dog ball chase.vb

Public Class Form1
    Public dy As Integer
    Public dx As Integer
    Public dogSpeed As Integer
    Public generator As New Random

    Private Sub tmrMoveBall_Tick(sender As Object, e As EventArgs) Handles tmrMoveBall.Tick
        picBall.Top = picBall.Top + dy
        picBall.Left = picBall.Left + dx

        If (picBall.Top > Me.Height - picBall.Height) Or (picBall.Top < 0) Then
            dy = -dy
        End If

        If (picBall.Left > Me.Width - picBall.Width) Or (picBall.Left < 0) Then
            dx = -dx
        End If
    End Sub



    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        dy = 7
        dx = 7
        dogSpeed = 8
    End Sub

    Private Sub tmrMoveDog_Tick(sender As Object, e As EventArgs) Handles tmrMoveDog.Tick

        If picDog.Top < picBall.Top Then
            picDog.Top = picDog.Top + dogSpeed
        Else
            picDog.Top = picDog.Top - dogSpeed
        End If

        If picDog.Left < picBall.Left Then
            picDog.Left = picDog.Left + dogSpeed
        Else
            picDog.Left = picDog.Left - dogSpeed
        End If

        If detectHits(picBall, picDog) = True Then
            picDog.Top = generator.Next(1, Me.Height - picDog.Height)
            picDog.Left = generator.Next(1, Me.Width - picDog.Width)

            dogSpeed = dogSpeed - 1

            If dogSpeed = 0 Then
                dogSpeed = 10
            End If
        End If
    End Sub

    Public Function detectHits(p1 As PictureBox, p2 As PictureBox) As Boolean
        If ((p1.Left + p1.Width > p2.Left) And
                (p1.Left < p2.Left + p2.Width) And
                (p1.Top + p1.Height > p2.Top) And
                (p1.Top < p2.Top + p2.Height)) Then
            Return True
        Else
            Return False
        End If
    End Function
End Class