OverflowException only in VB.net, not in C#

Question

for self educational purposes I tried to find a way to create a height map all by myself. I googled a little bit and found a function that creates pseudo-random numbers.

Answer 1

Like D Stanley pointed out, the reason for the OverFlowException in VB.net is that VB.net is automatically doing an overflow check on integer operations while C# is not.

In case someone else is interested in getting it to work in VB.net you can do the following:

Add this structure to your project

Public Structure LongToIntegerNoOverflow
    
    Public LongValue As Long
    
    Public IntValue As Integer
End Structure

and change the Noise function to

Private Function Noise(ByVal x As Integer) As Single
    Dim x1 As Long
    Dim x2 As LongToIntegerNoOverflow
    Dim x3 As LongToIntegerNoOverflow
    Dim x4 As Long

    x1 = (x << 13) Xor x

    x2.LongValue = x1 * x1 * 15731 + 789221
    x3.LongValue = x1 * x2.IntValue + 1376312589

    x4 = x3.IntValue And &H7FFFFFFF

    Return (1.0R - x4 / 1073741824.0R)
End Function

After these changes I got the same results in VB.net and in C#.