Option Explicit
'Script written by <insert name>
'Script copyrighted by <insert company name>
'Script version Friday, November 21, 2008 6:02:59 PM

Call Main()
Sub Main()

	Dim strCurv, arrPoints, arrptCent, strCentSurf, strOtherCurve, dblParam
	Dim arrOtherPoints, intRes, vectDir, strRib, arrptStart,dblDeep,intUnit,arrShapes()
	Dim	arrCurves01, arrDom,strLine, arrCurves02, boolClosed, arrInt, arrCross(),arrEmpty()
	Dim i,j, k, m
	
	'layer management
	If Not IsLayer("ribs01") Then : Rhino.AddLayer "ribs01",RGB(0,256,256): End If
	If Not IsLayer("ribs02") Then : Rhino.AddLayer "ribs02",RGB(256,256,256) : End If
	
	
	intUnit=Rhino.UnitSystem
	intRes=1
	If intUnit=9 Then
		intRes=intRes/12	
	End If
	
	arrCurves01=Rhino.GetObjects("select ring curves",4)
	If Not Isarray(arrCurves01) Then: Rhino.Print "no ring curves selected" : Exit Sub : End If
	
	arrCurves02=Rhino.GetObjects("select cross curves",4)
	If Not Isarray(arrCurves01) Then: Rhino.Print "no cross curves selected" : Exit Sub : End If
	
	'get rib depth and convert to correct units
	dblDeep=Rhino.GetReal("enter rib depth in inches",6)
	If IsNull(dblDeep) Then: Rhino.Print "no depth selected" : Exit Sub : End If

	If intUnit=9 Then
		dblDeep=dblDeep/12	
	End If
	
	Rhino.Print"working...."
	
	m=0
	Rhino.CurrentLayer "ribs01"
	
	Rhino.EnableRedraw False
	For Each strCurv In arrCurves01
		
		'--------------------make first set of ribs--------------------------
		arrPoints=Rhino.DivideCurveLength(strCurv,intRes)
	
		arrptCent=FpointCentroid(arrPoints)

		For i=0 To Ubound(arrPoints)

			arrptStart=arrPoints(i)
	
			vectDir=Rhino.VectorCreate(arrptCent,arrptStart)
			vectDir=rhino.VectorUnitize(vectDir)
			vectDir=Rhino.VectorScale(vectDir,dblDeep)
			vectDir=Rhino.VectorAdd(arrptStart,vectDir)
	
			strLine=Rhino.addLine(arrptStart,vectDir)
	
			ReDim Preserve arrShapes(i)
			arrShapes(i)=strLine
		
		Next
	
		'wrap loft array if curve is closed
		boolClosed=Rhino.IsCurveClosed (strCurv)
		
		If boolClosed=True Then
			ReDim Preserve arrShapes(Ubound(arrShapes)+1)
			arrShapes(Ubound(arrShapes))=arrShapes(0)
		End If
		
		strRib=Rhino.AddLoftSrf(arrShapes)
	
		'clean up
		Rhino.DeleteObjects(arrShapes)
		
		'----------------make arrCross curve array------------------------
		
		'set size of cross array
		ReDim Preserve arrCross(Ubound(arrCurves02))
		
		For k=0 To Ubound(arrCross)
			'place empty array in each position of cross array
			If m=0 Then 
				ReDim arrEmpty(Ubound(arrCurves01))
				arrCross(k)=arrEmpty
			End If
			
			'construct profile line
			arrInt=Rhino.CurveCurveIntersection(strCurv,arrCurves02(k))
			arrptStart=arrInt(0,1)
	
			vectDir=Rhino.VectorCreate(arrptCent,arrptStart)
			vectDir=rhino.VectorUnitize(vectDir)
			vectDir=Rhino.VectorScale(vectDir,dblDeep)
			vectDir=Rhino.VectorAdd(arrptStart,vectDir)
	
			strLine=Rhino.addLine(arrptStart,vectDir)
	
			'add profile line to cross aray at position			
			arrCross(k)(m)=strLine
		Next
	
		'increase count
		m=m+1
		
	Next
	
	'------------------------------loft second set of ribs using arrCross----------------------
	Rhino.CurrentLayer "ribs02"
	For Each arrShapes In arrCross
		strRib=Rhino.AddLoftSrf(arrShapes)
		'clean up
		'Rhino.DeleteObjects(arrShapes)
	Next
	
	Rhino.EnableRedraw True
End Sub

Function FpointCentroid(arrPoints)
	'this function returns an array of point coordinates at the centroid of an array of points
	Dim arrCent(2),i, j
	
	arrCent(0)=0
	arrCent(1)=0
	arrCent(2)=0
	
	For i=0 To Ubound(arrPoints)
		arrCent(0)=arrCent(0) + arrPoints(i)(0)
		arrCent(1)=arrCent(1) + arrPoints(i)(1)
		arrCent(2)=arrCent(2) + arrPoints(i)(2)
	Next
	
	j=i+1
	
	FpointCentroid=Array((arrCent(0)/i),(arrCent(1)/i),(arrCent(2)/i))
	
End Function

Function FSurfaceParameter(strObject,dblDist,intUV, intLine)
	'returns a double: the parameter along a curve or surface
	'that equals a given distance, in a given direction U=0, V=1
	
	'Rhino.Print intLine
	
	Dim arrDom, dblParam
	
	arrDom=rhino.SurfaceDomain(strObject,intUV)
	dblParam= (arrDom(0) + ((arrDom(1)-arrDom(0))*dblParam))
	
	FcurveParameter = Rhino.EvaluateCurve(strObject,dblParam)
	
End Function