Radial Blur Zoom

Hi, i programmed a function to radial blur (zoom) pictures in Vb6 (with a force from zero to 100% and a point of blur), it works well (better quality than photoshop) but it's a little slower.

my function is easy and i would like to know how to accelerate the process to get the same quality faster
i need a vb6 or C++ function.

here's my function :

'cx, cy = Center X and Center Y
'k = Force (0 to 100%)
'Quality = Quality : 1 = Best | 2 = Good | 4 = Medium | 16 = Bad
Public Sub RadialBlurZoom(ByVal cx As Long, ByVal cy As Long, ByVal k As Single, ByVal Quality as Long)

    Dim j               As Long
    Dim i               As Long
    Dim l               As Long
    Dim nX              As Long
    Dim nY              As Long
    Dim dX              As Long
    Dim dY              As Long
    Dim Alpha           As Single
    Dim Hypotenuse      As Long
    Dim vMax            As Long
    Dim TotalR          As Long
    Dim TotalG          As Long
    Dim TotalB          As Long
    Dim Dividor         As Long
    Dim NewBits()       As Byte

    'in the form, PicBits is a private array which contains bitmapbits (from GetBitmapBits)

    ReDim NewBits(LBound(PicBits) To UBound(PicBits))
   
    If K = 0 Then K = 1
    If K > 100 Then K = 100
    K = K / 400
   
    'shpSelection is a Shape which contains the rectangle area to be processed
    For j = shpSelection.Top + 1 To shpSelection.Top + shpSelection.Height
       
        dY = Abs(j - cY)
       
        For i = shpSelection.Left + 1 To shpSelection.Left + shpSelection.Width
           
            dX = Abs(i - cX)
            If dX = 0 Then dX = 1
           
            Alpha = Atn(dY / dX)
            Hypotenuse = Sqr(dX * dX + dY * dY)
           
            TotalR = 0
            TotalG = 0
            TotalB = 0
            Dividor = 0
           
            vMax = Hypotenuse * K
            
            For l = -vMax To vMax Step Quality
            If i < cX Then
                  nX = i + (Cos(Alpha) * l)
            ElseIf i >= cX Then
                  nX = i - (Cos(Alpha) * l)
            Else
                  nX = 0
            End If
            If j < cY Then
                  nY = j + (Sin(Alpha) * l)
            ElseIf j >= cY Then
                  nY = j - (Sin(Alpha) * l)
            Else
                  nY = 0
            End If
            
            'in this form, Matrix is a private array which contains indexes of
            'bits in PicBits to retrieve a point with X and Y values.
                If nX > 0 And nY > 0 And nX <= UBound(Matrix) And nY <= UBound(Matrix, 2) Then
                    TotalR = TotalR + PicBits(Matrix(nX, nY))
                    TotalG = TotalG + PicBits(Matrix(nX, nY) + 1)
                    TotalB = TotalB + PicBits(Matrix(nX, nY) + 2)
                    Dividor = Dividor + 1
                End If
            Next l
            If Dividor > 0 Then
                NewBits(Matrix(i, j)) = TotalR \ Dividor
                NewBits(Matrix(i, j) + 1) = TotalG \ Dividor
                NewBits(Matrix(i, j) + 2) = TotalB \ Dividor
            Else
                NewBits(Matrix(i, j)) = PicBits(Matrix(i, j))
                NewBits(Matrix(i, j) + 1) = PicBits(Matrix(i, j) + 1)
                NewBits(Matrix(i, j) + 2) = PicBits(Matrix(i, j) + 2)
            End If
        Next i
    Next j

    'P is the name of a pictureBox where the picture was loaded
    'sets the new bits to P.Image
    SetBitmapBits P.Image, UBound(NewBits), NewBits(1)
   
End Function