MonoGame RenderTarget Scaling

gistfile1.cs

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Media;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Input.Touch;

public class Game1 : Game {

	GraphicsDeviceManager graphics;
	SpriteBatch spriteBatch;
	RenderTarget2D renderTarget;

	const int VIRTUAL_WIDTH = 1366;
	const int VIRTUAL_HEIGHT = 768;

	public Game1 ()
	{
		graphics = new GraphicsDeviceManager (this);
		Content.RootDirectory = "Content";
		graphics.IsFullScreen = false;	
		
		TouchPanel.DisplayHeight = VIRTUAL_HEIGHT;
		TouchPanel.DisplayWidth = VIRTUAL_WIDTH;
		TouchPanel.EnableMouseTouchPoint = true;
	}

	protected override void Initialize ()
	{
		spriteBatch = new SpriteBatch (graphics.GraphicsDevice);

		PresentationParameters pp = graphics.GraphicsDevice.PresentationParameters;

		// create a surface to draw on which is then scaled to the screen size on the PC
		renderTarget = new RenderTarget2D(graphics.GraphicsDevice, VIRTUAL_WIDTH, VIRTUAL_HEIGHT, false,
			SurfaceFormat.Color, DepthFormat.None, pp.MultiSampleCount, RenderTargetUsage.DiscardContents);
		
		base.Initialize ();
	}

	protected override void Dispose (bool disposing)
	{
		if (disposing) {
			renderTarget.Dispose ();
			renderTarget = null;
		}
		base.Dispose (disposing);
	}

	protected override void LoadContent ()
	{
		base.LoadContent ();
	}

	protected override void Update (GameTime gameTime)
	{

		var gamePadState = GamePad.GetState (PlayerIndex.One);
		var keyboardState = Keyboard.GetState ();
		var touchPanelState = TouchPanel.GetState ();

		if (gamePadState.IsButtonDown (Buttons.A) || keyboardState.IsKeyDown (Keys.A)) {
			// do something
		}
		foreach (var touch in touchPanelState) {
			if (touch.State == TouchLocationState.Pressed) {
				// do something
			}
		}

		base.Update (gameTime);
	}

	protected override void Draw (GameTime gameTime)
	{
		graphics.GraphicsDevice.SetRenderTarget(renderTarget);

		//Draw your stuff
		graphics.GraphicsDevice.Clear (Color.MonoGameOrange);


		// draw render target
		float outputAspect = Window.ClientBounds.Width / (float)Window.ClientBounds.Height;
		float preferredAspect = VIRTUAL_WIDTH / (float)VIRTUAL_HEIGHT;

		Rectangle dst;

		if (outputAspect <= preferredAspect)
		{
			// output is taller than it is wider, bars on top/bottom
			int presentHeight = (int)((Window.ClientBounds.Width / preferredAspect) + 0.5f);
			int barHeight = (Window.ClientBounds.Height - presentHeight) / 2;

			dst = new Rectangle(0, barHeight, Window.ClientBounds.Width, presentHeight);
		}
		else
		{
			// output is wider than it is tall, bars left/right
			int presentWidth = (int)((Window.ClientBounds.Height * preferredAspect) + 0.5f);
			int barWidth = (Window.ClientBounds.Width - presentWidth) / 2;

			dst = new Rectangle(barWidth, 0, presentWidth, Window.ClientBounds.Height);
		}

		graphics.GraphicsDevice.SetRenderTarget(null);

		// clear to get black bars
		graphics.GraphicsDevice.Clear(ClearOptions.Target, Color.Black, 1.0f, 0);

		// draw a quad to get the draw buffer to the back buffer
		spriteBatch.Begin(SpriteSortMode.Immediate, BlendState.Opaque);
		spriteBatch.Draw(renderTarget, dst, Color.White);
		spriteBatch.End();

		base.Draw (gameTime);
	}
}

To improve on this, you can make a ScaledGame class which will give you the regular XNA calls (because ScaledGame inherits Microsoft.Xna.Framework.Game) but also scale the game when you base.Draw(gameTime). That would be a legitimate template. This code looks somewhat bloated.

The TouchPannel DisplayHeight and DisplayWidth change trick didn't worked for me to adapt input to screens with different resolutions.