include/SDL_hints.h
author Sam Lantinga <slouken@libsdl.org>
Sat, 31 Dec 2011 09:28:07 -0500
changeset 6138 4c64952a58fb
parent 5555 3ecad5e5dbe4
child 6472 d4623b7209db
permissions -rw-r--r--
Happy New Year!
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2012 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 /* *INDENT-OFF* */
    48 extern "C" {
    49 /* *INDENT-ON* */
    50 #endif
    51 
    52 /**
    53  *  \brief  A variable controlling how 3D acceleration is used to accelerate the SDL 1.2 screen surface. 
    54  *
    55  *  SDL can try to accelerate the SDL 1.2 screen surface by using streaming
    56  *  textures with a 3D rendering engine.  This variable controls whether and
    57  *  how this is done.
    58  *
    59  *  This variable can be set to the following values:
    60  *    "0"       - Disable 3D acceleration
    61  *    "1"       - Enable 3D acceleration, using the default renderer.
    62  *    "X"       - Enable 3D acceleration, using X where X is one of the valid rendering drivers.  (e.g. "direct3d", "opengl", etc.)
    63  *
    64  *  By default SDL tries to make a best guess for each platform whether
    65  *  to use acceleration or not.
    66  */
    67 #define SDL_HINT_FRAMEBUFFER_ACCELERATION   "SDL_FRAMEBUFFER_ACCELERATION"
    68 
    69 /**
    70  *  \brief  A variable specifying which render driver to use.
    71  *
    72  *  If the application doesn't pick a specific renderer to use, this variable
    73  *  specifies the name of the preferred renderer.  If the preferred renderer
    74  *  can't be initialized, the normal default renderer is used.
    75  *
    76  *  This variable is case insensitive and can be set to the following values:
    77  *    "direct3d"
    78  *    "opengl"
    79  *    "opengles2"
    80  *    "opengles"
    81  *    "software"
    82  *
    83  *  The default varies by platform, but it's the first one in the list that
    84  *  is available on the current platform.
    85  */
    86 #define SDL_HINT_RENDER_DRIVER              "SDL_RENDER_DRIVER"
    87 
    88 /**
    89  *  \brief  A variable controlling whether the OpenGL render driver uses shaders if they are available.
    90  *
    91  *  This variable can be set to the following values:
    92  *    "0"       - Disable shaders
    93  *    "1"       - Enable shaders
    94  *
    95  *  By default shaders are used if OpenGL supports them.
    96  */
    97 #define SDL_HINT_RENDER_OPENGL_SHADERS      "SDL_RENDER_OPENGL_SHADERS"
    98 
    99 /**
   100  *  \brief  A variable controlling the scaling quality
   101  *
   102  *  This variable can be set to the following values:
   103  *    "0" or "nearest" - Nearest pixel sampling
   104  *    "1" or "linear"  - Linear filtering (supported by OpenGL and Direct3D)
   105  *    "2" or "best"    - Anisotropic filtering (supported by Direct3D)
   106  *
   107  *  By default nearest pixel sampling is used
   108  */
   109 #define SDL_HINT_RENDER_SCALE_QUALITY       "SDL_RENDER_SCALE_QUALITY"
   110 
   111 /**
   112  *  \brief  A variable controlling whether updates to the SDL 1.2 screen surface should be synchronized with the vertical refresh, to avoid tearing.
   113  *
   114  *  This variable can be set to the following values:
   115  *    "0"       - Disable vsync
   116  *    "1"       - Enable vsync
   117  *
   118  *  By default SDL does not sync screen surface updates with vertical refresh.
   119  */
   120 #define SDL_HINT_RENDER_VSYNC               "SDL_RENDER_VSYNC"
   121 	
   122 /**
   123  *  \brief  A variable controlling whether the idle timer is disabled on iOS.
   124  *
   125  *  When an iOS app does not receive touches for some time, the screen is
   126  *  dimmed automatically. For games where the accelerometer is the only input
   127  *  this is problematic. This functionality can be disabled by setting this
   128  *  hint.
   129  *
   130  *  This variable can be set to the following values:
   131  *    "0"       - Enable idle timer
   132  *    "1"       - Disable idle timer
   133  */
   134 #define SDL_HINT_IDLE_TIMER_DISABLED "SDL_IOS_IDLE_TIMER_DISABLED"
   135 	
   136 /**
   137  *  \brief  A variable controlling which orientations are allowed on iOS.
   138  *
   139  *  In some circumstances it is necessary to be able to explicitly control
   140  *  which UI orientations are allowed.
   141  *
   142  *  This variable is a space delimited list of the following values:
   143  *    "LandscapeLeft", "LandscapeRight", "Portrait" "PortraitUpsideDown"
   144  */
   145 #define SDL_HINT_ORIENTATIONS "SDL_IOS_ORIENTATIONS"
   146 
   147 
   148 /**
   149  *  \brief  An enumeration of hint priorities
   150  */
   151 typedef enum
   152 {
   153     SDL_HINT_DEFAULT,
   154     SDL_HINT_NORMAL,
   155     SDL_HINT_OVERRIDE
   156 } SDL_HintPriority;
   157 
   158 
   159 /**
   160  *  \brief Set a hint with a specific priority
   161  *
   162  *  The priority controls the behavior when setting a hint that already
   163  *  has a value.  Hints will replace existing hints of their priority and
   164  *  lower.  Environment variables are considered to have override priority.
   165  * 
   166  *  \return SDL_TRUE if the hint was set, SDL_FALSE otherwise
   167  */
   168 extern DECLSPEC SDL_bool SDLCALL SDL_SetHintWithPriority(const char *name,
   169                                                          const char *value,
   170                                                          SDL_HintPriority priority);
   171 
   172 /**
   173  *  \brief Set a hint with normal priority
   174  * 
   175  *  \return SDL_TRUE if the hint was set, SDL_FALSE otherwise
   176  */
   177 extern DECLSPEC SDL_bool SDLCALL SDL_SetHint(const char *name,
   178                                              const char *value);
   179 
   180 
   181 /**
   182  *  \brief Get a hint
   183  *  
   184  *  \return The string value of a hint variable.
   185  */
   186 extern DECLSPEC const char * SDLCALL SDL_GetHint(const char *name);
   187 
   188 /**
   189  *  \brief  Clear all hints
   190  *
   191  *  This function is called during SDL_Quit() to free stored hints.
   192  */
   193 extern DECLSPEC void SDLCALL SDL_ClearHints(void);
   194 
   195 
   196 /* Ends C function definitions when using C++ */
   197 #ifdef __cplusplus
   198 /* *INDENT-OFF* */
   199 }
   200 /* *INDENT-ON* */
   201 #endif
   202 #include "close_code.h"
   203 
   204 #endif /* _SDL_hints_h */
   205 
   206 /* vi: set ts=4 sw=4 expandtab: */