###--------------------------------------------------------------------------------
#        Name : TubeAlongPath
#
# Description : Creates circular faced 'followme' tube extrusions along a path - 
#		Use it to make pipes, ducts, rails etc,
#		starting from a selection of joined edges
#
#      Author : TIG (c) 7/2005
#		based on an original wall making idea by Didier Bur
#		and using some vertex array ideas from Rick Wilson
#
#       Usage : Select joined lines, arcs, circles, curves, etc.
#		Select "Tube Along Path" from the Plugins menu. 
#		In dialog choose Circle or Polygon, enter radius, number of segements and OK.
#
#		The extrusion is made*.
#		*The extrusion is grouped so it does not interact with adjacent surfaces -
#		afterwards just explode it if appropriate. 
#
#		The selected path remains highlighted after the extrusion is made -
#		you can use this to move or delete unwanted central paths etc
#		The path stays selected even after an undo.
#		Any curves in the path become separate segments on edge etc.
#
#		A Circle has smoothed edges to faces but a Polygon shows all edges as lines.
#		The default for segments is 12, the minimum is 3.
#
#		The alignment is always 'Centroid' [along circle's centre line],
#
#		The radius is always measured square to the vector of the first path's line.
#		A radius that is less than the length of pieces of path edge might
#		give correct but unexpected extrusions, which might need manually tidying...
#		Closed loop paths are fully extruded, but might need manually tidying.
#		Multiple arc and other complex 3D paths might give unexpected results.
#
#		Radius cannot be zero and will return an error.
#		A branching path returns just the lone starting face - i.e gives an error.
#		Selected edges that are not joined (i.e. common end-starts) will not be 
#		extruded - only the first edge or joined group of edges will extrude.
#
#
#
#        Type : tool
#
#     Version : 1.0  30/7/5	first release.
#		1.1  1/8/5	face forced to avoid followme v5 bug simplified loop.
#		1.2  7/8/5	extrusion grouped to avoid rare coincident-face bug-splats,
#				circle or polygon extrusion added,
#				number of segments option added.
#
###--------------------------------------------------------------------------------

require 'sketchup.rb'

###

def tube_along_path

model = Sketchup.active_model
model.start_operation "tube_along_path"
entities = model.active_entities
ss = model.selection

if ss.empty? 
  UI.messagebox("No Selection.")
  return nil
end

### dialog ###

types = ["Circle","Polygon"]
enums = [types.join("|")]
if not $radiusIn
   values = ["Circle", 20.mm, 12]
else
   values = [$typeIn, $radiusIn, $segmentsIn] ### 7/8/5
end

prompts = ["Circle or Polygon ? : ", "Radius: ", "Number of Segments: "] ### 7/8/5

results = inputbox prompts, values, enums, "Tube Parameters (mm)" ### 7/8/5

return nil if not results ### i.e. the user cancelled the operation

$typeIn = results[0] ### 7/8/5
$radiusIn = results[1] ### 7/8/5
$segmentsIn = results[2] ### 7/8/5

radius = $radiusIn
if $radiusIn == 0.mm ### can't be 0 ###
   $radiusIn = 20.mm
   UI.messagebox("Zero Radius NOT allowed ! ")
   return nil
end
segs = $segmentsIn ### 7/8/5
if $segmentsIn < 3 ### can't be 0 ###
   $segmentsIn = 12
   UI.messagebox("Fewer than 3 Faces NOT allowed ! ")
   return nil
end ### 7/8/5


### this next bit is thanks to Rick Wilson's weld.rb

	model=Sketchup.active_model
	ents=model.active_entities
	sel=model.selection
	sl=sel.length
	verts=[]
	edges=[]
	newVerts=[]
	startEdge=startVert=nil

#CHECK FOR A VALID SELECTION

###	return UI.messagebox("Please select at least 2 edges") if sl < 2 ### WE can do 1 edge...
#	if sel.first.curve
#		return UI.messagebox("Please select at least 2 non-joined edges") if sel.length == sel.first.curve.count_edges
#	end

#DELETE NON-EDGES, GET THE VERTICES

	sel.each {|item| edges.push(item) if item.typename=="Edge"}
	edges.each {|edge| verts.push(edge.vertices)}
	verts.flatten!

#FIND AN END VERTEX

	vertsShort=[]
	vertsLong=[]
	verts.each do |v|
		if vertsLong.include?(v)
			vertsShort.push(v)
		else
			vertsLong.push(v)
		end
	end
	if (startVert=(vertsLong-vertsShort).first)==nil
		startVert=vertsLong.first
		closed=true
		startEdge = startVert.edges.first
	else
		closed=false
		startEdge = (edges & startVert.edges).first
	end
	sel.clear


#SORT VERTICES, LIMITING TO THOSE IN THE SELECTION SET

	if startVert==startEdge.start
		newVerts=[startVert]
		counter=0
		while newVerts.length < verts.length
			edges.each do |edge|
				if edge.end==newVerts.last
					newVerts.push(edge.start)
				elsif edge.start==newVerts.last
					newVerts.push(edge.end)
				end
			end
			counter+=1
			if counter > verts.length
				return nil if UI.messagebox("There seems to be a problem. Try again?", MB_YESNO)!=6
				newVerts.reverse!
				reversed=true
			end
		end
	else
		newVerts=[startVert]
		counter=0
		while newVerts.length < verts.length
			edges.each do |edge|
				if edge.end==newVerts.last
					newVerts.push(edge.start)
				elsif edge.start==newVerts.last
					newVerts.push(edge.end)
				end
			end
			counter+=1
			if counter > verts.length
				return nil if UI.messagebox("There seems to be a problem. Try again?", MB_YESNO)!=6
				newVerts.reverse!
				reversed=true
			end
		end
	end
	###newVerts.uniq! ### allow IF closed
	newVerts.reverse! if reversed


#CONVERT VERTICES TO POINT3Ds

	newVerts.collect!{|x| x.position}
	###newVerts.push(newVerts[0])

### now have an array of vertices in order with NO forced closed loop ...


### - do stuff - ###

pt1 = newVerts[0]
pt2 = newVerts[1]
vec = pt1.vector_to pt2

group=entities.add_group ### 7/8/5
entities=group.entities ### 7/8/5

if $typeIn == "Circle" ### 7/8/5
   theRim = entities.add_circle pt1, vec, radius, segs
else
   theRim = entities.add_ngon pt1, vec, radius, segs
end ### 7/8/5

theFace = entities.add_face theRim ### 7/8/5

if pt1.x == pt2.x and pt1.y == pt2.y and pt1.z < pt2.z ### flip so not inside out ! ### 7/8/5
  theFace.reverse!
end

@@theEdges= []
0.upto(newVerts.length-2) do |i|
  @@theEdges[i] = ents.add_line(newVerts[i],newVerts[i+1])  ### make vertices into edges
end

### follow me along selected edges

theExtrusion=theFace.reverse!.followme @@theEdges ###

###

if not theExtrusion
  UI.messagebox("The selected Path branches ! \nCannot extrude the Tube ! \nRe-select a single continuous path... ")
  entities.erase_entities theRim
end

###

model.commit_operation

### restore selection set of edges and display them

theEdgeX = []
0.upto(newVerts.length-2) do |i|
  theEdgeX[i] = ents.add_line(newVerts[i],newVerts[i+1])  ### make vertices into edges
end
model.selection.clear
model.selection.add theEdgeX

end ### end def

### menu bits

if( not file_loaded?("TubeAlongPath.rb") )###

   UI.menu("Plugins").add_separator
   UI.menu("Plugins").add_item("Tube Along Path") { tube_along_path }

end

###
file_loaded("TubeAlongPath.rb")###
###-----------------------------------------------------------------------------