1 files changed, 76 insertions, 0 deletions
diff --git a/Emulator/DisplayEngine.cs b/Emulator/DisplayEngine.cs
new file mode 100644
index 0000000..beb2bba
--- /dev/null
+++ b/Emulator/DisplayEngine.cs
@@ -0,0 +1,76 @@
+namespace Q1.Emulator;
+
+using System;
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Graphics;
+using Microsoft.Xna.Framework.Input;
+
+public class DisplayEngine : Game
+{
+    private readonly Action<Texture2D>     _onScreenTextureLoaded;
+    private readonly Action                _requestUpdate;
+    private readonly Func<bool>            _checkAbort;
+    private          GraphicsDeviceManager _graphics;
+    private          SpriteBatch           _spriteBatch;
+
+    private Texture2D _texture;
+    public int Scaling { get; }
+    public int Width { get; }
+    public int Height { get; }
+
+    public DisplayEngine(int width, int height, int scaling, Action<Texture2D> onScreenTextureLoaded, Action requestUpdate, Func<bool> checkAbort)
+    {
+        this.Width                  = width;
+        this.Height                 = height;
+        this.Scaling                = scaling;
+        this._onScreenTextureLoaded = onScreenTextureLoaded;
+        this._requestUpdate         = requestUpdate;
+        this._checkAbort            = checkAbort;
+
+        this._graphics             = new GraphicsDeviceManager(this);
+        this.Content.RootDirectory = "Content";
+        this.IsMouseVisible        = true;
+    }
+
+    protected override void Initialize()
+    {
+        this._texture = new Texture2D(this.GraphicsDevice, this.Width, this.Height);
+        this._onScreenTextureLoaded?.Invoke(this._texture);
+        // set window size
+        this._graphics.PreferredBackBufferWidth  = this.Width  * this.Scaling;
+        this._graphics.PreferredBackBufferHeight = this.Height * this.Scaling;
+        this._graphics.ApplyChanges();
+
+        base.Initialize();
+    }
+
+    protected override void LoadContent()
+    {
+        this._spriteBatch = new SpriteBatch(this.GraphicsDevice);
+    }
+
+    protected override void Update(GameTime gameTime)
+    {
+        var state = Keyboard.GetState();
+
+        if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed || state.IsKeyDown(Keys.Escape) || this._checkAbort())
+            this.Exit();
+        
+        base.Update(gameTime);
+    }
+
+    protected override void Draw(GameTime gameTime)
+    {
+        // GraphicsDevice.Clear(Color.CornflowerBlue);
+
+        this._requestUpdate();
+
+        this._spriteBatch.Begin(SpriteSortMode.Deferred, BlendState.NonPremultiplied, SamplerState.PointClamp, DepthStencilState.None, RasterizerState.CullNone);
+        // Draw the texture to the screen
+        this._spriteBatch.Draw(this._texture, new Rectangle(0, 0, this.Width * this.Scaling, this.Height * this.Scaling), Color.White);
+
+        this._spriteBatch.End();
+
+        base.Draw(gameTime);
+    }
+}
+\ No newline at end of file