recrownedgtk/RecrownedGTK/Game/GameEngine.cs

using OpenTK;
using OpenTK.Graphics.OpenGL;
using System;
using System.ComponentModel;
using RecrownedGTK.Persistence;
using RecrownedGTK.AssetsSystem;
namespace RecrownedGTK.Game {
    public sealed class GameEngine : GameWindow {
        private IState state;
        public readonly Preferences preferences;
        public readonly AssetManager assets;
        public GameEngine(IState initialState, Preferences preferences, AssetManager assets) : base() {
            this.state = initialState;
            this.assets = assets;
            this.preferences = preferences;
        }

        protected override void OnUpdateFrame(FrameEventArgs e) {
            state.Update(e.Time);
            IState potentialState = null;
            if ((potentialState = state.ChangeState()) != null) {
                if (potentialState.Shown(this)) {
                    state.Hidden();
                    state = potentialState;
                }
            }
            base.OnUpdateFrame(e);
        }

        protected override void OnRenderFrame(FrameEventArgs e) {
            state.Render(e.Time);
            SwapBuffers();
            base.OnRenderFrame(e);
        }
        
        protected override void OnClosed(EventArgs e) {
            if (state.CloseRequested()) {
                ((CancelEventArgs) e).Cancel = true;
            }
            base.OnClosed(e);
        }

        protected override void OnResize(EventArgs e) {
            state.WindowSizeUpdate(Width, Height);
            GL.Viewport(0, 0, Width, Height);
            base.OnResize(e);
        }
    }
}