# Copyright 2004, Rick Wilson 

# Permission to use, copy, modify, and distribute this software for 
# any purpose and without fee is hereby granted, provided that the above
# copyright notice appear in all copies.

# THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

# Name :          helix.rb 1.0
# Description :   Create a helix based on selected circle.
# Author :        Rick Wilson
# Usage :         1. Install into the plugins directory or into the 
#                    Plugins/examples directory and manually load from the ruby console "load 'examples/helix.rb'" 
#                 2. Select a face - any face!
#                 2. Run "Helix" from the Plugins menu.
# Date :          29.Jul.2004
# Type :          Tool
# History:
#			1.1 (30.Jul.2004) - added grouping option, fixed bug to draw final segment
#			1.0 (29.Jul.2004) - first version
# 
require 'sketchup.rb'

def helix
	model=Sketchup.active_model
	ss=model.selection.first
	return nil if ss.class!=Sketchup::Face	#Check selection, accept only a face
	@helix_grouping = "Yes" if not @helix_grouping
	@helix_height = 12.inch if not @helix_height
	@helix_turns = 10 if not @helix_turns
	helix_grouping_options = ["Yes","No"]
	prompts = ["Group", "Height", "Turns"]			#Prompt the user for the Helix settings
	values = [@helix_grouping, @helix_height, @helix_turns]
	enums = [helix_grouping_options.join("|")]
	results = inputbox prompts, values, enums, "Helix Settings"
	return nil if not results
	@helix_grouping = results[0]
	@helix_height = results[1]
	@helix_turns = results[2].to_i

	model.start_operation "Helix"

	eV = ss.vertices
	eL = eV.length
	tH = @helix_height / @helix_turns
	eH = tH / eL
	pts = []

	0.upto(@helix_turns-1) do |turns|
		0.upto(eL-1) do |verts|
			ht = (eH * verts) + (tH * turns)
			pos = eV[verts].position
			pts[pts.length] = [pos[0],pos[1],ht]
		end
	end

# ADD THE FINAL POINT
	pts[pts.length] = [eV[0].position[0],eV[0].position[1],@helix_height]

	if @helix_grouping == "Yes"			# DO THIS FOR GROUPING
		entities = model.active_entities
		group = entities.add_group
		entities = group.entities
		entities.add_curve(pts)
	else
		model.entities.add_curve(pts)		# DO THIS FOR NON-GROUPING
	end

	model.commit_operation

end

if( not file_loaded?("helix.rb") )

    # This will add a separator to the menu, but only once
    add_separator_to_menu("Plugins")
    
    # To add an item to a menu, you identify the menu, and then
    # provide a title to display and a block to execute.  In this case,
    # the block just calls the create_box function
    UI.menu("Plugins").add_item("Helix") { helix }

end

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