private struct TextDisplay
members:
	public string text
	public Vector2 position
	public int width
	public int height
	public Color color
	
private struct ValueDisplay
members:
	public string text
	public float value
	public Vector2 position
	public int width
	public int height
	
private struct ImageDisplay
members:
	public Texture2D image
	public Vector2 position
	public int width
	public int height
	public Color color

HeadsUpDisplay
members:
	private List<TextDisplay> textDisplays
	private List<ValueDisplay> valueDisplays
	private List<ImageDisplay> imageDisplays
	
functions:
	public HeadsUpDisplay(ContentManager content, Graphics)
	public int AddTextDisplay(string text, Vector2 position, int width, int height, Color color)
	public int AddValueDisplay(string text, float value, Vector2 position, int width, int height)
	public int AddImageDisplay(string text, Vector2 position, int width, int height, Color color)
	
	public void UpdateText(int index, string newText)
	public void UpdateValue(int index, float newValue)