include/SDL_hints.h
author David Ludwig <dludwig@pobox.com>
Fri, 01 Nov 2013 22:54:39 -0400
changeset 8540 724af2cd53b8
parent 8537 ea81cf5b6252
child 8543 b9dd3cf38585
permissions -rw-r--r--
WinRT: added support for SDL_HINT_RENDER_SCALE_QUALITY
     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 whether the Direct3D device is initialized for thread-safe operations.
    99  *
   100  *  This variable can be set to the following values:
   101  *    "0"       - Thread-safety is not enabled (faster)
   102  *    "1"       - Thread-safety is enabled
   103  *
   104  *  By default the Direct3D device is created with thread-safety disabled.
   105  */
   106 #define SDL_HINT_RENDER_DIRECT3D_THREADSAFE "SDL_RENDER_DIRECT3D_THREADSAFE"
   107 
   108 /**
   109  *  \brief  A variable controlling the scaling quality
   110  *
   111  *  This variable can be set to the following values:
   112  *    "0" or "nearest" - Nearest pixel sampling
   113  *    "1" or "linear"  - Linear filtering (supported by OpenGL and Direct3D)
   114  *    "2" or "best"    - Currently this is the same as "linear"
   115  *
   116  *  By default nearest pixel sampling is used
   117  */
   118 #define SDL_HINT_RENDER_SCALE_QUALITY       "SDL_RENDER_SCALE_QUALITY"
   119 
   120 /**
   121  *  \brief  A variable controlling whether updates to the SDL screen surface should be synchronized with the vertical refresh, to avoid tearing.
   122  *
   123  *  This variable can be set to the following values:
   124  *    "0"       - Disable vsync
   125  *    "1"       - Enable vsync
   126  *
   127  *  By default SDL does not sync screen surface updates with vertical refresh.
   128  */
   129 #define SDL_HINT_RENDER_VSYNC               "SDL_RENDER_VSYNC"
   130 
   131 /**
   132  *  \brief  A variable controlling whether to enable Direct3D 11+'s Debug Layer.
   133  *
   134  *  This variable does not have any effect on the Direct3D 9 based renderer,
   135  *  which is used in Win32-based (aka Windows Desktop) apps.
   136  *
   137  *  This variable can be set to the following values:
   138  *    "0"       - Disable Debug Layer use
   139  *    "1"       - Enable Debug Layer use
   140  *
   141  *  By default, SDL does not use Direct3D Debug Layer.
   142  */
   143 #define SDL_HINT_RENDER_DIRECT3D11_DEBUG    "SDL_HINT_RENDER_DIRECT3D11_DEBUG"
   144 
   145 /**
   146  *  \brief  A variable controlling whether the X11 VidMode extension should be used.
   147  *
   148  *  This variable can be set to the following values:
   149  *    "0"       - Disable XVidMode
   150  *    "1"       - Enable XVidMode
   151  *
   152  *  By default SDL will use XVidMode if it is available.
   153  */
   154 #define SDL_HINT_VIDEO_X11_XVIDMODE         "SDL_VIDEO_X11_XVIDMODE"
   155 
   156 /**
   157  *  \brief  A variable controlling whether the X11 Xinerama extension should be used.
   158  *
   159  *  This variable can be set to the following values:
   160  *    "0"       - Disable Xinerama
   161  *    "1"       - Enable Xinerama
   162  *
   163  *  By default SDL will use Xinerama if it is available.
   164  */
   165 #define SDL_HINT_VIDEO_X11_XINERAMA         "SDL_VIDEO_X11_XINERAMA"
   166 
   167 /**
   168  *  \brief  A variable controlling whether the X11 XRandR extension should be used.
   169  *
   170  *  This variable can be set to the following values:
   171  *    "0"       - Disable XRandR
   172  *    "1"       - Enable XRandR
   173  *
   174  *  By default SDL will not use XRandR because of window manager issues.
   175  */
   176 #define SDL_HINT_VIDEO_X11_XRANDR           "SDL_VIDEO_X11_XRANDR"
   177 
   178 /**
   179  *  \brief  A variable controlling whether grabbing input grabs the keyboard
   180  *
   181  *  This variable can be set to the following values:
   182  *    "0"       - Grab will affect only the mouse
   183  *    "1"       - Grab will affect mouse and keyboard
   184  *
   185  *  By default SDL will not grab the keyboard so system shortcuts still work.
   186  */
   187 #define SDL_HINT_GRAB_KEYBOARD              "SDL_GRAB_KEYBOARD"
   188 
   189 /**
   190  *  \brief Minimize your SDL_Window if it loses key focus when in Fullscreen mode. Defaults to true.
   191  *
   192  */
   193 #define SDL_HINT_VIDEO_MINIMIZE_ON_FOCUS_LOSS   "SDL_VIDEO_MINIMIZE_ON_FOCUS_LOSS"
   194 
   195 
   196 /**
   197  *  \brief  A variable controlling whether the idle timer is disabled on iOS.
   198  *
   199  *  When an iOS app does not receive touches for some time, the screen is
   200  *  dimmed automatically. For games where the accelerometer is the only input
   201  *  this is problematic. This functionality can be disabled by setting this
   202  *  hint.
   203  *
   204  *  This variable can be set to the following values:
   205  *    "0"       - Enable idle timer
   206  *    "1"       - Disable idle timer
   207  */
   208 #define SDL_HINT_IDLE_TIMER_DISABLED "SDL_IOS_IDLE_TIMER_DISABLED"
   209 
   210 /**
   211  *  \brief  A variable controlling which orientations are allowed on iOS.
   212  *
   213  *  In some circumstances it is necessary to be able to explicitly control
   214  *  which UI orientations are allowed.
   215  *
   216  *  This variable is a space delimited list of the following values:
   217  *    "LandscapeLeft", "LandscapeRight", "Portrait" "PortraitUpsideDown"
   218  */
   219 #define SDL_HINT_ORIENTATIONS "SDL_IOS_ORIENTATIONS"
   220 
   221 
   222 /**
   223  *  \brief  A variable that lets you disable the detection and use of Xinput gamepad devices
   224  *
   225  *  The variable can be set to the following values:
   226  *    "0"       - Disable XInput timer (only uses direct input)
   227  *    "1"       - Enable XInput timer (the default)
   228  */
   229 #define SDL_HINT_XINPUT_ENABLED "SDL_XINPUT_ENABLED"
   230 
   231 
   232 /**
   233  *  \brief  A variable that lets you manually hint extra gamecontroller db entries
   234  *
   235  *  The variable should be newline delimited rows of gamecontroller config data, see SDL_gamecontroller.h
   236  *
   237  *  This hint must be set before calling SDL_Init(SDL_INIT_GAMECONTROLLER)
   238  *  You can update mappings after the system is initialized with SDL_GameControllerMappingForGUID() and SDL_GameControllerAddMapping()
   239  */
   240 #define SDL_HINT_GAMECONTROLLERCONFIG "SDL_GAMECONTROLLERCONFIG"
   241 
   242 
   243 /**
   244  *  \brief  A variable that lets you enable joystick (and gamecontroller) events even when your app is in the background.
   245  *
   246  *  The variable can be set to the following values:
   247  *    "0"       - Disable joystick & gamecontroller input events when the
   248  *                application is in the background.
   249  *    "1"       - Enable joystick & gamecontroller input events when the
   250  *                application is in the backgroumd.
   251  *
   252  *  The default value is "0".  This hint may be set at any time.
   253  */
   254 #define SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS "SDL_JOYSTICK_ALLOW_BACKGROUND_EVENTS"
   255 
   256 
   257 /**
   258  *  \brief If set to 0 then never set the top most bit on a SDL Window, even if the video mode expects it.
   259  *      This is a debugging aid for developers and not expected to be used by end users. The default is "1"
   260  *
   261  *  This variable can be set to the following values:
   262  *    "0"       - don't allow topmost
   263  *    "1"       - allow topmost
   264  */
   265 #define SDL_HINT_ALLOW_TOPMOST "SDL_ALLOW_TOPMOST"
   266 
   267 
   268 /**
   269  *  \brief A variable that controls the timer resolution, in milliseconds.
   270  *
   271  *  The higher resolution the timer, the more frequently the CPU services
   272  *  timer interrupts, and the more precise delays are, but this takes up
   273  *  power and CPU time.  This hint is only used on Windows 7 and earlier.
   274  *
   275  *  See this blog post for more information:
   276  *  http://randomascii.wordpress.com/2013/07/08/windows-timer-resolution-megawatts-wasted/
   277  *
   278  *  If this variable is set to "0", the system timer resolution is not set.
   279  *
   280  *  The default value is "1". This hint may be set at any time.
   281  */
   282 #define SDL_HINT_TIMER_RESOLUTION "SDL_TIMER_RESOLUTION"
   283 
   284 
   285 /**
   286  *  \brief If set to 1, then do not allow high-DPI windows. ("Retina" on Mac)
   287  */
   288 #define SDL_HINT_VIDEO_HIGHDPI_DISABLED "SDL_VIDEO_HIGHDPI_DISABLED"
   289 
   290 
   291 /**
   292  *  \brief  An enumeration of hint priorities
   293  */
   294 typedef enum
   295 {
   296     SDL_HINT_DEFAULT,
   297     SDL_HINT_NORMAL,
   298     SDL_HINT_OVERRIDE
   299 } SDL_HintPriority;
   300 
   301 
   302 /**
   303  *  \brief Set a hint with a specific priority
   304  *
   305  *  The priority controls the behavior when setting a hint that already
   306  *  has a value.  Hints will replace existing hints of their priority and
   307  *  lower.  Environment variables are considered to have override priority.
   308  *
   309  *  \return SDL_TRUE if the hint was set, SDL_FALSE otherwise
   310  */
   311 extern DECLSPEC SDL_bool SDLCALL SDL_SetHintWithPriority(const char *name,
   312                                                          const char *value,
   313                                                          SDL_HintPriority priority);
   314 
   315 /**
   316  *  \brief Set a hint with normal priority
   317  *
   318  *  \return SDL_TRUE if the hint was set, SDL_FALSE otherwise
   319  */
   320 extern DECLSPEC SDL_bool SDLCALL SDL_SetHint(const char *name,
   321                                              const char *value);
   322 
   323 /**
   324  *  \brief Get a hint
   325  *
   326  *  \return The string value of a hint variable.
   327  */
   328 extern DECLSPEC const char * SDLCALL SDL_GetHint(const char *name);
   329 
   330 /**
   331  *  \brief Add a function to watch a particular hint
   332  *
   333  *  \param name The hint to watch
   334  *  \param callback The function to call when the hint value changes
   335  *  \param userdata A pointer to pass to the callback function
   336  */
   337 typedef void (*SDL_HintCallback)(void *userdata, const char *name, const char *oldValue, const char *newValue);
   338 extern DECLSPEC void SDLCALL SDL_AddHintCallback(const char *name,
   339                                                  SDL_HintCallback callback,
   340                                                  void *userdata);
   341 
   342 /**
   343  *  \brief Remove a function watching a particular hint
   344  *
   345  *  \param name The hint being watched
   346  *  \param callback The function being called when the hint value changes
   347  *  \param userdata A pointer being passed to the callback function
   348  */
   349 extern DECLSPEC void SDLCALL SDL_DelHintCallback(const char *name,
   350                                                  SDL_HintCallback callback,
   351                                                  void *userdata);
   352 
   353 /**
   354  *  \brief  Clear all hints
   355  *
   356  *  This function is called during SDL_Quit() to free stored hints.
   357  */
   358 extern DECLSPEC void SDLCALL SDL_ClearHints(void);
   359 
   360 
   361 /* Ends C function definitions when using C++ */
   362 #ifdef __cplusplus
   363 }
   364 #endif
   365 #include "close_code.h"
   366 
   367 #endif /* _SDL_hints_h */
   368 
   369 /* vi: set ts=4 sw=4 expandtab: */