- /* 
-   Simple DirectMedia Layer 
-   Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org> 
-   
-   This software is provided 'as-is', without any express or implied 
-   warranty.  In no event will the authors be held liable for any damages 
-   arising from the use of this software. 
-   
-   Permission is granted to anyone to use this software for any purpose, 
-   including commercial applications, and to alter it and redistribute it 
-   freely, subject to the following restrictions: 
-   
-   1. The origin of this software must not be misrepresented; you must not 
-      claim that you wrote the original software. If you use this software 
-      in a product, an acknowledgment in the product documentation would be 
-      appreciated but is not required. 
-   2. Altered source versions must be plainly marked as such, and must not be 
-      misrepresented as being the original software. 
-   3. This notice may not be removed or altered from any source distribution. 
- */ 
-   
- /** 
-  *  \file SDL_video.h 
-  * 
-  *  Header file for SDL video functions. 
-  */ 
-   
- #ifndef SDL_video_h_ 
- #define SDL_video_h_ 
-   
- #include "SDL_stdinc.h" 
- #include "SDL_pixels.h" 
- #include "SDL_rect.h" 
- #include "SDL_surface.h" 
-   
- #include "begin_code.h" 
- /* Set up for C function definitions, even when using C++ */ 
- #ifdef __cplusplus 
- extern "C" { 
- #endif 
-   
- /** 
-  *  \brief  The structure that defines a display mode 
-  * 
-  *  \sa SDL_GetNumDisplayModes() 
-  *  \sa SDL_GetDisplayMode() 
-  *  \sa SDL_GetDesktopDisplayMode() 
-  *  \sa SDL_GetCurrentDisplayMode() 
-  *  \sa SDL_GetClosestDisplayMode() 
-  *  \sa SDL_SetWindowDisplayMode() 
-  *  \sa SDL_GetWindowDisplayMode() 
-  */ 
- typedef struct 
- { 
-     Uint32 format;              /**< pixel format */ 
-     int w;                      /**< width, in screen coordinates */ 
-     int h;                      /**< height, in screen coordinates */ 
-     int refresh_rate;           /**< refresh rate (or zero for unspecified) */ 
-     void *driverdata;           /**< driver-specific data, initialize to 0 */ 
- } SDL_DisplayMode; 
-   
- /** 
-  *  \brief The type used to identify a window 
-  * 
-  *  \sa SDL_CreateWindow() 
-  *  \sa SDL_CreateWindowFrom() 
-  *  \sa SDL_DestroyWindow() 
-  *  \sa SDL_GetWindowData() 
-  *  \sa SDL_GetWindowFlags() 
-  *  \sa SDL_GetWindowGrab() 
-  *  \sa SDL_GetWindowPosition() 
-  *  \sa SDL_GetWindowSize() 
-  *  \sa SDL_GetWindowTitle() 
-  *  \sa SDL_HideWindow() 
-  *  \sa SDL_MaximizeWindow() 
-  *  \sa SDL_MinimizeWindow() 
-  *  \sa SDL_RaiseWindow() 
-  *  \sa SDL_RestoreWindow() 
-  *  \sa SDL_SetWindowData() 
-  *  \sa SDL_SetWindowFullscreen() 
-  *  \sa SDL_SetWindowGrab() 
-  *  \sa SDL_SetWindowIcon() 
-  *  \sa SDL_SetWindowPosition() 
-  *  \sa SDL_SetWindowSize() 
-  *  \sa SDL_SetWindowBordered() 
-  *  \sa SDL_SetWindowResizable() 
-  *  \sa SDL_SetWindowTitle() 
-  *  \sa SDL_ShowWindow() 
-  */ 
- typedef struct SDL_Window SDL_Window; 
-   
- /** 
-  *  \brief The flags on a window 
-  * 
-  *  \sa SDL_GetWindowFlags() 
-  */ 
- typedef enum 
- { 
-     /* !!! FIXME: change this to name = (1<<x). */ 
-     SDL_WINDOW_FULLSCREEN = 0x00000001,         /**< fullscreen window */ 
-     SDL_WINDOW_OPENGL = 0x00000002,             /**< window usable with OpenGL context */ 
-     SDL_WINDOW_SHOWN = 0x00000004,              /**< window is visible */ 
-     SDL_WINDOW_HIDDEN = 0x00000008,             /**< window is not visible */ 
-     SDL_WINDOW_BORDERLESS = 0x00000010,         /**< no window decoration */ 
-     SDL_WINDOW_RESIZABLE = 0x00000020,          /**< window can be resized */ 
-     SDL_WINDOW_MINIMIZED = 0x00000040,          /**< window is minimized */ 
-     SDL_WINDOW_MAXIMIZED = 0x00000080,          /**< window is maximized */ 
-     SDL_WINDOW_INPUT_GRABBED = 0x00000100,      /**< window has grabbed input focus */ 
-     SDL_WINDOW_INPUT_FOCUS = 0x00000200,        /**< window has input focus */ 
-     SDL_WINDOW_MOUSE_FOCUS = 0x00000400,        /**< window has mouse focus */ 
-     SDL_WINDOW_FULLSCREEN_DESKTOP = ( SDL_WINDOW_FULLSCREEN | 0x00001000 ), 
-     SDL_WINDOW_FOREIGN = 0x00000800,            /**< window not created by SDL */ 
-     SDL_WINDOW_ALLOW_HIGHDPI = 0x00002000,      /**< window should be created in high-DPI mode if supported */ 
-     SDL_WINDOW_MOUSE_CAPTURE = 0x00004000,      /**< window has mouse captured (unrelated to INPUT_GRABBED) */ 
-     SDL_WINDOW_ALWAYS_ON_TOP = 0x00008000,      /**< window should always be above others */ 
-     SDL_WINDOW_SKIP_TASKBAR  = 0x00010000,      /**< window should not be added to the taskbar */ 
-     SDL_WINDOW_UTILITY       = 0x00020000,      /**< window should be treated as a utility window */ 
-     SDL_WINDOW_TOOLTIP       = 0x00040000,      /**< window should be treated as a tooltip */ 
-     SDL_WINDOW_POPUP_MENU    = 0x00080000,      /**< window should be treated as a popup menu */ 
-     SDL_WINDOW_VULKAN        = 0x10000000       /**< window usable for Vulkan surface */ 
- } SDL_WindowFlags; 
-   
- /** 
-  *  \brief Used to indicate that you don't care what the window position is. 
-  */ 
- #define SDL_WINDOWPOS_UNDEFINED_MASK    0x1FFF0000u 
- #define SDL_WINDOWPOS_UNDEFINED_DISPLAY(X)  (SDL_WINDOWPOS_UNDEFINED_MASK|(X)) 
- #define SDL_WINDOWPOS_UNDEFINED         SDL_WINDOWPOS_UNDEFINED_DISPLAY(0) 
- #define SDL_WINDOWPOS_ISUNDEFINED(X)    \ 
-             (((X)&0xFFFF0000) == SDL_WINDOWPOS_UNDEFINED_MASK) 
-   
- /** 
-  *  \brief Used to indicate that the window position should be centered. 
-  */ 
- #define SDL_WINDOWPOS_CENTERED_MASK    0x2FFF0000u 
- #define SDL_WINDOWPOS_CENTERED_DISPLAY(X)  (SDL_WINDOWPOS_CENTERED_MASK|(X)) 
- #define SDL_WINDOWPOS_CENTERED         SDL_WINDOWPOS_CENTERED_DISPLAY(0) 
- #define SDL_WINDOWPOS_ISCENTERED(X)    \ 
-             (((X)&0xFFFF0000) == SDL_WINDOWPOS_CENTERED_MASK) 
-   
- /** 
-  *  \brief Event subtype for window events 
-  */ 
- typedef enum 
- { 
-     SDL_WINDOWEVENT_NONE,           /**< Never used */ 
-     SDL_WINDOWEVENT_SHOWN,          /**< Window has been shown */ 
-     SDL_WINDOWEVENT_HIDDEN,         /**< Window has been hidden */ 
-     SDL_WINDOWEVENT_EXPOSED,        /**< Window has been exposed and should be 
-                                          redrawn */ 
-     SDL_WINDOWEVENT_MOVED,          /**< Window has been moved to data1, data2 
-                                      */ 
-     SDL_WINDOWEVENT_RESIZED,        /**< Window has been resized to data1xdata2 */ 
-     SDL_WINDOWEVENT_SIZE_CHANGED,   /**< The window size has changed, either as 
-                                          a result of an API call or through the 
-                                          system or user changing the window size. */ 
-     SDL_WINDOWEVENT_MINIMIZED,      /**< Window has been minimized */ 
-     SDL_WINDOWEVENT_MAXIMIZED,      /**< Window has been maximized */ 
-     SDL_WINDOWEVENT_RESTORED,       /**< Window has been restored to normal size 
-                                          and position */ 
-     SDL_WINDOWEVENT_ENTER,          /**< Window has gained mouse focus */ 
-     SDL_WINDOWEVENT_LEAVE,          /**< Window has lost mouse focus */ 
-     SDL_WINDOWEVENT_FOCUS_GAINED,   /**< Window has gained keyboard focus */ 
-     SDL_WINDOWEVENT_FOCUS_LOST,     /**< Window has lost keyboard focus */ 
-     SDL_WINDOWEVENT_CLOSE,          /**< The window manager requests that the window be closed */ 
-     SDL_WINDOWEVENT_TAKE_FOCUS,     /**< Window is being offered a focus (should SetWindowInputFocus() on itself or a subwindow, or ignore) */ 
-     SDL_WINDOWEVENT_HIT_TEST        /**< Window had a hit test that wasn't SDL_HITTEST_NORMAL. */ 
- } SDL_WindowEventID; 
-   
- /** 
-  *  \brief An opaque handle to an OpenGL context. 
-  */ 
- typedef void *SDL_GLContext; 
-   
- /** 
-  *  \brief OpenGL configuration attributes 
-  */ 
- typedef enum 
- { 
-     SDL_GL_RED_SIZE, 
-     SDL_GL_GREEN_SIZE, 
-     SDL_GL_BLUE_SIZE, 
-     SDL_GL_ALPHA_SIZE, 
-     SDL_GL_BUFFER_SIZE, 
-     SDL_GL_DOUBLEBUFFER, 
-     SDL_GL_DEPTH_SIZE, 
-     SDL_GL_STENCIL_SIZE, 
-     SDL_GL_ACCUM_RED_SIZE, 
-     SDL_GL_ACCUM_GREEN_SIZE, 
-     SDL_GL_ACCUM_BLUE_SIZE, 
-     SDL_GL_ACCUM_ALPHA_SIZE, 
-     SDL_GL_STEREO, 
-     SDL_GL_MULTISAMPLEBUFFERS, 
-     SDL_GL_MULTISAMPLESAMPLES, 
-     SDL_GL_ACCELERATED_VISUAL, 
-     SDL_GL_RETAINED_BACKING, 
-     SDL_GL_CONTEXT_MAJOR_VERSION, 
-     SDL_GL_CONTEXT_MINOR_VERSION, 
-     SDL_GL_CONTEXT_EGL, 
-     SDL_GL_CONTEXT_FLAGS, 
-     SDL_GL_CONTEXT_PROFILE_MASK, 
-     SDL_GL_SHARE_WITH_CURRENT_CONTEXT, 
-     SDL_GL_FRAMEBUFFER_SRGB_CAPABLE, 
-     SDL_GL_CONTEXT_RELEASE_BEHAVIOR, 
-     SDL_GL_CONTEXT_RESET_NOTIFICATION, 
-     SDL_GL_CONTEXT_NO_ERROR 
- } SDL_GLattr; 
-   
- typedef enum 
- { 
-     SDL_GL_CONTEXT_PROFILE_CORE           = 0x0001, 
-     SDL_GL_CONTEXT_PROFILE_COMPATIBILITY  = 0x0002, 
-     SDL_GL_CONTEXT_PROFILE_ES             = 0x0004 /**< GLX_CONTEXT_ES2_PROFILE_BIT_EXT */ 
- } SDL_GLprofile; 
-   
- typedef enum 
- { 
-     SDL_GL_CONTEXT_DEBUG_FLAG              = 0x0001, 
-     SDL_GL_CONTEXT_FORWARD_COMPATIBLE_FLAG = 0x0002, 
-     SDL_GL_CONTEXT_ROBUST_ACCESS_FLAG      = 0x0004, 
-     SDL_GL_CONTEXT_RESET_ISOLATION_FLAG    = 0x0008 
- } SDL_GLcontextFlag; 
-   
- typedef enum 
- { 
-     SDL_GL_CONTEXT_RELEASE_BEHAVIOR_NONE   = 0x0000, 
-     SDL_GL_CONTEXT_RELEASE_BEHAVIOR_FLUSH  = 0x0001 
- } SDL_GLcontextReleaseFlag; 
-   
- typedef enum 
- { 
-     SDL_GL_CONTEXT_RESET_NO_NOTIFICATION = 0x0000, 
-     SDL_GL_CONTEXT_RESET_LOSE_CONTEXT    = 0x0001 
- } SDL_GLContextResetNotification; 
-   
- /* Function prototypes */ 
-   
- /** 
-  *  \brief Get the number of video drivers compiled into SDL 
-  * 
-  *  \sa SDL_GetVideoDriver() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GetNumVideoDrivers(void); 
-   
- /** 
-  *  \brief Get the name of a built in video driver. 
-  * 
-  *  \note The video drivers are presented in the order in which they are 
-  *        normally checked during initialization. 
-  * 
-  *  \sa SDL_GetNumVideoDrivers() 
-  */ 
- extern DECLSPEC const char *SDLCALL SDL_GetVideoDriver(int index); 
-   
- /** 
-  *  \brief Initialize the video subsystem, optionally specifying a video driver. 
-  * 
-  *  \param driver_name Initialize a specific driver by name, or NULL for the 
-  *                     default video driver. 
-  * 
-  *  \return 0 on success, -1 on error 
-  * 
-  *  This function initializes the video subsystem; setting up a connection 
-  *  to the window manager, etc, and determines the available display modes 
-  *  and pixel formats, but does not initialize a window or graphics mode. 
-  * 
-  *  \sa SDL_VideoQuit() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_VideoInit(const char *driver_name); 
-   
- /** 
-  *  \brief Shuts down the video subsystem. 
-  * 
-  *  This function closes all windows, and restores the original video mode. 
-  * 
-  *  \sa SDL_VideoInit() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_VideoQuit(void); 
-   
- /** 
-  *  \brief Returns the name of the currently initialized video driver. 
-  * 
-  *  \return The name of the current video driver or NULL if no driver 
-  *          has been initialized 
-  * 
-  *  \sa SDL_GetNumVideoDrivers() 
-  *  \sa SDL_GetVideoDriver() 
-  */ 
- extern DECLSPEC const char *SDLCALL SDL_GetCurrentVideoDriver(void); 
-   
- /** 
-  *  \brief Returns the number of available video displays. 
-  * 
-  *  \sa SDL_GetDisplayBounds() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GetNumVideoDisplays(void); 
-   
- /** 
-  *  \brief Get the name of a display in UTF-8 encoding 
-  * 
-  *  \return The name of a display, or NULL for an invalid display index. 
-  * 
-  *  \sa SDL_GetNumVideoDisplays() 
-  */ 
- extern DECLSPEC const char * SDLCALL SDL_GetDisplayName(int displayIndex); 
-   
- /** 
-  *  \brief Get the desktop area represented by a display, with the primary 
-  *         display located at 0,0 
-  * 
-  *  \return 0 on success, or -1 if the index is out of range. 
-  * 
-  *  \sa SDL_GetNumVideoDisplays() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GetDisplayBounds(int displayIndex, SDL_Rect * rect); 
-   
- /** 
-  *  \brief Get the dots/pixels-per-inch for a display 
-  * 
-  *  \note Diagonal, horizontal and vertical DPI can all be optionally 
-  *        returned if the parameter is non-NULL. 
-  * 
-  *  \return 0 on success, or -1 if no DPI information is available or the index is out of range. 
-  * 
-  *  \sa SDL_GetNumVideoDisplays() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GetDisplayDPI(int displayIndex, float * ddpi, float * hdpi, float * vdpi); 
-   
- /** 
-  *  \brief Get the usable desktop area represented by a display, with the 
-  *         primary display located at 0,0 
-  * 
-  *  This is the same area as SDL_GetDisplayBounds() reports, but with portions 
-  *  reserved by the system removed. For example, on Mac OS X, this subtracts 
-  *  the area occupied by the menu bar and dock. 
-  * 
-  *  Setting a window to be fullscreen generally bypasses these unusable areas, 
-  *  so these are good guidelines for the maximum space available to a 
-  *  non-fullscreen window. 
-  * 
-  *  \return 0 on success, or -1 if the index is out of range. 
-  * 
-  *  \sa SDL_GetDisplayBounds() 
-  *  \sa SDL_GetNumVideoDisplays() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GetDisplayUsableBounds(int displayIndex, SDL_Rect * rect); 
-   
- /** 
-  *  \brief Returns the number of available display modes. 
-  * 
-  *  \sa SDL_GetDisplayMode() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GetNumDisplayModes(int displayIndex); 
-   
- /** 
-  *  \brief Fill in information about a specific display mode. 
-  * 
-  *  \note The display modes are sorted in this priority: 
-  *        \li bits per pixel -> more colors to fewer colors 
-  *        \li width -> largest to smallest 
-  *        \li height -> largest to smallest 
-  *        \li refresh rate -> highest to lowest 
-  * 
-  *  \sa SDL_GetNumDisplayModes() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GetDisplayMode(int displayIndex, int modeIndex, 
-                                                SDL_DisplayMode * mode); 
-   
- /** 
-  *  \brief Fill in information about the desktop display mode. 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GetDesktopDisplayMode(int displayIndex, SDL_DisplayMode * mode); 
-   
- /** 
-  *  \brief Fill in information about the current display mode. 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GetCurrentDisplayMode(int displayIndex, SDL_DisplayMode * mode); 
-   
-   
- /** 
-  *  \brief Get the closest match to the requested display mode. 
-  * 
-  *  \param displayIndex The index of display from which mode should be queried. 
-  *  \param mode The desired display mode 
-  *  \param closest A pointer to a display mode to be filled in with the closest 
-  *                 match of the available display modes. 
-  * 
-  *  \return The passed in value \c closest, or NULL if no matching video mode 
-  *          was available. 
-  * 
-  *  The available display modes are scanned, and \c closest is filled in with the 
-  *  closest mode matching the requested mode and returned.  The mode format and 
-  *  refresh_rate default to the desktop mode if they are 0.  The modes are 
-  *  scanned with size being first priority, format being second priority, and 
-  *  finally checking the refresh_rate.  If all the available modes are too 
-  *  small, then NULL is returned. 
-  * 
-  *  \sa SDL_GetNumDisplayModes() 
-  *  \sa SDL_GetDisplayMode() 
-  */ 
- extern DECLSPEC SDL_DisplayMode * SDLCALL SDL_GetClosestDisplayMode(int displayIndex, const SDL_DisplayMode * mode, SDL_DisplayMode * closest); 
-   
- /** 
-  *  \brief Get the display index associated with a window. 
-  * 
-  *  \return the display index of the display containing the center of the 
-  *          window, or -1 on error. 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GetWindowDisplayIndex(SDL_Window * window); 
-   
- /** 
-  *  \brief Set the display mode used when a fullscreen window is visible. 
-  * 
-  *  By default the window's dimensions and the desktop format and refresh rate 
-  *  are used. 
-  * 
-  *  \param window The window for which the display mode should be set. 
-  *  \param mode The mode to use, or NULL for the default mode. 
-  * 
-  *  \return 0 on success, or -1 if setting the display mode failed. 
-  * 
-  *  \sa SDL_GetWindowDisplayMode() 
-  *  \sa SDL_SetWindowFullscreen() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_SetWindowDisplayMode(SDL_Window * window, 
-                                                      const SDL_DisplayMode 
-                                                          * mode); 
-   
- /** 
-  *  \brief Fill in information about the display mode used when a fullscreen 
-  *         window is visible. 
-  * 
-  *  \sa SDL_SetWindowDisplayMode() 
-  *  \sa SDL_SetWindowFullscreen() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GetWindowDisplayMode(SDL_Window * window, 
-                                                      SDL_DisplayMode * mode); 
-   
- /** 
-  *  \brief Get the pixel format associated with the window. 
-  */ 
- extern DECLSPEC Uint32 SDLCALL SDL_GetWindowPixelFormat(SDL_Window * window); 
-   
- /** 
-  *  \brief Create a window with the specified position, dimensions, and flags. 
-  * 
-  *  \param title The title of the window, in UTF-8 encoding. 
-  *  \param x     The x position of the window, ::SDL_WINDOWPOS_CENTERED, or 
-  *               ::SDL_WINDOWPOS_UNDEFINED. 
-  *  \param y     The y position of the window, ::SDL_WINDOWPOS_CENTERED, or 
-  *               ::SDL_WINDOWPOS_UNDEFINED. 
-  *  \param w     The width of the window, in screen coordinates. 
-  *  \param h     The height of the window, in screen coordinates. 
-  *  \param flags The flags for the window, a mask of any of the following: 
-  *               ::SDL_WINDOW_FULLSCREEN,    ::SDL_WINDOW_OPENGL, 
-  *               ::SDL_WINDOW_HIDDEN,        ::SDL_WINDOW_BORDERLESS, 
-  *               ::SDL_WINDOW_RESIZABLE,     ::SDL_WINDOW_MAXIMIZED, 
-  *               ::SDL_WINDOW_MINIMIZED,     ::SDL_WINDOW_INPUT_GRABBED, 
-  *               ::SDL_WINDOW_ALLOW_HIGHDPI, ::SDL_WINDOW_VULKAN. 
-  * 
-  *  \return The created window, or NULL if window creation failed. 
-  * 
-  *  If the window is created with the SDL_WINDOW_ALLOW_HIGHDPI flag, its size 
-  *  in pixels may differ from its size in screen coordinates on platforms with 
-  *  high-DPI support (e.g. iOS and Mac OS X). Use SDL_GetWindowSize() to query 
-  *  the client area's size in screen coordinates, and SDL_GL_GetDrawableSize(), 
-  *  SDL_Vulkan_GetDrawableSize(), or SDL_GetRendererOutputSize() to query the 
-  *  drawable size in pixels. 
-  * 
-  *  If the window is created with any of the SDL_WINDOW_OPENGL or 
-  *  SDL_WINDOW_VULKAN flags, then the corresponding LoadLibrary function 
-  *  (SDL_GL_LoadLibrary or SDL_Vulkan_LoadLibrary) is called and the 
-  *  corrensponding UnloadLibrary function is called by SDL_DestroyWindow(). 
-  * 
-  *  If SDL_WINDOW_VULKAN is specified and there isn't a working Vulkan driver, 
-  *  SDL_CreateWindow() will fail because SDL_Vulkan_LoadLibrary() will fail. 
-  * 
-  *  \note On non-Apple devices, SDL requires you to either not link to the 
-  *        Vulkan loader or link to a dynamic library version. This limitation 
-  *        may be removed in a future version of SDL. 
-  * 
-  *  \sa SDL_DestroyWindow() 
-  *  \sa SDL_GL_LoadLibrary() 
-  *  \sa SDL_Vulkan_LoadLibrary() 
-  */ 
- extern DECLSPEC SDL_Window * SDLCALL SDL_CreateWindow(const char *title, 
-                                                       int x, int y, int w, 
-                                                       int h, Uint32 flags); 
-   
- /** 
-  *  \brief Create an SDL window from an existing native window. 
-  * 
-  *  \param data A pointer to driver-dependent window creation data 
-  * 
-  *  \return The created window, or NULL if window creation failed. 
-  * 
-  *  \sa SDL_DestroyWindow() 
-  */ 
- extern DECLSPEC SDL_Window * SDLCALL SDL_CreateWindowFrom(const void *data); 
-   
- /** 
-  *  \brief Get the numeric ID of a window, for logging purposes. 
-  */ 
- extern DECLSPEC Uint32 SDLCALL SDL_GetWindowID(SDL_Window * window); 
-   
- /** 
-  *  \brief Get a window from a stored ID, or NULL if it doesn't exist. 
-  */ 
- extern DECLSPEC SDL_Window * SDLCALL SDL_GetWindowFromID(Uint32 id); 
-   
- /** 
-  *  \brief Get the window flags. 
-  */ 
- extern DECLSPEC Uint32 SDLCALL SDL_GetWindowFlags(SDL_Window * window); 
-   
- /** 
-  *  \brief Set the title of a window, in UTF-8 format. 
-  * 
-  *  \sa SDL_GetWindowTitle() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_SetWindowTitle(SDL_Window * window, 
-                                                 const char *title); 
-   
- /** 
-  *  \brief Get the title of a window, in UTF-8 format. 
-  * 
-  *  \sa SDL_SetWindowTitle() 
-  */ 
- extern DECLSPEC const char *SDLCALL SDL_GetWindowTitle(SDL_Window * window); 
-   
- /** 
-  *  \brief Set the icon for a window. 
-  * 
-  *  \param window The window for which the icon should be set. 
-  *  \param icon The icon for the window. 
-  */ 
- extern DECLSPEC void SDLCALL SDL_SetWindowIcon(SDL_Window * window, 
-                                                SDL_Surface * icon); 
-   
- /** 
-  *  \brief Associate an arbitrary named pointer with a window. 
-  * 
-  *  \param window   The window to associate with the pointer. 
-  *  \param name     The name of the pointer. 
-  *  \param userdata The associated pointer. 
-  * 
-  *  \return The previous value associated with 'name' 
-  * 
-  *  \note The name is case-sensitive. 
-  * 
-  *  \sa SDL_GetWindowData() 
-  */ 
- extern DECLSPEC void* SDLCALL SDL_SetWindowData(SDL_Window * window, 
-                                                 const char *name, 
-                                                 void *userdata); 
-   
- /** 
-  *  \brief Retrieve the data pointer associated with a window. 
-  * 
-  *  \param window   The window to query. 
-  *  \param name     The name of the pointer. 
-  * 
-  *  \return The value associated with 'name' 
-  * 
-  *  \sa SDL_SetWindowData() 
-  */ 
- extern DECLSPEC void *SDLCALL SDL_GetWindowData(SDL_Window * window, 
-                                                 const char *name); 
-   
- /** 
-  *  \brief Set the position of a window. 
-  * 
-  *  \param window   The window to reposition. 
-  *  \param x        The x coordinate of the window in screen coordinates, or 
-  *                  ::SDL_WINDOWPOS_CENTERED or ::SDL_WINDOWPOS_UNDEFINED. 
-  *  \param y        The y coordinate of the window in screen coordinates, or 
-  *                  ::SDL_WINDOWPOS_CENTERED or ::SDL_WINDOWPOS_UNDEFINED. 
-  * 
-  *  \note The window coordinate origin is the upper left of the display. 
-  * 
-  *  \sa SDL_GetWindowPosition() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_SetWindowPosition(SDL_Window * window, 
-                                                    int x, int y); 
-   
- /** 
-  *  \brief Get the position of a window. 
-  * 
-  *  \param window   The window to query. 
-  *  \param x        Pointer to variable for storing the x position, in screen 
-  *                  coordinates. May be NULL. 
-  *  \param y        Pointer to variable for storing the y position, in screen 
-  *                  coordinates. May be NULL. 
-  * 
-  *  \sa SDL_SetWindowPosition() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_GetWindowPosition(SDL_Window * window, 
-                                                    int *x, int *y); 
-   
- /** 
-  *  \brief Set the size of a window's client area. 
-  * 
-  *  \param window   The window to resize. 
-  *  \param w        The width of the window, in screen coordinates. Must be >0. 
-  *  \param h        The height of the window, in screen coordinates. Must be >0. 
-  * 
-  *  \note Fullscreen windows automatically match the size of the display mode, 
-  *        and you should use SDL_SetWindowDisplayMode() to change their size. 
-  * 
-  *  The window size in screen coordinates may differ from the size in pixels, if 
-  *  the window was created with SDL_WINDOW_ALLOW_HIGHDPI on a platform with 
-  *  high-dpi support (e.g. iOS or OS X). Use SDL_GL_GetDrawableSize() or 
-  *  SDL_GetRendererOutputSize() to get the real client area size in pixels. 
-  * 
-  *  \sa SDL_GetWindowSize() 
-  *  \sa SDL_SetWindowDisplayMode() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_SetWindowSize(SDL_Window * window, int w, 
-                                                int h); 
-   
- /** 
-  *  \brief Get the size of a window's client area. 
-  * 
-  *  \param window   The window to query. 
-  *  \param w        Pointer to variable for storing the width, in screen 
-  *                  coordinates. May be NULL. 
-  *  \param h        Pointer to variable for storing the height, in screen 
-  *                  coordinates. May be NULL. 
-  * 
-  *  The window size in screen coordinates may differ from the size in pixels, if 
-  *  the window was created with SDL_WINDOW_ALLOW_HIGHDPI on a platform with 
-  *  high-dpi support (e.g. iOS or OS X). Use SDL_GL_GetDrawableSize() or 
-  *  SDL_GetRendererOutputSize() to get the real client area size in pixels. 
-  * 
-  *  \sa SDL_SetWindowSize() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_GetWindowSize(SDL_Window * window, int *w, 
-                                                int *h); 
-   
- /** 
-  *  \brief Get the size of a window's borders (decorations) around the client area. 
-  * 
-  *  \param window The window to query. 
-  *  \param top Pointer to variable for storing the size of the top border. NULL is permitted. 
-  *  \param left Pointer to variable for storing the size of the left border. NULL is permitted. 
-  *  \param bottom Pointer to variable for storing the size of the bottom border. NULL is permitted. 
-  *  \param right Pointer to variable for storing the size of the right border. NULL is permitted. 
-  * 
-  *  \return 0 on success, or -1 if getting this information is not supported. 
-  * 
-  *  \note if this function fails (returns -1), the size values will be 
-  *        initialized to 0, 0, 0, 0 (if a non-NULL pointer is provided), as 
-  *        if the window in question was borderless. 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GetWindowBordersSize(SDL_Window * window, 
-                                                      int *top, int *left, 
-                                                      int *bottom, int *right); 
-   
- /** 
-  *  \brief Set the minimum size of a window's client area. 
-  * 
-  *  \param window    The window to set a new minimum size. 
-  *  \param min_w     The minimum width of the window, must be >0 
-  *  \param min_h     The minimum height of the window, must be >0 
-  * 
-  *  \note You can't change the minimum size of a fullscreen window, it 
-  *        automatically matches the size of the display mode. 
-  * 
-  *  \sa SDL_GetWindowMinimumSize() 
-  *  \sa SDL_SetWindowMaximumSize() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_SetWindowMinimumSize(SDL_Window * window, 
-                                                       int min_w, int min_h); 
-   
- /** 
-  *  \brief Get the minimum size of a window's client area. 
-  * 
-  *  \param window   The window to query. 
-  *  \param w        Pointer to variable for storing the minimum width, may be NULL 
-  *  \param h        Pointer to variable for storing the minimum height, may be NULL 
-  * 
-  *  \sa SDL_GetWindowMaximumSize() 
-  *  \sa SDL_SetWindowMinimumSize() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_GetWindowMinimumSize(SDL_Window * window, 
-                                                       int *w, int *h); 
-   
- /** 
-  *  \brief Set the maximum size of a window's client area. 
-  * 
-  *  \param window    The window to set a new maximum size. 
-  *  \param max_w     The maximum width of the window, must be >0 
-  *  \param max_h     The maximum height of the window, must be >0 
-  * 
-  *  \note You can't change the maximum size of a fullscreen window, it 
-  *        automatically matches the size of the display mode. 
-  * 
-  *  \sa SDL_GetWindowMaximumSize() 
-  *  \sa SDL_SetWindowMinimumSize() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_SetWindowMaximumSize(SDL_Window * window, 
-                                                       int max_w, int max_h); 
-   
- /** 
-  *  \brief Get the maximum size of a window's client area. 
-  * 
-  *  \param window   The window to query. 
-  *  \param w        Pointer to variable for storing the maximum width, may be NULL 
-  *  \param h        Pointer to variable for storing the maximum height, may be NULL 
-  * 
-  *  \sa SDL_GetWindowMinimumSize() 
-  *  \sa SDL_SetWindowMaximumSize() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_GetWindowMaximumSize(SDL_Window * window, 
-                                                       int *w, int *h); 
-   
- /** 
-  *  \brief Set the border state of a window. 
-  * 
-  *  This will add or remove the window's SDL_WINDOW_BORDERLESS flag and 
-  *  add or remove the border from the actual window. This is a no-op if the 
-  *  window's border already matches the requested state. 
-  * 
-  *  \param window The window of which to change the border state. 
-  *  \param bordered SDL_FALSE to remove border, SDL_TRUE to add border. 
-  * 
-  *  \note You can't change the border state of a fullscreen window. 
-  * 
-  *  \sa SDL_GetWindowFlags() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_SetWindowBordered(SDL_Window * window, 
-                                                    SDL_bool bordered); 
-   
- /** 
-  *  \brief Set the user-resizable state of a window. 
-  * 
-  *  This will add or remove the window's SDL_WINDOW_RESIZABLE flag and 
-  *  allow/disallow user resizing of the window. This is a no-op if the 
-  *  window's resizable state already matches the requested state. 
-  * 
-  *  \param window The window of which to change the resizable state. 
-  *  \param resizable SDL_TRUE to allow resizing, SDL_FALSE to disallow. 
-  * 
-  *  \note You can't change the resizable state of a fullscreen window. 
-  * 
-  *  \sa SDL_GetWindowFlags() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_SetWindowResizable(SDL_Window * window, 
-                                                     SDL_bool resizable); 
-   
- /** 
-  *  \brief Show a window. 
-  * 
-  *  \sa SDL_HideWindow() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_ShowWindow(SDL_Window * window); 
-   
- /** 
-  *  \brief Hide a window. 
-  * 
-  *  \sa SDL_ShowWindow() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_HideWindow(SDL_Window * window); 
-   
- /** 
-  *  \brief Raise a window above other windows and set the input focus. 
-  */ 
- extern DECLSPEC void SDLCALL SDL_RaiseWindow(SDL_Window * window); 
-   
- /** 
-  *  \brief Make a window as large as possible. 
-  * 
-  *  \sa SDL_RestoreWindow() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_MaximizeWindow(SDL_Window * window); 
-   
- /** 
-  *  \brief Minimize a window to an iconic representation. 
-  * 
-  *  \sa SDL_RestoreWindow() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_MinimizeWindow(SDL_Window * window); 
-   
- /** 
-  *  \brief Restore the size and position of a minimized or maximized window. 
-  * 
-  *  \sa SDL_MaximizeWindow() 
-  *  \sa SDL_MinimizeWindow() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_RestoreWindow(SDL_Window * window); 
-   
- /** 
-  *  \brief Set a window's fullscreen state. 
-  * 
-  *  \return 0 on success, or -1 if setting the display mode failed. 
-  * 
-  *  \sa SDL_SetWindowDisplayMode() 
-  *  \sa SDL_GetWindowDisplayMode() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_SetWindowFullscreen(SDL_Window * window, 
-                                                     Uint32 flags); 
-   
- /** 
-  *  \brief Get the SDL surface associated with the window. 
-  * 
-  *  \return The window's framebuffer surface, or NULL on error. 
-  * 
-  *  A new surface will be created with the optimal format for the window, 
-  *  if necessary. This surface will be freed when the window is destroyed. 
-  * 
-  *  \note You may not combine this with 3D or the rendering API on this window. 
-  * 
-  *  \sa SDL_UpdateWindowSurface() 
-  *  \sa SDL_UpdateWindowSurfaceRects() 
-  */ 
- extern DECLSPEC SDL_Surface * SDLCALL SDL_GetWindowSurface(SDL_Window * window); 
-   
- /** 
-  *  \brief Copy the window surface to the screen. 
-  * 
-  *  \return 0 on success, or -1 on error. 
-  * 
-  *  \sa SDL_GetWindowSurface() 
-  *  \sa SDL_UpdateWindowSurfaceRects() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_UpdateWindowSurface(SDL_Window * window); 
-   
- /** 
-  *  \brief Copy a number of rectangles on the window surface to the screen. 
-  * 
-  *  \return 0 on success, or -1 on error. 
-  * 
-  *  \sa SDL_GetWindowSurface() 
-  *  \sa SDL_UpdateWindowSurface() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_UpdateWindowSurfaceRects(SDL_Window * window, 
-                                                          const SDL_Rect * rects, 
-                                                          int numrects); 
-   
- /** 
-  *  \brief Set a window's input grab mode. 
-  * 
-  *  \param window The window for which the input grab mode should be set. 
-  *  \param grabbed This is SDL_TRUE to grab input, and SDL_FALSE to release input. 
-  * 
-  *  If the caller enables a grab while another window is currently grabbed, 
-  *  the other window loses its grab in favor of the caller's window. 
-  * 
-  *  \sa SDL_GetWindowGrab() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_SetWindowGrab(SDL_Window * window, 
-                                                SDL_bool grabbed); 
-   
- /** 
-  *  \brief Get a window's input grab mode. 
-  * 
-  *  \return This returns SDL_TRUE if input is grabbed, and SDL_FALSE otherwise. 
-  * 
-  *  \sa SDL_SetWindowGrab() 
-  */ 
- extern DECLSPEC SDL_bool SDLCALL SDL_GetWindowGrab(SDL_Window * window); 
-   
- /** 
-  *  \brief Get the window that currently has an input grab enabled. 
-  * 
-  *  \return This returns the window if input is grabbed, and NULL otherwise. 
-  * 
-  *  \sa SDL_SetWindowGrab() 
-  */ 
- extern DECLSPEC SDL_Window * SDLCALL SDL_GetGrabbedWindow(void); 
-   
- /** 
-  *  \brief Set the brightness (gamma correction) for a window. 
-  * 
-  *  \return 0 on success, or -1 if setting the brightness isn't supported. 
-  * 
-  *  \sa SDL_GetWindowBrightness() 
-  *  \sa SDL_SetWindowGammaRamp() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_SetWindowBrightness(SDL_Window * window, float brightness); 
-   
- /** 
-  *  \brief Get the brightness (gamma correction) for a window. 
-  * 
-  *  \return The last brightness value passed to SDL_SetWindowBrightness() 
-  * 
-  *  \sa SDL_SetWindowBrightness() 
-  */ 
- extern DECLSPEC float SDLCALL SDL_GetWindowBrightness(SDL_Window * window); 
-   
- /** 
-  *  \brief Set the opacity for a window 
-  * 
-  *  \param window The window which will be made transparent or opaque 
-  *  \param opacity Opacity (0.0f - transparent, 1.0f - opaque) This will be 
-  *                 clamped internally between 0.0f and 1.0f. 
-  * 
-  *  \return 0 on success, or -1 if setting the opacity isn't supported. 
-  * 
-  *  \sa SDL_GetWindowOpacity() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_SetWindowOpacity(SDL_Window * window, float opacity); 
-   
- /** 
-  *  \brief Get the opacity of a window. 
-  * 
-  *  If transparency isn't supported on this platform, opacity will be reported 
-  *  as 1.0f without error. 
-  * 
-  *  \param window The window in question. 
-  *  \param out_opacity Opacity (0.0f - transparent, 1.0f - opaque) 
-  * 
-  *  \return 0 on success, or -1 on error (invalid window, etc). 
-  * 
-  *  \sa SDL_SetWindowOpacity() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GetWindowOpacity(SDL_Window * window, float * out_opacity); 
-   
- /** 
-  *  \brief Sets the window as a modal for another window (TODO: reconsider this function and/or its name) 
-  * 
-  *  \param modal_window The window that should be modal 
-  *  \param parent_window The parent window 
-  * 
-  *  \return 0 on success, or -1 otherwise. 
-  */ 
- extern DECLSPEC int SDLCALL SDL_SetWindowModalFor(SDL_Window * modal_window, SDL_Window * parent_window); 
-   
- /** 
-  *  \brief Explicitly sets input focus to the window. 
-  * 
-  *  You almost certainly want SDL_RaiseWindow() instead of this function. Use 
-  *  this with caution, as you might give focus to a window that's completely 
-  *  obscured by other windows. 
-  * 
-  *  \param window The window that should get the input focus 
-  * 
-  *  \return 0 on success, or -1 otherwise. 
-  *  \sa SDL_RaiseWindow() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_SetWindowInputFocus(SDL_Window * window); 
-   
- /** 
-  *  \brief Set the gamma ramp for a window. 
-  * 
-  *  \param window The window for which the gamma ramp should be set. 
-  *  \param red The translation table for the red channel, or NULL. 
-  *  \param green The translation table for the green channel, or NULL. 
-  *  \param blue The translation table for the blue channel, or NULL. 
-  * 
-  *  \return 0 on success, or -1 if gamma ramps are unsupported. 
-  * 
-  *  Set the gamma translation table for the red, green, and blue channels 
-  *  of the video hardware.  Each table is an array of 256 16-bit quantities, 
-  *  representing a mapping between the input and output for that channel. 
-  *  The input is the index into the array, and the output is the 16-bit 
-  *  gamma value at that index, scaled to the output color precision. 
-  * 
-  *  \sa SDL_GetWindowGammaRamp() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_SetWindowGammaRamp(SDL_Window * window, 
-                                                    const Uint16 * red, 
-                                                    const Uint16 * green, 
-                                                    const Uint16 * blue); 
-   
- /** 
-  *  \brief Get the gamma ramp for a window. 
-  * 
-  *  \param window The window from which the gamma ramp should be queried. 
-  *  \param red   A pointer to a 256 element array of 16-bit quantities to hold 
-  *               the translation table for the red channel, or NULL. 
-  *  \param green A pointer to a 256 element array of 16-bit quantities to hold 
-  *               the translation table for the green channel, or NULL. 
-  *  \param blue  A pointer to a 256 element array of 16-bit quantities to hold 
-  *               the translation table for the blue channel, or NULL. 
-  * 
-  *  \return 0 on success, or -1 if gamma ramps are unsupported. 
-  * 
-  *  \sa SDL_SetWindowGammaRamp() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GetWindowGammaRamp(SDL_Window * window, 
-                                                    Uint16 * red, 
-                                                    Uint16 * green, 
-                                                    Uint16 * blue); 
-   
- /** 
-  *  \brief Possible return values from the SDL_HitTest callback. 
-  * 
-  *  \sa SDL_HitTest 
-  */ 
- typedef enum 
- { 
-     SDL_HITTEST_NORMAL,  /**< Region is normal. No special properties. */ 
-     SDL_HITTEST_DRAGGABLE,  /**< Region can drag entire window. */ 
-     SDL_HITTEST_RESIZE_TOPLEFT, 
-     SDL_HITTEST_RESIZE_TOP, 
-     SDL_HITTEST_RESIZE_TOPRIGHT, 
-     SDL_HITTEST_RESIZE_RIGHT, 
-     SDL_HITTEST_RESIZE_BOTTOMRIGHT, 
-     SDL_HITTEST_RESIZE_BOTTOM, 
-     SDL_HITTEST_RESIZE_BOTTOMLEFT, 
-     SDL_HITTEST_RESIZE_LEFT 
- } SDL_HitTestResult; 
-   
- /** 
-  *  \brief Callback used for hit-testing. 
-  * 
-  *  \sa SDL_SetWindowHitTest 
-  */ 
- typedef SDL_HitTestResult (SDLCALL *SDL_HitTest)(SDL_Window *win, 
-                                                  const SDL_Point *area, 
-                                                  void *data); 
-   
- /** 
-  *  \brief Provide a callback that decides if a window region has special properties. 
-  * 
-  *  Normally windows are dragged and resized by decorations provided by the 
-  *  system window manager (a title bar, borders, etc), but for some apps, it 
-  *  makes sense to drag them from somewhere else inside the window itself; for 
-  *  example, one might have a borderless window that wants to be draggable 
-  *  from any part, or simulate its own title bar, etc. 
-  * 
-  *  This function lets the app provide a callback that designates pieces of 
-  *  a given window as special. This callback is run during event processing 
-  *  if we need to tell the OS to treat a region of the window specially; the 
-  *  use of this callback is known as "hit testing." 
-  * 
-  *  Mouse input may not be delivered to your application if it is within 
-  *  a special area; the OS will often apply that input to moving the window or 
-  *  resizing the window and not deliver it to the application. 
-  * 
-  *  Specifying NULL for a callback disables hit-testing. Hit-testing is 
-  *  disabled by default. 
-  * 
-  *  Platforms that don't support this functionality will return -1 
-  *  unconditionally, even if you're attempting to disable hit-testing. 
-  * 
-  *  Your callback may fire at any time, and its firing does not indicate any 
-  *  specific behavior (for example, on Windows, this certainly might fire 
-  *  when the OS is deciding whether to drag your window, but it fires for lots 
-  *  of other reasons, too, some unrelated to anything you probably care about 
-  *  _and when the mouse isn't actually at the location it is testing_). 
-  *  Since this can fire at any time, you should try to keep your callback 
-  *  efficient, devoid of allocations, etc. 
-  * 
-  *  \param window The window to set hit-testing on. 
-  *  \param callback The callback to call when doing a hit-test. 
-  *  \param callback_data An app-defined void pointer passed to the callback. 
-  *  \return 0 on success, -1 on error (including unsupported). 
-  */ 
- extern DECLSPEC int SDLCALL SDL_SetWindowHitTest(SDL_Window * window, 
-                                                  SDL_HitTest callback, 
-                                                  void *callback_data); 
-   
- /** 
-  *  \brief Destroy a window. 
-  */ 
- extern DECLSPEC void SDLCALL SDL_DestroyWindow(SDL_Window * window); 
-   
-   
- /** 
-  *  \brief Returns whether the screensaver is currently enabled (default off). 
-  * 
-  *  \sa SDL_EnableScreenSaver() 
-  *  \sa SDL_DisableScreenSaver() 
-  */ 
- extern DECLSPEC SDL_bool SDLCALL SDL_IsScreenSaverEnabled(void); 
-   
- /** 
-  *  \brief Allow the screen to be blanked by a screensaver 
-  * 
-  *  \sa SDL_IsScreenSaverEnabled() 
-  *  \sa SDL_DisableScreenSaver() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_EnableScreenSaver(void); 
-   
- /** 
-  *  \brief Prevent the screen from being blanked by a screensaver 
-  * 
-  *  \sa SDL_IsScreenSaverEnabled() 
-  *  \sa SDL_EnableScreenSaver() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_DisableScreenSaver(void); 
-   
-   
- /** 
-  *  \name OpenGL support functions 
-  */ 
- /* @{ */ 
-   
- /** 
-  *  \brief Dynamically load an OpenGL library. 
-  * 
-  *  \param path The platform dependent OpenGL library name, or NULL to open the 
-  *              default OpenGL library. 
-  * 
-  *  \return 0 on success, or -1 if the library couldn't be loaded. 
-  * 
-  *  This should be done after initializing the video driver, but before 
-  *  creating any OpenGL windows.  If no OpenGL library is loaded, the default 
-  *  library will be loaded upon creation of the first OpenGL window. 
-  * 
-  *  \note If you do this, you need to retrieve all of the GL functions used in 
-  *        your program from the dynamic library using SDL_GL_GetProcAddress(). 
-  * 
-  *  \sa SDL_GL_GetProcAddress() 
-  *  \sa SDL_GL_UnloadLibrary() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GL_LoadLibrary(const char *path); 
-   
- /** 
-  *  \brief Get the address of an OpenGL function. 
-  */ 
- extern DECLSPEC void *SDLCALL SDL_GL_GetProcAddress(const char *proc); 
-   
- /** 
-  *  \brief Unload the OpenGL library previously loaded by SDL_GL_LoadLibrary(). 
-  * 
-  *  \sa SDL_GL_LoadLibrary() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_GL_UnloadLibrary(void); 
-   
- /** 
-  *  \brief Return true if an OpenGL extension is supported for the current 
-  *         context. 
-  */ 
- extern DECLSPEC SDL_bool SDLCALL SDL_GL_ExtensionSupported(const char 
-                                                            *extension); 
-   
- /** 
-  *  \brief Reset all previously set OpenGL context attributes to their default values 
-  */ 
- extern DECLSPEC void SDLCALL SDL_GL_ResetAttributes(void); 
-   
- /** 
-  *  \brief Set an OpenGL window attribute before window creation. 
-  * 
-  *  \return 0 on success, or -1 if the attribute could not be set. 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GL_SetAttribute(SDL_GLattr attr, int value); 
-   
- /** 
-  *  \brief Get the actual value for an attribute from the current context. 
-  * 
-  *  \return 0 on success, or -1 if the attribute could not be retrieved. 
-  *          The integer at \c value will be modified in either case. 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GL_GetAttribute(SDL_GLattr attr, int *value); 
-   
- /** 
-  *  \brief Create an OpenGL context for use with an OpenGL window, and make it 
-  *         current. 
-  * 
-  *  \sa SDL_GL_DeleteContext() 
-  */ 
- extern DECLSPEC SDL_GLContext SDLCALL SDL_GL_CreateContext(SDL_Window * 
-                                                            window); 
-   
- /** 
-  *  \brief Set up an OpenGL context for rendering into an OpenGL window. 
-  * 
-  *  \note The context must have been created with a compatible window. 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GL_MakeCurrent(SDL_Window * window, 
-                                                SDL_GLContext context); 
-   
- /** 
-  *  \brief Get the currently active OpenGL window. 
-  */ 
- extern DECLSPEC SDL_Window* SDLCALL SDL_GL_GetCurrentWindow(void); 
-   
- /** 
-  *  \brief Get the currently active OpenGL context. 
-  */ 
- extern DECLSPEC SDL_GLContext SDLCALL SDL_GL_GetCurrentContext(void); 
-   
- /** 
-  *  \brief Get the size of a window's underlying drawable in pixels (for use 
-  *         with glViewport). 
-  * 
-  *  \param window   Window from which the drawable size should be queried 
-  *  \param w        Pointer to variable for storing the width in pixels, may be NULL 
-  *  \param h        Pointer to variable for storing the height in pixels, may be NULL 
-  * 
-  * This may differ from SDL_GetWindowSize() if we're rendering to a high-DPI 
-  * drawable, i.e. the window was created with SDL_WINDOW_ALLOW_HIGHDPI on a 
-  * platform with high-DPI support (Apple calls this "Retina"), and not disabled 
-  * by the SDL_HINT_VIDEO_HIGHDPI_DISABLED hint. 
-  * 
-  *  \sa SDL_GetWindowSize() 
-  *  \sa SDL_CreateWindow() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_GL_GetDrawableSize(SDL_Window * window, int *w, 
-                                                     int *h); 
-   
- /** 
-  *  \brief Set the swap interval for the current OpenGL context. 
-  * 
-  *  \param interval 0 for immediate updates, 1 for updates synchronized with the 
-  *                  vertical retrace. If the system supports it, you may 
-  *                  specify -1 to allow late swaps to happen immediately 
-  *                  instead of waiting for the next retrace. 
-  * 
-  *  \return 0 on success, or -1 if setting the swap interval is not supported. 
-  * 
-  *  \sa SDL_GL_GetSwapInterval() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GL_SetSwapInterval(int interval); 
-   
- /** 
-  *  \brief Get the swap interval for the current OpenGL context. 
-  * 
-  *  \return 0 if there is no vertical retrace synchronization, 1 if the buffer 
-  *          swap is synchronized with the vertical retrace, and -1 if late 
-  *          swaps happen immediately instead of waiting for the next retrace. 
-  *          If the system can't determine the swap interval, or there isn't a 
-  *          valid current context, this will return 0 as a safe default. 
-  * 
-  *  \sa SDL_GL_SetSwapInterval() 
-  */ 
- extern DECLSPEC int SDLCALL SDL_GL_GetSwapInterval(void); 
-   
- /** 
-  * \brief Swap the OpenGL buffers for a window, if double-buffering is 
-  *        supported. 
-  */ 
- extern DECLSPEC void SDLCALL SDL_GL_SwapWindow(SDL_Window * window); 
-   
- /** 
-  *  \brief Delete an OpenGL context. 
-  * 
-  *  \sa SDL_GL_CreateContext() 
-  */ 
- extern DECLSPEC void SDLCALL SDL_GL_DeleteContext(SDL_GLContext context); 
-   
- /* @} *//* OpenGL support functions */ 
-   
-   
- /* Ends C function definitions when using C++ */ 
- #ifdef __cplusplus 
- } 
- #endif 
- #include "close_code.h" 
-   
- #endif /* SDL_video_h_ */ 
-   
- /* vi: set ts=4 sw=4 expandtab: */ 
-