Option Explicit
'Script written by <David Mans>
'Script copyrighted by <Neoarchaic Design>
'Script version Sunday, June 08, 2008 1:19:49 AM

Call Main()
Sub Main()
	Dim crv: crv = Rhino.GetObjects("Select Curves",4)
	If isNull(crv) Then Exit Sub
	Dim arrItems, arrValues, arrResults
	arrItems = array("scale_width","twist_angle","tip_location","tip_angle","start_width","end_width","tip_length","type_(1)or(2)","curved arrows")
	arrValues = array(1,0,.95,45,.2,.5,1,1,True)
	arrResults = Rhino.PropertyListBox (arrItems, arrValues ,,"Arrow Parameters")
	Dim i
	If arrResults(0) < .1 Then
		arrResults(0) = .1
	End If
	If arrResults(2) > .99 Then
		arrResults(2) = .99
	End If
	If arrResults(4) < .01 Then
		arrResults(4) = .01
	End If
	If arrResults(5) < .01 Then
		arrResults(5) = .01
	End If
	If arrResults(7) < 1 Then
		arrResults(7) = 0
	ElseIf arrResults(7) > 1 Then
		arrResults(7) = 1
	End If

	Call Rhino.EnableRedraw(False)
	For i = 0 To uBound(crv) Step 1
		Call reparameterize(crv(i))
		Call curveArrows(crv(i),CDbl(arrResults(0)),CDbl(arrResults(1)),CDbl(arrResults(2)),CDbl(arrResults(3)),CDbl(arrResults(4)),CDbl(arrResults(5)),CDbl(arrResults(6)),CInt(arrResults(7)),CBool(arrResults(8)))
	Next
	Call Rhino.EnableRedraw(True)
End Sub
Function curveArrows(curve, dblScale,twistAngle,tip,headAngle,edgeParaA,edgeParaB,width,dblType,CrvBln)
	curveArrows = Null
	Dim i,j, crv, tipEdge, crvCpy, crvDom, dis,scale, count, crvFrame, strProfSet(1),tempCrv, crvX, srf(3)
	Dim endPt, midPtA, midPtB
	count = 2+CInt(twistAngle/90)
	ReDim frame(count), pt(count*2+1), swProfSetA(count-1), swProfSetB(count-1),crvA(count-1),crvB(count-1),parameter(count)
	ReDim srfEdge(2), edgeA(count-1), edgeB(count-1)

	If width <> 0 Then
		tip = (Rhino.CurveLength(curve)-width)/Rhino.CurveLength (curve)
	End If
	crvDom = Rhino.CurveDomain(curve)(1)
	parameter(0) = 0
	For i = 0 To count-1 Step 1
		parameter(i) = (crvDom*tip/(count-1))*i
	Next
	parameter(count) = crvDom-(crvDom-crvDom*tip)*.5

	dis = Rhino.Distance(Rhino.EvaluateCurve(curve,crvDom*tip),Rhino.EvaluateCurve(curve,crvDom))*dblScale
	scale = dis*0.5

	j=0
	For i = 0 To count Step 1
		crvFrame = Rhino.CurveFrame(curve,parameter(i))
		If i = count Then
			frame(i) = Rhino.RotatePlane(crvFrame,(twistAngle/(count-1))*(i-1),crvFrame(1))
		Else
			frame(i) = Rhino.RotatePlane(crvFrame,(twistAngle/(count-1))*i,crvFrame(1))
		End If
		pt(j) = Rhino.PointAdd(frame(i)(0),Rhino.VectorRotate(Rhino.VectorScale(frame(i)(2),scale),90-headAngle,frame(i)(3)))
		j=j+1
		pt(j) = Rhino.PointAdd(frame(i)(0),Rhino.VectorRotate(Rhino.VectorScale(frame(i)(2),scale),90+headAngle,frame(i)(3)))
		j=j+1
		If i<count Then
			If CrvBln = True Then
				tempCrv = Rhino.AddInterpCurve(array(pt(j-2),frame(i)(0),pt(j-1)),3)
			Else
				tempCrv = Rhino.AddInterpCurve(array(pt(j-2),frame(i)(0),pt(j-1)),1)
			End If
			crvX = Rhino.SplitCurve(tempCrv,Rhino.CurveDomain(tempCrv)(1)*.5,True)
			reparameterize(crvX(0))
			crvA(i) = crvX(0)
			reparameterize(crvX(1))
			crvB(i) = crvX(1)
		End If
	Next
	crvCpy = Rhino.CopyObject(curve)
	crv = Rhino.SplitCurve (crvCpy , crvDom*tip,True)
	endPt = Rhino.EvaluateCurve(curve,crvDom)
	midPtA= Rhino.PointAdd(frame(count)(0),Rhino.VectorRotate(Rhino.VectorScale(frame(count)(2),scale*.5),90-headAngle,frame(count)(3)))
	midPtB= Rhino.PointAdd(frame(count)(0),Rhino.VectorRotate(Rhino.VectorScale(frame(count)(2),scale*.5),90+headAngle,frame(count)(3)))

	srfEdge(0) = Rhino.AddInterpCurve(array(endPt,midPtA,pt(j-4)))
	srfEdge(1) = Rhino.AddInterpCurve(array(endPt,midPtB,pt(j-3)))
	srfEdge(2) = Rhino.AddInterpCurve(array(endPt,frame(count)(0),frame(count-1)(0)))
	If dblType = 1 Then
		srf(0) = Rhino.AddEdgeSrf (array(crvA(count-1),crv(1),srfEdge(0)))
	End If
	srf(1) = Rhino.AddEdgeSrf (array(crvB(count-1),crv(1),srfEdge(1)))
	If edgeParaA>edgeParaB Then
		edgeParaB = -(edgeParaA-edgeParaB)/(count-1)
	ElseIf edgeParaB>edgeParaA Then
		edgeParaB = (edgeParaB-edgeParaA)/(count-1)
	Else
		edgeParaB = 0
	End If
	For i = 0 To  count-1 Step 1
		edgeA(i) = Rhino.SplitCurve(crvA(i),Rhino.CurveDomain(crvA(i))(1)*(1-(edgeParaA+edgeParaB*i)),True)
		edgeB(i) = Rhino.SplitCurve(crvB(i),Rhino.CurveDomain(crvB(i))(1)*(edgeParaA+edgeParaB*i),True)
	Next
	For i = 0 To count-1 Step 1
		swProfSetA(i) = ("_SelID " & edgeA(i)(1) & " ")
		swProfSetB(i) = ("_SelID " & edgeB(i)(0) & " ")

	Next
	strProfSet(0) = Join(swProfSetA)
	strProfSet(1) = Join(swProfSetB)
	If dblType = 1 Then
		Call Rhino.Command( "-_Sweep1 " & "_SelID " & crv(0) & " " & strProfSet(0) & " _Enter _Simplify=None Enter")
		srf(2)= Rhino.FirstObject()
	End If
	Call Rhino.Command( "-_Sweep1 " & "_SelID " & crv(0) & " " & strProfSet(1) & " _Enter  _Simplify=None Enter")
	srf(3)= Rhino.FirstObject()

	If dblType = 1 Then
		Call Rhino.JoinSurfaces(srf,True)
	Else
		Call Rhino.JoinSurfaces(array(srf(1),srf(3)),True)
	End If
	Call Rhino.DeleteObjects(crv)
	Call Rhino.DeleteObjects(srfEdge)
	For i = 0 To count-1 Step 1
		Call Rhino.DeleteObjects(edgeA(i))
		Call Rhino.DeleteObjects(edgeB(i))
	Next
End Function
Function reparameterize(strCurveID)
	If Rhino.IsCurve(strCurveID) = True Then
		Call rhino.SelectObject(strCurveID)
		Call rhino.Command("reparameterize 0 1")
		Call rhino.UnselectAllObjects()
	End If
	If Rhino.IsSurface(strCurveID) = True Then
		Call rhino.SelectObject(strCurveID)
		Call rhino.Command("reparameterize 0 1 0 1")
		Call rhino.UnselectAllObjects()
	End If
End Function