secondo voi per eliminare le squadrettature nelle linee oblique dei grafici nell'immagine



come si potrebbe fare?

il codice che uso per creare il grafico è questo

codice:
Sub DrawNetCoin(curSpeed As Single, picGraph As PictureBox)
Dim topSpeed As Single
Static oldSpeed(1 To 20) As Single
Static PointY(1 To 20) As Single
Dim PointX(1 To 20) As Single
Dim pointTemp(1 To 19) As Single
Dim i As Integer

    picGraph.ScaleMode = vbPixels
    picGraph.Cls
    
    For i = LBound(PointY) + 1 To UBound(PointY)
        pointTemp(i - 1) = PointY(i)
        PointY(i - 1) = pointTemp(i - 1)
        pointTemp(i - 1) = oldSpeed(i)
        oldSpeed(i - 1) = pointTemp(i - 1)
        If topSpeed < oldSpeed(i - 1) Then
            topSpeed = oldSpeed(i - 1)
        End If
    Next i
    
    If topSpeed < curSpeed Then topSpeed = curSpeed
    If topSpeed = 0 Then topSpeed = 1
    
    oldSpeed(UBound(oldSpeed)) = curSpeed
    PointY(UBound(PointY)) = (picGraph.ScaleHeight - (picGraph.ScaleHeight - 4) * curSpeed / topSpeed) - 2
    
    For i = UBound(PointY) To LBound(PointY) Step -1
        PointX(i) = picGraph.ScaleWidth / 19 * (i - 1)
        If i < UBound(PointY) Then
            picGraph.Line (PointX(i + 1), PointY(i + 1))- _
                          (PointX(i), PointY(i)), _
                          vbGreen
        End If
    Next i
            
End Sub