include/SDL_hints.h
author Ethan Lee <flibitijibibo@flibitijibibo.com>
Wed, 17 Jul 2019 23:20:57 -0400
changeset 12950 05dddfb66b85
parent 12896 b91647e1a977
permissions -rw-r--r--
Copypaste SDL_NSLog to UIKit backend, document it as such
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2019 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 double click time, in milliseconds.
   267  */
   268 #define SDL_HINT_MOUSE_DOUBLE_CLICK_TIME    "SDL_MOUSE_DOUBLE_CLICK_TIME"
   269 
   270 /**
   271  *  \brief  A variable setting the double click radius, in pixels.
   272  */
   273 #define SDL_HINT_MOUSE_DOUBLE_CLICK_RADIUS    "SDL_MOUSE_DOUBLE_CLICK_RADIUS"
   274 
   275 /**
   276  *  \brief  A variable setting the speed scale for mouse motion, in floating point, when the mouse is not in relative mode
   277  */
   278 #define SDL_HINT_MOUSE_NORMAL_SPEED_SCALE    "SDL_MOUSE_NORMAL_SPEED_SCALE"
   279 
   280 /**
   281  *  \brief  A variable setting the scale for mouse motion, in floating point, when the mouse is in relative mode
   282  */
   283 #define SDL_HINT_MOUSE_RELATIVE_SPEED_SCALE    "SDL_MOUSE_RELATIVE_SPEED_SCALE"
   284 
   285 /**
   286  *  \brief  A variable controlling whether relative mouse mode is implemented using mouse warping
   287  *
   288  *  This variable can be set to the following values:
   289  *    "0"       - Relative mouse mode uses raw input
   290  *    "1"       - Relative mouse mode uses mouse warping
   291  *
   292  *  By default SDL will use raw input for relative mouse mode
   293  */
   294 #define SDL_HINT_MOUSE_RELATIVE_MODE_WARP    "SDL_MOUSE_RELATIVE_MODE_WARP"
   295 
   296 /**
   297  *  \brief Allow mouse click events when clicking to focus an SDL window
   298  *
   299  *  This variable can be set to the following values:
   300  *    "0"       - Ignore mouse clicks that activate a window
   301  *    "1"       - Generate events for mouse clicks that activate a window
   302  *
   303  *  By default SDL will ignore mouse clicks that activate a window
   304  */
   305 #define SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH "SDL_MOUSE_FOCUS_CLICKTHROUGH"
   306 
   307 /**
   308  *  \brief  A variable controlling whether touch events should generate synthetic mouse events
   309  *
   310  *  This variable can be set to the following values:
   311  *    "0"       - Touch events will not generate mouse events
   312  *    "1"       - Touch events will generate mouse events
   313  *
   314  *  By default SDL will generate mouse events for touch events
   315  */
   316 #define SDL_HINT_TOUCH_MOUSE_EVENTS    "SDL_TOUCH_MOUSE_EVENTS"
   317 
   318 /**
   319  *  \brief  A variable controlling whether mouse events should generate synthetic touch events
   320  *
   321  *  This variable can be set to the following values:
   322  *    "0"       - Mouse events will not generate touch events (default for desktop platforms)
   323  *    "1"       - Mouse events will generate touch events (default for mobile platforms, such as Android and iOS)
   324  */
   325 
   326 #define SDL_HINT_MOUSE_TOUCH_EVENTS    "SDL_MOUSE_TOUCH_EVENTS"
   327 
   328 /**
   329  *  \brief Minimize your SDL_Window if it loses key focus when in fullscreen mode. Defaults to true.
   330  *
   331  */
   332 #define SDL_HINT_VIDEO_MINIMIZE_ON_FOCUS_LOSS   "SDL_VIDEO_MINIMIZE_ON_FOCUS_LOSS"
   333 
   334 /**
   335  *  \brief  A variable controlling whether the idle timer is disabled on iOS.
   336  *
   337  *  When an iOS app does not receive touches for some time, the screen is
   338  *  dimmed automatically. For games where the accelerometer is the only input
   339  *  this is problematic. This functionality can be disabled by setting this
   340  *  hint.
   341  *
   342  *  As of SDL 2.0.4, SDL_EnableScreenSaver() and SDL_DisableScreenSaver()
   343  *  accomplish the same thing on iOS. They should be preferred over this hint.
   344  *
   345  *  This variable can be set to the following values:
   346  *    "0"       - Enable idle timer
   347  *    "1"       - Disable idle timer
   348  */
   349 #define SDL_HINT_IDLE_TIMER_DISABLED "SDL_IOS_IDLE_TIMER_DISABLED"
   350 
   351 /**
   352  *  \brief  A variable controlling which orientations are allowed on iOS/Android.
   353  *
   354  *  In some circumstances it is necessary to be able to explicitly control
   355  *  which UI orientations are allowed.
   356  *
   357  *  This variable is a space delimited list of the following values:
   358  *    "LandscapeLeft", "LandscapeRight", "Portrait" "PortraitUpsideDown"
   359  */
   360 #define SDL_HINT_ORIENTATIONS "SDL_IOS_ORIENTATIONS"
   361 
   362 /**
   363  *  \brief  A variable controlling whether controllers used with the Apple TV
   364  *  generate UI events.
   365  *
   366  * When UI events are generated by controller input, the app will be
   367  * backgrounded when the Apple TV remote's menu button is pressed, and when the
   368  * pause or B buttons on gamepads are pressed.
   369  *
   370  * More information about properly making use of controllers for the Apple TV
   371  * can be found here:
   372  * https://developer.apple.com/tvos/human-interface-guidelines/remote-and-controllers/
   373  *
   374  *  This variable can be set to the following values:
   375  *    "0"       - Controller input does not generate UI events (the default).
   376  *    "1"       - Controller input generates UI events.
   377  */
   378 #define SDL_HINT_APPLE_TV_CONTROLLER_UI_EVENTS "SDL_APPLE_TV_CONTROLLER_UI_EVENTS"
   379 
   380 /**
   381  * \brief  A variable controlling whether the Apple TV remote's joystick axes
   382  *         will automatically match the rotation of the remote.
   383  *
   384  *  This variable can be set to the following values:
   385  *    "0"       - Remote orientation does not affect joystick axes (the default).
   386  *    "1"       - Joystick axes are based on the orientation of the remote.
   387  */
   388 #define SDL_HINT_APPLE_TV_REMOTE_ALLOW_ROTATION "SDL_APPLE_TV_REMOTE_ALLOW_ROTATION"
   389 
   390 /**
   391  * \brief  A variable controlling whether the home indicator bar on iPhone X
   392  *         should be hidden.
   393  *
   394  *  This variable can be set to the following values:
   395  *    "0"       - The indicator bar is not hidden (default for windowed applications)
   396  *    "1"       - The indicator bar is hidden and is shown when the screen is touched (useful for movie playback applications)
   397  *    "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)
   398  */
   399 #define SDL_HINT_IOS_HIDE_HOME_INDICATOR "SDL_IOS_HIDE_HOME_INDICATOR"
   400 
   401 /**
   402  *  \brief  A variable controlling whether the Android / iOS built-in
   403  *  accelerometer should be listed as a joystick device.
   404  *
   405  *  This variable can be set to the following values:
   406  *    "0"       - The accelerometer is not listed as a joystick
   407  *    "1"       - The accelerometer is available as a 3 axis joystick (the default).
   408  */
   409 #define SDL_HINT_ACCELEROMETER_AS_JOYSTICK "SDL_ACCELEROMETER_AS_JOYSTICK"
   410 
   411 /**
   412  *  \brief  A variable controlling whether the Android / tvOS remotes
   413  *  should be listed as joystick devices, instead of sending keyboard events.
   414  *
   415  *  This variable can be set to the following values:
   416  *    "0"       - Remotes send enter/escape/arrow key events
   417  *    "1"       - Remotes are available as 2 axis, 2 button joysticks (the default).
   418  */
   419 #define SDL_HINT_TV_REMOTE_AS_JOYSTICK "SDL_TV_REMOTE_AS_JOYSTICK"
   420 
   421 /**
   422  *  \brief  A variable that lets you disable the detection and use of Xinput gamepad devices
   423  *
   424  *  The variable can be set to the following values:
   425  *    "0"       - Disable XInput detection (only uses direct input)
   426  *    "1"       - Enable XInput detection (the default)
   427  */
   428 #define SDL_HINT_XINPUT_ENABLED "SDL_XINPUT_ENABLED"
   429 
   430 /**
   431  *  \brief  A variable that causes SDL to use the old axis and button mapping for XInput devices.
   432  *
   433  *  This hint is for backwards compatibility only and will be removed in SDL 2.1
   434  *
   435  *  The default value is "0".  This hint must be set before SDL_Init()
   436  */
   437 #define SDL_HINT_XINPUT_USE_OLD_JOYSTICK_MAPPING "SDL_XINPUT_USE_OLD_JOYSTICK_MAPPING"
   438 
   439 /**
   440  *  \brief  A variable that lets you manually hint extra gamecontroller db entries.
   441  *
   442  *  The variable should be newline delimited rows of gamecontroller config data, see SDL_gamecontroller.h
   443  *
   444  *  This hint must be set before calling SDL_Init(SDL_INIT_GAMECONTROLLER)
   445  *  You can update mappings after the system is initialized with SDL_GameControllerMappingForGUID() and SDL_GameControllerAddMapping()
   446  */
   447 #define SDL_HINT_GAMECONTROLLERCONFIG "SDL_GAMECONTROLLERCONFIG"
   448 
   449 /**
   450  *  \brief  A variable that lets you provide a file with extra gamecontroller db entries.
   451  *
   452  *  The file should contain lines of gamecontroller config data, see SDL_gamecontroller.h
   453  *
   454  *  This hint must be set before calling SDL_Init(SDL_INIT_GAMECONTROLLER)
   455  *  You can update mappings after the system is initialized with SDL_GameControllerMappingForGUID() and SDL_GameControllerAddMapping()
   456  */
   457 #define SDL_HINT_GAMECONTROLLERCONFIG_FILE "SDL_GAMECONTROLLERCONFIG_FILE"
   458 
   459 /**
   460  *  \brief  A variable containing a list of devices to skip when scanning for game controllers.
   461  *
   462  *  The format of the string is a comma separated list of USB VID/PID pairs
   463  *  in hexadecimal form, e.g.
   464  *
   465  *      0xAAAA/0xBBBB,0xCCCC/0xDDDD
   466  *
   467  *  The variable can also take the form of @file, in which case the named
   468  *  file will be loaded and interpreted as the value of the variable.
   469  */
   470 #define SDL_HINT_GAMECONTROLLER_IGNORE_DEVICES "SDL_GAMECONTROLLER_IGNORE_DEVICES"
   471 
   472 /**
   473  *  \brief  If set, all devices will be skipped when scanning for game controllers except for the ones listed in this variable.
   474  *
   475  *  The format of the string is a comma separated list of USB VID/PID pairs
   476  *  in hexadecimal form, e.g.
   477  *
   478  *      0xAAAA/0xBBBB,0xCCCC/0xDDDD
   479  *
   480  *  The variable can also take the form of @file, in which case the named
   481  *  file will be loaded and interpreted as the value of the variable.
   482  */
   483 #define SDL_HINT_GAMECONTROLLER_IGNORE_DEVICES_EXCEPT "SDL_GAMECONTROLLER_IGNORE_DEVICES_EXCEPT"
   484 
   485 /**
   486  *  \brief  A variable that lets you enable joystick (and gamecontroller) events even when your app is in the background.
   487  *
   488  *  The variable can be set to the following values:
   489  *    "0"       - Disable joystick & gamecontroller input events when the
   490  *                application is in the background.
   491  *    "1"       - Enable joystick & gamecontroller input events when the
   492  *                application is in the background.
   493  *
   494  *  The default value is "0".  This hint may be set at any time.
   495  */
   496 #define SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS "SDL_JOYSTICK_ALLOW_BACKGROUND_EVENTS"
   497 
   498 /**
   499  *  \brief  A variable controlling whether the HIDAPI joystick drivers should be used.
   500  *
   501  *  This variable can be set to the following values:
   502  *    "0"       - HIDAPI drivers are not used
   503  *    "1"       - HIDAPI drivers are used (the default)
   504  *
   505  *  This variable is the default for all drivers, but can be overridden by the hints for specific drivers below.
   506  */
   507 #define SDL_HINT_JOYSTICK_HIDAPI "SDL_JOYSTICK_HIDAPI"
   508 
   509 /**
   510  *  \brief  A variable controlling whether the HIDAPI driver for PS4 controllers should be used.
   511  *
   512  *  This variable can be set to the following values:
   513  *    "0"       - HIDAPI driver is not used
   514  *    "1"       - HIDAPI driver is used
   515  *
   516  *  The default is the value of SDL_HINT_JOYSTICK_HIDAPI
   517  */
   518 #define SDL_HINT_JOYSTICK_HIDAPI_PS4 "SDL_JOYSTICK_HIDAPI_PS4"
   519 
   520 /**
   521  *  \brief  A variable controlling whether extended input reports should be used for PS4 controllers when using the HIDAPI driver.
   522  *
   523  *  This variable can be set to the following values:
   524  *    "0"       - extended reports are not enabled (the default)
   525  *    "1"       - extended reports
   526  *
   527  *  Extended input reports allow rumble on Bluetooth PS4 controllers, but
   528  *  break DirectInput handling for applications that don't use SDL.
   529  *
   530  *  Once extended reports are enabled, they can not be disabled without
   531  *  power cycling the controller.
   532  */
   533 #define SDL_HINT_JOYSTICK_HIDAPI_PS4_RUMBLE "SDL_JOYSTICK_HIDAPI_PS4_RUMBLE"
   534 
   535 /**
   536  *  \brief  A variable controlling whether the HIDAPI driver for Steam Controllers should be used.
   537  *
   538  *  This variable can be set to the following values:
   539  *    "0"       - HIDAPI driver is not used
   540  *    "1"       - HIDAPI driver is used
   541  *
   542  *  The default is the value of SDL_HINT_JOYSTICK_HIDAPI
   543  */
   544 #define SDL_HINT_JOYSTICK_HIDAPI_STEAM "SDL_JOYSTICK_HIDAPI_STEAM"
   545 
   546 /**
   547  *  \brief  A variable controlling whether the HIDAPI driver for Nintendo Switch controllers should be used.
   548  *
   549  *  This variable can be set to the following values:
   550  *    "0"       - HIDAPI driver is not used
   551  *    "1"       - HIDAPI driver is used
   552  *
   553  *  The default is the value of SDL_HINT_JOYSTICK_HIDAPI
   554  */
   555 #define SDL_HINT_JOYSTICK_HIDAPI_SWITCH "SDL_JOYSTICK_HIDAPI_SWITCH"
   556 
   557 /**
   558  *  \brief  A variable controlling whether the HIDAPI driver for XBox controllers should be used.
   559  *
   560  *  This variable can be set to the following values:
   561  *    "0"       - HIDAPI driver is not used
   562  *    "1"       - HIDAPI driver is used
   563  *
   564  *  The default is the value of SDL_HINT_JOYSTICK_HIDAPI
   565  */
   566 #define SDL_HINT_JOYSTICK_HIDAPI_XBOX   "SDL_JOYSTICK_HIDAPI_XBOX"
   567 
   568 /**
   569  *  \brief  A variable that controls whether Steam Controllers should be exposed using the SDL joystick and game controller APIs
   570  *
   571  *  The variable can be set to the following values:
   572  *    "0"       - Do not scan for Steam Controllers
   573  *    "1"       - Scan for Steam Controllers (the default)
   574  *
   575  *  The default value is "1".  This hint must be set before initializing the joystick subsystem.
   576  */
   577 #define SDL_HINT_ENABLE_STEAM_CONTROLLERS "SDL_ENABLE_STEAM_CONTROLLERS"
   578 
   579 
   580 /**
   581  *  \brief If set to "0" then never set the top most bit on a SDL Window, even if the video mode expects it.
   582  *      This is a debugging aid for developers and not expected to be used by end users. The default is "1"
   583  *
   584  *  This variable can be set to the following values:
   585  *    "0"       - don't allow topmost
   586  *    "1"       - allow topmost
   587  */
   588 #define SDL_HINT_ALLOW_TOPMOST "SDL_ALLOW_TOPMOST"
   589 
   590 /**
   591  *  \brief A variable that controls the timer resolution, in milliseconds.
   592  *
   593  *  The higher resolution the timer, the more frequently the CPU services
   594  *  timer interrupts, and the more precise delays are, but this takes up
   595  *  power and CPU time.  This hint is only used on Windows 7 and earlier.
   596  *
   597  *  See this blog post for more information:
   598  *  http://randomascii.wordpress.com/2013/07/08/windows-timer-resolution-megawatts-wasted/
   599  *
   600  *  If this variable is set to "0", the system timer resolution is not set.
   601  *
   602  *  The default value is "1". This hint may be set at any time.
   603  */
   604 #define SDL_HINT_TIMER_RESOLUTION "SDL_TIMER_RESOLUTION"
   605 
   606 
   607 /**
   608  *  \brief  A variable describing the content orientation on QtWayland-based platforms.
   609  *
   610  *  On QtWayland platforms, windows are rotated client-side to allow for custom
   611  *  transitions. In order to correctly position overlays (e.g. volume bar) and
   612  *  gestures (e.g. events view, close/minimize gestures), the system needs to
   613  *  know in which orientation the application is currently drawing its contents.
   614  *
   615  *  This does not cause the window to be rotated or resized, the application
   616  *  needs to take care of drawing the content in the right orientation (the
   617  *  framebuffer is always in portrait mode).
   618  *
   619  *  This variable can be one of the following values:
   620  *    "primary" (default), "portrait", "landscape", "inverted-portrait", "inverted-landscape"
   621  */
   622 #define SDL_HINT_QTWAYLAND_CONTENT_ORIENTATION "SDL_QTWAYLAND_CONTENT_ORIENTATION"
   623 
   624 /**
   625  *  \brief  Flags to set on QtWayland windows to integrate with the native window manager.
   626  *
   627  *  On QtWayland platforms, this hint controls the flags to set on the windows.
   628  *  For example, on Sailfish OS "OverridesSystemGestures" disables swipe gestures.
   629  *
   630  *  This variable is a space-separated list of the following values (empty = no flags):
   631  *    "OverridesSystemGestures", "StaysOnTop", "BypassWindowManager"
   632  */
   633 #define SDL_HINT_QTWAYLAND_WINDOW_FLAGS "SDL_QTWAYLAND_WINDOW_FLAGS"
   634 
   635 /**
   636 *  \brief  A string specifying SDL's threads stack size in bytes or "0" for the backend's default size
   637 *
   638 *  Use this hint in case you need to set SDL's threads stack size to other than the default.
   639 *  This is specially useful if you build SDL against a non glibc libc library (such as musl) which
   640 *  provides a relatively small default thread stack size (a few kilobytes versus the default 8MB glibc uses).
   641 *  Support for this hint is currently available only in the pthread, Windows, and PSP backend.
   642 *
   643 *  Instead of this hint, in 2.0.9 and later, you can use
   644 *  SDL_CreateThreadWithStackSize(). This hint only works with the classic
   645 *  SDL_CreateThread().
   646 */
   647 #define SDL_HINT_THREAD_STACK_SIZE              "SDL_THREAD_STACK_SIZE"
   648 
   649 /**
   650  *  \brief If set to 1, then do not allow high-DPI windows. ("Retina" on Mac and iOS)
   651  */
   652 #define SDL_HINT_VIDEO_HIGHDPI_DISABLED "SDL_VIDEO_HIGHDPI_DISABLED"
   653 
   654 /**
   655  *  \brief A variable that determines whether ctrl+click should generate a right-click event on Mac
   656  *
   657  *  If present, holding ctrl while left clicking will generate a right click
   658  *  event when on Mac.
   659  */
   660 #define SDL_HINT_MAC_CTRL_CLICK_EMULATE_RIGHT_CLICK "SDL_MAC_CTRL_CLICK_EMULATE_RIGHT_CLICK"
   661 
   662 /**
   663 *  \brief  A variable specifying which shader compiler to preload when using the Chrome ANGLE binaries
   664 *
   665 *  SDL has EGL and OpenGL ES2 support on Windows via the ANGLE project. It
   666 *  can use two different sets of binaries, those compiled by the user from source
   667 *  or those provided by the Chrome browser. In the later case, these binaries require
   668 *  that SDL loads a DLL providing the shader compiler.
   669 *
   670 *  This variable can be set to the following values:
   671 *    "d3dcompiler_46.dll" - default, best for Vista or later.
   672 *    "d3dcompiler_43.dll" - for XP support.
   673 *    "none" - do not load any library, useful if you compiled ANGLE from source and included the compiler in your binaries.
   674 *
   675 */
   676 #define SDL_HINT_VIDEO_WIN_D3DCOMPILER              "SDL_VIDEO_WIN_D3DCOMPILER"
   677 
   678 /**
   679 *  \brief  A variable that is the address of another SDL_Window* (as a hex string formatted with "%p").
   680 *  
   681 *  If this hint is set before SDL_CreateWindowFrom() and the SDL_Window* it is set to has
   682 *  SDL_WINDOW_OPENGL set (and running on WGL only, currently), then two things will occur on the newly 
   683 *  created SDL_Window:
   684 *
   685 *  1. Its pixel format will be set to the same pixel format as this SDL_Window.  This is
   686 *  needed for example when sharing an OpenGL context across multiple windows.
   687 *
   688 *  2. The flag SDL_WINDOW_OPENGL will be set on the new window so it can be used for
   689 *  OpenGL rendering.
   690 *
   691 *  This variable can be set to the following values:
   692 *    The address (as a string "%p") of the SDL_Window* that new windows created with SDL_CreateWindowFrom() should
   693 *    share a pixel format with.
   694 */
   695 #define SDL_HINT_VIDEO_WINDOW_SHARE_PIXEL_FORMAT    "SDL_VIDEO_WINDOW_SHARE_PIXEL_FORMAT"
   696 
   697 /**
   698  *  \brief A URL to a WinRT app's privacy policy
   699  *
   700  *  All network-enabled WinRT apps must make a privacy policy available to its
   701  *  users.  On Windows 8, 8.1, and RT, Microsoft mandates that this policy be
   702  *  be available in the Windows Settings charm, as accessed from within the app.
   703  *  SDL provides code to add a URL-based link there, which can point to the app's
   704  *  privacy policy.
   705  *
   706  *  To setup a URL to an app's privacy policy, set SDL_HINT_WINRT_PRIVACY_POLICY_URL
   707  *  before calling any SDL_Init() functions.  The contents of the hint should
   708  *  be a valid URL.  For example, "http://www.example.com".
   709  *
   710  *  The default value is "", which will prevent SDL from adding a privacy policy
   711  *  link to the Settings charm.  This hint should only be set during app init.
   712  *
   713  *  The label text of an app's "Privacy Policy" link may be customized via another
   714  *  hint, SDL_HINT_WINRT_PRIVACY_POLICY_LABEL.
   715  *
   716  *  Please note that on Windows Phone, Microsoft does not provide standard UI
   717  *  for displaying a privacy policy link, and as such, SDL_HINT_WINRT_PRIVACY_POLICY_URL
   718  *  will not get used on that platform.  Network-enabled phone apps should display
   719  *  their privacy policy through some other, in-app means.
   720  */
   721 #define SDL_HINT_WINRT_PRIVACY_POLICY_URL "SDL_WINRT_PRIVACY_POLICY_URL"
   722 
   723 /** \brief Label text for a WinRT app's privacy policy link
   724  *
   725  *  Network-enabled WinRT apps must include a privacy policy.  On Windows 8, 8.1, and RT,
   726  *  Microsoft mandates that this policy be available via the Windows Settings charm.
   727  *  SDL provides code to add a link there, with its label text being set via the
   728  *  optional hint, SDL_HINT_WINRT_PRIVACY_POLICY_LABEL.
   729  *
   730  *  Please note that a privacy policy's contents are not set via this hint.  A separate
   731  *  hint, SDL_HINT_WINRT_PRIVACY_POLICY_URL, is used to link to the actual text of the
   732  *  policy.
   733  *
   734  *  The contents of this hint should be encoded as a UTF8 string.
   735  *
   736  *  The default value is "Privacy Policy".  This hint should only be set during app
   737  *  initialization, preferably before any calls to SDL_Init().
   738  *
   739  *  For additional information on linking to a privacy policy, see the documentation for
   740  *  SDL_HINT_WINRT_PRIVACY_POLICY_URL.
   741  */
   742 #define SDL_HINT_WINRT_PRIVACY_POLICY_LABEL "SDL_WINRT_PRIVACY_POLICY_LABEL"
   743 
   744 /** \brief Allows back-button-press events on Windows Phone to be marked as handled
   745  *
   746  *  Windows Phone devices typically feature a Back button.  When pressed,
   747  *  the OS will emit back-button-press events, which apps are expected to
   748  *  handle in an appropriate manner.  If apps do not explicitly mark these
   749  *  events as 'Handled', then the OS will invoke its default behavior for
   750  *  unhandled back-button-press events, which on Windows Phone 8 and 8.1 is to
   751  *  terminate the app (and attempt to switch to the previous app, or to the
   752  *  device's home screen).
   753  *
   754  *  Setting the SDL_HINT_WINRT_HANDLE_BACK_BUTTON hint to "1" will cause SDL
   755  *  to mark back-button-press events as Handled, if and when one is sent to
   756  *  the app.
   757  *
   758  *  Internally, Windows Phone sends back button events as parameters to
   759  *  special back-button-press callback functions.  Apps that need to respond
   760  *  to back-button-press events are expected to register one or more
   761  *  callback functions for such, shortly after being launched (during the
   762  *  app's initialization phase).  After the back button is pressed, the OS
   763  *  will invoke these callbacks.  If the app's callback(s) do not explicitly
   764  *  mark the event as handled by the time they return, or if the app never
   765  *  registers one of these callback, the OS will consider the event
   766  *  un-handled, and it will apply its default back button behavior (terminate
   767  *  the app).
   768  *
   769  *  SDL registers its own back-button-press callback with the Windows Phone
   770  *  OS.  This callback will emit a pair of SDL key-press events (SDL_KEYDOWN
   771  *  and SDL_KEYUP), each with a scancode of SDL_SCANCODE_AC_BACK, after which
   772  *  it will check the contents of the hint, SDL_HINT_WINRT_HANDLE_BACK_BUTTON.
   773  *  If the hint's value is set to "1", the back button event's Handled
   774  *  property will get set to 'true'.  If the hint's value is set to something
   775  *  else, or if it is unset, SDL will leave the event's Handled property
   776  *  alone.  (By default, the OS sets this property to 'false', to note.)
   777  *
   778  *  SDL apps can either set SDL_HINT_WINRT_HANDLE_BACK_BUTTON well before a
   779  *  back button is pressed, or can set it in direct-response to a back button
   780  *  being pressed.
   781  *
   782  *  In order to get notified when a back button is pressed, SDL apps should
   783  *  register a callback function with SDL_AddEventWatch(), and have it listen
   784  *  for SDL_KEYDOWN events that have a scancode of SDL_SCANCODE_AC_BACK.
   785  *  (Alternatively, SDL_KEYUP events can be listened-for.  Listening for
   786  *  either event type is suitable.)  Any value of SDL_HINT_WINRT_HANDLE_BACK_BUTTON
   787  *  set by such a callback, will be applied to the OS' current
   788  *  back-button-press event.
   789  *
   790  *  More details on back button behavior in Windows Phone apps can be found
   791  *  at the following page, on Microsoft's developer site:
   792  *  http://msdn.microsoft.com/en-us/library/windowsphone/develop/jj247550(v=vs.105).aspx
   793  */
   794 #define SDL_HINT_WINRT_HANDLE_BACK_BUTTON "SDL_WINRT_HANDLE_BACK_BUTTON"
   795 
   796 /**
   797  *  \brief  A variable that dictates policy for fullscreen Spaces on Mac OS X.
   798  *
   799  *  This hint only applies to Mac OS X.
   800  *
   801  *  The variable can be set to the following values:
   802  *    "0"       - Disable Spaces support (FULLSCREEN_DESKTOP won't use them and
   803  *                SDL_WINDOW_RESIZABLE windows won't offer the "fullscreen"
   804  *                button on their titlebars).
   805  *    "1"       - Enable Spaces support (FULLSCREEN_DESKTOP will use them and
   806  *                SDL_WINDOW_RESIZABLE windows will offer the "fullscreen"
   807  *                button on their titlebars).
   808  *
   809  *  The default value is "1". Spaces are disabled regardless of this hint if
   810  *   the OS isn't at least Mac OS X Lion (10.7). This hint must be set before
   811  *   any windows are created.
   812  */
   813 #define SDL_HINT_VIDEO_MAC_FULLSCREEN_SPACES    "SDL_VIDEO_MAC_FULLSCREEN_SPACES"
   814 
   815 /**
   816 *  \brief  When set don't force the SDL app to become a foreground process
   817 *
   818 *  This hint only applies to Mac OS X.
   819 *
   820 */
   821 #define SDL_HINT_MAC_BACKGROUND_APP    "SDL_MAC_BACKGROUND_APP"
   822 
   823 /**
   824  * \brief Android APK expansion main file version. Should be a string number like "1", "2" etc.
   825  *
   826  * Must be set together with SDL_HINT_ANDROID_APK_EXPANSION_PATCH_FILE_VERSION.
   827  *
   828  * If both hints were set then SDL_RWFromFile() will look into expansion files
   829  * after a given relative path was not found in the internal storage and assets.
   830  *
   831  * By default this hint is not set and the APK expansion files are not searched.
   832  */
   833 #define SDL_HINT_ANDROID_APK_EXPANSION_MAIN_FILE_VERSION "SDL_ANDROID_APK_EXPANSION_MAIN_FILE_VERSION"
   834  
   835 /**
   836  * \brief Android APK expansion patch file version. Should be a string number like "1", "2" etc.
   837  *
   838  * Must be set together with SDL_HINT_ANDROID_APK_EXPANSION_MAIN_FILE_VERSION.
   839  *
   840  * If both hints were set then SDL_RWFromFile() will look into expansion files
   841  * after a given relative path was not found in the internal storage and assets.
   842  *
   843  * By default this hint is not set and the APK expansion files are not searched.
   844  */
   845 #define SDL_HINT_ANDROID_APK_EXPANSION_PATCH_FILE_VERSION "SDL_ANDROID_APK_EXPANSION_PATCH_FILE_VERSION"
   846 
   847 /**
   848  * \brief A variable to control whether certain IMEs should handle text editing internally instead of sending SDL_TEXTEDITING events.
   849  *
   850  * The variable can be set to the following values:
   851  *   "0"       - SDL_TEXTEDITING events are sent, and it is the application's
   852  *               responsibility to render the text from these events and 
   853  *               differentiate it somehow from committed text. (default)
   854  *   "1"       - If supported by the IME then SDL_TEXTEDITING events are not sent, 
   855  *               and text that is being composed will be rendered in its own UI.
   856  */
   857 #define SDL_HINT_IME_INTERNAL_EDITING "SDL_IME_INTERNAL_EDITING"
   858 
   859 /**
   860  * \brief A variable to control whether we trap the Android back button to handle it manually.
   861  *        This is necessary for the right mouse button to work on some Android devices, or
   862  *        to be able to trap the back button for use in your code reliably.  If set to true,
   863  *        the back button will show up as an SDL_KEYDOWN / SDL_KEYUP pair with a keycode of 
   864  *        SDL_SCANCODE_AC_BACK.
   865  *
   866  * The variable can be set to the following values:
   867  *   "0"       - Back button will be handled as usual for system. (default)
   868  *   "1"       - Back button will be trapped, allowing you to handle the key press
   869  *               manually.  (This will also let right mouse click work on systems 
   870  *               where the right mouse button functions as back.)
   871  *
   872  * The value of this hint is used at runtime, so it can be changed at any time.
   873  */
   874 #define SDL_HINT_ANDROID_TRAP_BACK_BUTTON "SDL_ANDROID_TRAP_BACK_BUTTON"
   875 
   876 /**
   877  * \brief A variable to control whether the event loop will block itself when the app is paused.
   878  *
   879  * The variable can be set to the following values:
   880  *   "0"       - Non blocking.
   881  *   "1"       - Blocking. (default)
   882  *
   883  * The value should be set before SDL is initialized.
   884  */
   885 #define SDL_HINT_ANDROID_BLOCK_ON_PAUSE "SDL_ANDROID_BLOCK_ON_PAUSE"
   886 
   887  /**
   888  * \brief A variable to control whether the return key on the soft keyboard
   889  *        should hide the soft keyboard on Android and iOS.
   890  *
   891  * The variable can be set to the following values:
   892  *   "0"       - The return key will be handled as a key event. This is the behaviour of SDL <= 2.0.3. (default)
   893  *   "1"       - The return key will hide the keyboard.
   894  *
   895  * The value of this hint is used at runtime, so it can be changed at any time.
   896  */
   897 #define SDL_HINT_RETURN_KEY_HIDES_IME "SDL_RETURN_KEY_HIDES_IME"
   898 
   899 /**
   900  *  \brief override the binding element for keyboard inputs for Emscripten builds
   901  *
   902  * This hint only applies to the emscripten platform
   903  *
   904  * The variable can be one of
   905  *    "#window"      - The javascript window object (this is the default)
   906  *    "#document"    - The javascript document object
   907  *    "#screen"      - the javascript window.screen object
   908  *    "#canvas"      - the WebGL canvas element
   909  *    any other string without a leading # sign applies to the element on the page with that ID.
   910  */
   911 #define SDL_HINT_EMSCRIPTEN_KEYBOARD_ELEMENT   "SDL_EMSCRIPTEN_KEYBOARD_ELEMENT"
   912 
   913 /**
   914  *  \brief Tell SDL not to catch the SIGINT or SIGTERM signals.
   915  *
   916  * This hint only applies to Unix-like platforms.
   917  *
   918  * The variable can be set to the following values:
   919  *   "0"       - SDL will install a SIGINT and SIGTERM handler, and when it
   920  *               catches a signal, convert it into an SDL_QUIT event.
   921  *   "1"       - SDL will not install a signal handler at all.
   922  */
   923 #define SDL_HINT_NO_SIGNAL_HANDLERS   "SDL_NO_SIGNAL_HANDLERS"
   924 
   925 /**
   926  *  \brief Tell SDL not to generate window-close events for Alt+F4 on Windows.
   927  *
   928  * The variable can be set to the following values:
   929  *   "0"       - SDL will generate a window-close event when it sees Alt+F4.
   930  *   "1"       - SDL will only do normal key handling for Alt+F4.
   931  */
   932 #define SDL_HINT_WINDOWS_NO_CLOSE_ON_ALT_F4 "SDL_WINDOWS_NO_CLOSE_ON_ALT_F4"
   933 
   934 /**
   935  *  \brief Prevent SDL from using version 4 of the bitmap header when saving BMPs.
   936  *
   937  * The bitmap header version 4 is required for proper alpha channel support and
   938  * SDL will use it when required. Should this not be desired, this hint can
   939  * force the use of the 40 byte header version which is supported everywhere.
   940  *
   941  * The variable can be set to the following values:
   942  *   "0"       - Surfaces with a colorkey or an alpha channel are saved to a
   943  *               32-bit BMP file with an alpha mask. SDL will use the bitmap
   944  *               header version 4 and set the alpha mask accordingly.
   945  *   "1"       - Surfaces with a colorkey or an alpha channel are saved to a
   946  *               32-bit BMP file without an alpha mask. The alpha channel data
   947  *               will be in the file, but applications are going to ignore it.
   948  *
   949  * The default value is "0".
   950  */
   951 #define SDL_HINT_BMP_SAVE_LEGACY_FORMAT "SDL_BMP_SAVE_LEGACY_FORMAT"
   952 
   953 /**
   954  * \brief Tell SDL not to name threads on Windows with the 0x406D1388 Exception.
   955  *        The 0x406D1388 Exception is a trick used to inform Visual Studio of a
   956  *        thread's name, but it tends to cause problems with other debuggers,
   957  *        and the .NET runtime. Note that SDL 2.0.6 and later will still use
   958  *        the (safer) SetThreadDescription API, introduced in the Windows 10
   959  *        Creators Update, if available.
   960  *
   961  * The variable can be set to the following values:
   962  *   "0"       - SDL will raise the 0x406D1388 Exception to name threads.
   963  *               This is the default behavior of SDL <= 2.0.4.
   964  *   "1"       - SDL will not raise this exception, and threads will be unnamed. (default)
   965  *               This is necessary with .NET languages or debuggers that aren't Visual Studio.
   966  */
   967 #define SDL_HINT_WINDOWS_DISABLE_THREAD_NAMING "SDL_WINDOWS_DISABLE_THREAD_NAMING"
   968 
   969 /**
   970  * \brief Tell SDL which Dispmanx layer to use on a Raspberry PI
   971  *
   972  * Also known as Z-order. The variable can take a negative or positive value.
   973  * The default is 10000.
   974  */
   975 #define SDL_HINT_RPI_VIDEO_LAYER           "SDL_RPI_VIDEO_LAYER"
   976 
   977 /**
   978  * \brief Tell the video driver that we only want a double buffer.
   979  *
   980  * By default, most lowlevel 2D APIs will use a triple buffer scheme that 
   981  * wastes no CPU time on waiting for vsync after issuing a flip, but
   982  * introduces a frame of latency. On the other hand, using a double buffer
   983  * scheme instead is recommended for cases where low latency is an important
   984  * factor because we save a whole frame of latency.
   985  * We do so by waiting for vsync immediately after issuing a flip, usually just
   986  * after eglSwapBuffers call in the backend's *_SwapWindow function.
   987  *
   988  * Since it's driver-specific, it's only supported where possible and
   989  * implemented. Currently supported the following drivers:
   990  * - KMSDRM (kmsdrm)
   991  * - Raspberry Pi (raspberrypi)
   992  */
   993 #define SDL_HINT_VIDEO_DOUBLE_BUFFER      "SDL_VIDEO_DOUBLE_BUFFER"
   994 
   995 /**
   996  *  \brief  A variable controlling what driver to use for OpenGL ES contexts.
   997  *
   998  *  On some platforms, currently Windows and X11, OpenGL drivers may support
   999  *  creating contexts with an OpenGL ES profile. By default SDL uses these
  1000  *  profiles, when available, otherwise it attempts to load an OpenGL ES
  1001  *  library, e.g. that provided by the ANGLE project. This variable controls
  1002  *  whether SDL follows this default behaviour or will always load an
  1003  *  OpenGL ES library.
  1004  *
  1005  *  Circumstances where this is useful include
  1006  *  - Testing an app with a particular OpenGL ES implementation, e.g ANGLE,
  1007  *    or emulator, e.g. those from ARM, Imagination or Qualcomm.
  1008  *  - Resolving OpenGL ES function addresses at link time by linking with
  1009  *    the OpenGL ES library instead of querying them at run time with
  1010  *    SDL_GL_GetProcAddress().
  1011  *
  1012  *  Caution: for an application to work with the default behaviour across
  1013  *  different OpenGL drivers it must query the OpenGL ES function
  1014  *  addresses at run time using SDL_GL_GetProcAddress().
  1015  *
  1016  *  This variable is ignored on most platforms because OpenGL ES is native
  1017  *  or not supported.
  1018  *
  1019  *  This variable can be set to the following values:
  1020  *    "0"       - Use ES profile of OpenGL, if available. (Default when not set.)
  1021  *    "1"       - Load OpenGL ES library using the default library names.
  1022  *
  1023  */
  1024 #define SDL_HINT_OPENGL_ES_DRIVER   "SDL_OPENGL_ES_DRIVER"
  1025 
  1026 /**
  1027  *  \brief  A variable controlling speed/quality tradeoff of audio resampling.
  1028  *
  1029  *  If available, SDL can use libsamplerate ( http://www.mega-nerd.com/SRC/ )
  1030  *  to handle audio resampling. There are different resampling modes available
  1031  *  that produce different levels of quality, using more CPU.
  1032  *
  1033  *  If this hint isn't specified to a valid setting, or libsamplerate isn't
  1034  *  available, SDL will use the default, internal resampling algorithm.
  1035  *
  1036  *  Note that this is currently only applicable to resampling audio that is
  1037  *  being written to a device for playback or audio being read from a device
  1038  *  for capture. SDL_AudioCVT always uses the default resampler (although this
  1039  *  might change for SDL 2.1).
  1040  *
  1041  *  This hint is currently only checked at audio subsystem initialization.
  1042  *
  1043  *  This variable can be set to the following values:
  1044  *
  1045  *    "0" or "default" - Use SDL's internal resampling (Default when not set - low quality, fast)
  1046  *    "1" or "fast"    - Use fast, slightly higher quality resampling, if available
  1047  *    "2" or "medium"  - Use medium quality resampling, if available
  1048  *    "3" or "best"    - Use high quality resampling, if available
  1049  */
  1050 #define SDL_HINT_AUDIO_RESAMPLING_MODE   "SDL_AUDIO_RESAMPLING_MODE"
  1051 
  1052 /**
  1053  *  \brief  A variable controlling the audio category on iOS and Mac OS X
  1054  *
  1055  *  This variable can be set to the following values:
  1056  *
  1057  *    "ambient"     - Use the AVAudioSessionCategoryAmbient audio category, will be muted by the phone mute switch (default)
  1058  *    "playback"    - Use the AVAudioSessionCategoryPlayback category
  1059  *
  1060  *  For more information, see Apple's documentation:
  1061  *  https://developer.apple.com/library/content/documentation/Audio/Conceptual/AudioSessionProgrammingGuide/AudioSessionCategoriesandModes/AudioSessionCategoriesandModes.html
  1062  */
  1063 #define SDL_HINT_AUDIO_CATEGORY   "SDL_AUDIO_CATEGORY"
  1064 
  1065 /**
  1066  *  \brief  A variable controlling whether the 2D render API is compatible or efficient.
  1067  *
  1068  *  This variable can be set to the following values:
  1069  *
  1070  *    "0"     - Don't use batching to make rendering more efficient.
  1071  *    "1"     - Use batching, but might cause problems if app makes its own direct OpenGL calls.
  1072  *
  1073  *  Up to SDL 2.0.9, the render API would draw immediately when requested. Now
  1074  *  it batches up draw requests and sends them all to the GPU only when forced
  1075  *  to (during SDL_RenderPresent, when changing render targets, by updating a
  1076  *  texture that the batch needs, etc). This is significantly more efficient,
  1077  *  but it can cause problems for apps that expect to render on top of the
  1078  *  render API's output. As such, SDL will disable batching if a specific
  1079  *  render backend is requested (since this might indicate that the app is
  1080  *  planning to use the underlying graphics API directly). This hint can
  1081  *  be used to explicitly request batching in this instance. It is a contract
  1082  *  that you will either never use the underlying graphics API directly, or
  1083  *  if you do, you will call SDL_RenderFlush() before you do so any current
  1084  *  batch goes to the GPU before your work begins. Not following this contract
  1085  *  will result in undefined behavior.
  1086  */
  1087 #define SDL_HINT_RENDER_BATCHING  "SDL_RENDER_BATCHING"
  1088 
  1089 
  1090 /**
  1091  *  \brief  A variable controlling whether SDL logs all events pushed onto its internal queue.
  1092  *
  1093  *  This variable can be set to the following values:
  1094  *
  1095  *    "0"     - Don't log any events (default)
  1096  *    "1"     - Log all events except mouse and finger motion, which are pretty spammy.
  1097  *    "2"     - Log all events.
  1098  *
  1099  *  This is generally meant to be used to debug SDL itself, but can be useful
  1100  *  for application developers that need better visibility into what is going
  1101  *  on in the event queue. Logged events are sent through SDL_Log(), which
  1102  *  means by default they appear on stdout on most platforms or maybe
  1103  *  OutputDebugString() on Windows, and can be funneled by the app with
  1104  *  SDL_LogSetOutputFunction(), etc.
  1105  *
  1106  *  This hint can be toggled on and off at runtime, if you only need to log
  1107  *  events for a small subset of program execution.
  1108  */
  1109 #define SDL_HINT_EVENT_LOGGING   "SDL_EVENT_LOGGING"
  1110 
  1111 
  1112 
  1113 /**
  1114  *  \brief  Controls how the size of the RIFF chunk affects the loading of a WAVE file.
  1115  *
  1116  *  The size of the RIFF chunk (which includes all the sub-chunks of the WAVE
  1117  *  file) is not always reliable. In case the size is wrong, it's possible to
  1118  *  just ignore it and step through the chunks until a fixed limit is reached.
  1119  *
  1120  *  Note that files that have trailing data unrelated to the WAVE file or
  1121  *  corrupt files may slow down the loading process without a reliable boundary.
  1122  *  By default, SDL stops after 10000 chunks to prevent wasting time. Use the
  1123  *  environment variable SDL_WAVE_CHUNK_LIMIT to adjust this value.
  1124  *
  1125  *  This variable can be set to the following values:
  1126  *
  1127  *    "force"        - Always use the RIFF chunk size as a boundary for the chunk search
  1128  *    "ignorezero"   - Like "force", but a zero size searches up to 4 GiB (default)
  1129  *    "ignore"       - Ignore the RIFF chunk size and always search up to 4 GiB
  1130  *    "maximum"      - Search for chunks until the end of file (not recommended)
  1131  */
  1132 #define SDL_HINT_WAVE_RIFF_CHUNK_SIZE   "SDL_WAVE_RIFF_CHUNK_SIZE"
  1133 
  1134 /**
  1135  *  \brief  Controls how a truncated WAVE file is handled.
  1136  *
  1137  *  A WAVE file is considered truncated if any of the chunks are incomplete or
  1138  *  the data chunk size is not a multiple of the block size. By default, SDL
  1139  *  decodes until the first incomplete block, as most applications seem to do.
  1140  *
  1141  *  This variable can be set to the following values:
  1142  *
  1143  *    "verystrict" - Raise an error if the file is truncated
  1144  *    "strict"     - Like "verystrict", but the size of the RIFF chunk is ignored
  1145  *    "dropframe"  - Decode until the first incomplete sample frame
  1146  *    "dropblock"  - Decode until the first incomplete block (default)
  1147  */
  1148 #define SDL_HINT_WAVE_TRUNCATION   "SDL_WAVE_TRUNCATION"
  1149 
  1150 /**
  1151  *  \brief  Controls how the fact chunk affects the loading of a WAVE file.
  1152  *
  1153  *  The fact chunk stores information about the number of samples of a WAVE
  1154  *  file. The Standards Update from Microsoft notes that this value can be used
  1155  *  to 'determine the length of the data in seconds'. This is especially useful
  1156  *  for compressed formats (for which this is a mandatory chunk) if they produce
  1157  *  multiple sample frames per block and truncating the block is not allowed.
  1158  *  The fact chunk can exactly specify how many sample frames there should be
  1159  *  in this case.
  1160  *
  1161  *  Unfortunately, most application seem to ignore the fact chunk and so SDL
  1162  *  ignores it by default as well.
  1163  *
  1164  *  This variable can be set to the following values:
  1165  *
  1166  *    "truncate"    - Use the number of samples to truncate the wave data if
  1167  *                    the fact chunk is present and valid
  1168  *    "strict"      - Like "truncate", but raise an error if the fact chunk
  1169  *                    is invalid, not present for non-PCM formats, or if the
  1170  *                    data chunk doesn't have that many samples
  1171  *    "ignorezero"  - Like "truncate", but ignore fact chunk if the number of
  1172  *                    samples is zero
  1173  *    "ignore"      - Ignore fact chunk entirely (default)
  1174  */
  1175 #define SDL_HINT_WAVE_FACT_CHUNK   "SDL_WAVE_FACT_CHUNK"
  1176 
  1177 /**
  1178  *  \brief  An enumeration of hint priorities
  1179  */
  1180 typedef enum
  1181 {
  1182     SDL_HINT_DEFAULT,
  1183     SDL_HINT_NORMAL,
  1184     SDL_HINT_OVERRIDE
  1185 } SDL_HintPriority;
  1186 
  1187 
  1188 /**
  1189  *  \brief Set a hint with a specific priority
  1190  *
  1191  *  The priority controls the behavior when setting a hint that already
  1192  *  has a value.  Hints will replace existing hints of their priority and
  1193  *  lower.  Environment variables are considered to have override priority.
  1194  *
  1195  *  \return SDL_TRUE if the hint was set, SDL_FALSE otherwise
  1196  */
  1197 extern DECLSPEC SDL_bool SDLCALL SDL_SetHintWithPriority(const char *name,
  1198                                                          const char *value,
  1199                                                          SDL_HintPriority priority);
  1200 
  1201 /**
  1202  *  \brief Set a hint with normal priority
  1203  *
  1204  *  \return SDL_TRUE if the hint was set, SDL_FALSE otherwise
  1205  */
  1206 extern DECLSPEC SDL_bool SDLCALL SDL_SetHint(const char *name,
  1207                                              const char *value);
  1208 
  1209 /**
  1210  *  \brief Get a hint
  1211  *
  1212  *  \return The string value of a hint variable.
  1213  */
  1214 extern DECLSPEC const char * SDLCALL SDL_GetHint(const char *name);
  1215 
  1216 /**
  1217  *  \brief Get a hint
  1218  *
  1219  *  \return The boolean value of a hint variable.
  1220  */
  1221 extern DECLSPEC SDL_bool SDLCALL SDL_GetHintBoolean(const char *name, SDL_bool default_value);
  1222 
  1223 /**
  1224  * \brief type definition of the hint callback function.
  1225  */
  1226 typedef void (SDLCALL *SDL_HintCallback)(void *userdata, const char *name, const char *oldValue, const char *newValue);
  1227 
  1228 /**
  1229  *  \brief Add a function to watch a particular hint
  1230  *
  1231  *  \param name The hint to watch
  1232  *  \param callback The function to call when the hint value changes
  1233  *  \param userdata A pointer to pass to the callback function
  1234  */
  1235 extern DECLSPEC void SDLCALL SDL_AddHintCallback(const char *name,
  1236                                                  SDL_HintCallback callback,
  1237                                                  void *userdata);
  1238 
  1239 /**
  1240  *  \brief Remove a function watching a particular hint
  1241  *
  1242  *  \param name The hint being watched
  1243  *  \param callback The function being called when the hint value changes
  1244  *  \param userdata A pointer being passed to the callback function
  1245  */
  1246 extern DECLSPEC void SDLCALL SDL_DelHintCallback(const char *name,
  1247                                                  SDL_HintCallback callback,
  1248                                                  void *userdata);
  1249 
  1250 /**
  1251  *  \brief  Clear all hints
  1252  *
  1253  *  This function is called during SDL_Quit() to free stored hints.
  1254  */
  1255 extern DECLSPEC void SDLCALL SDL_ClearHints(void);
  1256 
  1257 
  1258 /* Ends C function definitions when using C++ */
  1259 #ifdef __cplusplus
  1260 }
  1261 #endif
  1262 #include "close_code.h"
  1263 
  1264 #endif /* SDL_hints_h_ */
  1265 
  1266 /* vi: set ts=4 sw=4 expandtab: */