SDL  2.0
SDL_hints.h
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1 /*
2  Simple DirectMedia Layer
3  Copyright (C) 1997-2021 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 whether the Android / iOS built-in
52  * accelerometer should be listed as a joystick device.
53  *
54  * This variable can be set to the following values:
55  * "0" - The accelerometer is not listed as a joystick
56  * "1" - The accelerometer is available as a 3 axis joystick (the default).
57  */
58 #define SDL_HINT_ACCELEROMETER_AS_JOYSTICK "SDL_ACCELEROMETER_AS_JOYSTICK"
59 
60 /**
61  * \brief Specify the behavior of Alt+Tab while the keyboard is grabbed.
62  *
63  * By default, SDL emulates Alt+Tab functionality while the keyboard is grabbed
64  * and your window is full-screen. This prevents the user from getting stuck in
65  * your application if you've enabled keyboard grab.
66  *
67  * The variable can be set to the following values:
68  * "0" - SDL will not handle Alt+Tab. Your application is responsible
69  for handling Alt+Tab while the keyboard is grabbed.
70  * "1" - SDL will minimize your window when Alt+Tab is pressed (default)
71 */
72 #define SDL_HINT_ALLOW_ALT_TAB_WHILE_GRABBED "SDL_ALLOW_ALT_TAB_WHILE_GRABBED"
73 
74 /**
75  * \brief If set to "0" then never set the top most bit on a SDL Window, even if the video mode expects it.
76  * This is a debugging aid for developers and not expected to be used by end users. The default is "1"
77  *
78  * This variable can be set to the following values:
79  * "0" - don't allow topmost
80  * "1" - allow topmost
81  */
82 #define SDL_HINT_ALLOW_TOPMOST "SDL_ALLOW_TOPMOST"
83 
84 /**
85  * \brief Android APK expansion main file version. Should be a string number like "1", "2" etc.
86  *
87  * Must be set together with SDL_HINT_ANDROID_APK_EXPANSION_PATCH_FILE_VERSION.
88  *
89  * If both hints were set then SDL_RWFromFile() will look into expansion files
90  * after a given relative path was not found in the internal storage and assets.
91  *
92  * By default this hint is not set and the APK expansion files are not searched.
93  */
94 #define SDL_HINT_ANDROID_APK_EXPANSION_MAIN_FILE_VERSION "SDL_ANDROID_APK_EXPANSION_MAIN_FILE_VERSION"
95 
96 /**
97  * \brief Android APK expansion patch file version. Should be a string number like "1", "2" etc.
98  *
99  * Must be set together with SDL_HINT_ANDROID_APK_EXPANSION_MAIN_FILE_VERSION.
100  *
101  * If both hints were set then SDL_RWFromFile() will look into expansion files
102  * after a given relative path was not found in the internal storage and assets.
103  *
104  * By default this hint is not set and the APK expansion files are not searched.
105  */
106 #define SDL_HINT_ANDROID_APK_EXPANSION_PATCH_FILE_VERSION "SDL_ANDROID_APK_EXPANSION_PATCH_FILE_VERSION"
107 
108 /**
109  * \brief A variable to control whether the event loop will block itself when the app is paused.
110  *
111  * The variable can be set to the following values:
112  * "0" - Non blocking.
113  * "1" - Blocking. (default)
114  *
115  * The value should be set before SDL is initialized.
116  */
117 #define SDL_HINT_ANDROID_BLOCK_ON_PAUSE "SDL_ANDROID_BLOCK_ON_PAUSE"
118 
119 /**
120  * \brief A variable to control whether SDL will pause audio in background
121  * (Requires SDL_ANDROID_BLOCK_ON_PAUSE as "Non blocking")
122  *
123  * The variable can be set to the following values:
124  * "0" - Non paused.
125  * "1" - Paused. (default)
126  *
127  * The value should be set before SDL is initialized.
128  */
129 #define SDL_HINT_ANDROID_BLOCK_ON_PAUSE_PAUSEAUDIO "SDL_ANDROID_BLOCK_ON_PAUSE_PAUSEAUDIO"
130 
131 /**
132  * \brief A variable to control whether we trap the Android back button to handle it manually.
133  * This is necessary for the right mouse button to work on some Android devices, or
134  * to be able to trap the back button for use in your code reliably. If set to true,
135  * the back button will show up as an SDL_KEYDOWN / SDL_KEYUP pair with a keycode of
136  * SDL_SCANCODE_AC_BACK.
137  *
138  * The variable can be set to the following values:
139  * "0" - Back button will be handled as usual for system. (default)
140  * "1" - Back button will be trapped, allowing you to handle the key press
141  * manually. (This will also let right mouse click work on systems
142  * where the right mouse button functions as back.)
143  *
144  * The value of this hint is used at runtime, so it can be changed at any time.
145  */
146 #define SDL_HINT_ANDROID_TRAP_BACK_BUTTON "SDL_ANDROID_TRAP_BACK_BUTTON"
147 
148 /**
149  * \brief A variable controlling whether controllers used with the Apple TV
150  * generate UI events.
151  *
152  * When UI events are generated by controller input, the app will be
153  * backgrounded when the Apple TV remote's menu button is pressed, and when the
154  * pause or B buttons on gamepads are pressed.
155  *
156  * More information about properly making use of controllers for the Apple TV
157  * can be found here:
158  * https://developer.apple.com/tvos/human-interface-guidelines/remote-and-controllers/
159  *
160  * This variable can be set to the following values:
161  * "0" - Controller input does not generate UI events (the default).
162  * "1" - Controller input generates UI events.
163  */
164 #define SDL_HINT_APPLE_TV_CONTROLLER_UI_EVENTS "SDL_APPLE_TV_CONTROLLER_UI_EVENTS"
165 
166 /**
167  * \brief A variable controlling whether the Apple TV remote's joystick axes
168  * will automatically match the rotation of the remote.
169  *
170  * This variable can be set to the following values:
171  * "0" - Remote orientation does not affect joystick axes (the default).
172  * "1" - Joystick axes are based on the orientation of the remote.
173  */
174 #define SDL_HINT_APPLE_TV_REMOTE_ALLOW_ROTATION "SDL_APPLE_TV_REMOTE_ALLOW_ROTATION"
175 
176 /**
177  * \brief A variable controlling the audio category on iOS and Mac OS X
178  *
179  * This variable can be set to the following values:
180  *
181  * "ambient" - Use the AVAudioSessionCategoryAmbient audio category, will be muted by the phone mute switch (default)
182  * "playback" - Use the AVAudioSessionCategoryPlayback category
183  *
184  * For more information, see Apple's documentation:
185  * https://developer.apple.com/library/content/documentation/Audio/Conceptual/AudioSessionProgrammingGuide/AudioSessionCategoriesandModes/AudioSessionCategoriesandModes.html
186  */
187 #define SDL_HINT_AUDIO_CATEGORY "SDL_AUDIO_CATEGORY"
188 
189 /**
190  * \brief Specify an application name for an audio device.
191  *
192  * Some audio backends (such as PulseAudio) allow you to describe your audio
193  * stream. Among other things, this description might show up in a system
194  * control panel that lets the user adjust the volume on specific audio
195  * streams instead of using one giant master volume slider.
196  *
197  * This hints lets you transmit that information to the OS. The contents of
198  * this hint are used while opening an audio device. You should use a string
199  * that describes your program ("My Game 2: The Revenge")
200  *
201  * Setting this to "" or leaving it unset will have SDL use a reasonable
202  * default: probably the application's name or "SDL Application" if SDL
203  * doesn't have any better information.
204  *
205  * On targets where this is not supported, this hint does nothing.
206  */
207 #define SDL_HINT_AUDIO_DEVICE_APP_NAME "SDL_AUDIO_DEVICE_APP_NAME"
208 
209 /**
210  * \brief Specify an application name for an audio device.
211  *
212  * Some audio backends (such as PulseAudio) allow you to describe your audio
213  * stream. Among other things, this description might show up in a system
214  * control panel that lets the user adjust the volume on specific audio
215  * streams instead of using one giant master volume slider.
216  *
217  * This hints lets you transmit that information to the OS. The contents of
218  * this hint are used while opening an audio device. You should use a string
219  * that describes your what your program is playing ("audio stream" is
220  * probably sufficient in many cases, but this could be useful for something
221  * like "team chat" if you have a headset playing VoIP audio separately).
222  *
223  * Setting this to "" or leaving it unset will have SDL use a reasonable
224  * default: "audio stream" or something similar.
225  *
226  * On targets where this is not supported, this hint does nothing.
227  */
228 #define SDL_HINT_AUDIO_DEVICE_STREAM_NAME "SDL_AUDIO_DEVICE_STREAM_NAME"
229 
230 /**
231  * \brief Specify an application role for an audio device.
232  *
233  * Some audio backends (such as Pipewire) allow you to describe the role of
234  * your audio stream. Among other things, this description might show up in
235  * a system control panel or software for displaying and manipulating media
236  * playback/capture graphs.
237  *
238  * This hints lets you transmit that information to the OS. The contents of
239  * this hint are used while opening an audio device. You should use a string
240  * that describes your what your program is playing (Game, Music, Movie,
241  * etc...).
242  *
243  * Setting this to "" or leaving it unset will have SDL use a reasonable
244  * default: "Game" or something similar.
245  *
246  * On targets where this is not supported, this hint does nothing.
247  */
248 #define SDL_HINT_AUDIO_DEVICE_STREAM_ROLE "SDL_AUDIO_DEVICE_STREAM_ROLE"
249 
250 /**
251  * \brief A variable controlling speed/quality tradeoff of audio resampling.
252  *
253  * If available, SDL can use libsamplerate ( http://www.mega-nerd.com/SRC/ )
254  * to handle audio resampling. There are different resampling modes available
255  * that produce different levels of quality, using more CPU.
256  *
257  * If this hint isn't specified to a valid setting, or libsamplerate isn't
258  * available, SDL will use the default, internal resampling algorithm.
259  *
260  * Note that this is currently only applicable to resampling audio that is
261  * being written to a device for playback or audio being read from a device
262  * for capture. SDL_AudioCVT always uses the default resampler (although this
263  * might change for SDL 2.1).
264  *
265  * This hint is currently only checked at audio subsystem initialization.
266  *
267  * This variable can be set to the following values:
268  *
269  * "0" or "default" - Use SDL's internal resampling (Default when not set - low quality, fast)
270  * "1" or "fast" - Use fast, slightly higher quality resampling, if available
271  * "2" or "medium" - Use medium quality resampling, if available
272  * "3" or "best" - Use high quality resampling, if available
273  */
274 #define SDL_HINT_AUDIO_RESAMPLING_MODE "SDL_AUDIO_RESAMPLING_MODE"
275 
276 /**
277  * \brief A variable controlling whether SDL updates joystick state when getting input events
278  *
279  * This variable can be set to the following values:
280  *
281  * "0" - You'll call SDL_JoystickUpdate() manually
282  * "1" - SDL will automatically call SDL_JoystickUpdate() (default)
283  *
284  * This hint can be toggled on and off at runtime.
285  */
286 #define SDL_HINT_AUTO_UPDATE_JOYSTICKS "SDL_AUTO_UPDATE_JOYSTICKS"
287 
288 /**
289  * \brief A variable controlling whether SDL updates sensor state when getting input events
290  *
291  * This variable can be set to the following values:
292  *
293  * "0" - You'll call SDL_SensorUpdate() manually
294  * "1" - SDL will automatically call SDL_SensorUpdate() (default)
295  *
296  * This hint can be toggled on and off at runtime.
297  */
298 #define SDL_HINT_AUTO_UPDATE_SENSORS "SDL_AUTO_UPDATE_SENSORS"
299 
300 /**
301  * \brief Prevent SDL from using version 4 of the bitmap header when saving BMPs.
302  *
303  * The bitmap header version 4 is required for proper alpha channel support and
304  * SDL will use it when required. Should this not be desired, this hint can
305  * force the use of the 40 byte header version which is supported everywhere.
306  *
307  * The variable can be set to the following values:
308  * "0" - Surfaces with a colorkey or an alpha channel are saved to a
309  * 32-bit BMP file with an alpha mask. SDL will use the bitmap
310  * header version 4 and set the alpha mask accordingly.
311  * "1" - Surfaces with a colorkey or an alpha channel are saved to a
312  * 32-bit BMP file without an alpha mask. The alpha channel data
313  * will be in the file, but applications are going to ignore it.
314  *
315  * The default value is "0".
316  */
317 #define SDL_HINT_BMP_SAVE_LEGACY_FORMAT "SDL_BMP_SAVE_LEGACY_FORMAT"
318 
319 /**
320  * \brief Override for SDL_GetDisplayUsableBounds()
321  *
322  * If set, this hint will override the expected results for
323  * SDL_GetDisplayUsableBounds() for display index 0. Generally you don't want
324  * to do this, but this allows an embedded system to request that some of the
325  * screen be reserved for other uses when paired with a well-behaved
326  * application.
327  *
328  * The contents of this hint must be 4 comma-separated integers, the first
329  * is the bounds x, then y, width and height, in that order.
330  */
331 #define SDL_HINT_DISPLAY_USABLE_BOUNDS "SDL_DISPLAY_USABLE_BOUNDS"
332 
333 /**
334  * \brief Disable giving back control to the browser automatically
335  * when running with asyncify
336  *
337  * With -s ASYNCIFY, SDL2 calls emscripten_sleep during operations
338  * such as refreshing the screen or polling events.
339  *
340  * This hint only applies to the emscripten platform
341  *
342  * The variable can be set to the following values:
343  * "0" - Disable emscripten_sleep calls (if you give back browser control manually or use asyncify for other purposes)
344  * "1" - Enable emscripten_sleep calls (the default)
345  */
346 #define SDL_HINT_EMSCRIPTEN_ASYNCIFY "SDL_EMSCRIPTEN_ASYNCIFY"
347 
348 /**
349  * \brief override the binding element for keyboard inputs for Emscripten builds
350  *
351  * This hint only applies to the emscripten platform
352  *
353  * The variable can be one of
354  * "#window" - The javascript window object (this is the default)
355  * "#document" - The javascript document object
356  * "#screen" - the javascript window.screen object
357  * "#canvas" - the WebGL canvas element
358  * any other string without a leading # sign applies to the element on the page with that ID.
359  */
360 #define SDL_HINT_EMSCRIPTEN_KEYBOARD_ELEMENT "SDL_EMSCRIPTEN_KEYBOARD_ELEMENT"
361 
362 /**
363  * \brief A variable that controls whether Steam Controllers should be exposed using the SDL joystick and game controller APIs
364  *
365  * The variable can be set to the following values:
366  * "0" - Do not scan for Steam Controllers
367  * "1" - Scan for Steam Controllers (the default)
368  *
369  * The default value is "1". This hint must be set before initializing the joystick subsystem.
370  */
371 #define SDL_HINT_ENABLE_STEAM_CONTROLLERS "SDL_ENABLE_STEAM_CONTROLLERS"
372 
373 /**
374  * \brief A variable controlling whether SDL logs all events pushed onto its internal queue.
375  *
376  * This variable can be set to the following values:
377  *
378  * "0" - Don't log any events (default)
379  * "1" - Log all events except mouse and finger motion, which are pretty spammy.
380  * "2" - Log all events.
381  *
382  * This is generally meant to be used to debug SDL itself, but can be useful
383  * for application developers that need better visibility into what is going
384  * on in the event queue. Logged events are sent through SDL_Log(), which
385  * means by default they appear on stdout on most platforms or maybe
386  * OutputDebugString() on Windows, and can be funneled by the app with
387  * SDL_LogSetOutputFunction(), etc.
388  *
389  * This hint can be toggled on and off at runtime, if you only need to log
390  * events for a small subset of program execution.
391  */
392 #define SDL_HINT_EVENT_LOGGING "SDL_EVENT_LOGGING"
393 
394 /**
395  * \brief A variable controlling how 3D acceleration is used to accelerate the SDL screen surface.
396  *
397  * SDL can try to accelerate the SDL screen surface by using streaming
398  * textures with a 3D rendering engine. This variable controls whether and
399  * how this is done.
400  *
401  * This variable can be set to the following values:
402  * "0" - Disable 3D acceleration
403  * "1" - Enable 3D acceleration, using the default renderer.
404  * "X" - Enable 3D acceleration, using X where X is one of the valid rendering drivers. (e.g. "direct3d", "opengl", etc.)
405  *
406  * By default SDL tries to make a best guess for each platform whether
407  * to use acceleration or not.
408  */
409 #define SDL_HINT_FRAMEBUFFER_ACCELERATION "SDL_FRAMEBUFFER_ACCELERATION"
410 
411 /**
412  * \brief A variable that lets you manually hint extra gamecontroller db entries.
413  *
414  * The variable should be newline delimited rows of gamecontroller config data, see SDL_gamecontroller.h
415  *
416  * This hint must be set before calling SDL_Init(SDL_INIT_GAMECONTROLLER)
417  * You can update mappings after the system is initialized with SDL_GameControllerMappingForGUID() and SDL_GameControllerAddMapping()
418  */
419 #define SDL_HINT_GAMECONTROLLERCONFIG "SDL_GAMECONTROLLERCONFIG"
420 
421 /**
422  * \brief A variable that lets you provide a file with extra gamecontroller db entries.
423  *
424  * The file should contain lines of gamecontroller config data, see SDL_gamecontroller.h
425  *
426  * This hint must be set before calling SDL_Init(SDL_INIT_GAMECONTROLLER)
427  * You can update mappings after the system is initialized with SDL_GameControllerMappingForGUID() and SDL_GameControllerAddMapping()
428  */
429 #define SDL_HINT_GAMECONTROLLERCONFIG_FILE "SDL_GAMECONTROLLERCONFIG_FILE"
430 
431 /**
432  * \brief A variable that overrides the automatic controller type detection
433  *
434  * The variable should be comma separated entries, in the form: VID/PID=type
435  *
436  * The VID and PID should be hexadecimal with exactly 4 digits, e.g. 0x00fd
437  *
438  * The type should be one of:
439  * Xbox360
440  * XboxOne
441  * PS3
442  * PS4
443  * PS5
444  * SwitchPro
445  *
446  * This hint affects what driver is used, and must be set before calling SDL_Init(SDL_INIT_GAMECONTROLLER)
447  */
448 #define SDL_HINT_GAMECONTROLLERTYPE "SDL_GAMECONTROLLERTYPE"
449 
450 /**
451  * \brief A variable containing a list of devices to skip when scanning for game controllers.
452  *
453  * The format of the string is a comma separated list of USB VID/PID pairs
454  * in hexadecimal form, e.g.
455  *
456  * 0xAAAA/0xBBBB,0xCCCC/0xDDDD
457  *
458  * The variable can also take the form of @file, in which case the named
459  * file will be loaded and interpreted as the value of the variable.
460  */
461 #define SDL_HINT_GAMECONTROLLER_IGNORE_DEVICES "SDL_GAMECONTROLLER_IGNORE_DEVICES"
462 
463 /**
464  * \brief If set, all devices will be skipped when scanning for game controllers except for the ones listed in this variable.
465  *
466  * The format of the string is a comma separated list of USB VID/PID pairs
467  * in hexadecimal form, e.g.
468  *
469  * 0xAAAA/0xBBBB,0xCCCC/0xDDDD
470  *
471  * The variable can also take the form of @file, in which case the named
472  * file will be loaded and interpreted as the value of the variable.
473  */
474 #define SDL_HINT_GAMECONTROLLER_IGNORE_DEVICES_EXCEPT "SDL_GAMECONTROLLER_IGNORE_DEVICES_EXCEPT"
475 
476 /**
477  * \brief If set, game controller face buttons report their values according to their labels instead of their positional layout.
478  *
479  * For example, on Nintendo Switch controllers, normally you'd get:
480  *
481  * (Y)
482  * (X) (B)
483  * (A)
484  *
485  * but if this hint is set, you'll get:
486  *
487  * (X)
488  * (Y) (A)
489  * (B)
490  *
491  * The variable can be set to the following values:
492  * "0" - Report the face buttons by position, as though they were on an Xbox controller.
493  * "1" - Report the face buttons by label instead of position
494  *
495  * The default value is "1". This hint may be set at any time.
496  */
497 #define SDL_HINT_GAMECONTROLLER_USE_BUTTON_LABELS "SDL_GAMECONTROLLER_USE_BUTTON_LABELS"
498 
499 /**
500  * \brief A variable controlling whether grabbing input grabs the keyboard
501  *
502  * This variable can be set to the following values:
503  * "0" - Grab will affect only the mouse
504  * "1" - Grab will affect mouse and keyboard
505  *
506  * By default SDL will not grab the keyboard so system shortcuts still work.
507  */
508 #define SDL_HINT_GRAB_KEYBOARD "SDL_GRAB_KEYBOARD"
509 
510 /**
511  * \brief A variable controlling whether the idle timer is disabled on iOS.
512  *
513  * When an iOS app does not receive touches for some time, the screen is
514  * dimmed automatically. For games where the accelerometer is the only input
515  * this is problematic. This functionality can be disabled by setting this
516  * hint.
517  *
518  * As of SDL 2.0.4, SDL_EnableScreenSaver() and SDL_DisableScreenSaver()
519  * accomplish the same thing on iOS. They should be preferred over this hint.
520  *
521  * This variable can be set to the following values:
522  * "0" - Enable idle timer
523  * "1" - Disable idle timer
524  */
525 #define SDL_HINT_IDLE_TIMER_DISABLED "SDL_IOS_IDLE_TIMER_DISABLED"
526 
527 /**
528  * \brief A variable to control whether certain IMEs should handle text editing internally instead of sending SDL_TEXTEDITING events.
529  *
530  * The variable can be set to the following values:
531  * "0" - SDL_TEXTEDITING events are sent, and it is the application's
532  * responsibility to render the text from these events and
533  * differentiate it somehow from committed text. (default)
534  * "1" - If supported by the IME then SDL_TEXTEDITING events are not sent,
535  * and text that is being composed will be rendered in its own UI.
536  */
537 #define SDL_HINT_IME_INTERNAL_EDITING "SDL_IME_INTERNAL_EDITING"
538 
539 /**
540  * \brief A variable controlling whether the home indicator bar on iPhone X
541  * should be hidden.
542  *
543  * This variable can be set to the following values:
544  * "0" - The indicator bar is not hidden (default for windowed applications)
545  * "1" - The indicator bar is hidden and is shown when the screen is touched (useful for movie playback applications)
546  * "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)
547  */
548 #define SDL_HINT_IOS_HIDE_HOME_INDICATOR "SDL_IOS_HIDE_HOME_INDICATOR"
549 
550 /**
551  * \brief A variable that lets you enable joystick (and gamecontroller) events even when your app is in the background.
552  *
553  * The variable can be set to the following values:
554  * "0" - Disable joystick & gamecontroller input events when the
555  * application is in the background.
556  * "1" - Enable joystick & gamecontroller input events when the
557  * application is in the background.
558  *
559  * The default value is "0". This hint may be set at any time.
560  */
561 #define SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS "SDL_JOYSTICK_ALLOW_BACKGROUND_EVENTS"
562 
563 /**
564  * \brief A variable controlling whether the HIDAPI joystick drivers should be used.
565  *
566  * This variable can be set to the following values:
567  * "0" - HIDAPI drivers are not used
568  * "1" - HIDAPI drivers are used (the default)
569  *
570  * This variable is the default for all drivers, but can be overridden by the hints for specific drivers below.
571  */
572 #define SDL_HINT_JOYSTICK_HIDAPI "SDL_JOYSTICK_HIDAPI"
573 
574 /**
575  * \brief A variable controlling whether the HIDAPI driver for Nintendo GameCube controllers should be used.
576  *
577  * This variable can be set to the following values:
578  * "0" - HIDAPI driver is not used
579  * "1" - HIDAPI driver is used
580  *
581  * The default is the value of SDL_HINT_JOYSTICK_HIDAPI
582  */
583 #define SDL_HINT_JOYSTICK_HIDAPI_GAMECUBE "SDL_JOYSTICK_HIDAPI_GAMECUBE"
584 
585  /**
586  * \brief A variable controlling whether Switch Joy-Cons should be treated the same as Switch Pro Controllers when using the HIDAPI driver.
587  *
588  * This variable can be set to the following values:
589  * "0" - basic Joy-Con support with no analog input (the default)
590  * "1" - Joy-Cons treated as half full Pro Controllers with analog inputs and sensors
591  *
592  * This does not combine Joy-Cons into a single controller. That's up to the user.
593  */
594 #define SDL_HINT_JOYSTICK_HIDAPI_JOY_CONS "SDL_JOYSTICK_HIDAPI_JOY_CONS"
595 
596  /**
597  * \brief A variable controlling whether the HIDAPI driver for Amazon Luna controllers connected via Bluetooth should be used.
598  *
599  * This variable can be set to the following values:
600  * "0" - HIDAPI driver is not used
601  * "1" - HIDAPI driver is used
602  *
603  * The default is the value of SDL_HINT_JOYSTICK_HIDAPI
604  */
605 #define SDL_HINT_JOYSTICK_HIDAPI_LUNA "SDL_JOYSTICK_HIDAPI_LUNA"
606 
607 /**
608  * \brief A variable controlling whether the HIDAPI driver for PS4 controllers should be used.
609  *
610  * This variable can be set to the following values:
611  * "0" - HIDAPI driver is not used
612  * "1" - HIDAPI driver is used
613  *
614  * The default is the value of SDL_HINT_JOYSTICK_HIDAPI
615  */
616 #define SDL_HINT_JOYSTICK_HIDAPI_PS4 "SDL_JOYSTICK_HIDAPI_PS4"
617 
618 /**
619  * \brief A variable controlling whether extended input reports should be used for PS4 controllers when using the HIDAPI driver.
620  *
621  * This variable can be set to the following values:
622  * "0" - extended reports are not enabled (the default)
623  * "1" - extended reports
624  *
625  * Extended input reports allow rumble on Bluetooth PS4 controllers, but
626  * break DirectInput handling for applications that don't use SDL.
627  *
628  * Once extended reports are enabled, they can not be disabled without
629  * power cycling the controller.
630  *
631  * For compatibility with applications written for versions of SDL prior
632  * to the introduction of PS5 controller support, this value will also
633  * control the state of extended reports on PS5 controllers when the
634  * SDL_HINT_JOYSTICK_HIDAPI_PS5_RUMBLE hint is not explicitly set.
635  */
636 #define SDL_HINT_JOYSTICK_HIDAPI_PS4_RUMBLE "SDL_JOYSTICK_HIDAPI_PS4_RUMBLE"
637 
638 /**
639  * \brief A variable controlling whether the HIDAPI driver for PS5 controllers should be used.
640  *
641  * This variable can be set to the following values:
642  * "0" - HIDAPI driver is not used
643  * "1" - HIDAPI driver is used
644  *
645  * The default is the value of SDL_HINT_JOYSTICK_HIDAPI
646  */
647 #define SDL_HINT_JOYSTICK_HIDAPI_PS5 "SDL_JOYSTICK_HIDAPI_PS5"
648 
649 /**
650  * \brief A variable controlling whether the player LEDs should be lit to indicate which player is associated with a PS5 controller.
651  *
652  * This variable can be set to the following values:
653  * "0" - player LEDs are not enabled
654  * "1" - player LEDs are enabled (the default)
655  */
656 #define SDL_HINT_JOYSTICK_HIDAPI_PS5_PLAYER_LED "SDL_JOYSTICK_HIDAPI_PS5_PLAYER_LED"
657 
658 /**
659  * \brief A variable controlling whether extended input reports should be used for PS5 controllers when using the HIDAPI driver.
660  *
661  * This variable can be set to the following values:
662  * "0" - extended reports are not enabled (the default)
663  * "1" - extended reports
664  *
665  * Extended input reports allow rumble on Bluetooth PS5 controllers, but
666  * break DirectInput handling for applications that don't use SDL.
667  *
668  * Once extended reports are enabled, they can not be disabled without
669  * power cycling the controller.
670  *
671  * For compatibility with applications written for versions of SDL prior
672  * to the introduction of PS5 controller support, this value defaults to
673  * the value of SDL_HINT_JOYSTICK_HIDAPI_PS4_RUMBLE.
674  */
675 #define SDL_HINT_JOYSTICK_HIDAPI_PS5_RUMBLE "SDL_JOYSTICK_HIDAPI_PS5_RUMBLE"
676 
677 /**
678  * \brief A variable controlling whether the HIDAPI driver for Google Stadia controllers should be used.
679  *
680  * This variable can be set to the following values:
681  * "0" - HIDAPI driver is not used
682  * "1" - HIDAPI driver is used
683  *
684  * The default is the value of SDL_HINT_JOYSTICK_HIDAPI
685  */
686 #define SDL_HINT_JOYSTICK_HIDAPI_STADIA "SDL_JOYSTICK_HIDAPI_STADIA"
687 
688 /**
689  * \brief A variable controlling whether the HIDAPI driver for Steam Controllers should be used.
690  *
691  * This variable can be set to the following values:
692  * "0" - HIDAPI driver is not used
693  * "1" - HIDAPI driver is used
694  *
695  * The default is the value of SDL_HINT_JOYSTICK_HIDAPI
696  */
697 #define SDL_HINT_JOYSTICK_HIDAPI_STEAM "SDL_JOYSTICK_HIDAPI_STEAM"
698 
699 /**
700  * \brief A variable controlling whether the HIDAPI driver for Nintendo Switch controllers should be used.
701  *
702  * This variable can be set to the following values:
703  * "0" - HIDAPI driver is not used
704  * "1" - HIDAPI driver is used
705  *
706  * The default is the value of SDL_HINT_JOYSTICK_HIDAPI
707  */
708 #define SDL_HINT_JOYSTICK_HIDAPI_SWITCH "SDL_JOYSTICK_HIDAPI_SWITCH"
709 
710 /**
711  * \brief A variable controlling whether the Home button LED should be turned on when a Nintendo Switch controller is opened
712  *
713  * This variable can be set to the following values:
714  * "0" - home button LED is left off
715  * "1" - home button LED is turned on (the default)
716  */
717 #define SDL_HINT_JOYSTICK_HIDAPI_SWITCH_HOME_LED "SDL_JOYSTICK_HIDAPI_SWITCH_HOME_LED"
718 
719 /**
720  * \brief A variable controlling whether the HIDAPI driver for XBox controllers should be used.
721  *
722  * This variable can be set to the following values:
723  * "0" - HIDAPI driver is not used
724  * "1" - HIDAPI driver is used
725  *
726  * The default is "0" on Windows, otherwise the value of SDL_HINT_JOYSTICK_HIDAPI
727  */
728 #define SDL_HINT_JOYSTICK_HIDAPI_XBOX "SDL_JOYSTICK_HIDAPI_XBOX"
729 
730  /**
731  * \brief A variable controlling whether the RAWINPUT joystick drivers should be used for better handling XInput-capable devices.
732  *
733  * This variable can be set to the following values:
734  * "0" - RAWINPUT drivers are not used
735  * "1" - RAWINPUT drivers are used (the default)
736  *
737  */
738 #define SDL_HINT_JOYSTICK_RAWINPUT "SDL_JOYSTICK_RAWINPUT"
739 
740  /**
741  * \brief A variable controlling whether the RAWINPUT driver should pull correlated data from XInput.
742  *
743  * This variable can be set to the following values:
744  * "0" - RAWINPUT driver will only use data from raw input APIs
745  * "1" - RAWINPUT driver will also pull data from XInput, providing
746  * better trigger axes, guide button presses, and rumble support
747  * for Xbox controllers
748  *
749  * The default is "1". This hint applies to any joysticks opened after setting the hint.
750  */
751 #define SDL_HINT_JOYSTICK_RAWINPUT_CORRELATE_XINPUT "SDL_JOYSTICK_RAWINPUT_CORRELATE_XINPUT"
752 
753  /**
754  * \brief A variable controlling whether a separate thread should be used
755  * for handling joystick detection and raw input messages on Windows
756  *
757  * This variable can be set to the following values:
758  * "0" - A separate thread is not used (the default)
759  * "1" - A separate thread is used for handling raw input messages
760  *
761  */
762 #define SDL_HINT_JOYSTICK_THREAD "SDL_JOYSTICK_THREAD"
763 
764 /**
765  * \brief Determines whether SDL enforces that DRM master is required in order
766  * to initialize the KMSDRM video backend.
767  *
768  * The DRM subsystem has a concept of a "DRM master" which is a DRM client that
769  * has the ability to set planes, set cursor, etc. When SDL is DRM master, it
770  * can draw to the screen using the SDL rendering APIs. Without DRM master, SDL
771  * is still able to process input and query attributes of attached displays,
772  * but it cannot change display state or draw to the screen directly.
773  *
774  * In some cases, it can be useful to have the KMSDRM backend even if it cannot
775  * be used for rendering. An app may want to use SDL for input processing while
776  * using another rendering API (such as an MMAL overlay on Raspberry Pi) or
777  * using its own code to render to DRM overlays that SDL doesn't support.
778  *
779  * This hint must be set before initializing the video subsystem.
780  *
781  * This variable can be set to the following values:
782  * "0" - SDL will allow usage of the KMSDRM backend without DRM master
783  * "1" - SDL Will require DRM master to use the KMSDRM backend (default)
784  */
785 #define SDL_HINT_KMSDRM_REQUIRE_DRM_MASTER "SDL_KMSDRM_REQUIRE_DRM_MASTER"
786 
787  /**
788  * \brief A variable controlling whether joysticks on Linux adhere to their HID-defined deadzones or return unfiltered values.
789  *
790  * This variable can be set to the following values:
791  * "0" - Return unfiltered joystick axis values (the default)
792  * "1" - Return axis values with deadzones taken into account
793  */
794 #define SDL_HINT_LINUX_JOYSTICK_DEADZONES "SDL_LINUX_JOYSTICK_DEADZONES"
795 
796 /**
797 * \brief When set don't force the SDL app to become a foreground process
798 *
799 * This hint only applies to Mac OS X.
800 *
801 */
802 #define SDL_HINT_MAC_BACKGROUND_APP "SDL_MAC_BACKGROUND_APP"
803 
804 /**
805  * \brief A variable that determines whether ctrl+click should generate a right-click event on Mac
806  *
807  * If present, holding ctrl while left clicking will generate a right click
808  * event when on Mac.
809  */
810 #define SDL_HINT_MAC_CTRL_CLICK_EMULATE_RIGHT_CLICK "SDL_MAC_CTRL_CLICK_EMULATE_RIGHT_CLICK"
811 
812 /**
813  * \brief A variable setting the double click radius, in pixels.
814  */
815 #define SDL_HINT_MOUSE_DOUBLE_CLICK_RADIUS "SDL_MOUSE_DOUBLE_CLICK_RADIUS"
816 
817 /**
818  * \brief A variable setting the double click time, in milliseconds.
819  */
820 #define SDL_HINT_MOUSE_DOUBLE_CLICK_TIME "SDL_MOUSE_DOUBLE_CLICK_TIME"
821 
822 /**
823  * \brief Allow mouse click events when clicking to focus an SDL window
824  *
825  * This variable can be set to the following values:
826  * "0" - Ignore mouse clicks that activate a window
827  * "1" - Generate events for mouse clicks that activate a window
828  *
829  * By default SDL will ignore mouse clicks that activate a window
830  */
831 #define SDL_HINT_MOUSE_FOCUS_CLICKTHROUGH "SDL_MOUSE_FOCUS_CLICKTHROUGH"
832 
833 /**
834  * \brief A variable setting the speed scale for mouse motion, in floating point, when the mouse is not in relative mode
835  */
836 #define SDL_HINT_MOUSE_NORMAL_SPEED_SCALE "SDL_MOUSE_NORMAL_SPEED_SCALE"
837 
838 /**
839  * \brief A variable controlling whether relative mouse mode is implemented using mouse warping
840  *
841  * This variable can be set to the following values:
842  * "0" - Relative mouse mode uses raw input
843  * "1" - Relative mouse mode uses mouse warping
844  *
845  * By default SDL will use raw input for relative mouse mode
846  */
847 #define SDL_HINT_MOUSE_RELATIVE_MODE_WARP "SDL_MOUSE_RELATIVE_MODE_WARP"
848 
849 /**
850  * \brief A variable controlling whether relative mouse motion is affected by renderer scaling
851  *
852  * This variable can be set to the following values:
853  * "0" - Relative motion is unaffected by DPI or renderer's logical size
854  * "1" - Relative motion is scaled according to DPI scaling and logical size
855  *
856  * By default relative mouse deltas are affected by DPI and renderer scaling
857  */
858 #define SDL_HINT_MOUSE_RELATIVE_SCALING "SDL_MOUSE_RELATIVE_SCALING"
859 
860 /**
861  * \brief A variable setting the scale for mouse motion, in floating point, when the mouse is in relative mode
862  */
863 #define SDL_HINT_MOUSE_RELATIVE_SPEED_SCALE "SDL_MOUSE_RELATIVE_SPEED_SCALE"
864 
865 /**
866  * \brief A variable controlling whether mouse events should generate synthetic touch events
867  *
868  * This variable can be set to the following values:
869  * "0" - Mouse events will not generate touch events (default for desktop platforms)
870  * "1" - Mouse events will generate touch events (default for mobile platforms, such as Android and iOS)
871  */
872 #define SDL_HINT_MOUSE_TOUCH_EVENTS "SDL_MOUSE_TOUCH_EVENTS"
873 
874 /**
875  * \brief Tell SDL not to catch the SIGINT or SIGTERM signals.
876  *
877  * This hint only applies to Unix-like platforms, and should set before
878  * any calls to SDL_Init()
879  *
880  * The variable can be set to the following values:
881  * "0" - SDL will install a SIGINT and SIGTERM handler, and when it
882  * catches a signal, convert it into an SDL_QUIT event.
883  * "1" - SDL will not install a signal handler at all.
884  */
885 #define SDL_HINT_NO_SIGNAL_HANDLERS "SDL_NO_SIGNAL_HANDLERS"
886 
887 /**
888  * \brief A variable controlling what driver to use for OpenGL ES contexts.
889  *
890  * On some platforms, currently Windows and X11, OpenGL drivers may support
891  * creating contexts with an OpenGL ES profile. By default SDL uses these
892  * profiles, when available, otherwise it attempts to load an OpenGL ES
893  * library, e.g. that provided by the ANGLE project. This variable controls
894  * whether SDL follows this default behaviour or will always load an
895  * OpenGL ES library.
896  *
897  * Circumstances where this is useful include
898  * - Testing an app with a particular OpenGL ES implementation, e.g ANGLE,
899  * or emulator, e.g. those from ARM, Imagination or Qualcomm.
900  * - Resolving OpenGL ES function addresses at link time by linking with
901  * the OpenGL ES library instead of querying them at run time with
902  * SDL_GL_GetProcAddress().
903  *
904  * Caution: for an application to work with the default behaviour across
905  * different OpenGL drivers it must query the OpenGL ES function
906  * addresses at run time using SDL_GL_GetProcAddress().
907  *
908  * This variable is ignored on most platforms because OpenGL ES is native
909  * or not supported.
910  *
911  * This variable can be set to the following values:
912  * "0" - Use ES profile of OpenGL, if available. (Default when not set.)
913  * "1" - Load OpenGL ES library using the default library names.
914  *
915  */
916 #define SDL_HINT_OPENGL_ES_DRIVER "SDL_OPENGL_ES_DRIVER"
917 
918 /**
919  * \brief A variable controlling which orientations are allowed on iOS/Android.
920  *
921  * In some circumstances it is necessary to be able to explicitly control
922  * which UI orientations are allowed.
923  *
924  * This variable is a space delimited list of the following values:
925  * "LandscapeLeft", "LandscapeRight", "Portrait" "PortraitUpsideDown"
926  */
927 #define SDL_HINT_ORIENTATIONS "SDL_IOS_ORIENTATIONS"
928 
929 /**
930  * \brief Override for SDL_GetPreferredLocales()
931  *
932  * If set, this will be favored over anything the OS might report for the
933  * user's preferred locales. Changing this hint at runtime will not generate
934  * a SDL_LOCALECHANGED event (but if you can change the hint, you can push
935  * your own event, if you want).
936  *
937  * The format of this hint is a comma-separated list of language and locale,
938  * combined with an underscore, as is a common format: "en_GB". Locale is
939  * optional: "en". So you might have a list like this: "en_GB,jp,es_PT"
940  */
941 #define SDL_HINT_PREFERRED_LOCALES "SDL_PREFERRED_LOCALES"
942 
943 /**
944  * \brief A variable describing the content orientation on QtWayland-based platforms.
945  *
946  * On QtWayland platforms, windows are rotated client-side to allow for custom
947  * transitions. In order to correctly position overlays (e.g. volume bar) and
948  * gestures (e.g. events view, close/minimize gestures), the system needs to
949  * know in which orientation the application is currently drawing its contents.
950  *
951  * This does not cause the window to be rotated or resized, the application
952  * needs to take care of drawing the content in the right orientation (the
953  * framebuffer is always in portrait mode).
954  *
955  * This variable can be one of the following values:
956  * "primary" (default), "portrait", "landscape", "inverted-portrait", "inverted-landscape"
957  */
958 #define SDL_HINT_QTWAYLAND_CONTENT_ORIENTATION "SDL_QTWAYLAND_CONTENT_ORIENTATION"
959 
960 /**
961  * \brief Flags to set on QtWayland windows to integrate with the native window manager.
962  *
963  * On QtWayland platforms, this hint controls the flags to set on the windows.
964  * For example, on Sailfish OS "OverridesSystemGestures" disables swipe gestures.
965  *
966  * This variable is a space-separated list of the following values (empty = no flags):
967  * "OverridesSystemGestures", "StaysOnTop", "BypassWindowManager"
968  */
969 #define SDL_HINT_QTWAYLAND_WINDOW_FLAGS "SDL_QTWAYLAND_WINDOW_FLAGS"
970 
971 /**
972  * \brief A variable controlling whether the 2D render API is compatible or efficient.
973  *
974  * This variable can be set to the following values:
975  *
976  * "0" - Don't use batching to make rendering more efficient.
977  * "1" - Use batching, but might cause problems if app makes its own direct OpenGL calls.
978  *
979  * Up to SDL 2.0.9, the render API would draw immediately when requested. Now
980  * it batches up draw requests and sends them all to the GPU only when forced
981  * to (during SDL_RenderPresent, when changing render targets, by updating a
982  * texture that the batch needs, etc). This is significantly more efficient,
983  * but it can cause problems for apps that expect to render on top of the
984  * render API's output. As such, SDL will disable batching if a specific
985  * render backend is requested (since this might indicate that the app is
986  * planning to use the underlying graphics API directly). This hint can
987  * be used to explicitly request batching in this instance. It is a contract
988  * that you will either never use the underlying graphics API directly, or
989  * if you do, you will call SDL_RenderFlush() before you do so any current
990  * batch goes to the GPU before your work begins. Not following this contract
991  * will result in undefined behavior.
992  */
993 #define SDL_HINT_RENDER_BATCHING "SDL_RENDER_BATCHING"
994 
995 /**
996  * \brief A variable controlling whether to enable Direct3D 11+'s Debug Layer.
997  *
998  * This variable does not have any effect on the Direct3D 9 based renderer.
999  *
1000  * This variable can be set to the following values:
1001  * "0" - Disable Debug Layer use
1002  * "1" - Enable Debug Layer use
1003  *
1004  * By default, SDL does not use Direct3D Debug Layer.
1005  */
1006 #define SDL_HINT_RENDER_DIRECT3D11_DEBUG "SDL_RENDER_DIRECT3D11_DEBUG"
1007 
1008 /**
1009  * \brief A variable controlling whether the Direct3D device is initialized for thread-safe operations.
1010  *
1011  * This variable can be set to the following values:
1012  * "0" - Thread-safety is not enabled (faster)
1013  * "1" - Thread-safety is enabled
1014  *
1015  * By default the Direct3D device is created with thread-safety disabled.
1016  */
1017 #define SDL_HINT_RENDER_DIRECT3D_THREADSAFE "SDL_RENDER_DIRECT3D_THREADSAFE"
1018 
1019 /**
1020  * \brief A variable specifying which render driver to use.
1021  *
1022  * If the application doesn't pick a specific renderer to use, this variable
1023  * specifies the name of the preferred renderer. If the preferred renderer
1024  * can't be initialized, the normal default renderer is used.
1025  *
1026  * This variable is case insensitive and can be set to the following values:
1027  * "direct3d"
1028  * "opengl"
1029  * "opengles2"
1030  * "opengles"
1031  * "metal"
1032  * "software"
1033  *
1034  * The default varies by platform, but it's the first one in the list that
1035  * is available on the current platform.
1036  */
1037 #define SDL_HINT_RENDER_DRIVER "SDL_RENDER_DRIVER"
1038 
1039 /**
1040  * \brief A variable controlling the scaling policy for SDL_RenderSetLogicalSize.
1041  *
1042  * This variable can be set to the following values:
1043  * "0" or "letterbox" - Uses letterbox/sidebars to fit the entire rendering on screen
1044  * "1" or "overscan" - Will zoom the rendering so it fills the entire screen, allowing edges to be drawn offscreen
1045  *
1046  * By default letterbox is used
1047  */
1048 #define SDL_HINT_RENDER_LOGICAL_SIZE_MODE "SDL_RENDER_LOGICAL_SIZE_MODE"
1049 
1050 /**
1051  * \brief A variable controlling whether the OpenGL render driver uses shaders if they are available.
1052  *
1053  * This variable can be set to the following values:
1054  * "0" - Disable shaders
1055  * "1" - Enable shaders
1056  *
1057  * By default shaders are used if OpenGL supports them.
1058  */
1059 #define SDL_HINT_RENDER_OPENGL_SHADERS "SDL_RENDER_OPENGL_SHADERS"
1060 
1061 /**
1062  * \brief A variable controlling the scaling quality
1063  *
1064  * This variable can be set to the following values:
1065  * "0" or "nearest" - Nearest pixel sampling
1066  * "1" or "linear" - Linear filtering (supported by OpenGL and Direct3D)
1067  * "2" or "best" - Currently this is the same as "linear"
1068  *
1069  * By default nearest pixel sampling is used
1070  */
1071 #define SDL_HINT_RENDER_SCALE_QUALITY "SDL_RENDER_SCALE_QUALITY"
1072 
1073 /**
1074  * \brief A variable controlling whether updates to the SDL screen surface should be synchronized with the vertical refresh, to avoid tearing.
1075  *
1076  * This variable can be set to the following values:
1077  * "0" - Disable vsync
1078  * "1" - Enable vsync
1079  *
1080  * By default SDL does not sync screen surface updates with vertical refresh.
1081  */
1082 #define SDL_HINT_RENDER_VSYNC "SDL_RENDER_VSYNC"
1083 
1084  /**
1085  * \brief A variable to control whether the return key on the soft keyboard
1086  * should hide the soft keyboard on Android and iOS.
1087  *
1088  * The variable can be set to the following values:
1089  * "0" - The return key will be handled as a key event. This is the behaviour of SDL <= 2.0.3. (default)
1090  * "1" - The return key will hide the keyboard.
1091  *
1092  * The value of this hint is used at runtime, so it can be changed at any time.
1093  */
1094 #define SDL_HINT_RETURN_KEY_HIDES_IME "SDL_RETURN_KEY_HIDES_IME"
1095 
1096 /**
1097  * \brief Tell SDL which Dispmanx layer to use on a Raspberry PI
1098  *
1099  * Also known as Z-order. The variable can take a negative or positive value.
1100  * The default is 10000.
1101  */
1102 #define SDL_HINT_RPI_VIDEO_LAYER "SDL_RPI_VIDEO_LAYER"
1103 
1104 /**
1105  * \brief Specifies whether SDL_THREAD_PRIORITY_TIME_CRITICAL should be treated as realtime.
1106  *
1107  * On some platforms, like Linux, a realtime priority thread may be subject to restrictions
1108  * that require special handling by the application. This hint exists to let SDL know that
1109  * the app is prepared to handle said restrictions.
1110  *
1111  * On Linux, SDL will apply the following configuration to any thread that becomes realtime:
1112  * * The SCHED_RESET_ON_FORK bit will be set on the scheduling policy,
1113  * * An RLIMIT_RTTIME budget will be configured to the rtkit specified limit.
1114  * * Exceeding this limit will result in the kernel sending SIGKILL to the app,
1115  * * Refer to the man pages for more information.
1116  *
1117  * This variable can be set to the following values:
1118  * "0" - default platform specific behaviour
1119  * "1" - Force SDL_THREAD_PRIORITY_TIME_CRITICAL to a realtime scheduling policy
1120  */
1121 #define SDL_HINT_THREAD_FORCE_REALTIME_TIME_CRITICAL "SDL_THREAD_FORCE_REALTIME_TIME_CRITICAL"
1122 
1123 /**
1124 * \brief A string specifying additional information to use with SDL_SetThreadPriority.
1125 *
1126 * By default SDL_SetThreadPriority will make appropriate system changes in order to
1127 * apply a thread priority. For example on systems using pthreads the scheduler policy
1128 * is changed automatically to a policy that works well with a given priority.
1129 * Code which has specific requirements can override SDL's default behavior with this hint.
1130 *
1131 * pthread hint values are "current", "other", "fifo" and "rr".
1132 * Currently no other platform hint values are defined but may be in the future.
1133 *
1134 * \note On Linux, the kernel may send SIGKILL to realtime tasks which exceed the distro
1135 * configured execution budget for rtkit. This budget can be queried through RLIMIT_RTTIME
1136 * after calling SDL_SetThreadPriority().
1137 */
1138 #define SDL_HINT_THREAD_PRIORITY_POLICY "SDL_THREAD_PRIORITY_POLICY"
1139 
1140 /**
1141 * \brief A string specifying SDL's threads stack size in bytes or "0" for the backend's default size
1142 *
1143 * Use this hint in case you need to set SDL's threads stack size to other than the default.
1144 * This is specially useful if you build SDL against a non glibc libc library (such as musl) which
1145 * provides a relatively small default thread stack size (a few kilobytes versus the default 8MB glibc uses).
1146 * Support for this hint is currently available only in the pthread, Windows, and PSP backend.
1147 *
1148 * Instead of this hint, in 2.0.9 and later, you can use
1149 * SDL_CreateThreadWithStackSize(). This hint only works with the classic
1150 * SDL_CreateThread().
1151 */
1152 #define SDL_HINT_THREAD_STACK_SIZE "SDL_THREAD_STACK_SIZE"
1153 
1154 /**
1155  * \brief A variable that controls the timer resolution, in milliseconds.
1156  *
1157  * The higher resolution the timer, the more frequently the CPU services
1158  * timer interrupts, and the more precise delays are, but this takes up
1159  * power and CPU time. This hint is only used on Windows.
1160  *
1161  * See this blog post for more information:
1162  * http://randomascii.wordpress.com/2013/07/08/windows-timer-resolution-megawatts-wasted/
1163  *
1164  * If this variable is set to "0", the system timer resolution is not set.
1165  *
1166  * The default value is "1". This hint may be set at any time.
1167  */
1168 #define SDL_HINT_TIMER_RESOLUTION "SDL_TIMER_RESOLUTION"
1169 
1170 /**
1171  * \brief A variable controlling whether touch events should generate synthetic mouse events
1172  *
1173  * This variable can be set to the following values:
1174  * "0" - Touch events will not generate mouse events
1175  * "1" - Touch events will generate mouse events
1176  *
1177  * By default SDL will generate mouse events for touch events
1178  */
1179 #define SDL_HINT_TOUCH_MOUSE_EVENTS "SDL_TOUCH_MOUSE_EVENTS"
1180 
1181 /**
1182  * \brief A variable controlling whether the Android / tvOS remotes
1183  * should be listed as joystick devices, instead of sending keyboard events.
1184  *
1185  * This variable can be set to the following values:
1186  * "0" - Remotes send enter/escape/arrow key events
1187  * "1" - Remotes are available as 2 axis, 2 button joysticks (the default).
1188  */
1189 #define SDL_HINT_TV_REMOTE_AS_JOYSTICK "SDL_TV_REMOTE_AS_JOYSTICK"
1190 
1191 /**
1192  * \brief A variable controlling whether the screensaver is enabled.
1193  *
1194  * This variable can be set to the following values:
1195  * "0" - Disable screensaver
1196  * "1" - Enable screensaver
1197  *
1198  * By default SDL will disable the screensaver.
1199  */
1200 #define SDL_HINT_VIDEO_ALLOW_SCREENSAVER "SDL_VIDEO_ALLOW_SCREENSAVER"
1201 
1202 /**
1203  * \brief Tell the video driver that we only want a double buffer.
1204  *
1205  * By default, most lowlevel 2D APIs will use a triple buffer scheme that
1206  * wastes no CPU time on waiting for vsync after issuing a flip, but
1207  * introduces a frame of latency. On the other hand, using a double buffer
1208  * scheme instead is recommended for cases where low latency is an important
1209  * factor because we save a whole frame of latency.
1210  * We do so by waiting for vsync immediately after issuing a flip, usually just
1211  * after eglSwapBuffers call in the backend's *_SwapWindow function.
1212  *
1213  * Since it's driver-specific, it's only supported where possible and
1214  * implemented. Currently supported the following drivers:
1215  *
1216  * - KMSDRM (kmsdrm)
1217  * - Raspberry Pi (raspberrypi)
1218  */
1219 #define SDL_HINT_VIDEO_DOUBLE_BUFFER "SDL_VIDEO_DOUBLE_BUFFER"
1220 
1221 /**
1222  * \brief A variable controlling whether the graphics context is externally managed.
1223  *
1224  * This variable can be set to the following values:
1225  * "0" - SDL will manage graphics contexts that are attached to windows.
1226  * "1" - Disable graphics context management on windows.
1227  *
1228  * By default SDL will manage OpenGL contexts in certain situations. For example, on Android the
1229  * context will be automatically saved and restored when pausing the application. Additionally, some
1230  * platforms will assume usage of OpenGL if Vulkan isn't used. Setting this to "1" will prevent this
1231  * behavior, which is desireable when the application manages the graphics context, such as
1232  * an externally managed OpenGL context or attaching a Vulkan surface to the window.
1233  */
1234 #define SDL_HINT_VIDEO_EXTERNAL_CONTEXT "SDL_VIDEO_EXTERNAL_CONTEXT"
1235 
1236 /**
1237  * \brief If set to 1, then do not allow high-DPI windows. ("Retina" on Mac and iOS)
1238  */
1239 #define SDL_HINT_VIDEO_HIGHDPI_DISABLED "SDL_VIDEO_HIGHDPI_DISABLED"
1240 
1241 /**
1242  * \brief A variable that dictates policy for fullscreen Spaces on Mac OS X.
1243  *
1244  * This hint only applies to Mac OS X.
1245  *
1246  * The variable can be set to the following values:
1247  * "0" - Disable Spaces support (FULLSCREEN_DESKTOP won't use them and
1248  * SDL_WINDOW_RESIZABLE windows won't offer the "fullscreen"
1249  * button on their titlebars).
1250  * "1" - Enable Spaces support (FULLSCREEN_DESKTOP will use them and
1251  * SDL_WINDOW_RESIZABLE windows will offer the "fullscreen"
1252  * button on their titlebars).
1253  *
1254  * The default value is "1". Spaces are disabled regardless of this hint if
1255  * the OS isn't at least Mac OS X Lion (10.7). This hint must be set before
1256  * any windows are created.
1257  */
1258 #define SDL_HINT_VIDEO_MAC_FULLSCREEN_SPACES "SDL_VIDEO_MAC_FULLSCREEN_SPACES"
1259 
1260 /**
1261  * \brief Minimize your SDL_Window if it loses key focus when in fullscreen mode. Defaults to false.
1262  * \warning Before SDL 2.0.14, this defaulted to true! In 2.0.14, we're
1263  * seeing if "true" causes more problems than it solves in modern times.
1264  *
1265  */
1266 #define SDL_HINT_VIDEO_MINIMIZE_ON_FOCUS_LOSS "SDL_VIDEO_MINIMIZE_ON_FOCUS_LOSS"
1267 
1268 /**
1269  * \brief A variable controlling whether the libdecor Wayland backend is allowed to be used.
1270  *
1271  * This variable can be set to the following values:
1272  * "0" - libdecor use is disabled.
1273  * "1" - libdecor use is enabled (default).
1274  *
1275  * libdecor is used over xdg-shell when xdg-decoration protocol is unavailable.
1276  */
1277 #define SDL_HINT_VIDEO_WAYLAND_ALLOW_LIBDECOR "SDL_VIDEO_WAYLAND_ALLOW_LIBDECOR"
1278 
1279 /**
1280 * \brief A variable that is the address of another SDL_Window* (as a hex string formatted with "%p").
1281 *
1282 * If this hint is set before SDL_CreateWindowFrom() and the SDL_Window* it is set to has
1283 * SDL_WINDOW_OPENGL set (and running on WGL only, currently), then two things will occur on the newly
1284 * created SDL_Window:
1285 *
1286 * 1. Its pixel format will be set to the same pixel format as this SDL_Window. This is
1287 * needed for example when sharing an OpenGL context across multiple windows.
1288 *
1289 * 2. The flag SDL_WINDOW_OPENGL will be set on the new window so it can be used for
1290 * OpenGL rendering.
1291 *
1292 * This variable can be set to the following values:
1293 * The address (as a string "%p") of the SDL_Window* that new windows created with SDL_CreateWindowFrom() should
1294 * share a pixel format with.
1295 */
1296 #define SDL_HINT_VIDEO_WINDOW_SHARE_PIXEL_FORMAT "SDL_VIDEO_WINDOW_SHARE_PIXEL_FORMAT"
1297 
1298 /**
1299 * \brief A variable specifying which shader compiler to preload when using the Chrome ANGLE binaries
1300 *
1301 * SDL has EGL and OpenGL ES2 support on Windows via the ANGLE project. It
1302 * can use two different sets of binaries, those compiled by the user from source
1303 * or those provided by the Chrome browser. In the later case, these binaries require
1304 * that SDL loads a DLL providing the shader compiler.
1305 *
1306 * This variable can be set to the following values:
1307 * "d3dcompiler_46.dll" - default, best for Vista or later.
1308 * "d3dcompiler_43.dll" - for XP support.
1309 * "none" - do not load any library, useful if you compiled ANGLE from source and included the compiler in your binaries.
1310 *
1311 */
1312 #define SDL_HINT_VIDEO_WIN_D3DCOMPILER "SDL_VIDEO_WIN_D3DCOMPILER"
1313 
1314 /**
1315  * \brief A variable controlling whether X11 should use GLX or EGL by default
1316  *
1317  * This variable can be set to the following values:
1318  * "0" - Use GLX
1319  * "1" - Use EGL
1320  *
1321  * By default SDL will use GLX when both are present.
1322  */
1323 #define SDL_HINT_VIDEO_X11_FORCE_EGL "SDL_VIDEO_X11_FORCE_EGL"
1324 
1325 /**
1326  * \brief A variable controlling whether the X11 _NET_WM_BYPASS_COMPOSITOR hint should be used.
1327  *
1328  * This variable can be set to the following values:
1329  * "0" - Disable _NET_WM_BYPASS_COMPOSITOR
1330  * "1" - Enable _NET_WM_BYPASS_COMPOSITOR
1331  *
1332  * By default SDL will use _NET_WM_BYPASS_COMPOSITOR
1333  *
1334  */
1335 #define SDL_HINT_VIDEO_X11_NET_WM_BYPASS_COMPOSITOR "SDL_VIDEO_X11_NET_WM_BYPASS_COMPOSITOR"
1336 
1337 /**
1338  * \brief A variable controlling whether the X11 _NET_WM_PING protocol should be supported.
1339  *
1340  * This variable can be set to the following values:
1341  * "0" - Disable _NET_WM_PING
1342  * "1" - Enable _NET_WM_PING
1343  *
1344  * By default SDL will use _NET_WM_PING, but for applications that know they
1345  * will not always be able to respond to ping requests in a timely manner they can
1346  * turn it off to avoid the window manager thinking the app is hung.
1347  * The hint is checked in CreateWindow.
1348  */
1349 #define SDL_HINT_VIDEO_X11_NET_WM_PING "SDL_VIDEO_X11_NET_WM_PING"
1350 
1351 /**
1352  * \brief A variable forcing the visual ID chosen for new X11 windows
1353  *
1354  */
1355 #define SDL_HINT_VIDEO_X11_WINDOW_VISUALID "SDL_VIDEO_X11_WINDOW_VISUALID"
1356 
1357 /**
1358  * \brief A variable controlling whether the X11 Xinerama extension should be used.
1359  *
1360  * This variable can be set to the following values:
1361  * "0" - Disable Xinerama
1362  * "1" - Enable Xinerama
1363  *
1364  * By default SDL will use Xinerama if it is available.
1365  */
1366 #define SDL_HINT_VIDEO_X11_XINERAMA "SDL_VIDEO_X11_XINERAMA"
1367 
1368 /**
1369  * \brief A variable controlling whether the X11 XRandR extension should be used.
1370  *
1371  * This variable can be set to the following values:
1372  * "0" - Disable XRandR
1373  * "1" - Enable XRandR
1374  *
1375  * By default SDL will not use XRandR because of window manager issues.
1376  */
1377 #define SDL_HINT_VIDEO_X11_XRANDR "SDL_VIDEO_X11_XRANDR"
1378 
1379 /**
1380  * \brief A variable controlling whether the X11 VidMode extension should be used.
1381  *
1382  * This variable can be set to the following values:
1383  * "0" - Disable XVidMode
1384  * "1" - Enable XVidMode
1385  *
1386  * By default SDL will use XVidMode if it is available.
1387  */
1388 #define SDL_HINT_VIDEO_X11_XVIDMODE "SDL_VIDEO_X11_XVIDMODE"
1389 
1390 /**
1391  * \brief Controls how the fact chunk affects the loading of a WAVE file.
1392  *
1393  * The fact chunk stores information about the number of samples of a WAVE
1394  * file. The Standards Update from Microsoft notes that this value can be used
1395  * to 'determine the length of the data in seconds'. This is especially useful
1396  * for compressed formats (for which this is a mandatory chunk) if they produce
1397  * multiple sample frames per block and truncating the block is not allowed.
1398  * The fact chunk can exactly specify how many sample frames there should be
1399  * in this case.
1400  *
1401  * Unfortunately, most application seem to ignore the fact chunk and so SDL
1402  * ignores it by default as well.
1403  *
1404  * This variable can be set to the following values:
1405  *
1406  * "truncate" - Use the number of samples to truncate the wave data if
1407  * the fact chunk is present and valid
1408  * "strict" - Like "truncate", but raise an error if the fact chunk
1409  * is invalid, not present for non-PCM formats, or if the
1410  * data chunk doesn't have that many samples
1411  * "ignorezero" - Like "truncate", but ignore fact chunk if the number of
1412  * samples is zero
1413  * "ignore" - Ignore fact chunk entirely (default)
1414  */
1415 #define SDL_HINT_WAVE_FACT_CHUNK "SDL_WAVE_FACT_CHUNK"
1416 
1417 /**
1418  * \brief Controls how the size of the RIFF chunk affects the loading of a WAVE file.
1419  *
1420  * The size of the RIFF chunk (which includes all the sub-chunks of the WAVE
1421  * file) is not always reliable. In case the size is wrong, it's possible to
1422  * just ignore it and step through the chunks until a fixed limit is reached.
1423  *
1424  * Note that files that have trailing data unrelated to the WAVE file or
1425  * corrupt files may slow down the loading process without a reliable boundary.
1426  * By default, SDL stops after 10000 chunks to prevent wasting time. Use the
1427  * environment variable SDL_WAVE_CHUNK_LIMIT to adjust this value.
1428  *
1429  * This variable can be set to the following values:
1430  *
1431  * "force" - Always use the RIFF chunk size as a boundary for the chunk search
1432  * "ignorezero" - Like "force", but a zero size searches up to 4 GiB (default)
1433  * "ignore" - Ignore the RIFF chunk size and always search up to 4 GiB
1434  * "maximum" - Search for chunks until the end of file (not recommended)
1435  */
1436 #define SDL_HINT_WAVE_RIFF_CHUNK_SIZE "SDL_WAVE_RIFF_CHUNK_SIZE"
1437 
1438 /**
1439  * \brief Controls how a truncated WAVE file is handled.
1440  *
1441  * A WAVE file is considered truncated if any of the chunks are incomplete or
1442  * the data chunk size is not a multiple of the block size. By default, SDL
1443  * decodes until the first incomplete block, as most applications seem to do.
1444  *
1445  * This variable can be set to the following values:
1446  *
1447  * "verystrict" - Raise an error if the file is truncated
1448  * "strict" - Like "verystrict", but the size of the RIFF chunk is ignored
1449  * "dropframe" - Decode until the first incomplete sample frame
1450  * "dropblock" - Decode until the first incomplete block (default)
1451  */
1452 #define SDL_HINT_WAVE_TRUNCATION "SDL_WAVE_TRUNCATION"
1453 
1454 /**
1455  * \brief Tell SDL not to name threads on Windows with the 0x406D1388 Exception.
1456  * The 0x406D1388 Exception is a trick used to inform Visual Studio of a
1457  * thread's name, but it tends to cause problems with other debuggers,
1458  * and the .NET runtime. Note that SDL 2.0.6 and later will still use
1459  * the (safer) SetThreadDescription API, introduced in the Windows 10
1460  * Creators Update, if available.
1461  *
1462  * The variable can be set to the following values:
1463  * "0" - SDL will raise the 0x406D1388 Exception to name threads.
1464  * This is the default behavior of SDL <= 2.0.4.
1465  * "1" - SDL will not raise this exception, and threads will be unnamed. (default)
1466  * This is necessary with .NET languages or debuggers that aren't Visual Studio.
1467  */
1468 #define SDL_HINT_WINDOWS_DISABLE_THREAD_NAMING "SDL_WINDOWS_DISABLE_THREAD_NAMING"
1469 
1470 /**
1471  * \brief A variable controlling whether the windows message loop is processed by SDL
1472  *
1473  * This variable can be set to the following values:
1474  * "0" - The window message loop is not run
1475  * "1" - The window message loop is processed in SDL_PumpEvents()
1476  *
1477  * By default SDL will process the windows message loop
1478  */
1479 #define SDL_HINT_WINDOWS_ENABLE_MESSAGELOOP "SDL_WINDOWS_ENABLE_MESSAGELOOP"
1480 
1481 /**
1482  * \brief Force SDL to use Critical Sections for mutexes on Windows.
1483  * On Windows 7 and newer, Slim Reader/Writer Locks are available.
1484  * They offer better performance, allocate no kernel ressources and
1485  * use less memory. SDL will fall back to Critical Sections on older
1486  * OS versions or if forced to by this hint.
1487  * This also affects Condition Variables. When SRW mutexes are used,
1488  * SDL will use Windows Condition Variables as well. Else, a generic
1489  * SDL_cond implementation will be used that works with all mutexes.
1490  *
1491  * This variable can be set to the following values:
1492  * "0" - Use SRW Locks when available. If not, fall back to Critical Sections. (default)
1493  * "1" - Force the use of Critical Sections in all cases.
1494  *
1495  */
1496 #define SDL_HINT_WINDOWS_FORCE_MUTEX_CRITICAL_SECTIONS "SDL_WINDOWS_FORCE_MUTEX_CRITICAL_SECTIONS"
1497 
1498 /**
1499  * \brief Force SDL to use Kernel Semaphores on Windows.
1500  * Kernel Semaphores are inter-process and require a context
1501  * switch on every interaction. On Windows 8 and newer, the
1502  * WaitOnAddress API is available. Using that and atomics to
1503  * implement semaphores increases performance.
1504  * SDL will fall back to Kernel Objects on older OS versions
1505  * or if forced to by this hint.
1506  *
1507  * This variable can be set to the following values:
1508  * "0" - Use Atomics and WaitOnAddress API when available. If not, fall back to Kernel Objects. (default)
1509  * "1" - Force the use of Kernel Objects in all cases.
1510  *
1511  */
1512 #define SDL_HINT_WINDOWS_FORCE_SEMAPHORE_KERNEL "SDL_WINDOWS_FORCE_SEMAPHORE_KERNEL"
1513 
1514 /**
1515  * \brief A variable to specify custom icon resource id from RC file on Windows platform
1516  */
1517 #define SDL_HINT_WINDOWS_INTRESOURCE_ICON "SDL_WINDOWS_INTRESOURCE_ICON"
1518 #define SDL_HINT_WINDOWS_INTRESOURCE_ICON_SMALL "SDL_WINDOWS_INTRESOURCE_ICON_SMALL"
1519 
1520 /**
1521  * \brief Tell SDL not to generate window-close events for Alt+F4 on Windows.
1522  *
1523  * The variable can be set to the following values:
1524  * "0" - SDL will generate a window-close event when it sees Alt+F4.
1525  * "1" - SDL will only do normal key handling for Alt+F4.
1526  */
1527 #define SDL_HINT_WINDOWS_NO_CLOSE_ON_ALT_F4 "SDL_WINDOWS_NO_CLOSE_ON_ALT_F4"
1528 
1529 /**
1530  * \brief Use the D3D9Ex API introduced in Windows Vista, instead of normal D3D9.
1531  * Direct3D 9Ex contains changes to state management that can eliminate device
1532  * loss errors during scenarios like Alt+Tab or UAC prompts. D3D9Ex may require
1533  * some changes to your application to cope with the new behavior, so this
1534  * is disabled by default.
1535  *
1536  * This hint must be set before initializing the video subsystem.
1537  *
1538  * For more information on Direct3D 9Ex, see:
1539  * - https://docs.microsoft.com/en-us/windows/win32/direct3darticles/graphics-apis-in-windows-vista#direct3d-9ex
1540  * - https://docs.microsoft.com/en-us/windows/win32/direct3darticles/direct3d-9ex-improvements
1541  *
1542  * This variable can be set to the following values:
1543  * "0" - Use the original Direct3D 9 API (default)
1544  * "1" - Use the Direct3D 9Ex API on Vista and later (and fall back if D3D9Ex is unavailable)
1545  *
1546  */
1547 #define SDL_HINT_WINDOWS_USE_D3D9EX "SDL_WINDOWS_USE_D3D9EX"
1548 
1549 /**
1550  * \brief A variable controlling whether the window frame and title bar are interactive when the cursor is hidden
1551  *
1552  * This variable can be set to the following values:
1553  * "0" - The window frame is not interactive when the cursor is hidden (no move, resize, etc)
1554  * "1" - The window frame is interactive when the cursor is hidden
1555  *
1556  * By default SDL will allow interaction with the window frame when the cursor is hidden
1557  */
1558 #define SDL_HINT_WINDOW_FRAME_USABLE_WHILE_CURSOR_HIDDEN "SDL_WINDOW_FRAME_USABLE_WHILE_CURSOR_HIDDEN"
1559 
1560 /** \brief Allows back-button-press events on Windows Phone to be marked as handled
1561  *
1562  * Windows Phone devices typically feature a Back button. When pressed,
1563  * the OS will emit back-button-press events, which apps are expected to
1564  * handle in an appropriate manner. If apps do not explicitly mark these
1565  * events as 'Handled', then the OS will invoke its default behavior for
1566  * unhandled back-button-press events, which on Windows Phone 8 and 8.1 is to
1567  * terminate the app (and attempt to switch to the previous app, or to the
1568  * device's home screen).
1569  *
1570  * Setting the SDL_HINT_WINRT_HANDLE_BACK_BUTTON hint to "1" will cause SDL
1571  * to mark back-button-press events as Handled, if and when one is sent to
1572  * the app.
1573  *
1574  * Internally, Windows Phone sends back button events as parameters to
1575  * special back-button-press callback functions. Apps that need to respond
1576  * to back-button-press events are expected to register one or more
1577  * callback functions for such, shortly after being launched (during the
1578  * app's initialization phase). After the back button is pressed, the OS
1579  * will invoke these callbacks. If the app's callback(s) do not explicitly
1580  * mark the event as handled by the time they return, or if the app never
1581  * registers one of these callback, the OS will consider the event
1582  * un-handled, and it will apply its default back button behavior (terminate
1583  * the app).
1584  *
1585  * SDL registers its own back-button-press callback with the Windows Phone
1586  * OS. This callback will emit a pair of SDL key-press events (SDL_KEYDOWN
1587  * and SDL_KEYUP), each with a scancode of SDL_SCANCODE_AC_BACK, after which
1588  * it will check the contents of the hint, SDL_HINT_WINRT_HANDLE_BACK_BUTTON.
1589  * If the hint's value is set to "1", the back button event's Handled
1590  * property will get set to 'true'. If the hint's value is set to something
1591  * else, or if it is unset, SDL will leave the event's Handled property
1592  * alone. (By default, the OS sets this property to 'false', to note.)
1593  *
1594  * SDL apps can either set SDL_HINT_WINRT_HANDLE_BACK_BUTTON well before a
1595  * back button is pressed, or can set it in direct-response to a back button
1596  * being pressed.
1597  *
1598  * In order to get notified when a back button is pressed, SDL apps should
1599  * register a callback function with SDL_AddEventWatch(), and have it listen
1600  * for SDL_KEYDOWN events that have a scancode of SDL_SCANCODE_AC_BACK.
1601  * (Alternatively, SDL_KEYUP events can be listened-for. Listening for
1602  * either event type is suitable.) Any value of SDL_HINT_WINRT_HANDLE_BACK_BUTTON
1603  * set by such a callback, will be applied to the OS' current
1604  * back-button-press event.
1605  *
1606  * More details on back button behavior in Windows Phone apps can be found
1607  * at the following page, on Microsoft's developer site:
1608  * http://msdn.microsoft.com/en-us/library/windowsphone/develop/jj247550(v=vs.105).aspx
1609  */
1610 #define SDL_HINT_WINRT_HANDLE_BACK_BUTTON "SDL_WINRT_HANDLE_BACK_BUTTON"
1611 
1612 /** \brief Label text for a WinRT app's privacy policy link
1613  *
1614  * Network-enabled WinRT apps must include a privacy policy. On Windows 8, 8.1, and RT,
1615  * Microsoft mandates that this policy be available via the Windows Settings charm.
1616  * SDL provides code to add a link there, with its label text being set via the
1617  * optional hint, SDL_HINT_WINRT_PRIVACY_POLICY_LABEL.
1618  *
1619  * Please note that a privacy policy's contents are not set via this hint. A separate
1620  * hint, SDL_HINT_WINRT_PRIVACY_POLICY_URL, is used to link to the actual text of the
1621  * policy.
1622  *
1623  * The contents of this hint should be encoded as a UTF8 string.
1624  *
1625  * The default value is "Privacy Policy". This hint should only be set during app
1626  * initialization, preferably before any calls to SDL_Init().
1627  *
1628  * For additional information on linking to a privacy policy, see the documentation for
1629  * SDL_HINT_WINRT_PRIVACY_POLICY_URL.
1630  */
1631 #define SDL_HINT_WINRT_PRIVACY_POLICY_LABEL "SDL_WINRT_PRIVACY_POLICY_LABEL"
1632 
1633 /**
1634  * \brief A URL to a WinRT app's privacy policy
1635  *
1636  * All network-enabled WinRT apps must make a privacy policy available to its
1637  * users. On Windows 8, 8.1, and RT, Microsoft mandates that this policy be
1638  * be available in the Windows Settings charm, as accessed from within the app.
1639  * SDL provides code to add a URL-based link there, which can point to the app's
1640  * privacy policy.
1641  *
1642  * To setup a URL to an app's privacy policy, set SDL_HINT_WINRT_PRIVACY_POLICY_URL
1643  * before calling any SDL_Init() functions. The contents of the hint should
1644  * be a valid URL. For example, "http://www.example.com".
1645  *
1646  * The default value is "", which will prevent SDL from adding a privacy policy
1647  * link to the Settings charm. This hint should only be set during app init.
1648  *
1649  * The label text of an app's "Privacy Policy" link may be customized via another
1650  * hint, SDL_HINT_WINRT_PRIVACY_POLICY_LABEL.
1651  *
1652  * Please note that on Windows Phone, Microsoft does not provide standard UI
1653  * for displaying a privacy policy link, and as such, SDL_HINT_WINRT_PRIVACY_POLICY_URL
1654  * will not get used on that platform. Network-enabled phone apps should display
1655  * their privacy policy through some other, in-app means.
1656  */
1657 #define SDL_HINT_WINRT_PRIVACY_POLICY_URL "SDL_WINRT_PRIVACY_POLICY_URL"
1658 
1659 /**
1660  * \brief Mark X11 windows as override-redirect.
1661  *
1662  * If set, this _might_ increase framerate at the expense of the desktop
1663  * not working as expected. Override-redirect windows aren't noticed by the
1664  * window manager at all.
1665  *
1666  * You should probably only use this for fullscreen windows, and you probably
1667  * shouldn't even use it for that. But it's here if you want to try!
1668  */
1669 #define SDL_HINT_X11_FORCE_OVERRIDE_REDIRECT "SDL_X11_FORCE_OVERRIDE_REDIRECT"
1670 
1671 /**
1672  * \brief A variable that lets you disable the detection and use of Xinput gamepad devices
1673  *
1674  * The variable can be set to the following values:
1675  * "0" - Disable XInput detection (only uses direct input)
1676  * "1" - Enable XInput detection (the default)
1677  */
1678 #define SDL_HINT_XINPUT_ENABLED "SDL_XINPUT_ENABLED"
1679 
1680 /**
1681  * \brief A variable that causes SDL to use the old axis and button mapping for XInput devices.
1682  *
1683  * This hint is for backwards compatibility only and will be removed in SDL 2.1
1684  *
1685  * The default value is "0". This hint must be set before SDL_Init()
1686  */
1687 #define SDL_HINT_XINPUT_USE_OLD_JOYSTICK_MAPPING "SDL_XINPUT_USE_OLD_JOYSTICK_MAPPING"
1688 
1689 /**
1690  * \brief A variable that causes SDL to not ignore audio "monitors"
1691  *
1692  * This is currently only used for PulseAudio and ignored elsewhere.
1693  *
1694  * By default, SDL ignores audio devices that aren't associated with physical
1695  * hardware. Changing this hint to "1" will expose anything SDL sees that
1696  * appears to be an audio source or sink. This will add "devices" to the list
1697  * that the user probably doesn't want or need, but it can be useful in
1698  * scenarios where you want to hook up SDL to some sort of virtual device,
1699  * etc.
1700  *
1701  * The default value is "0". This hint must be set before SDL_Init().
1702  *
1703  * This hint is available since SDL 2.0.16. Before then, virtual devices are
1704  * always ignored.
1705  */
1706 #define SDL_HINT_AUDIO_INCLUDE_MONITORS "SDL_AUDIO_INCLUDE_MONITORS"
1707 
1708 
1709 /**
1710  * \brief An enumeration of hint priorities
1711  */
1712 typedef enum
1713 {
1718 
1719 
1720 /**
1721  * Set a hint with a specific priority.
1722  *
1723  * The priority controls the behavior when setting a hint that already has a
1724  * value. Hints will replace existing hints of their priority and lower.
1725  * Environment variables are considered to have override priority.
1726  *
1727  * \param name the hint to set
1728  * \param value the value of the hint variable
1729  * \param priority the SDL_HintPriority level for the hint
1730  * \returns SDL_TRUE if the hint was set, SDL_FALSE otherwise.
1731  *
1732  * \sa SDL_GetHint
1733  * \sa SDL_SetHint
1734  */
1735 extern DECLSPEC SDL_bool SDLCALL SDL_SetHintWithPriority(const char *name,
1736  const char *value,
1737  SDL_HintPriority priority);
1738 
1739 /**
1740  * Set a hint with normal priority.
1741  *
1742  * Hints will not be set if there is an existing override hint or environment
1743  * variable that takes precedence. You can use SDL_SetHintWithPriority() to
1744  * set the hint with override priority instead.
1745  *
1746  * \param name the hint to set
1747  * \param value the value of the hint variable
1748  * \returns SDL_TRUE if the hint was set, SDL_FALSE otherwise.
1749  *
1750  * \sa SDL_GetHint
1751  * \sa SDL_SetHintWithPriority
1752  */
1753 extern DECLSPEC SDL_bool SDLCALL SDL_SetHint(const char *name,
1754  const char *value);
1755 
1756 /**
1757  * Get the value of a hint.
1758  *
1759  * \param name the hint to query
1760  * \returns the string value of a hint or NULL if the hint isn't set.
1761  *
1762  * \sa SDL_SetHint
1763  * \sa SDL_SetHintWithPriority
1764  */
1765 extern DECLSPEC const char * SDLCALL SDL_GetHint(const char *name);
1766 
1767 /**
1768  * Get the boolean value of a hint variable.
1769  *
1770  * \param name the name of the hint to get the boolean value from
1771  * \param default_value the value to return if the hint does not exist
1772  * \returns the boolean value of a hint or the provided default value if the
1773  * hint does not exist.
1774  *
1775  * \since This function is available since SDL 2.0.5.
1776  *
1777  * \sa SDL_GetHint
1778  * \sa SDL_SetHint
1779  */
1780 extern DECLSPEC SDL_bool SDLCALL SDL_GetHintBoolean(const char *name, SDL_bool default_value);
1781 
1782 /**
1783  * Type definition of the hint callback function.
1784  *
1785  * \param userdata what was passed as `userdata` to SDL_AddHintCallback()
1786  * \param name what was passed as `name` to SDL_AddHintCallback()
1787  * \param oldValue the previous hint value
1788  * \param newValue the new value hint is to be set to
1789  */
1790 typedef void (SDLCALL *SDL_HintCallback)(void *userdata, const char *name, const char *oldValue, const char *newValue);
1791 
1792 /**
1793  * Add a function to watch a particular hint.
1794  *
1795  * \param name the hint to watch
1796  * \param callback An SDL_HintCallback function that will be called when the
1797  * hint value changes
1798  * \param userdata a pointer to pass to the callback function
1799  *
1800  * \since This function is available since SDL 2.0.0.
1801  *
1802  * \sa SDL_DelHintCallback
1803  */
1804 extern DECLSPEC void SDLCALL SDL_AddHintCallback(const char *name,
1805  SDL_HintCallback callback,
1806  void *userdata);
1807 
1808 /**
1809  * Remove a function watching a particular hint.
1810  *
1811  * \param name the hint being watched
1812  * \param callback An SDL_HintCallback function that will be called when the
1813  * hint value changes
1814  * \param userdata a pointer being passed to the callback function
1815  *
1816  * \since This function is available since SDL 2.0.0.
1817  *
1818  * \sa SDL_AddHintCallback
1819  */
1820 extern DECLSPEC void SDLCALL SDL_DelHintCallback(const char *name,
1821  SDL_HintCallback callback,
1822  void *userdata);
1823 
1824 /**
1825  * Clear all hints.
1826  *
1827  * This function is automatically called during SDL_Quit().
1828  */
1829 extern DECLSPEC void SDLCALL SDL_ClearHints(void);
1830 
1831 
1832 /* Ends C function definitions when using C++ */
1833 #ifdef __cplusplus
1834 }
1835 #endif
1836 #include "close_code.h"
1837 
1838 #endif /* SDL_hints_h_ */
1839 
1840 /* vi: set ts=4 sw=4 expandtab: */
SDL_bool SDL_GetHintBoolean(const char *name, SDL_bool default_value)
void(* SDL_HintCallback)(void *userdata, const char *name, const char *oldValue, const char *newValue)
Definition: SDL_hints.h:1790
void SDL_DelHintCallback(const char *name, SDL_HintCallback callback, void *userdata)
void SDL_ClearHints(void)
SDL_bool SDL_SetHintWithPriority(const char *name, const char *value, SDL_HintPriority priority)
SDL_bool SDL_SetHint(const char *name, const char *value)
SDL_HintPriority
An enumeration of hint priorities.
Definition: SDL_hints.h:1713
@ SDL_HINT_DEFAULT
Definition: SDL_hints.h:1714
@ SDL_HINT_OVERRIDE
Definition: SDL_hints.h:1716
@ SDL_HINT_NORMAL
Definition: SDL_hints.h:1715
const char * SDL_GetHint(const char *name)
void SDL_AddHintCallback(const char *name, SDL_HintCallback callback, void *userdata)
SDL_bool
Definition: SDL_stdinc.h:168