Implement GLFW window system

[rudrabeniwal]

Window Management with GLFW

Summary

This pr adds a new window management system to the Cyfra project, under the io.computenode.cyfra.window package. The main goal is to separate window handling from the Vulkan rendering logic and give us a consistent way to manage windows across platforms.

The initial version includes a general WindowSystem trait for abstraction, and a working GLFW-based implementation called GLFWWindowSystem.

Features

• Window Lifecycle Management: You can now easily create, display, move, and close windows using a simpler API. The system also makes sure GLFW is cleaned up properly when done.
• Event Handling: A unified way to handle events like resizing, key presses, mouse input, scrolling, and closing. All events are queued and processed consistently.
• GLFW Backend Implementation: GLFWWindowSystem provides a good implementation using the GLFW library.
• Vulkan Surface Integration: The WindowHandle (specifically GLFWWindowHandle) is designed for easy Vulkan surface creation, exposing the native window pointer (nativePtr) required to create a VkSurfaceKHR.
• Demo Application: Includes WindowSystemTest to demonstrate the system's functionality.

Implementation Details

1. Architecture

• The core abstraction is the WindowSystem trait defining methods like createWindow, pollEvents, and shouldWindowClose.
• GLFWWindowSystem handles all GLFW-specific stuff like initializing the library, setting platform hints, and wiring up callbacks.
• WindowHandle (implemented as GLFWWindowHandle) gives access to the raw window pointer, which is needed for Vulkan surface creation.
• There's a utility object called GLFWSystem that handles GLFW init and error checks, and ensures Vulkan compatibility.

2. Event System

• GLFW callbacks (e.g., GLFWKeyCallback, GLFWCursorPosCallback) are registered within GLFWWindowSystem.setupCallbacks.
• These callbacks convert GLFW events into custom WindowEvent types (like Key, Resize, etc.).
• Events are added to a thread-safe queue ConcurrentLinkedQueue.
• The pollEvents method calls GLFW.glfwPollEvents() to trigger callbacks, then queue is drained and events are returned as a list to process (assumes single-threaded usage).

3. Vulkan Integration

• Sets GLFW_CLIENT_API to GLFW_NO_API so Vulkan can handle rendering.
• WindowHandle.nativePtr provides the underlying GLFWwindow pointer, essential for creating the Vulkan VkSurfaceKHR via glfwCreateWindowSurface, which connects the window to Vulkan’s rendering system (swapchain).

Testing

• Includes WindowSystemTest, a runnable standalone test/demo application.
• Run command: sbt "runMain io.computenode.cyfra.window.WindowSystemTest".
• Manual Verification Performed On: Windows.
  • Verified window creation, visibility, positioning, closing correctly (via button and events).
  • Confirmed correct logging and handling of Resize, Keyboard, MouseButton, MouseMove, Scroll, and Close events.

Potential Issues & Limitations

• Currently, only the GLFW backend (GLFWWindowSystem) is implemented and supported.
• The current design does not explicitly support managing multiple windows simultaneously, though the architecture might allow it.
• High-DPI handling is basic and mostly depends on OS settings.
• Might run into OS-specific issues (not tested on macOS or Linux)

Future Work

• Add support for managing multiple application windows, potentially with independent event loops.
• Maybe support other backends like SDL2 or native APIs (Win32, etc.).
• Maybe add drag-and-drop support.

This provides a base for window management in Cyfra.