connectSVG/connectPaths.py

# -*- coding:utf-8 -*-

##
# This file is part of connectSVG.
#
# connectSVG 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.
#
# connectSVG 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 connectSVG. If not, see <https://www.gnu.org/licenses/>.
##

import logging
log = logging.getLogger("connectsvg")

TOLERANCE = 0.0000000000005

def connect(path, other) :
	if abs(path.end - other.start) <= TOLERANCE :
		log.debug("Appending path %s--%s", other.start, other.end)
		other.start = path.end
		path.extend(other)
		return path, True

	elif abs(path.end - other.end) <= TOLERANCE:
		log.debug("Appending path %s--%s", other.start, other.end)
		other.end = path.end;
		path.extend(other.reversed())
		return path, True

	elif abs(path.start - other.start) <= TOLERANCE :
		log.debug("Appending path %s--%s", other.start, other.end)
		other.start = path.start
		path = path.reversed()
		path.extend(other)
		return path, True

	elif abs(path.start - other.end) <= TOLERANCE :
		log.debug("Appending path %s--%s", other.start, other.end)
		other.end = path.start
		path = path.reversed()
		path.extend(other.reversed())
		return path, True

	return path, False

def connectPaths(paths, attributes) :
	log.info("Starting with %d paths", len(paths))
	processedPaths = []
	processedAttributes = []

	while len(paths) > 0 :
		path = paths.pop()
		attr = attributes.pop()
		log.debug("Processing path %s--%s", path.start, path.end)

		i = 0
		while i < len(paths) :
			if attr['style'] == attributes[i]['style'] :
				path, used = connect(path, paths[i])
				
				if used :
					paths.pop(i)
					attributes.pop(i)
					i = -1

			i += 1

		processedPaths.append(path)
		processedAttributes.append({
			'style': attr['style'],
			'id': 'path'+str(len(processedPaths))
			})

	log.info("Ending with %d paths", len(processedPaths))
	return processedPaths, processedAttributes