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#!/usr/bin/env python3
# Command line program to create svg apollonian circles
# Copyright (c) 2014 Ludger Sandig
# This file is part of apollon.
# Apollon 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 3 of the License, or
# (at your option) any later version.
# Apollon is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# GNU General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with Apollon. If not, see <>.
import math
from apollon import ApollonianGasket
def ag_to_svg(circles, colors, tresh=0.00005):
Convert a list of circles to svg, optionally color them.
@param circles: A list of L{Circle}s
@param colors: A L{ColorMap} object
@param tresh: Only circles with a radius greater than the product of tresh and maximal radius are saved
svg = []
tresh = .000005
print ('>>', tresh)
# Find the biggest circle, which hopefully is the enclosing one
# and has a negative radius because of this. Note that this does
# not have to be the case if we picked an unlucky set of radii at
# the start. If that was the case, we're screwed now.
big = min(circles, key=lambda c: c.r.real)
# Move biggest circle to front so it gets drawn first
circles.insert(0, big)
if big.r.real < 0:
# Bounding box from biggest circle, lower left corner and two
# times the radius as width
corner = big.m - ( abs(big.r) + abs(big.r) * 1j )
vbwidth = abs(big.r)*2
width = 500 # Hardcoded!
# Line width independent of circle size
lw = (vbwidth/width)
svg.append('<svg xmlns="" width="%f" height="%f" viewBox="%f %f %f %f">\n' % (width, width, corner.real, corner.imag, vbwidth, vbwidth))
# Keep stroke width relative
svg.append('<g stroke-width="%f">\n' % lw)
# Iterate through circle list, circles with radius<radmin
# will not be saved because they are too small for printing.
radmin = tresh * abs(big.r)
for c in circles:
if abs(c.r) > radmin:
fill = colors.color_for(abs(c.r))
svg.append(( '<circle cx="%f" cy="%f" r="%f" fill="%s" stroke="black"/>\n' % (c.m.real, c.m.imag, abs(c.r), fill)))
return ''.join(svg)
def impossible_combination(c1, c2, c3):
# If any curvatures x, y, z satisfy the equation
# x = 2*sqrt(y*z) + y + z
# then no fourth enclosing circle can be genereated, because it
# would be a line.
# We need to see for c1, c2, c3 if they could be "x".
impossible = False
sets = [(c1,c2,c3), (c2,c3,c1), (c3,c1,c2)]
for (x, y, z) in sets:
if x == 2*math.sqrt(y*z) + y + z:
impossible = True
return impossible
def main(c1=3.,c2=2.,c3=2.,depth=5):
# Sanity checks
for c in [c1, c2,c3]:
if c == 0:
print("Error: curvature or radius can't be 0")
if impossible_combination(c1, c2, c3):
print("Error: no apollonian gasket possible for these curvatures")
ag = ApollonianGasket(c1, c2, c3)
# Get smallest and biggest radius
smallest = abs(min(ag.genCircles, key=lambda c: abs(c.r.real)).r.real)
biggest = abs(max(ag.genCircles, key=lambda c: abs(c.r.real)).r.real)
return ag.genCircles