Time for action – falling pieces

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

2. Add the Inherits line after the class declaration as follows:

   Inherits GamePiece

3. Add the following declarations to the FallingPiece class:

   Public VerticalOffset As Integer
   Public Shared FallRate As Integer = 5

4. Add a constructor for the FallingPiece class:

   Public Sub New(type As String, verticalOffset As Integer)
       MyBase.New(type)
       Me.VerticalOffset = verticalOffset
   End Sub

5. Add a method to update the piece:

   Public Sub UpdatePiece()
       VerticalOffset =
           CInt(MathHelper.Max(0, VerticalOffset - FallRate))
   End Sub

What just happened?

Simpler than a RotatingPiece, a FallingPiece is also a child of the GamePiece class. A FallingPiece has an offset (how high above its final destination it is currently located) and a falling speed (the number of pixels it will move per update).

As with a RotatingPiece, the constructor passes the type parameter to its base class constructor, and uses the verticalOffset...