Window

Represents a cross-platform application window.

This class creates and manages the operating system window, the graphics context, and propagates input events from the OS. Construct one in your main, call Initialize, then drive it with PollEvents and SwapBuffers each frame.

vglx::Window window({
  .title = "My App",
  .width = 1920,
  .height = 1080,
  .antialiasing = 4,
  .vsync = true
});

auto ok = window.Initialize();
if (!ok) {
  HandleError(ok.error());
}

This class defines the windowing interface only. The actual implementation may be platform-specific or provided by an external dependency such as GLFW.

Construction

Constructors

Window()

Constructs a window.

Resources are not created until Initialize is called.

Window::Window(const Window::Parameters& params);

Parameter	Description
params	Initialization parameters for constructing the window.

Types

Window::Parameters struct

Parameters for constructing a Window object.

Parameter	Description
title std::string	Window title.
width int	Client-area width in pixels.
height int	Client-area height in pixels.
vsync bool	Enable or disable vertical sync.

ResizeCallback typedef

Function signature for window-resize notifications.

The callback is invoked when the window’s client-area size changes. Use the provided sizes to update camera projections and canvas layout.

using ResizeCallback = std::function<void(const ResizeParameters& params)>

Functions

AspectRatio() float

Returns the aspect ratio (width / height).

float Window::AspectRatio() const;

BeginUIFrame() void

Marks the beginning of a new UI frame.

Must be called before issuing any UI commands. If no UI system is active, this is a no-op.

void Window::BeginUIFrame();

EndUIFrame() void

Marks the end of the current UI frame.

Must be called after all UI commands have been issued. If no UI system is active, this is a no-op.

void Window::EndUIFrame();

FramebufferHeight() int

Returns the current framebuffer height in pixels.

On high-DPI displays this may differ from Height.

int Window::FramebufferHeight() const;

FramebufferWidth() int

Returns the current framebuffer width in pixels.

On high-DPI displays this may differ from Width.

int Window::FramebufferWidth() const;

Height() int

Returns the current logical window height in pixels.

int Window::Height() const;

Initialize() std::expected<void, std::string>

Initializes the underlying OS window and graphics context.

std::expected<void, std::string> Window::Initialize();

OnResize() void

Registers a callback to be invoked when the window is resized.

The callback is executed whenever the client-area dimensions change, including user drag-resizes and OS-driven scaling changes on high-DPI displays. It is also invoked once with the initial size on the first PollEvents call, so size-dependent state can be fully initialized through this callback. The callback receives both logical window sizes and the framebuffer sizes in physical pixels.

void Window::OnResize(ResizeCallback callback);

Parameter	Description
callback	A function to invoke on resize with the new sizes.

operator=() Window&

Window& Window::operator=(Window&& ) noexcept;

Parameter	Description

PollEvents() void

Processes pending window and input events.

Polls the operating system for events such as input, window resize, or close requests. Must be called at the top of the main loop to keep the application responsive.

void Window::PollEvents();

RequestClose() void

Requests that the window be closed.

Sets the internal close flag so that ShouldClose returns true. This allows the application to exit the main loop gracefully.

void Window::RequestClose();

SetTitle() void

Updates the window title.

void Window::SetTitle(std::string_view title);

Parameter	Description
title	UTF-8 string to display in the window title bar.

ShouldClose() bool

Returns whether the window has been flagged for closing.

This flag is set when the user requests the window to close through the operating system or when RequestClose is called.

bool Window::ShouldClose();

SwapBuffers() void

Swaps the front and back buffers.

Presents the rendered frame to the display.

void Window::SwapBuffers();

Width() int

Returns the current logical window width in pixels.

int Window::Width() const;