Voile/Voile/Source/Game.cs

using Voile.Input;
using Voile.Rendering;
using Voile.Resources;

namespace Voile
{
    /// <summary>
    /// Entry point for the Voile game.
    /// </summary>
    public abstract class Game
    {
        /// <summary>
        /// The ResourceManager associated with this game.
        /// </summary>
        protected ResourceManager ResourceManager { get; private set; }
        /// <summary>
        /// The InputHandler associated with this game. Uses <see cref="RaylibInputSystem"/> by default.
        /// </summary>
        protected InputSystem Input { get; private set; }

        /// <summary>
        /// The Renderer associated with this game. Uses <see cref="RaylibRenderSystem"/> by default.
        /// </summary>
        protected RenderSystem Renderer { get; private set; }

        /// <summary>
        /// Resource root path for this game.
        /// </summary>
        public virtual string ResourceRoot => "Resources/";

        /// <summary>
        /// Path to the engine configuration file.
        /// </summary>
        public virtual string EngineConfigPath => "engine.config";

        /// <summary>
        /// Name of this game. Also used as a default window title.
        /// </summary>
        public virtual string Name => "";

        /// <summary>
        /// Default game constructor.
        /// </summary>
        public Game()
        {
            ResourceManager = new ResourceManager();
            Input = new RaylibInputSystem();
            Renderer = new RaylibRenderSystem();
        }

        /// <summary>
        /// Game constructor with custom systems.
        /// </summary>
        /// <param name="resourceManager"></param>
        /// <param name="inputSystem"></param>
        /// <param name="renderSystem"></param>
        public Game(ResourceManager resourceManager, InputSystem inputSystem, RenderSystem renderSystem)
        {
            ResourceManager = resourceManager;
            Input = inputSystem;
            Renderer = renderSystem;
        }

        /// <summary>
        /// Starts the game application.
        /// This involves initializing the required subsystems, loading resources from the disk, and then preparing the subsystems for running in the main loop.
        /// </summary>
        public void Start()
        {
            if (Renderer is null)
            {
                throw new NullReferenceException("No renderer provided.");
            }

            if (Input is null)
            {
                throw new NullReferenceException("No input system provided.");
            }

            if (ResourceManager is null)
            {
                throw new NullReferenceException("No ResourceManager provided.");
            }

            Initialize();
            LoadResources();
            Ready();
            Run();
            Shutdown();
        }

        /// <summary>
        /// Initializes subsystems using default types and settings.
        /// </summary>
        public void InitializeDefault()
        {
            ResourceManager.ResourceRoot = ResourceRoot;

            Input = new RaylibInputSystem();
            Renderer = new RaylibRenderSystem();

            Input.Start();

            InitializeRenderer();
        }

        public void ShutdownDefault()
        {
            Input.Dispose();
            Renderer.Dispose();
            ResourceManager.Dispose();
        }

        /// <summary>
        /// Called when it's time to initialize the subsystems, or modify default game settings or system settings.
        /// </summary>
        public abstract void Initialize();
        /// <summary>
        /// Called when it's time to load the game's resources, such as images or sounds.
        /// </summary>
        protected abstract void LoadResources();
        /// <summary>
        /// Called when it's safe to manipulate the resources or/and systems.
        /// You can safely create game objects, scenes, etc. in this method.
        /// </summary>
        protected abstract void Ready();
        /// <summary>
        /// Called when everything has been readied to start the main loop.
        /// </summary>
        protected abstract void Run();
        /// <summary>
        /// Called when the application quits and it's safe to clean up.
        /// </summary>
        public abstract void Shutdown();

        private void InitializeRenderer()
        {
            var windowSettings = WindowSettings.Default;

            if (!string.IsNullOrWhiteSpace(Name))
                windowSettings.Title = Name;

            Renderer.Start(RendererSettings.Default);
        }
    }
}