render_fibonaccipattern.py

#!/usr/bin/env python 
'''
Copyright (C) 2015-2015 Carlos Mostek carlosmostek@gmail.com

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
'''
# standard library
import math
from math import pi

# local library
import inkex
import simplestyle

inkex.localize()

# This is basically the draw method from the help guides for inkscape
def draw_SVG_ellipse(rx, ry, cx, cy, parent, start_end=(0,2*pi),transform='' ):

    style = {   'stroke'        : '#000000',
                'stroke-width'  : '1',
                'fill'          : 'none'            }
    ell_attribs = {'style':simplestyle.formatStyle(style),
        inkex.addNS('cx','sodipodi')        :str(cx),
        inkex.addNS('cy','sodipodi')        :str(cy),
        inkex.addNS('rx','sodipodi')        :str(rx),
        inkex.addNS('ry','sodipodi')        :str(ry),
        inkex.addNS('start','sodipodi')     :str(start_end[0]),
        inkex.addNS('end','sodipodi')       :str(start_end[1]),
        inkex.addNS('open','sodipodi')      :'true',    #all ellipse sectors we will draw are open
        inkex.addNS('type','sodipodi')      :'arc',
        'transform'                         :transform
            }
    ell = inkex.etree.SubElement(parent, inkex.addNS('path','svg'), ell_attribs )

# This is the workhorse, it draws the circle based on which node number
def drawKthCircle(k,firstRadius,lastRadius,numNodes,spreadFactor,parent):
	# Use golden circle phi
	phi = (math.sqrt(5) - 1)/2
	
	# Calculate the node radius
	growth = lastRadius - firstRadius
	nodeRadius = firstRadius + growth*float(k - 1)/float(numNodes)
	
	# Calculate X and Y from theta = 2 pi phi k and radius = sqrt(k)
	r = spreadFactor * math.sqrt(k)
	theta = 2*pi*phi*k

	# use simple trig to get cx and cy
	x = r * math.cos(theta)
	y = r * math.sin(theta)

	# Add the px to the size
	nodeRadiusTxt = "%spx"%nodeRadius
	
	# Draw the node
	draw_SVG_ellipse(nodeRadiusTxt,nodeRadiusTxt,x,y,parent)


class FibonacciSpiral(inkex.Effect):
	def __init__(self):
		inkex.Effect.__init__(self)
		self.OptionParser.add_option("-f", "--FirstRadius",
						action="store", type="int", 
						dest="firstRadius", default="5",
						help="The radius of the first layer of circles in pixels.")
		self.OptionParser.add_option("-l", "--LastRadius",
						action="store", type="int", 
						dest="lastRadius", default="10",
						help="The radius of the last layer of circles in pixels.")
		self.OptionParser.add_option("-n", "--NumberOfNodes",
						action="store", type="int", 
						dest="numNodes", default="5",
						help="The number of layers in the fibonacci spiral")
		self.OptionParser.add_option("-s", "--SpreadFactor",
						action="store", type="int", 
						dest="spreadFactor", default="10",
						help="This will create a larger spread between the nodes from the center.")

	def effect(self):
		# Foreach Node
		for k in range(1,self.options.numNodes):
			# Draw the circle
			drawKthCircle(k,
				self.options.firstRadius,
				self.options.lastRadius,
				self.options.numNodes,
				self.options.spreadFactor,
				self.current_layer)
			
if __name__ == '__main__':
    e = FibonacciSpiral()
    e.affect()