Option Explicit
'Script written by Russell Loveridge
'Script copyrighted by RAL:lapa.epfl.ch

'This script shows the difference between the AddCurve and AddInterpCurve commands.

Call Makepolyline()
Sub Makepolyline()
	Dim arrPolyline(), arrPt(2), arrPtF(2)
	Dim intPolyPoints, i, intDegree, intPeriodic
	Dim strPoly1
	
	intPolyPoints = Rhino.GetInteger("How many points do you want on your polyline?", 6, 2 ) ' minimum number of points 2, no maximum.
	intDegree = Rhino.GetInteger("Spline = 0, Straight segments = 1", 1, 0, 1 ) ' minimum number of points 2, no maximum.
	intPeriodic = Rhino.GetInteger("Periodic (smooth closed)= 1, Not Periodic = 0", 1, 0, 1 )

	For i=0 To (intPolyPoints) 'This is a loop that makes all of the calculations for the points o the polyline.
		ReDim Preserve arrPolyline(i)  ' This command allows you to change the number of points in an array dynamically
		If i<intPolyPoints Then
		arrPt(0) = Rhino.GetReal("X coordinate: " & i) ' this asks for input of the current X.
		arrPt(1) = Rhino.GetReal("Y coordinate: " & i) ' this asks for input of the current X.
		arrPt(2) = Rhino.GetReal("Z coordinate: " & i) ' this asks for input of the current X.
			arrPolyline(i) = arrPt ' this line combines all of the clicked points into an array.
			If i=0 Then 
				arrPtF(0) = arrPt(0)
				arrPtF(1) = arrPt(1)
				arrPtF(2) = arrPt(2)
			End If
		Else 
			arrPolyline(i) = arrPtF
		End If
	Next


	If IsArray(arrPolyline) Then
		If intPeriodic = 1 Then
			strPoly1 = Rhino.AddInterpCurve (arrPolyline,,4)  'Note the value of a PERIODIC KNOT.
		Else
		If intDegree = 1 Then
			strPoly1 = Rhino.AddInterpCurve (arrPolyline) ' this line creates a curve based on the array of chosen points.
		Else
			strPoly1 = Rhino.AddInterpCurve (arrPolyline) ' as the default for AddCurve is a degree 3 spline, anything other than degree 1 will be a curve.
				'
			End If
		End If
	End If

End Sub