Time for action – fading pieces

1. Add a new class to the Flood Control project called "FadingPiece".

2. Add using Microsoft.Xna.Framework; to the using area at the top of the class.

3. Update the declaration of the class to read class FadingPiece : GamePiece

4. Add the following declarations to the FadingPiece class:

   public float alphaLevel = 1.0f;
   public static float alphaChangeRate = 0.02f;

5. Add a constructor for the FadingPiece class:

   public FadingPiece(string pieceType, string suffix)
       : base(pieceType, suffix)
   {
   
   }
   

6. Add a method to update the piece:

   public void UpdatePiece()
   {
       alphaLevel = MathHelper.Max(
           0, 
           alphaLevel - alphaChangeRate);
   }

What just happened?

The simplest of our animated pieces, the FadingPiece only requires an alpha value (which always starts at 1.0f, or fully opaque) and a rate of change. The FadingPiece constructor simply passes the parameters along to the base constructor.

When a FadingPiece is updated, alphaLevel is reduced by alphaChangeRate, making the piece...