include/SDL_hints.h
author Sam Lantinga <slouken@libsdl.org>
Fri, 27 Sep 2013 23:19:22 -0700
changeset 7747 0ebf642117f4
parent 7746 6a05d7352575
child 7764 0f48b5f28668
permissions -rw-r--r--
Fixed the name of the environment variable to match the name of the hint.
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2013 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  *    "software"
    80  *
    81  *  The default varies by platform, but it's the first one in the list that
    82  *  is available on the current platform.
    83  */
    84 #define SDL_HINT_RENDER_DRIVER              "SDL_RENDER_DRIVER"
    85 
    86 /**
    87  *  \brief  A variable controlling whether the OpenGL render driver uses shaders if they are available.
    88  *
    89  *  This variable can be set to the following values:
    90  *    "0"       - Disable shaders
    91  *    "1"       - Enable shaders
    92  *
    93  *  By default shaders are used if OpenGL supports them.
    94  */
    95 #define SDL_HINT_RENDER_OPENGL_SHADERS      "SDL_RENDER_OPENGL_SHADERS"
    96 
    97 /**
    98  *  \brief  A variable controlling the scaling quality
    99  *
   100  *  This variable can be set to the following values:
   101  *    "0" or "nearest" - Nearest pixel sampling
   102  *    "1" or "linear"  - Linear filtering (supported by OpenGL and Direct3D)
   103  *    "2" or "best"    - Currently this is the same as "linear"
   104  *
   105  *  By default nearest pixel sampling is used
   106  */
   107 #define SDL_HINT_RENDER_SCALE_QUALITY       "SDL_RENDER_SCALE_QUALITY"
   108 
   109 /**
   110  *  \brief  A variable controlling whether updates to the SDL screen surface should be synchronized with the vertical refresh, to avoid tearing.
   111  *
   112  *  This variable can be set to the following values:
   113  *    "0"       - Disable vsync
   114  *    "1"       - Enable vsync
   115  *
   116  *  By default SDL does not sync screen surface updates with vertical refresh.
   117  */
   118 #define SDL_HINT_RENDER_VSYNC               "SDL_RENDER_VSYNC"
   119 
   120 /**
   121  *  \brief  A variable controlling whether the X11 VidMode extension should be used.
   122  *
   123  *  This variable can be set to the following values:
   124  *    "0"       - Disable XVidMode
   125  *    "1"       - Enable XVidMode
   126  *
   127  *  By default SDL will use XVidMode if it is available.
   128  */
   129 #define SDL_HINT_VIDEO_X11_XVIDMODE         "SDL_VIDEO_X11_XVIDMODE"
   130 
   131 /**
   132  *  \brief  A variable controlling whether the X11 Xinerama extension should be used.
   133  *
   134  *  This variable can be set to the following values:
   135  *    "0"       - Disable Xinerama
   136  *    "1"       - Enable Xinerama
   137  *
   138  *  By default SDL will use Xinerama if it is available.
   139  */
   140 #define SDL_HINT_VIDEO_X11_XINERAMA         "SDL_VIDEO_X11_XINERAMA"
   141 
   142 /**
   143  *  \brief  A variable controlling whether the X11 XRandR extension should be used.
   144  *
   145  *  This variable can be set to the following values:
   146  *    "0"       - Disable XRandR
   147  *    "1"       - Enable XRandR
   148  *
   149  *  By default SDL will not use XRandR because of window manager issues.
   150  */
   151 #define SDL_HINT_VIDEO_X11_XRANDR           "SDL_VIDEO_X11_XRANDR"
   152 
   153 /**
   154  *  \brief  A variable controlling whether grabbing input grabs the keyboard
   155  *
   156  *  This variable can be set to the following values:
   157  *    "0"       - Grab will affect only the mouse
   158  *    "1"       - Grab will affect mouse and keyboard
   159  *
   160  *  By default SDL will not grab the keyboard so system shortcuts still work.
   161  */
   162 #define SDL_HINT_GRAB_KEYBOARD              "SDL_GRAB_KEYBOARD"
   163 
   164 /**
   165  *  \brief Minimize your SDL_Window if it loses key focus when in Fullscreen mode. Defaults to true.
   166  *
   167  */
   168 #define SDL_HINT_VIDEO_MINIMIZE_ON_FOCUS_LOSS   "SDL_VIDEO_MINIMIZE_ON_FOCUS_LOSS"
   169 
   170 
   171 /**
   172  *  \brief  A variable controlling whether the idle timer is disabled on iOS.
   173  *
   174  *  When an iOS app does not receive touches for some time, the screen is
   175  *  dimmed automatically. For games where the accelerometer is the only input
   176  *  this is problematic. This functionality can be disabled by setting this
   177  *  hint.
   178  *
   179  *  This variable can be set to the following values:
   180  *    "0"       - Enable idle timer
   181  *    "1"       - Disable idle timer
   182  */
   183 #define SDL_HINT_IDLE_TIMER_DISABLED "SDL_IOS_IDLE_TIMER_DISABLED"
   184 
   185 /**
   186  *  \brief  A variable controlling which orientations are allowed on iOS.
   187  *
   188  *  In some circumstances it is necessary to be able to explicitly control
   189  *  which UI orientations are allowed.
   190  *
   191  *  This variable is a space delimited list of the following values:
   192  *    "LandscapeLeft", "LandscapeRight", "Portrait" "PortraitUpsideDown"
   193  */
   194 #define SDL_HINT_ORIENTATIONS "SDL_IOS_ORIENTATIONS"
   195 
   196 
   197 /**
   198  *  \brief  A variable that lets you disable the detection and use of Xinput gamepad devices
   199  *
   200  *  The variable can be set to the following values:
   201  *    "0"       - Disable XInput timer (only uses direct input)
   202  *    "1"       - Enable XInput timer (the default)
   203  */
   204 #define SDL_HINT_XINPUT_ENABLED "SDL_XINPUT_ENABLED"
   205 
   206 
   207 /**
   208  *  \brief  A variable that lets you manually hint extra gamecontroller db entries
   209  *
   210  *  The variable should be newline delimited rows of gamecontroller config data, see SDL_gamecontroller.h
   211  *
   212  *  This hint must be set before calling SDL_Init(SDL_INIT_GAMECONTROLLER)
   213  *  You can update mappings after the system is initialized with SDL_GameControllerMappingForGUID() and SDL_GameControllerAddMapping()
   214  */
   215 #define SDL_HINT_GAMECONTROLLERCONFIG "SDL_GAMECONTROLLERCONFIG"
   216 
   217 
   218 /**
   219  *  \brief  A variable that lets you enable joystick (and gamecontroller) events even when your app is in the background.
   220  *
   221  *  The variable can be set to the following values:
   222  *    "0"       - Disable joystick & gamecontroller input events when the
   223  *                application is in the background.
   224  *    "1"       - Enable joystick & gamecontroller input events when the
   225  *                application is in the backgroumd.
   226  *
   227  *  The default value is "0".  This hint may be set at any time.
   228  */
   229 #define SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS "SDL_JOYSTICK_ALLOW_BACKGROUND_EVENTS"
   230 
   231 
   232 /**
   233  *  \brief If set to 0 then never set the top most bit on a SDL Window, even if the video mode expects it.
   234  *      This is a debugging aid for developers and not expected to be used by end users. The default is "1"
   235  *
   236  *  This variable can be set to the following values:
   237  *    "0"       - don't allow topmost
   238  *    "1"       - allow topmost
   239  */
   240 #define SDL_HINT_ALLOW_TOPMOST "SDL_ALLOW_TOPMOST"
   241 
   242 
   243 /**
   244  *  \brief A variable that controls the timer resolution, in milliseconds.
   245  *
   246  *  The higher resolution the timer, the more frequently the CPU services
   247  *  timer interrupts, and the more precise delays are, but this takes up
   248  *  power and CPU time.  This hint is only used on Windows 7 and earlier.
   249  *
   250  *  See this blog post for more information:
   251  *  http://randomascii.wordpress.com/2013/07/08/windows-timer-resolution-megawatts-wasted/
   252  *
   253  *  If this variable is set to "0", the system timer resolution is not set.
   254  *
   255  *  The default value is "1". This hint may be set at any time.
   256  */
   257 #define SDL_HINT_TIMER_RESOLUTION "SDL_TIMER_RESOLUTION"
   258 
   259 
   260 /**
   261  *  \brief If set to 1, then do not allow high-DPI windows. ("Retina" on Mac)
   262  */
   263 #define SDL_HINT_VIDEO_HIGHDPI_DISABLED "SDL_VIDEO_HIGHDPI_DISABLED"
   264 
   265 
   266 /**
   267  *  \brief  An enumeration of hint priorities
   268  */
   269 typedef enum
   270 {
   271     SDL_HINT_DEFAULT,
   272     SDL_HINT_NORMAL,
   273     SDL_HINT_OVERRIDE
   274 } SDL_HintPriority;
   275 
   276 
   277 /**
   278  *  \brief Set a hint with a specific priority
   279  *
   280  *  The priority controls the behavior when setting a hint that already
   281  *  has a value.  Hints will replace existing hints of their priority and
   282  *  lower.  Environment variables are considered to have override priority.
   283  *
   284  *  \return SDL_TRUE if the hint was set, SDL_FALSE otherwise
   285  */
   286 extern DECLSPEC SDL_bool SDLCALL SDL_SetHintWithPriority(const char *name,
   287                                                          const char *value,
   288                                                          SDL_HintPriority priority);
   289 
   290 /**
   291  *  \brief Set a hint with normal priority
   292  *
   293  *  \return SDL_TRUE if the hint was set, SDL_FALSE otherwise
   294  */
   295 extern DECLSPEC SDL_bool SDLCALL SDL_SetHint(const char *name,
   296                                              const char *value);
   297 
   298 /**
   299  *  \brief Get a hint
   300  *
   301  *  \return The string value of a hint variable.
   302  */
   303 extern DECLSPEC const char * SDLCALL SDL_GetHint(const char *name);
   304 
   305 /**
   306  *  \brief Add a function to watch a particular hint
   307  *
   308  *  \param name The hint to watch
   309  *  \param callback The function to call when the hint value changes
   310  *  \param userdata A pointer to pass to the callback function
   311  */
   312 typedef void (*SDL_HintCallback)(void *userdata, const char *name, const char *oldValue, const char *newValue);
   313 extern DECLSPEC void SDLCALL SDL_AddHintCallback(const char *name,
   314                                                  SDL_HintCallback callback,
   315                                                  void *userdata);
   316 
   317 /**
   318  *  \brief Remove a function watching a particular hint
   319  *
   320  *  \param name The hint being watched
   321  *  \param callback The function being called when the hint value changes
   322  *  \param userdata A pointer being passed to the callback function
   323  */
   324 extern DECLSPEC void SDLCALL SDL_DelHintCallback(const char *name,
   325                                                  SDL_HintCallback callback,
   326                                                  void *userdata);
   327 
   328 /**
   329  *  \brief  Clear all hints
   330  *
   331  *  This function is called during SDL_Quit() to free stored hints.
   332  */
   333 extern DECLSPEC void SDLCALL SDL_ClearHints(void);
   334 
   335 
   336 /* Ends C function definitions when using C++ */
   337 #ifdef __cplusplus
   338 }
   339 #endif
   340 #include "close_code.h"
   341 
   342 #endif /* _SDL_hints_h */
   343 
   344 /* vi: set ts=4 sw=4 expandtab: */