere.
   892  *
   893  * The variable can be set to the following values:
   894  *   "0"       - Surfaces with a colorkey or an alpha channel are saved to a
   895  *               32-bit BMP file with an alpha mask. SDL will use the bitmap
   896  *               header version 4 and set the alpha mask accordingly.
   897  *   "1"       - Surfaces with a colorkey or an alpha channel are saved to a
   898  *               32-bit BMP file without an alpha mask. The alpha channel data
   899  *               will be in the file, but applications are going to ignore it.
   900  *
   901  * The default value is "0".
   902  */
   903 #define SDL_HINT_BMP_SAVE_LEGACY_FORMAT "SDL_BMP_SAVE_LEGACY_FORMAT"
   904 
   905 /**
   906  * \brief Tell SDL not to name threads on Windows with the 0x406D1388 Exception.
   907  *        The 0x406D1388 Exception is a trick used to inform Visual Studio of a
   908  *        thread's name, but it tends to cause problems with other debuggers,
   909  *        and the .NET runtime. Note that SDL 2.0.6 and later will still use
   910  *        the (safer) SetThreadDescription API, introduced in the Windows 10
   911  *        Creators Update, if available.
   912  *
   913  * The variable can be set to the following values:
   914  *   "0"       - SDL will raise the 0x406D1388 Exception to name threads.
   915  *               This is the default behavior of SDL <= 2.0.4.
   916  *   "1"       - SDL will not raise this exception, and threads will be unnamed. (default)
   917  *               This is necessary with .NET languages or debuggers that aren't Visual Studio.
   918  */
   919 #define SDL_HINT_WINDOWS_DISABLE_THREAD_NAMING "SDL_WINDOWS_DISABLE_THREAD_NAMING"
   920 
   921 /**
   922  * \brief Tell SDL which Dispmanx layer to use on a Raspberry PI
   923  *
   924  * Also known as Z-order. The variable can take a negative or positive value.
   925  * The default is 10000.
   926  */
   927 #define SDL_HINT_RPI_VIDEO_LAYER           "SDL_RPI_VIDEO_LAYER"
   928 
   929 /**
   930  * \brief Tell the video driver that we only want a double buffer.
   931  *
   932  * By default, most lowlevel 2D APIs will use a triple buffer scheme that 
   933  * wastes no CPU time on waiting for vsync after issuing a flip, but
   934  * introduces a frame of latency. On the other hand, using a double buffer
   935  * scheme instead is recommended for cases where low latency is an important
   936  * factor because we save a whole frame of latency.
   937  * We do so by waiting for vsync immediately after issuing a flip, usually just
   938  * after eglSwapBuffers call in the backend's *_SwapWindow function.
   939  *
   940  * Since it's driver-specific, it's only supported where possible and
   941  * implemented. Currently supported the following drivers:
   942  * - KMSDRM (kmsdrm)
   943  * - Raspberry Pi (raspberrypi)
   944  */
   945 #define SDL_HINT_VIDEO_DOUBLE_BUFFER      "SDL_VIDEO_DOUBLE_BUFFER"
   946 
   947 /**
   948  *  \brief  A variable controlling what driver to use for OpenGL ES contexts.
   949  *
   950  *  On some platforms, currently Windows and X11, OpenGL drivers may support
   951  *  creating contexts with an OpenGL ES profile. By default SDL uses these
   952  *  profiles, when available, otherwise it attempts to load an OpenGL ES
   953  *  library, e.g. that provided by the ANGLE project. This variable controls
   954  *  whether SDL follows this default behaviour or will always load an
   955  *  OpenGL ES library.
   956  *
   957  *  Circumstances where this is useful include
   958  *  - Testing an app with a particular OpenGL ES implementation, e.g ANGLE,
   959  *    or emulator, e.g. those from ARM, Imagination or Qualcomm.
   960  *  - Resolving OpenGL ES function addresses at link time by linking with
   961  *    the OpenGL ES library instead of querying them at run time with
   962  *    SDL_GL_GetProcAddress().
   963  *
   964  *  Caution: for an application to work with the default behaviour across
   965  *  different OpenGL drivers it must query the OpenGL ES function
   966  *  addresses at run time using SDL_GL_GetProcAddress().
   967  *
   968  *  This variable is ignored on most platforms because OpenGL ES is native
   969  *  or not supported.
   970  *
   971  *  This variable can be set to the following values:
   972  *    "0"       - Use ES profile of OpenGL, if available. (Default when not set.)
   973  *    "1"       - Load OpenGL ES library using the default library names.
   974  *
   975  */
   976 #define SDL_HINT_OPENGL_ES_DRIVER   "SDL_OPENGL_ES_DRIVER"
   977 
   978 /**
   979  *  \brief  A variable controlling speed/quality tradeoff of audio resampling.
   980  *
   981  *  If available, SDL can use libsamplerate ( http://www.mega-nerd.com/SRC/ )
   982  *  to handle audio resampling. There are different resampling modes available
   983  *  that produce different levels of quality, using more CPU.
   984  *
   985  *  If this hint isn't specified to a valid setting, or libsamplerate isn't
   986  *  available, SDL will use the default, internal resampling algorithm.
   987  *
   988  *  Note that this is currently only applicable to resampling audio that is
   989  *  being written to a device for playback or audio being read from a device
   990  *  for capture. SDL_AudioCVT always uses the default resampler (although this
   991  *  might change for SDL 2.1).
   992  *
   993  *  This hint is currently only checked at audio subsystem initialization.
   994  *
   995  *  This variable can be set to the following values:
   996  *
   997  *    "0" or "default" - Use SDL's internal resampling (Default when not set - low quality, fast)
   998  *    "1" or "fast"    - Use fast, slightly higher quality resampling, if available
   999  *    "2" or "medium"  - Use medium quality resampling, if available
  1000  *    "3" or "best"    - Use high quality resampling, if available
  1001  */
  1002 #define SDL_HINT_AUDIO_RESAMPLING_MODE   "SDL_AUDIO_RESAMPLING_MODE"
  1003 
  1004 /**
  1005  *  \brief  A variable controlling the audio category on iOS and Mac OS X
  1006  *
  1007  *  This variable can be set to the following values:
  1008  *
  1009  *    "ambient"     - Use the AVAudioSessionCategoryAmbient audio category, will be muted by the phone mute switch (default)
  1010  *    "playback"    - Use the AVAudioSessionCategoryPlayback category
  1011  *
  1012  *  For more information, see Apple's documentation:
  1013  *  https://developer.apple.com/library/content/documentation/Audio/Conceptual/AudioSessionProgrammingGuide/AudioSessionCategoriesandModes/AudioSessionCategoriesandModes.html
  1014  */
  1015 #define SDL_HINT_AUDIO_CATEGORY   "SDL_AUDIO_CATEGORY"
  1016 
  1017 /**
  1018  *  \brief  An enumeration of hint priorities
  1019  */
  1020 typedef enum
  1021 {
  1022     SDL_HINT_DEFAULT,
  1023     SDL_HINT_NORMAL,
  1024     SDL_HINT_OVERRIDE
  1025 } SDL_HintPriority;
  1026 
  1027 
  1028 /**
  1029  *  \brief Set a hint with a specific priority
  1030  *
  1031  *  The priority controls the behavior when setting a hint that already
  1032  *  has a value.  Hints will replace existing hints of their priority and
  1033  *  lower.  Environment variables are considered to have override priority.
  1034  *
  1035  *  \return SDL_TRUE if the hint was set, SDL_FALSE otherwise
  1036  */
  1037 extern DECLSPEC SDL_bool SDLCALL SDL_SetHintWithPriority(const char *name,
  1038                                                          const char *value,
  1039                                                          SDL_HintPriority priority);
  1040 
  1041 /**
  1042  *  \brief Set a hint with normal priority
  1043  *
  1044  *  \return SDL_TRUE if the hint was set, SDL_FALSE otherwise
  1045  */
  1046 extern DECLSPEC SDL_bool SDLCALL SDL_SetHint(const char *name,
  1047                                              const char *value);
  1048 
  1049 /**
  1050  *  \brief Get a hint
  1051  *
  1052  *  \return The string value of a hint variable.
  1053  */
  1054 extern DECLSPEC const char * SDLCALL SDL_GetHint(const char *name);
  1055 
  1056 /**
  1057  *  \brief Get a hint
  1058  *
  1059  *  \return The boolean value of a hint variable.
  1060  */
  1061 extern DECLSPEC SDL_bool SDLCALL SDL_GetHintBoolean(const char *name, SDL_bool default_value);
  1062 
  1063 /**
  1064  * \brief type definition of the hint callback function.
  1065  */
  1066 typedef void (SDLCALL *SDL_HintCallback)(void *userdata, const char *name, const char *oldValue, const char *newValue);
  1067 
  1068 /**
  1069  *  \brief Add a function to watch a particular hint
  1070  *
  1071  *  \param name The hint to watch
  1072  *  \param callback The function to call when the hint value changes
  1073  *  \param userdata A pointer to pass to the callback function
  1074  */
  1075 extern DECLSPEC void SDLCALL SDL_AddHintCallback(const char *name,
  1076                                                  SDL_HintCallback callback,
  1077                                                  void *userdata);
  1078 
  1079 /**
  1080  *  \brief Remove a function watching a particular hint
  1081  *
  1082  *  \param name The hint being watched
  1083  *  \param callback The function being called when the hint value changes
  1084  *  \param userdata A pointer being passed to the callback function
  1085  */
  1086 extern DECLSPEC void SDLCALL SDL_DelHintCallback(const char *name,
  1087                                                  SDL_HintCallback callback,
  1088                                                  void *userdata);
  1089 
  1090 /**
  1091  *  \brief  Clear all hints
  1092  *
  1093  *  This function is called during SDL_Quit() to free stored hints.
  1094  */
  1095 extern DECLSPEC void SDLCALL SDL_ClearHints(void);
  1096 
  1097 
  1098 /* Ends C function definitions when using C++ */
  1099 #ifdef __cplusplus
  1100 }
  1101 #endif
  1102 #include "close_code.h"
  1103 
  1104 #endif /* SDL_hints_h_ */
  1105 
  1106 /* vi: set ts=4 sw=4 expandtab: */