SFML/include/SFML/Window/Window.hpp

////////////////////////////////////////////////////////////
//
// SFML - Simple and Fast Multimedia Library
// Copyright (C) 2007-2023 Laurent Gomila (laurent@sfml-dev.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.
//
////////////////////////////////////////////////////////////

#pragma once

////////////////////////////////////////////////////////////
// Headers
////////////////////////////////////////////////////////////
#include <SFML/System/Clock.hpp>
#include <SFML/System/Time.hpp>
#include <SFML/Window/ContextSettings.hpp>
#include <SFML/Window/GlResource.hpp>
#include <SFML/Window/WindowBase.hpp>

#include <memory>


namespace sf
{
namespace priv
{
class GlContext;
}

class Event;

////////////////////////////////////////////////////////////
/// \brief Window that serves as a target for OpenGL rendering
///
////////////////////////////////////////////////////////////
class SFML_WINDOW_API Window : public WindowBase, GlResource
{
public:
    ////////////////////////////////////////////////////////////
    /// \brief Default constructor
    ///
    /// This constructor doesn't actually create the window,
    /// use the other constructors or call create() to do so.
    ///
    ////////////////////////////////////////////////////////////
    Window();

    ////////////////////////////////////////////////////////////
    /// \brief Construct a new window
    ///
    /// This constructor creates the window with the size and pixel
    /// depth defined in \a mode. An optional style can be passed to
    /// customize the look and behavior of the window (borders,
    /// title bar, resizable, closable, ...). If \a style contains
    /// Style::Fullscreen, then \a mode must be a valid video mode.
    ///
    /// The fourth parameter is an optional structure specifying
    /// advanced OpenGL context settings such as antialiasing,
    /// depth-buffer bits, etc.
    ///
    /// \param mode     Video mode to use (defines the width, height and depth of the rendering area of the window)
    /// \param title    Title of the window
    /// \param style    %Window style, a bitwise OR combination of sf::Style enumerators
    /// \param settings Additional settings for the underlying OpenGL context
    ///
    ////////////////////////////////////////////////////////////
    Window(VideoMode              mode,
           const String&          title,
           std::uint32_t          style    = Style::Default,
           const ContextSettings& settings = ContextSettings());

    ////////////////////////////////////////////////////////////
    /// \brief Construct the window from an existing control
    ///
    /// Use this constructor if you want to create an OpenGL
    /// rendering area into an already existing control.
    ///
    /// The second parameter is an optional structure specifying
    /// advanced OpenGL context settings such as antialiasing,
    /// depth-buffer bits, etc.
    ///
    /// \param handle   Platform-specific handle of the control
    /// \param settings Additional settings for the underlying OpenGL context
    ///
    ////////////////////////////////////////////////////////////
    explicit Window(WindowHandle handle, const ContextSettings& settings = ContextSettings());

    ////////////////////////////////////////////////////////////
    /// \brief Destructor
    ///
    /// Closes the window and frees all the resources attached to it.
    ///
    ////////////////////////////////////////////////////////////
    ~Window() override;

    ////////////////////////////////////////////////////////////
    /// \brief Create (or recreate) the window
    ///
    /// If the window was already created, it closes it first.
    /// If \a style contains Style::Fullscreen, then \a mode
    /// must be a valid video mode.
    ///
    /// \param mode     Video mode to use (defines the width, height and depth of the rendering area of the window)
    /// \param title    Title of the window
    /// \param style    %Window style, a bitwise OR combination of sf::Style enumerators
    ///
    ////////////////////////////////////////////////////////////
    void create(VideoMode mode, const String& title, std::uint32_t style = Style::Default) override;

    ////////////////////////////////////////////////////////////
    /// \brief Create (or recreate) the window
    ///
    /// If the window was already created, it closes it first.
    /// If \a style contains Style::Fullscreen, then \a mode
    /// must be a valid video mode.
    ///
    /// The fourth parameter is an optional structure specifying
    /// advanced OpenGL context settings such as antialiasing,
    /// depth-buffer bits, etc.
    ///
    /// \param mode     Video mode to use (defines the width, height and depth of the rendering area of the window)
    /// \param title    Title of the window
    /// \param style    %Window style, a bitwise OR combination of sf::Style enumerators
    /// \param settings Additional settings for the underlying OpenGL context
    ///
    ////////////////////////////////////////////////////////////
    virtual void create(VideoMode mode, const String& title, std::uint32_t style, const ContextSettings& settings);

    ////////////////////////////////////////////////////////////
    /// \brief Create (or recreate) the window from an existing control
    ///
    /// Use this function if you want to create an OpenGL
    /// rendering area into an already existing control.
    /// If the window was already created, it closes it first.
    ///
    /// \param handle   Platform-specific handle of the control
    ///
    ////////////////////////////////////////////////////////////
    void create(WindowHandle handle) override;

    ////////////////////////////////////////////////////////////
    /// \brief Create (or recreate) the window from an existing control
    ///
    /// Use this function if you want to create an OpenGL
    /// rendering area into an already existing control.
    /// If the window was already created, it closes it first.
    ///
    /// The second parameter is an optional structure specifying
    /// advanced OpenGL context settings such as antialiasing,
    /// depth-buffer bits, etc.
    ///
    /// \param handle   Platform-specific handle of the control
    /// \param settings Additional settings for the underlying OpenGL context
    ///
    ////////////////////////////////////////////////////////////
    virtual void create(WindowHandle handle, const ContextSettings& settings);

    ////////////////////////////////////////////////////////////
    /// \brief Close the window and destroy all the attached resources
    ///
    /// After calling this function, the sf::Window instance remains
    /// valid and you can call create() to recreate the window.
    /// All other functions such as pollEvent() or display() will
    /// still work (i.e. you don't have to test isOpen() every time),
    /// and will have no effect on closed windows.
    ///
    ////////////////////////////////////////////////////////////
    void close() override;

    ////////////////////////////////////////////////////////////
    /// \brief Get the settings of the OpenGL context of the window
    ///
    /// Note that these settings may be different from what was
    /// passed to the constructor or the create() function,
    /// if one or more settings were not supported. In this case,
    /// SFML chose the closest match.
    ///
    /// \return Structure containing the OpenGL context settings
    ///
    ////////////////////////////////////////////////////////////
    const ContextSettings& getSettings() const;

    ////////////////////////////////////////////////////////////
    /// \brief Enable or disable vertical synchronization
    ///
    /// Activating vertical synchronization will limit the number
    /// of frames displayed to the refresh rate of the monitor.
    /// This can avoid some visual artifacts, and limit the framerate
    /// to a good value (but not constant across different computers).
    ///
    /// Vertical synchronization is disabled by default.
    ///
    /// \param enabled True to enable v-sync, false to deactivate it
    ///
    ////////////////////////////////////////////////////////////
    void setVerticalSyncEnabled(bool enabled);

    ////////////////////////////////////////////////////////////
    /// \brief Limit the framerate to a maximum fixed frequency
    ///
    /// If a limit is set, the window will use a small delay after
    /// each call to display() to ensure that the current frame
    /// lasted long enough to match the framerate limit.
    /// SFML will try to match the given limit as much as it can,
    /// but since it internally uses sf::sleep, whose precision
    /// depends on the underlying OS, the results may be a little
    /// unprecise as well (for example, you can get 65 FPS when
    /// requesting 60).
    ///
    /// \param limit Framerate limit, in frames per seconds (use 0 to disable limit)
    ///
    ////////////////////////////////////////////////////////////
    void setFramerateLimit(unsigned int limit);

    ////////////////////////////////////////////////////////////
    /// \brief Activate or deactivate the window as the current target
    ///        for OpenGL rendering
    ///
    /// A window is active only on the current thread, if you want to
    /// make it active on another thread you have to deactivate it
    /// on the previous thread first if it was active.
    /// Only one window can be active on a thread at a time, thus
    /// the window previously active (if any) automatically gets deactivated.
    /// This is not to be confused with requestFocus().
    ///
    /// \param active True to activate, false to deactivate
    ///
    /// \return True if operation was successful, false otherwise
    ///
    ////////////////////////////////////////////////////////////
    [[nodiscard]] bool setActive(bool active = true) const;

    ////////////////////////////////////////////////////////////
    /// \brief Display on screen what has been rendered to the window so far
    ///
    /// This function is typically called after all OpenGL rendering
    /// has been done for the current frame, in order to show
    /// it on screen.
    ///
    ////////////////////////////////////////////////////////////
    void display();

private:
    ////////////////////////////////////////////////////////////
    /// \brief Processes an event before it is sent to the user
    ///
    /// This function is called every time an event is received
    /// from the internal window (through pollEvent or waitEvent).
    /// It filters out unwanted events, and performs whatever internal
    /// stuff the window needs before the event is returned to the
    /// user.
    ///
    /// \param event Event to filter
    ///
    ////////////////////////////////////////////////////////////
    bool filterEvent(const Event& event);

    ////////////////////////////////////////////////////////////
    /// \brief Perform some common internal initializations
    ///
    ////////////////////////////////////////////////////////////
    void initialize();

    ////////////////////////////////////////////////////////////
    // Member data
    ////////////////////////////////////////////////////////////
    std::unique_ptr<priv::GlContext> m_context;        //!< Platform-specific implementation of the OpenGL context
    Clock                            m_clock;          //!< Clock for measuring the elapsed time between frames
    Time                             m_frameTimeLimit; //!< Current framerate limit
};

} // namespace sf


////////////////////////////////////////////////////////////
/// \class sf::Window
/// \ingroup window
///
/// sf::Window is the main class of the Window module. It defines
/// an OS window that is able to receive an OpenGL rendering.
///
/// A sf::Window can create its own new window, or be embedded into
/// an already existing control using the create(handle) function.
/// This can be useful for embedding an OpenGL rendering area into
/// a view which is part of a bigger GUI with existing windows,
/// controls, etc. It can also serve as embedding an OpenGL rendering
/// area into a window created by another (probably richer) GUI library
/// like Qt or wxWidgets.
///
/// The sf::Window class provides a simple interface for manipulating
/// the window: move, resize, show/hide, control mouse cursor, etc.
/// It also provides event handling through its pollEvent() and waitEvent()
/// functions.
///
/// Note that OpenGL experts can pass their own parameters (antialiasing
/// level, bits for the depth and stencil buffers, etc.) to the
/// OpenGL context attached to the window, with the sf::ContextSettings
/// structure which is passed as an optional argument when creating the
/// window.
///
/// On dual-graphics systems consisting of a low-power integrated GPU
/// and a powerful discrete GPU, the driver picks which GPU will run an
/// SFML application. In order to inform the driver that an SFML application
/// can benefit from being run on the more powerful discrete GPU,
/// #SFML_DEFINE_DISCRETE_GPU_PREFERENCE can be placed in a source file
/// that is compiled and linked into the final application. The macro
/// should be placed outside of any scopes in the global namespace.
///
/// Usage example:
/// \code
/// // Declare and create a new window
/// sf::Window window(sf::VideoMode({800, 600}), "SFML window");
///
/// // Limit the framerate to 60 frames per second (this step is optional)
/// window.setFramerateLimit(60);
///
/// // The main loop - ends as soon as the window is closed
/// while (window.isOpen())
/// {
///    // Event processing
///    for (sf::Event event; window.pollEvent(event);)
///    {
///        // Request for closing the window
///        if (event.type == sf::Event::Closed)
///            window.close();
///    }
///
///    // Activate the window for OpenGL rendering
///    window.setActive();
///
///    // OpenGL drawing commands go here...
///
///    // End the current frame and display its contents on screen
///    window.display();
/// }
/// \endcode
///
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