SDL/include/SDL_video.h

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2021 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_FlashWindow()
 *  \sa SDL_GetWindowData()
 *  \sa SDL_GetWindowFlags()
 *  \sa SDL_GetWindowGrab()
 *  \sa SDL_GetWindowKeyboardGrab()
 *  \sa SDL_GetWindowMouseGrab()
 *  \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_SetWindowKeyboardGrab()
 *  \sa SDL_SetWindowMouseGrab()
 *  \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
{
    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_MOUSE_GRABBED = 0x00000100,      /**< window has grabbed mouse input */
    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.
                                                     On macOS NSHighResolutionCapable must be set true in the
                                                     application's Info.plist for this to have any effect. */
    SDL_WINDOW_MOUSE_CAPTURE    = 0x00004000,   /**< window has mouse captured (unrelated to MOUSE_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_KEYBOARD_GRABBED = 0x00100000,   /**< window has grabbed keyboard input */
    SDL_WINDOW_VULKAN           = 0x10000000,   /**< window usable for Vulkan surface */
    SDL_WINDOW_METAL            = 0x20000000,   /**< window usable for Metal view */

    SDL_WINDOW_INPUT_GRABBED = SDL_WINDOW_MOUSE_GRABBED /**< equivalent to SDL_WINDOW_MOUSE_GRABBED for compatibility */
} 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 Event subtype for display events
 */
typedef enum
{
    SDL_DISPLAYEVENT_NONE,          /**< Never used */
    SDL_DISPLAYEVENT_ORIENTATION,   /**< Display orientation has changed to data1 */
    SDL_DISPLAYEVENT_CONNECTED,     /**< Display has been added to the system */
    SDL_DISPLAYEVENT_DISCONNECTED   /**< Display has been removed from the system */
} SDL_DisplayEventID;

/**
 *  \brief Display orientation
 */
typedef enum
{
    SDL_ORIENTATION_UNKNOWN,            /**< The display orientation can't be determined */
    SDL_ORIENTATION_LANDSCAPE,          /**< The display is in landscape mode, with the right side up, relative to portrait mode */
    SDL_ORIENTATION_LANDSCAPE_FLIPPED,  /**< The display is in landscape mode, with the left side up, relative to portrait mode */
    SDL_ORIENTATION_PORTRAIT,           /**< The display is in portrait mode */
    SDL_ORIENTATION_PORTRAIT_FLIPPED    /**< The display is in portrait mode, upside down */
} SDL_DisplayOrientation;

/**
 *  \brief Window flash operation
 */
typedef enum
{
    SDL_FLASH_CANCEL,                   /**< Cancel any window flash state */
    SDL_FLASH_BRIEFLY,                  /**< Flash the window briefly to get attention */
    SDL_FLASH_UNTIL_FOCUSED             /**< Flash the window until it gets focus */
} SDL_FlashOperation;

/**
 *  \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 */

/**
 * Get the number of video drivers compiled into SDL.
 *
 * \returns a number >= 1 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_GetVideoDriver
 */
extern DECLSPEC int SDLCALL SDL_GetNumVideoDrivers(void);

/**
 * Get the name of a built in video driver.
 *
 * The video drivers are presented in the order in which they are normally
 * checked during initialization.
 *
 * \param index the index of a video driver
 * \returns the name of the video driver with the given **index**.
 *
 * \sa SDL_GetNumVideoDrivers
 */
extern DECLSPEC const char *SDLCALL SDL_GetVideoDriver(int index);

/**
 * Initialize the video subsystem, optionally specifying a video driver.
 *
 * 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.
 *
 * If you use this function and you haven't used the SDL_INIT_VIDEO flag with
 * either SDL_Init() or SDL_InitSubSystem(), you should call SDL_VideoQuit()
 * before calling SDL_Quit().
 *
 * It is safe to call this function multiple times. SDL_VideoInit() will call
 * SDL_VideoQuit() itself if the video subsystem has already been initialized.
 *
 * You can use SDL_GetNumVideoDrivers() and SDL_GetVideoDriver() to find a
 * specific `driver_name`.
 *
 * \param driver_name the name of a video driver to initialize, or NULL for
 *                    the default driver
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_GetNumVideoDrivers
 * \sa SDL_GetVideoDriver
 * \sa SDL_InitSubSystem
 * \sa SDL_VideoQuit
 */
extern DECLSPEC int SDLCALL SDL_VideoInit(const char *driver_name);

/**
 * Shut down the video subsystem, if initialized with SDL_VideoInit().
 *
 * This function closes all windows, and restores the original video mode.
 *
 * \sa SDL_VideoInit
 */
extern DECLSPEC void SDLCALL SDL_VideoQuit(void);

/**
 * Get the name of the currently initialized video driver.
 *
 * \returns the name of the current video driver or NULL if no driver has been
 *          initialized.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_GetNumVideoDrivers
 * \sa SDL_GetVideoDriver
 */
extern DECLSPEC const char *SDLCALL SDL_GetCurrentVideoDriver(void);

/**
 * Get the number of available video displays.
 *
 * \returns a number >= 1 or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_GetDisplayBounds
 */
extern DECLSPEC int SDLCALL SDL_GetNumVideoDisplays(void);

/**
 * Get the name of a display in UTF-8 encoding.
 *
 * \param displayIndex the index of display from which the name should be
 *                     queried
 * \returns the name of a display or NULL for an invalid display index or
 *          failure; call SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_GetNumVideoDisplays
 */
extern DECLSPEC const char * SDLCALL SDL_GetDisplayName(int displayIndex);

/**
 * Get the desktop area represented by a display.
 *
 * The primary display (`displayIndex` zero) is always located at 0,0.
 *
 * \param displayIndex the index of the display to query
 * \param rect the SDL_Rect structure filled in with the display bounds
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_GetNumVideoDisplays
 */
extern DECLSPEC int SDLCALL SDL_GetDisplayBounds(int displayIndex, SDL_Rect * rect);

/**
 * Get the usable desktop area represented by a display.
 *
 * The primary display (`displayIndex` zero) is always located at 0,0.
 *
 * This is the same area as SDL_GetDisplayBounds() reports, but with portions
 * reserved by the system removed. For example, on Apple's macOS, 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.
 *
 * The parameter `rect` is ignored if it is NULL.
 *
 * This function also returns -1 if the parameter `displayIndex` is out of
 * range.
 *
 * \param displayIndex the index of the display to query the usable bounds
 *                     from
 * \param rect the SDL_Rect structure filled in with the display bounds
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.5.
 *
 * \sa SDL_GetDisplayBounds
 * \sa SDL_GetNumVideoDisplays
 */
extern DECLSPEC int SDLCALL SDL_GetDisplayUsableBounds(int displayIndex, SDL_Rect * rect);

/**
 * Get the dots/pixels-per-inch for a display.
 *
 * Diagonal, horizontal and vertical DPI can all be optionally returned if the
 * appropriate parameter is non-NULL.
 *
 * A failure of this function usually means that either no DPI information is
 * available or the `displayIndex` is out of range.
 *
 * \param displayIndex the index of the display from which DPI information
 *                     should be queried
 * \param ddpi a pointer filled in with the diagonal DPI of the display; may
 *             be NULL
 * \param hdpi a pointer filled in with the horizontal DPI of the display; may
 *             be NULL
 * \param vdpi a pointer filled in with the vertical DPI of the display; may
 *             be NULL
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.4.
 *
 * \sa SDL_GetNumVideoDisplays
 */
extern DECLSPEC int SDLCALL SDL_GetDisplayDPI(int displayIndex, float * ddpi, float * hdpi, float * vdpi);

/**
 * Get the orientation of a display.
 *
 * \param displayIndex the index of the display to query
 * \returns The SDL_DisplayOrientation enum value of the display, or
 *          `SDL_ORIENTATION_UNKNOWN` if it isn't available.
 *
 * \sa SDL_GetNumVideoDisplays
 */
extern DECLSPEC SDL_DisplayOrientation SDLCALL SDL_GetDisplayOrientation(int displayIndex);

/**
 * Get the number of available display modes.
 *
 * The `displayIndex` needs to be in the range from 0 to
 * SDL_GetNumVideoDisplays() - 1.
 *
 * \param displayIndex the index of the display to query
 * \returns a number >= 1 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_GetDisplayMode
 * \sa SDL_GetNumVideoDisplays
 */
extern DECLSPEC int SDLCALL SDL_GetNumDisplayModes(int displayIndex);

/**
 * Get information about a specific display mode.
 *
 * The display modes are sorted in this priority:
 *
 * - width -> largest to smallest
 * - height -> largest to smallest
 * - bits per pixel -> more colors to fewer colors
 * - packed pixel layout -> largest to smallest
 * - refresh rate -> highest to lowest
 *
 * \param displayIndex the index of the display to query
 * \param modeIndex the index of the display mode to query
 * \param mode an SDL_DisplayMode structure filled in with the mode at
 *             `modeIndex`
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_GetNumDisplayModes
 */
extern DECLSPEC int SDLCALL SDL_GetDisplayMode(int displayIndex, int modeIndex,
                                               SDL_DisplayMode * mode);

/**
 * Get information about the desktop's display mode.
 *
 * There's a difference between this function and SDL_GetCurrentDisplayMode()
 * when SDL runs fullscreen and has changed the resolution. In that case this
 * function will return the previous native display mode, and not the current
 * display mode.
 *
 * \param displayIndex the index of the display to query
 * \param mode an SDL_DisplayMode structure filled in with the current display
 *             mode
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_GetCurrentDisplayMode
 * \sa SDL_GetDisplayMode
 * \sa SDL_SetWindowDisplayMode
 */
extern DECLSPEC int SDLCALL SDL_GetDesktopDisplayMode(int displayIndex, SDL_DisplayMode * mode);

/**
 * Get information about the current display mode.
 *
 * There's a difference between this function and SDL_GetDesktopDisplayMode()
 * when SDL runs fullscreen and has changed the resolution. In that case this
 * function will return the current display mode, and not the previous native
 * display mode.
 *
 * \param displayIndex the index of the display to query
 * \param mode an SDL_DisplayMode structure filled in with the current display
 *             mode
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_GetDesktopDisplayMode
 * \sa SDL_GetDisplayMode
 * \sa SDL_GetNumVideoDisplays
 * \sa SDL_SetWindowDisplayMode
 */
extern DECLSPEC int SDLCALL SDL_GetCurrentDisplayMode(int displayIndex, SDL_DisplayMode * mode);


/**
 * Get the closest match to the requested display mode.
 *
 * The available display modes are scanned and `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 set to 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.
 *
 * \param displayIndex the index of the display to query
 * \param mode an SDL_DisplayMode structure containing the desired display
 *             mode
 * \param closest an SDL_DisplayMode structure filled in with the closest
 *                match of the available display modes
 * \returns the passed in value `closest` or NULL if no matching video mode
 *          was available; call SDL_GetError() for more information.
 *
 * \sa SDL_GetDisplayMode
 * \sa SDL_GetNumDisplayModes
 */
extern DECLSPEC SDL_DisplayMode * SDLCALL SDL_GetClosestDisplayMode(int displayIndex, const SDL_DisplayMode * mode, SDL_DisplayMode * closest);

/**
 * Get the index of the display associated with a window.
 *
 * \param window the window to query
 * \returns the index of the display containing the center of the window on
 *          success or a negative error code on failure; call SDL_GetError()
 *          for more information.
 *
 * \sa SDL_GetDisplayBounds
 * \sa SDL_GetNumVideoDisplays
 */
extern DECLSPEC int SDLCALL SDL_GetWindowDisplayIndex(SDL_Window * window);

/**
 * Set the display mode to use when a window is visible at fullscreen.
 *
 * This only affects the display mode used when the window is fullscreen. To
 * change the window size when the window is not fullscreen, use
 * SDL_SetWindowSize().
 *
 * \param window the window to affect
 * \param mode the SDL_DisplayMode structure representing the mode to use, or
 *             NULL to use the window's dimensions and the desktop's format
 *             and refresh rate
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_GetWindowDisplayMode
 * \sa SDL_SetWindowFullscreen
 */
extern DECLSPEC int SDLCALL SDL_SetWindowDisplayMode(SDL_Window * window,
                                                     const SDL_DisplayMode * mode);

/**
 * Query the display mode to use when a window is visible at fullscreen.
 *
 * \param window the window to query
 * \param mode an SDL_DisplayMode structure filled in with the fullscreen
 *             display mode
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_SetWindowDisplayMode
 * \sa SDL_SetWindowFullscreen
 */
extern DECLSPEC int SDLCALL SDL_GetWindowDisplayMode(SDL_Window * window,
                                                     SDL_DisplayMode * mode);

/**
 * Get the pixel format associated with the window.
 *
 * \param window the window to query
 * \returns the pixel format of the window on success or
 *          SDL_PIXELFORMAT_UNKNOWN on failure; call SDL_GetError() for more
 *          information.
 */
extern DECLSPEC Uint32 SDLCALL SDL_GetWindowPixelFormat(SDL_Window * window);

/**
 * Create a window with the specified position, dimensions, and flags.
 *
 * `flags` may be any of the following OR'd together:
 *
 * - `SDL_WINDOW_FULLSCREEN`: fullscreen window
 * - `SDL_WINDOW_FULLSCREEN_DESKTOP`: fullscreen window at desktop resolution
 * - `SDL_WINDOW_OPENGL`: window usable with an OpenGL context
 * - `SDL_WINDOW_VULKAN`: window usable with a Vulkan instance
 * - `SDL_WINDOW_METAL`: window usable with a Metal instance
 * - `SDL_WINDOW_HIDDEN`: window is not visible
 * - `SDL_WINDOW_BORDERLESS`: no window decoration
 * - `SDL_WINDOW_RESIZABLE`: window can be resized
 * - `SDL_WINDOW_MINIMIZED`: window is minimized
 * - `SDL_WINDOW_MAXIMIZED`: window is maximized
 * - `SDL_WINDOW_INPUT_GRABBED`: window has grabbed input focus
 * - `SDL_WINDOW_ALLOW_HIGHDPI`: window should be created in high-DPI mode if
 *   supported (>= SDL 2.0.1)
 *
 * `SDL_WINDOW_SHOWN` is ignored by SDL_CreateWindow(). The SDL_Window is
 * implicitly shown if SDL_WINDOW_HIDDEN is not set. `SDL_WINDOW_SHOWN` may be
 * queried later using SDL_GetWindowFlags().
 *
 * On Apple's macOS, you **must** set the NSHighResolutionCapable Info.plist
 * property to YES, otherwise you will not receive a High-DPI OpenGL canvas.
 *
 * 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 macOS). Use SDL_GetWindowSize() to query the
 * client area's size in screen coordinates, and SDL_GL_GetDrawableSize() or
 * SDL_GetRendererOutputSize() to query the drawable size in pixels.
 *
 * If the window is set fullscreen, the width and height parameters `w` and
 * `h` will not be used. However, invalid size parameters (e.g. too large) may
 * still fail. Window size is actually limited to 16384 x 16384 for all
 * platforms at window creation.
 *
 * 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
 * corresponding 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.
 *
 * If SDL_WINDOW_METAL is specified on an OS that does not support Metal,
 * SDL_CreateWindow() will fail.
 *
 * 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.
 *
 * \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 0, or one or more SDL_WindowFlags OR'd together
 * \returns the window that was created or NULL on failure; call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_CreateWindowFrom
 * \sa SDL_DestroyWindow
 */
extern DECLSPEC SDL_Window * SDLCALL SDL_CreateWindow(const char *title,
                                                      int x, int y, int w,
                                                      int h, Uint32 flags);

/**
 * Create an SDL window from an existing native window.
 *
 * In some cases (e.g. OpenGL) and on some platforms (e.g. Microsoft Windows)
 * the hint `SDL_HINT_VIDEO_WINDOW_SHARE_PIXEL_FORMAT` needs to be configured
 * before using SDL_CreateWindowFrom().
 *
 * \param data a pointer to driver-dependent window creation data, typically
 *             your native window cast to a void*
 * \returns the window that was created or NULL on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_CreateWindow
 * \sa SDL_DestroyWindow
 */
extern DECLSPEC SDL_Window * SDLCALL SDL_CreateWindowFrom(const void *data);

/**
 * Get the numeric ID of a window.
 *
 * The numeric ID is what SDL_WindowEvent references, and is necessary to map
 * these events to specific SDL_Window objects.
 *
 * \param window the window to query
 * \returns the ID of the window on success or 0 on failure; call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_GetWindowFromID
 */
extern DECLSPEC Uint32 SDLCALL SDL_GetWindowID(SDL_Window * window);

/**
 * Get a window from a stored ID.
 *
 * The numeric ID is what SDL_WindowEvent references, and is necessary to map
 * these events to specific SDL_Window objects.
 *
 * \param id the ID of the window
 * \returns the window associated with `id` or NULL if it doesn't exist; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_GetWindowID
 */
extern DECLSPEC SDL_Window * SDLCALL SDL_GetWindowFromID(Uint32 id);

/**
 * Get the window flags.
 *
 * \param window the window to query
 * \returns a mask of the SDL_WindowFlags associated with `window`
 *
 * \sa SDL_CreateWindow
 * \sa SDL_HideWindow
 * \sa SDL_MaximizeWindow
 * \sa SDL_MinimizeWindow
 * \sa SDL_SetWindowFullscreen
 * \sa SDL_SetWindowGrab
 * \sa SDL_ShowWindow
 */
extern DECLSPEC Uint32 SDLCALL SDL_GetWindowFlags(SDL_Window * window);

/**
 * Set the title of a window.
 *
 * This string is expected to be in UTF-8 encoding.
 *
 * \param window the window to change
 * \param title the desired window title in UTF-8 format
 *
 * \sa SDL_GetWindowTitle
 */
extern DECLSPEC void SDLCALL SDL_SetWindowTitle(SDL_Window * window,
                                                const char *title);

/**
 * Get the title of a window.
 *
 * \param window the window to query
 * \returns the title of the window in UTF-8 format or "" if there is no
 *          title.
 *
 * \sa SDL_SetWindowTitle
 */
extern DECLSPEC const char *SDLCALL SDL_GetWindowTitle(SDL_Window * window);

/**
 * Set the icon for a window.
 *
 * \param window the window to change
 * \param icon an SDL_Surface structure containing the icon for the window
 */
extern DECLSPEC void SDLCALL SDL_SetWindowIcon(SDL_Window * window,
                                               SDL_Surface * icon);

/**
 * Associate an arbitrary named pointer with a window.
 *
 * `name` is case-sensitive.
 *
 * \param window the window to associate with the pointer
 * \param name the name of the pointer
 * \param userdata the associated pointer
 * \returns the previous value associated with `name`.
 *
 * \sa SDL_GetWindowData
 */
extern DECLSPEC void* SDLCALL SDL_SetWindowData(SDL_Window * window,
                                                const char *name,
                                                void *userdata);

/**
 * Retrieve the data pointer associated with a window.
 *
 * \param window the window to query
 * \param name the name of the pointer
 * \returns the value associated with `name`.
 *
 * \sa SDL_SetWindowData
 */
extern DECLSPEC void *SDLCALL SDL_GetWindowData(SDL_Window * window,
                                                const char *name);

/**
 * Set the position of a window.
 *
 * The window coordinate origin is the upper left of the display.
 *
 * \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`
 *
 * \sa SDL_GetWindowPosition
 */
extern DECLSPEC void SDLCALL SDL_SetWindowPosition(SDL_Window * window,
                                                   int x, int y);

/**
 * Get the position of a window.
 *
 * If you do not need the value for one of the positions a NULL may be passed
 * in the `x` or `y` parameter.
 *
 * \param window the window to query
 * \param x a pointer filled in with the x position of the window, in screen
 *          coordinates, may be NULL
 * \param y a pointer filled in with the y position of the window, in screen
 *          coordinates, may be NULL
 *
 * \sa SDL_SetWindowPosition
 */
extern DECLSPEC void SDLCALL SDL_GetWindowPosition(SDL_Window * window,
                                                   int *x, int *y);

/**
 * Set the size of a window's client area.
 *
 * 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 macOS). Use SDL_GL_GetDrawableSize() or
 * SDL_GetRendererOutputSize() to get the real client area size in pixels.
 *
 * Fullscreen windows automatically match the size of the display mode, and
 * you should use SDL_SetWindowDisplayMode() to change their size.
 *
 * \param window the window to change
 * \param w the width of the window in pixels, in screen coordinates, must be
 *          > 0
 * \param h the height of the window in pixels, in screen coordinates, must be
 *          > 0
 *
 * \sa SDL_GetWindowSize
 * \sa SDL_SetWindowDisplayMode
 */
extern DECLSPEC void SDLCALL SDL_SetWindowSize(SDL_Window * window, int w,
                                               int h);

/**
 * Get the size of a window's client area.
 *
 * NULL can safely be passed as the `w` or `h` parameter if the width or
 * height value is not desired.
 *
 * 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 macOS). Use SDL_GL_GetDrawableSize(),
 * SDL_Vulkan_GetDrawableSize(), or SDL_GetRendererOutputSize() to get the
 * real client area size in pixels.
 *
 * \param window the window to query the width and height from
 * \param w a pointer filled in with the width of the window, in screen
 *          coordinates, may be NULL
 * \param h a pointer filled in with the height of the window, in screen
 *          coordinates, may be NULL
 *
 * \sa SDL_GL_GetDrawableSize
 * \sa SDL_Vulkan_GetDrawableSize
 * \sa SDL_SetWindowSize
 */
extern DECLSPEC void SDLCALL SDL_GetWindowSize(SDL_Window * window, int *w,
                                               int *h);

/**
 * Get the size of a window's borders (decorations) around the client area.
 *
 * 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.
 *
 * Note: This function may fail on systems where the window has not yet been
 * decorated by the display server (for example, immediately after calling
 * SDL_CreateWindow). It is recommended that you wait at least until the
 * window has been presented and composited, so that the window system has a
 * chance to decorate the window and provide the border dimensions to SDL.
 *
 * This function also returns -1 if getting the information is not supported.
 *
 * \param window the window to query the size values of the border
 *               (decorations) from
 * \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
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.5.
 *
 * \sa SDL_GetWindowSize
 */
extern DECLSPEC int SDLCALL SDL_GetWindowBordersSize(SDL_Window * window,
                                                     int *top, int *left,
                                                     int *bottom, int *right);

/**
 * Set the minimum size of a window's client area.
 *
 * \param window the window to change
 * \param min_w the minimum width of the window in pixels
 * \param min_h the minimum height of the window in pixels
 *
 * \sa SDL_GetWindowMinimumSize
 * \sa SDL_SetWindowMaximumSize
 */
extern DECLSPEC void SDLCALL SDL_SetWindowMinimumSize(SDL_Window * window,
                                                      int min_w, int min_h);

/**
 * Get the minimum size of a window's client area.
 *
 * \param window the window to query
 * \param w a pointer filled in with the minimum width of the window, may be
 *          NULL
 * \param h a pointer filled in with the minimum height of the window, may be
 *          NULL
 *
 * \sa SDL_GetWindowMaximumSize
 * \sa SDL_SetWindowMinimumSize
 */
extern DECLSPEC void SDLCALL SDL_GetWindowMinimumSize(SDL_Window * window,
                                                      int *w, int *h);

/**
 * Set the maximum size of a window's client area.
 *
 * \param window the window to change
 * \param max_w the maximum width of the window in pixels
 * \param max_h the maximum height of the window in pixels
 *
 * \sa SDL_GetWindowMaximumSize
 * \sa SDL_SetWindowMinimumSize
 */
extern DECLSPEC void SDLCALL SDL_SetWindowMaximumSize(SDL_Window * window,
                                                      int max_w, int max_h);

/**
 * Get the maximum size of a window's client area.
 *
 * \param window the window to query
 * \param w a pointer filled in with the maximum width of the window, may be
 *          NULL
 * \param h a pointer filled in with the maximum height of the window, may be
 *          NULL
 *
 * \sa SDL_GetWindowMinimumSize
 * \sa SDL_SetWindowMaximumSize
 */
extern DECLSPEC void SDLCALL SDL_GetWindowMaximumSize(SDL_Window * window,
                                                      int *w, int *h);

/**
 * 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.
 *
 * You can't change the border state of a fullscreen window.
 *
 * \param window the window of which to change the border state
 * \param bordered SDL_FALSE to remove border, SDL_TRUE to add border
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_GetWindowFlags
 */
extern DECLSPEC void SDLCALL SDL_SetWindowBordered(SDL_Window * window,
                                                   SDL_bool bordered);

/**
 * 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.
 *
 * You can't change the resizable state of a fullscreen window.
 *
 * \param window the window of which to change the resizable state
 * \param resizable SDL_TRUE to allow resizing, SDL_FALSE to disallow
 *
 * \since This function is available since SDL 2.0.5.
 *
 * \sa SDL_GetWindowFlags
 */
extern DECLSPEC void SDLCALL SDL_SetWindowResizable(SDL_Window * window,
                                                    SDL_bool resizable);

/**
 *  \brief Set the window to always be above the others.
 *
 *  This will add or remove the window's `SDL_WINDOW_ALWAYS_ON_TOP`
 *  flag. This will bring the window to the front and keep the window above
 *  the rest.
 *
 *  \param window The window of which to change the always on top state.
 *  \param on_top  SDL_TRUE to set the window always on top, SDL_FALSE to disable.
 *
 *  \sa SDL_SetWindowAlwaysOnTop
 */

extern DECLSPEC void SDLCALL SDL_SetWindowAlwaysOnTop(SDL_Window * window,
                                                      SDL_bool on_top);
/**
 * Show a window.
 *
 * \param window the window to show
 *
 * \sa SDL_HideWindow
 * \sa SDL_RaiseWindow
 */
extern DECLSPEC void SDLCALL SDL_ShowWindow(SDL_Window * window);

/**
 * Hide a window.
 *
 * \param window the window to hide
 *
 * \sa SDL_ShowWindow
 */
extern DECLSPEC void SDLCALL SDL_HideWindow(SDL_Window * window);

/**
 * Raise a window above other windows and set the input focus.
 *
 * \param window the window to raise
 */
extern DECLSPEC void SDLCALL SDL_RaiseWindow(SDL_Window * window);

/**
 * Make a window as large as possible.
 *
 * \param window the window to maximize
 *
 * \sa SDL_MinimizeWindow
 * \sa SDL_RestoreWindow
 */
extern DECLSPEC void SDLCALL SDL_MaximizeWindow(SDL_Window * window);

/**
 * Minimize a window to an iconic representation.
 *
 * \param window the window to minimize
 *
 * \sa SDL_MaximizeWindow
 * \sa SDL_RestoreWindow
 */
extern DECLSPEC void SDLCALL SDL_MinimizeWindow(SDL_Window * window);

/**
 * Restore the size and position of a minimized or maximized window.
 *
 * \param window the window to restore
 *
 * \sa SDL_MaximizeWindow
 * \sa SDL_MinimizeWindow
 */
extern DECLSPEC void SDLCALL SDL_RestoreWindow(SDL_Window * window);

/**
 * Set a window's fullscreen state.
 *
 * `flags` may be `SDL_WINDOW_FULLSCREEN`, for "real" fullscreen with a
 * videomode change; `SDL_WINDOW_FULLSCREEN_DESKTOP` for "fake" fullscreen
 * that takes the size of the desktop; and 0 for windowed mode.
 *
 * \param window the window to change
 * \param flags `SDL_WINDOW_FULLSCREEN`, `SDL_WINDOW_FULLSCREEN_DESKTOP` or 0
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_GetWindowDisplayMode
 * \sa SDL_SetWindowDisplayMode
 */
extern DECLSPEC int SDLCALL SDL_SetWindowFullscreen(SDL_Window * window,
                                                    Uint32 flags);

/**
 * Get the SDL surface associated with the window.
 *
 * 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. Do not
 * free this surface.
 *
 * This surface will be invalidated if the window is resized. After resizing a
 * window this function must be called again to return a valid surface.
 *
 * You may not combine this with 3D or the rendering API on this window.
 *
 * This function is affected by `SDL_HINT_FRAMEBUFFER_ACCELERATION`.
 *
 * \param window the window to query
 * \returns the surface associated with the window, or NULL on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_UpdateWindowSurface
 * \sa SDL_UpdateWindowSurfaceRects
 */
extern DECLSPEC SDL_Surface * SDLCALL SDL_GetWindowSurface(SDL_Window * window);

/**
 * Copy the window surface to the screen.
 *
 * This is the function you use to reflect any changes to the surface on the
 * screen.
 *
 * This function is equivalent to the SDL 1.2 API SDL_Flip().
 *
 * \param window the window to update
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_GetWindowSurface
 * \sa SDL_UpdateWindowSurfaceRects
 */
extern DECLSPEC int SDLCALL SDL_UpdateWindowSurface(SDL_Window * window);

/**
 * Copy areas of the window surface to the screen.
 *
 * This is the function you use to reflect changes to portions of the surface
 * on the screen.
 *
 * This function is equivalent to the SDL 1.2 API SDL_UpdateRects().
 *
 * \param window the window to update
 * \param rects an array of SDL_Rect structures representing areas of the
 *              surface to copy
 * \param numrects the number of rectangles
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_GetWindowSurface
 * \sa SDL_UpdateWindowSurface
 */
extern DECLSPEC int SDLCALL SDL_UpdateWindowSurfaceRects(SDL_Window * window,
                                                         const SDL_Rect * rects,
                                                         int numrects);

/**
 * Set a window's input grab mode.
 *
 * When input is grabbed the mouse is confined to the window.
 *
 * 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.
 *
 * \param window the window for which the input grab mode should be set
 * \param grabbed SDL_TRUE to grab input or SDL_FALSE to release input
 *
 * \sa SDL_GetGrabbedWindow
 * \sa SDL_GetWindowGrab
 */
extern DECLSPEC void SDLCALL SDL_SetWindowGrab(SDL_Window * window,
                                               SDL_bool grabbed);

/**
 * Set a window's keyboard grab mode.
 *
 * 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.
 *
 * \param window The window for which the keyboard grab mode should be set.
 * \param grabbed This is SDL_TRUE to grab keyboard, and SDL_FALSE to release.
 *
 * \sa SDL_GetWindowKeyboardGrab
 * \sa SDL_SetWindowMouseGrab
 * \sa SDL_SetWindowGrab
 */
extern DECLSPEC void SDLCALL SDL_SetWindowKeyboardGrab(SDL_Window * window,
                                                       SDL_bool grabbed);

/**
 * Set a window's mouse grab mode.
 *
 * \param window The window for which the mouse grab mode should be set.
 *
 * \sa SDL_GetWindowMouseGrab
 * \sa SDL_SetWindowKeyboardGrab
 * \sa SDL_SetWindowGrab
 */
extern DECLSPEC void SDLCALL SDL_SetWindowMouseGrab(SDL_Window * window,
                                                    SDL_bool grabbed);

/**
 * Get a window's input grab mode.
 *
 * \param window the window to query
 * \returns SDL_TRUE if input is grabbed, SDL_FALSE otherwise.
 *
 * \sa SDL_SetWindowGrab
 */
extern DECLSPEC SDL_bool SDLCALL SDL_GetWindowGrab(SDL_Window * window);

/**
 * Get a window's keyboard grab mode.
 *
 * \param window the window to query
 * \returns SDL_TRUE if keyboard is grabbed, and SDL_FALSE otherwise.
 *
 * \sa SDL_SetWindowKeyboardGrab
 * \sa SDL_GetWindowGrab
 */
extern DECLSPEC SDL_bool SDLCALL SDL_GetWindowKeyboardGrab(SDL_Window * window);

/**
 * Get a window's mouse grab mode.
 *
 * \param window the window to query
 * \returns SDL_TRUE if mouse is grabbed, and SDL_FALSE otherwise.
 *
 * \sa SDL_SetWindowKeyboardGrab
 * \sa SDL_GetWindowGrab
 */
extern DECLSPEC SDL_bool SDLCALL SDL_GetWindowMouseGrab(SDL_Window * window);

/**
 * Get the window that currently has an input grab enabled.
 *
 * \returns the window if input is grabbed or NULL otherwise.
 *
 * \since This function is available since SDL 2.0.4.
 *
 * \sa SDL_GetWindowGrab
 * \sa SDL_SetWindowGrab
 */
extern DECLSPEC SDL_Window * SDLCALL SDL_GetGrabbedWindow(void);

/**
 * Set the brightness (gamma multiplier) for a given window's display.
 *
 * Despite the name and signature, this method sets the brightness of the
 * entire display, not an individual window. A window is considered to be
 * owned by the display that contains the window's center pixel. (The index of
 * this display can be retrieved using SDL_GetWindowDisplayIndex().) The
 * brightness set will not follow the window if it is moved to another
 * display.
 *
 * Many platforms will refuse to set the display brightness in modern times.
 * You are better off using a shader to adjust gamma during rendering, or
 * something similar.
 *
 * \param window the window used to select the display whose brightness will
 *               be changed
 * \param brightness the brightness (gamma multiplier) value to set where 0.0
 *                   is completely dark and 1.0 is normal brightness
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_GetWindowBrightness
 * \sa SDL_SetWindowGammaRamp
 */
extern DECLSPEC int SDLCALL SDL_SetWindowBrightness(SDL_Window * window, float brightness);

/**
 * Get the brightness (gamma multiplier) for a given window's display.
 *
 * Despite the name and signature, this method retrieves the brightness of the
 * entire display, not an individual window. A window is considered to be
 * owned by the display that contains the window's center pixel. (The index of
 * this display can be retrieved using SDL_GetWindowDisplayIndex().)
 *
 * \param window the window used to select the display whose brightness will
 *               be queried
 * \returns the brightness for the display where 0.0 is completely dark and
 *          1.0 is normal brightness.
 *
 * \sa SDL_SetWindowBrightness
 */
extern DECLSPEC float SDLCALL SDL_GetWindowBrightness(SDL_Window * window);

/**
 * Set the opacity for a window.
 *
 * The parameter `opacity` will be clamped internally between 0.0f
 * (transparent) and 1.0f (opaque).
 *
 * This function also returns -1 if setting the opacity isn't supported.
 *
 * \param window the window which will be made transparent or opaque
 * \param opacity the opacity value (0.0f - transparent, 1.0f - opaque)
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.5.
 *
 * \sa SDL_GetWindowOpacity
 */
extern DECLSPEC int SDLCALL SDL_SetWindowOpacity(SDL_Window * window, float opacity);

/**
 * Get the opacity of a window.
 *
 * If transparency isn't supported on this platform, opacity will be reported
 * as 1.0f without error.
 *
 * The parameter `opacity` is ignored if it is NULL.
 *
 * This function also returns -1 if an invalid window was provided.
 *
 * \param window the window to get the current opacity value from
 * \param out_opacity the float filled in (0.0f - transparent, 1.0f - opaque)
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.5.
 *
 * \sa SDL_SetWindowOpacity
 */
extern DECLSPEC int SDLCALL SDL_GetWindowOpacity(SDL_Window * window, float * out_opacity);

/**
 * Set the window as a modal for another window.
 *
 * \param modal_window the window that should be set modal
 * \param parent_window the parent window for the modal window
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.5.
 */
extern DECLSPEC int SDLCALL SDL_SetWindowModalFor(SDL_Window * modal_window, SDL_Window * parent_window);

/**
 * Explicitly set 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 is completely
 * obscured by other windows.
 *
 * \param window the window that should get the input focus
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.5.
 *
 * \sa SDL_RaiseWindow
 */
extern DECLSPEC int SDLCALL SDL_SetWindowInputFocus(SDL_Window * window);

/**
 * Set the gamma ramp for the display that owns a given window.
 *
 * 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.
 *
 * Despite the name and signature, this method sets the gamma ramp of the
 * entire display, not an individual window. A window is considered to be
 * owned by the display that contains the window's center pixel. (The index of
 * this display can be retrieved using SDL_GetWindowDisplayIndex().) The gamma
 * ramp set will not follow the window if it is moved to another display.
 *
 * \param window the window used to select the display whose gamma ramp will
 *               be changed
 * \param red a 256 element array of 16-bit quantities representing the
 *            translation table for the red channel, or NULL
 * \param green a 256 element array of 16-bit quantities representing the
 *              translation table for the green channel, or NULL
 * \param blue a 256 element array of 16-bit quantities representing the
 *             translation table for the blue channel, or NULL
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_GetWindowGammaRamp
 */
extern DECLSPEC int SDLCALL SDL_SetWindowGammaRamp(SDL_Window * window,
                                                   const Uint16 * red,
                                                   const Uint16 * green,
                                                   const Uint16 * blue);

/**
 * Get the gamma ramp for a given window's display.
 *
 * Despite the name and signature, this method retrieves the gamma ramp of the
 * entire display, not an individual window. A window is considered to be
 * owned by the display that contains the window's center pixel. (The index of
 * this display can be retrieved using SDL_GetWindowDisplayIndex().)
 *
 * \param window the window used to select the display whose gamma ramp will
 *               be queried
 * \param red a 256 element array of 16-bit quantities filled in with the
 *            translation table for the red channel, or NULL
 * \param green a 256 element array of 16-bit quantities filled in with the
 *              translation table for the green channel, or NULL
 * \param blue a 256 element array of 16-bit quantities filled in with the
 *             translation table for the blue channel, or NULL
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_SetWindowGammaRamp
 */
extern DECLSPEC int SDLCALL SDL_GetWindowGammaRamp(SDL_Window * window,
                                                   Uint16 * red,
                                                   Uint16 * green,
                                                   Uint16 * blue);

/**
 * 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;

/**
 * Callback used for hit-testing.
 *
 * \param win the SDL_Window where hit-testing was set on
 * \param area an SDL_Point which should be hit-tested
 * \param data what was passed as `callback_data` to SDL_SetWindowHitTest()
 * \return an SDL_HitTestResult value.
 *
 * \sa SDL_SetWindowHitTest
 */
typedef SDL_HitTestResult (SDLCALL *SDL_HitTest)(SDL_Window *win,
                                                 const SDL_Point *area,
                                                 void *data);

/**
 * 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 function to call when doing a hit-test
 * \param callback_data an app-defined void pointer passed to **callback**
 * \returns 0 on success or -1 on error (including unsupported); call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.4.
 */
extern DECLSPEC int SDLCALL SDL_SetWindowHitTest(SDL_Window * window,
                                                 SDL_HitTest callback,
                                                 void *callback_data);

/**
 * Request a window to demand attention from the user.
 *
 * \param window the window to be flashed
 * \param operation the flash operation
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 */
extern DECLSPEC int SDLCALL SDL_FlashWindow(SDL_Window * window, SDL_FlashOperation operation);

/**
 * Destroy a window.
 *
 * If `window` is NULL, this function will return immediately after setting
 * the SDL error message to "Invalid window". See SDL_GetError().
 *
 * \param window the window to destroy
 *
 * \sa SDL_CreateWindow
 * \sa SDL_CreateWindowFrom
 */
extern DECLSPEC void SDLCALL SDL_DestroyWindow(SDL_Window * window);


/**
 * Check whether the screensaver is currently enabled.
 *
 * The screensaver is disabled by default since SDL 2.0.2. Before SDL 2.0.2
 * the screensaver was enabled by default.
 *
 * The default can also be changed using `SDL_HINT_VIDEO_ALLOW_SCREENSAVER`.
 *
 * \returns SDL_TRUE if the screensaver is enabled, SDL_FALSE if it is
 *          disabled.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_DisableScreenSaver
 * \sa SDL_EnableScreenSaver
 */
extern DECLSPEC SDL_bool SDLCALL SDL_IsScreenSaverEnabled(void);

/**
 * Allow the screen to be blanked by a screen saver.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_DisableScreenSaver
 * \sa SDL_IsScreenSaverEnabled
 */
extern DECLSPEC void SDLCALL SDL_EnableScreenSaver(void);

/**
 * Prevent the screen from being blanked by a screen saver.
 *
 * If you disable the screensaver, it is automatically re-enabled when SDL
 * quits.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_EnableScreenSaver
 * \sa SDL_IsScreenSaverEnabled
 */
extern DECLSPEC void SDLCALL SDL_DisableScreenSaver(void);


/**
 *  \name OpenGL support functions
 */
/* @{ */

/**
 * Dynamically load an OpenGL library.
 *
 * 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.
 *
 * 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().
 *
 * \param path the platform dependent OpenGL library name, or NULL to open the
 *             default OpenGL library
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_GL_GetProcAddress
 * \sa SDL_GL_UnloadLibrary
 */
extern DECLSPEC int SDLCALL SDL_GL_LoadLibrary(const char *path);

/**
 * Get an OpenGL function by name.
 *
 * If the GL library is loaded at runtime with SDL_GL_LoadLibrary(), then all
 * GL functions must be retrieved this way. Usually this is used to retrieve
 * function pointers to OpenGL extensions.
 *
 * There are some quirks to looking up OpenGL functions that require some
 * extra care from the application. If you code carefully, you can handle
 * these quirks without any platform-specific code, though:
 *
 * - On Windows, function pointers are specific to the current GL context;
 *   this means you need to have created a GL context and made it current
 *   before calling SDL_GL_GetProcAddress(). If you recreate your context or
 *   create a second context, you should assume that any existing function
 *   pointers aren't valid to use with it. This is (currently) a
 *   Windows-specific limitation, and in practice lots of drivers don't suffer
 *   this limitation, but it is still the way the wgl API is documented to
 *   work and you should expect crashes if you don't respect it. Store a copy
 *   of the function pointers that comes and goes with context lifespan.
 * - On X11, function pointers returned by this function are valid for any
 *   context, and can even be looked up before a context is created at all.
 *   This means that, for at least some common OpenGL implementations, if you
 *   look up a function that doesn't exist, you'll get a non-NULL result that
 *   is _NOT_ safe to call. You must always make sure the function is actually
 *   available for a given GL context before calling it, by checking for the
 *   existence of the appropriate extension with SDL_GL_ExtensionSupported(),
 *   or verifying that the version of OpenGL you're using offers the function
 *   as core functionality.
 * - Some OpenGL drivers, on all platforms, *will* return NULL if a function
 *   isn't supported, but you can't count on this behavior. Check for
 *   extensions you use, and if you get a NULL anyway, act as if that
 *   extension wasn't available. This is probably a bug in the driver, but you
 *   can code defensively for this scenario anyhow.
 * - Just because you're on Linux/Unix, don't assume you'll be using X11.
 *   Next-gen display servers are waiting to replace it, and may or may not
 *   make the same promises about function pointers.
 * - OpenGL function pointers must be declared `APIENTRY` as in the example
 *   code. This will ensure the proper calling convention is followed on
 *   platforms where this matters (Win32) thereby avoiding stack corruption.
 *
 * \param proc the name of an OpenGL function
 * \returns a pointer to the named OpenGL function. The returned pointer
 *          should be cast to the appropriate function signature.
 *
 * \sa SDL_GL_ExtensionSupported
 * \sa SDL_GL_LoadLibrary
 * \sa SDL_GL_UnloadLibrary
 */
extern DECLSPEC void *SDLCALL SDL_GL_GetProcAddress(const char *proc);

/**
 * Unload the OpenGL library previously loaded by SDL_GL_LoadLibrary().
 *
 * \sa SDL_GL_LoadLibrary
 */
extern DECLSPEC void SDLCALL SDL_GL_UnloadLibrary(void);

/**
 * Check if an OpenGL extension is supported for the current context.
 *
 * This function operates on the current GL context; you must have created a
 * context and it must be current before calling this function. Do not assume
 * that all contexts you create will have the same set of extensions
 * available, or that recreating an existing context will offer the same
 * extensions again.
 *
 * While it's probably not a massive overhead, this function is not an O(1)
 * operation. Check the extensions you care about after creating the GL
 * context and save that information somewhere instead of calling the function
 * every time you need to know.
 *
 * \param extension the name of the extension to check
 * \returns SDL_TRUE if the extension is supported, SDL_FALSE otherwise.
 *
 * \since This function is available since SDL 2.0.0.
 */
extern DECLSPEC SDL_bool SDLCALL SDL_GL_ExtensionSupported(const char
                                                           *extension);

/**
 * Reset all previously set OpenGL context attributes to their default values.
 *
 * \since This function is available since SDL 2.0.2.
 *
 * \sa SDL_GL_GetAttribute
 * \sa SDL_GL_SetAttribute
 */
extern DECLSPEC void SDLCALL SDL_GL_ResetAttributes(void);

/**
 * Set an OpenGL window attribute before window creation.
 *
 * This function sets the OpenGL attribute `attr` to `value`. The requested
 * attributes should be set before creating an OpenGL window. You should use
 * SDL_GL_GetAttribute() to check the values after creating the OpenGL
 * context, since the values obtained can differ from the requested ones.
 *
 * \param attr an SDL_GLattr enum value specifying the OpenGL attribute to set
 * \param value the desired value for the attribute
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_GL_GetAttribute
 * \sa SDL_GL_ResetAttributes
 */
extern DECLSPEC int SDLCALL SDL_GL_SetAttribute(SDL_GLattr attr, int value);

/**
 * Get the actual value for an attribute from the current context.
 *
 * \param attr an SDL_GLattr enum value specifying the OpenGL attribute to get
 * \param value a pointer filled in with the current value of `attr`
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_GL_ResetAttributes
 * \sa SDL_GL_SetAttribute
 */
extern DECLSPEC int SDLCALL SDL_GL_GetAttribute(SDL_GLattr attr, int *value);

/**
 * Create an OpenGL context for an OpenGL window, and make it current.
 *
 * Windows users new to OpenGL should note that, for historical reasons, GL
 * functions added after OpenGL version 1.1 are not available by default.
 * Those functions must be loaded at run-time, either with an OpenGL
 * extension-handling library or with SDL_GL_GetProcAddress() and its related
 * functions.
 *
 * SDL_GLContext is an alias for `void *`. It's opaque to the application.
 *
 * \param window the window to associate with the context
 * \returns the OpenGL context associated with `window` or NULL on error; call
 *          SDL_GetError() for more details.
 *
 * \sa SDL_GL_DeleteContext
 * \sa SDL_GL_MakeCurrent
 */
extern DECLSPEC SDL_GLContext SDLCALL SDL_GL_CreateContext(SDL_Window *
                                                           window);

/**
 * Set up an OpenGL context for rendering into an OpenGL window.
 *
 * The context must have been created with a compatible window.
 *
 * \param window the window to associate with the context
 * \param context the OpenGL context to associate with the window
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \sa SDL_GL_CreateContext
 */
extern DECLSPEC int SDLCALL SDL_GL_MakeCurrent(SDL_Window * window,
                                               SDL_GLContext context);

/**
 * Get the currently active OpenGL window.
 *
 * \returns the currently active OpenGL window on success or NULL on failure;
 *          call SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 */
extern DECLSPEC SDL_Window* SDLCALL SDL_GL_GetCurrentWindow(void);

/**
 * Get the currently active OpenGL context.
 *
 * \returns the currently active OpenGL context or NULL on failure; call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_GL_MakeCurrent
 */
extern DECLSPEC SDL_GLContext SDLCALL SDL_GL_GetCurrentContext(void);

/**
 * Get the size of a window's underlying drawable in pixels.
 *
 * This returns info useful for calling glViewport().
 *
 * 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.
 *
 * \param window the window from which the drawable size should be queried
 * \param w a pointer to variable for storing the width in pixels, may be NULL
 * \param h a pointer to variable for storing the height in pixels, may be
 *          NULL
 *
 * \since This function is available since SDL 2.0.1.
 *
 * \sa SDL_CreateWindow
 * \sa SDL_GetWindowSize
 */
extern DECLSPEC void SDLCALL SDL_GL_GetDrawableSize(SDL_Window * window, int *w,
                                                    int *h);

/**
 * Set the swap interval for the current OpenGL context.
 *
 * Some systems allow specifying -1 for the interval, to enable adaptive
 * vsync. Adaptive vsync works the same as vsync, but if you've already missed
 * the vertical retrace for a given frame, it swaps buffers immediately, which
 * might be less jarring for the user during occasional framerate drops. If an
 * application requests adaptive vsync and the system does not support it,
 * this function will fail and return -1. In such a case, you should probably
 * retry the call with 1 for the interval.
 *
 * Adaptive vsync is implemented for some glX drivers with
 * GLX_EXT_swap_control_tear:
 *
 * https://www.opengl.org/registry/specs/EXT/glx_swap_control_tear.txt
 *
 * and for some Windows drivers with WGL_EXT_swap_control_tear:
 *
 * https://www.opengl.org/registry/specs/EXT/wgl_swap_control_tear.txt
 *
 * Read more on the Khronos wiki:
 * https://www.khronos.org/opengl/wiki/Swap_Interval#Adaptive_Vsync
 *
 * \param interval 0 for immediate updates, 1 for updates synchronized with
 *                 the vertical retrace, -1 for adaptive vsync
 * \returns 0 on success or -1 if setting the swap interval is not supported;
 *          call SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_GL_GetSwapInterval
 */
extern DECLSPEC int SDLCALL SDL_GL_SetSwapInterval(int interval);

/**
 * Get the swap interval for the current OpenGL context.
 *
 * If the system can't determine the swap interval, or there isn't a valid
 * current context, this function will return 0 as a safe default.
 *
 * \returns 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;
 *          call SDL_GetError() for more information.
 *
 * \since This function is available since SDL 2.0.0.
 *
 * \sa SDL_GL_SetSwapInterval
 */
extern DECLSPEC int SDLCALL SDL_GL_GetSwapInterval(void);

/**
 * Update a window with OpenGL rendering.
 *
 * This is used with double-buffered OpenGL contexts, which are the default.
 *
 * On macOS, make sure you bind 0 to the draw framebuffer before swapping the
 * window, otherwise nothing will happen. If you aren't using
 * glBindFramebuffer(), this is the default and you won't have to do anything
 * extra.
 *
 * \param window the window to change
 */
extern DECLSPEC void SDLCALL SDL_GL_SwapWindow(SDL_Window * window);

/**
 * Delete an OpenGL context.
 *
 * \param context the OpenGL context to be deleted
 *
 * \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: */