Application

The runtime entry point for defining and launching an app.

The Application class is the runtime: it sets up the window, rendering context, a main loop, and calls your hooks. Subclass it and override Configure, CreateScene, and Update to define behavior.

This is the preferred way to initialize a new app. If you need complete control, you can also assemble a program manually (window, renderer, loop, etc.), but that is outside the scope of this runtime API.

class MyApp : public vglx::Application {
 public:
  auto Configure() -> Application::Parameters override {
    return {
      .title = "My App",
      .width = 1024,
      .height = 768,
      .clear_color = 0x444444,
      .vsync = true,
      .show_stats = true
    };
  }

  auto CreateScene() -> std::shared_ptr<vglx::Scene> override {
    auto scene = vglx::Scene::Create();
    // Add nodes to the scene...
    return scene;
  }

  // Optional: override CreateCamera() to provide your own camera.
  // Returning nullptr creates a default perspective camera.
  // auto CreateCamera() -> std::shared_ptr<vglx::Camera> override { ... }

  auto Update(float delta) -> bool override {
    // Per-frame logic. Return false to exit the main loop.
    return true;
  }
};

int main() {
  MyApp app;
  app.Start();
  return 0;
}

Calling Start initializes the runtime, constructs the user scene (and camera, if provided), then runs the main loop while invoking Update each frame.

Construction

Constructors

Application()

vglx::Application::Application()

Constructs an Application instance. Initializes internal state but does not start the application loop.

Types

Application::Parameters struct

Configuration parameters for the application context.

Name	Type	Description
antialiasing	int	Antialiasing level (e.g., 4x MSAA).
clear_color	Color	Background clear color.
height	int	Window height in pixels.
show_stats	bool	Show stats UI overlay.
title	std::string	Window title.
vsync	bool	Enables vertical sync.
width	int	Window width in pixels.

Functions

Configure() Parameters virtual

virtual Parameters vglx::Application::Configure()

Provides configuration parameters for the application. Override this method to customize window settings, clear color, antialiasing, vsync, and other runtime options before the application starts.

CreateCamera() std::shared_ptr<Camera> virtual

virtual std::shared_ptr< Camera > vglx::Application::CreateCamera()

Creates the main camera. This method can be optionally overridden. If null is returned, a default perspective camera will be created automatically.

CreateScene() std::shared_ptr<Scene> pure virtual

virtual std::shared_ptr< Scene > vglx::Application::CreateScene()=0

Creates the root scene graph. This method must be implemented by the user and returns the primary scene used for rendering and updates.

GetCamera() Camera*

Camera * vglx::Application::GetCamera() const

Returns the current camera pointer.

GetContext() SharedContextPointer

SharedContextPointer vglx::Application::GetContext() const

Returns a pointer to current active shared context. The shared context holds runtime parameters (e.g., window size, framebuffer size, aspect ratio, active camera) and provides access to built-in resource loaders. It is created internally during application startup and is guaranteed to remain valid for the lifetime of the application.

GetScene() Scene*

Scene * vglx::Application::GetScene() const

Returns the current scene pointer.

SetCamera() void

void vglx::Application::SetCamera(std::shared_ptr< Camera > camera)

Parameter	Description
camera	Shared pointer to the new camera.

Sets the active camera.

SetScene() void

void vglx::Application::SetScene(std::shared_ptr< Scene > scene)

Parameter	Description
scene	Shared pointer to the new scene.

Sets the active scene.

Start() void

void vglx::Application::Start()

Starts the application loop. This method initializes the window, rendering context, and user scene and enters the main loop until the application exits.

Update() bool pure virtual

virtual bool vglx::Application::Update(float delta)=0

Parameter	Description
delta	Time in seconds since the last frame.

Per-frame update callback. This method must be implemented and is called every frame with the elapsed time since the last frame. Return false to exit the main loop.