Вычисляем пробег мыши

Public Class Form1
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If Timer1.Enabled = False Then
            Timer1.Enabled = True
            Button1.Text = "Стоп"
        Else
            Timer1.Enabled = False
            Button1.Text = "Старт"
        End If
    End Sub
    Dim zx1, zx2, zy1, zy2 As Integer
    Dim total As Decimal = 0
    Dim z As Boolean = True
    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        If z = True Then
            zx1 = MousePosition.X
            zy1 = MousePosition.Y
            z = False
        Else
            zx2 = MousePosition.X
            zy2 = MousePosition.Y
            Dim a As Integer = (zx1 - zx2) ^ 2
            Dim b As Integer = (zy1 - zy2) ^ 2
            Dim c As Decimal = (a + b) ^ 0.5
            total += (0.3 * c) / 1023
            zx1 = zx2
            zy1 = zy2
          
        End If
        Me.Text = Math.Round(total, 2) & " м"
 
    End Sub