Android Question Parse KML Polygones, Save, check if inside?

Type ePoint(X As Double, Y As Double)

Public Sub IsPointInPolygon(polygon() As ePoint, X As Double, Y As Double) As Boolean
    Dim result As Boolean = False
    Dim j As Int = polygon.length - 1
    For i = 0 To polygon.length - 1
        If polygon(i).Y < Y And polygon(j).Y >= Y Or polygon(j).Y < Y And polygon(i).Y >= Y Then
            If polygon(i).X + (Y - polygon(i).Y) / (polygon(j).Y - polygon(i).Y) * (polygon(j).X - polygon(i).X) < X Then
                result = Not(result)
            End If
        End If
        j = i
    Next
    Return result
End Sub