VBMath Rnd() 1:1 Clone

VBMathCLE.vb

' removed Compiler dependcies.

Public NotInheritable Class VBMathCLE
    Private Shared Power2 As Integer()
    Private Shared m_rndSeed As Integer

    Shared Sub New()
        Dim numArray() As Integer = {0, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144, 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, 67108864, 134217728, 268435456, 536870912, 1073741824}
        Power2 = numArray
    End Sub

    Private Shared Function GetTimer() As Single
        Dim now As DateTime = DateTime.Now
        Return CSng((CDbl(((60 * now.Hour + now.Minute) * 60 + now.Second)) + CDbl(now.Millisecond) / 1000))
    End Function

    Public Shared Sub Randomize()
        Dim timer As Single = GetTimer()
        Dim mRndSeed As Integer = m_rndSeed
        Dim num As Integer = BitConverter.ToInt32(BitConverter.GetBytes(timer), 0)
        num = ShiftLeft(num And 65535 Xor ShiftRight(num, 16), 8)
        m_rndSeed = mRndSeed And -16776961 Or num
    End Sub

    Public Shared Sub Randomize(ByVal Number As Double)
        Dim num As Integer
        Dim mRndSeed As Integer = m_rndSeed
        num = If(Not BitConverter.IsLittleEndian, BitConverter.ToInt32(BitConverter.GetBytes(Number), 0), BitConverter.ToInt32(BitConverter.GetBytes(Number), 4))
        num = ShiftLeft(num And 65535 Xor ShiftRight(num, 16), 8)
        mRndSeed = mRndSeed And -16776961 Or num
        m_rndSeed = mRndSeed
    End Sub

    Public Shared Function Rnd() As Single
        Return Rnd(1.0!)
    End Function

    Public Shared Function Rnd(ByVal Number As Single) As Single
        Dim mRndSeed As Integer = m_rndSeed
        If (CDbl(Number) <> 0) Then
            If (CDbl(Number) < 0) Then
                mRndSeed = BitConverter.ToInt32(BitConverter.GetBytes(Number), 0)
                Dim num As Long = CLng(mRndSeed)
                num = num And 4294967295L
                mRndSeed = CInt((num + num / 16777216L And 16777215L))
            End If
            mRndSeed = CInt((CLng(mRndSeed) * 1140671485L + 12820163L And 16777215L))
        End If
        m_rndSeed = mRndSeed
        Return CSng(mRndSeed) / 16777216.0!
    End Function

    Private Shared Function ShiftLeft(ByVal value As Integer, ByVal shift As Integer) As Integer
        Dim power2 As Long = CLng(value)
        power2 = power2 * CLng(VBMathCLE.Power2(shift))
        power2 = power2 And 4294967295L
        If ((power2 And 2147483648L) <> 0L) Then
            power2 = power2 Or -4294967296L
        End If
        Return CInt(power2)
    End Function

    Private Shared Function ShiftRight(ByVal value As Integer, ByVal shift As Integer) As Integer
        Dim power2 As Long = CLng((value And 2147483647))
        If ((value And -2147483648) <> 0) Then
            power2 = power2 Or 2147483648L
        End If
        power2 = power2 / CLng(VBMathCLE.Power2(shift))
        Return CInt(power2)
    End Function
End Class