include/SDL_hints.h
author Sam Lantinga <slouken@libsdl.org>
Fri, 08 Apr 2011 13:03:26 -0700
changeset 5535 96594ac5fd1a
parent 5484 e20c93bc9122
child 5554 4b4258be8699
permissions -rw-r--r--
SDL 1.3 is now under the zlib license.
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2011 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 /**
   124  *  \brief  An enumeration of hint priorities
   125  */
   126 typedef enum
   127 {
   128     SDL_HINT_DEFAULT,
   129     SDL_HINT_NORMAL,
   130     SDL_HINT_OVERRIDE
   131 } SDL_HintPriority;
   132 
   133 
   134 /**
   135  *  \brief Set a hint with a specific priority
   136  *
   137  *  The priority controls the behavior when setting a hint that already
   138  *  has a value.  Hints will replace existing hints of their priority and
   139  *  lower.  Environment variables are considered to have override priority.
   140  * 
   141  *  \return SDL_TRUE if the hint was set, SDL_FALSE otherwise
   142  */
   143 extern DECLSPEC SDL_bool SDLCALL SDL_SetHintWithPriority(const char *name,
   144                                                          const char *value,
   145                                                          SDL_HintPriority priority);
   146 
   147 /**
   148  *  \brief Set a hint with normal priority
   149  * 
   150  *  \return SDL_TRUE if the hint was set, SDL_FALSE otherwise
   151  */
   152 extern DECLSPEC SDL_bool SDLCALL SDL_SetHint(const char *name,
   153                                              const char *value);
   154 
   155 
   156 /**
   157  *  \brief Get a hint
   158  *  
   159  *  \return The string value of a hint variable.
   160  */
   161 extern DECLSPEC const char * SDLCALL SDL_GetHint(const char *name);
   162 
   163 /**
   164  *  \brief  Clear all hints
   165  *
   166  *  This function is called during SDL_Quit() to free stored hints.
   167  */
   168 extern DECLSPEC void SDLCALL SDL_ClearHints(void);
   169 
   170 
   171 /* Ends C function definitions when using C++ */
   172 #ifdef __cplusplus
   173 /* *INDENT-OFF* */
   174 }
   175 /* *INDENT-ON* */
   176 #endif
   177 #include "close_code.h"
   178 
   179 #endif /* _SDL_hints_h */
   180 
   181 /* vi: set ts=4 sw=4 expandtab: */