198 lines
8.1 KiB
Python
198 lines
8.1 KiB
Python
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#! /usr/bin/python3
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'''
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Copyright (C) 2020 Scott Pakin, scott-ink@pakin.org
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301, USA.
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'''
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import inkex
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import numpy as np
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import random
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import sys
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from inkex import Group, Line, Polygon, TextElement
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from inkex.styles import Style
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from inkex.transforms import Vector2d
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from scipy.spatial import Delaunay
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class DelaunayTriangulation(inkex.EffectExtension):
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'Overlay selected objects with triangles.'
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def add_arguments(self, pars):
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pars.add_argument('--tab', help='The selected UI tab when OK was pressed')
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pars.add_argument('--joggling', type=inkex.Boolean, default=False, help='Use joggled input instead of merged facets')
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pars.add_argument('--furthest', type=inkex.Boolean, default=False, help='Furthest-site Delaunay triangulation')
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pars.add_argument('--elt_type', default='poly', help='Element type to generate ("poly" or "line")')
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pars.add_argument('--qhull', help='Triangulation options to pass to qhull')
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pars.add_argument('--fill_type', help='How to fill generated polygons')
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pars.add_argument('--fill_color', type=inkex.Color, help='Fill color to use with a fill type of "specified"')
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pars.add_argument('--stroke_type', help='How to stroke generated polygons')
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pars.add_argument('--stroke_color', type=inkex.Color, help='Stroke color to use with a stroke type of "specified"')
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def _path_points(self, elt):
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'Return a list of all points on a path (endpoints, not control points).'
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pts = set()
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first = None
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prev = Vector2d()
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for cmd in elt.path.to_absolute():
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if first is None:
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first = cmd.end_point(first, prev)
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ep = cmd.end_point(first, prev)
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pts.add((ep.x, ep.y))
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prev = ep
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return pts
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def _create_styles(self, n):
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'Return a style to use for the generated objects.'
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# Use either the first or the last element's stroke for line caps,
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# stroke widths, etc.
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fstyle = self.svg.selection.first().style
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lstyle = self.svg.selection[-1].style
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if self.options.stroke_type == 'last_sel':
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style = Style(lstyle)
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else:
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style = Style(fstyle)
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# Apply the specified fill color.
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if self.options.fill_type == 'first_sel':
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fcolor = fstyle.get_color('fill')
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style.set_color(fcolor, 'fill')
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elif self.options.fill_type == 'last_sel':
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fcolor = lstyle.get_color('fill')
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style.set_color(fcolor, 'fill')
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elif self.options.fill_type == 'specified':
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style.set_color(self.options.fill_color, 'fill')
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elif self.options.fill_type == 'random':
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pass # Handled below
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else:
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sys.exit(inkex.utils.errormsg(_('Internal error: Unrecognized fill type "%s".')) % self.options.fill_type)
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# Apply the specified stroke color.
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if self.options.stroke_type == 'first_sel':
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scolor = fstyle.get_color('stroke')
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style.set_color(scolor, 'stroke')
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elif self.options.stroke_type == 'last_sel':
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scolor = lstyle.get_color('stroke')
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style.set_color(scolor, 'stroke')
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elif self.options.stroke_type == 'specified':
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style.set_color(self.options.stroke_color, 'stroke')
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elif self.options.stroke_type == 'random':
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pass # Handled below
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else:
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sys.exit(inkex.utils.errormsg(_('Internal error: Unrecognized stroke type "%s".')) % self.options.stroke_type)
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# Produce n copies of the style.
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styles = [Style(style) for i in range(n)]
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if self.options.fill_type == 'random':
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for s in styles:
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r = random.randint(0, 255)
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g = random.randint(0, 255)
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b = random.randint(0, 255)
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s.set_color('#%02x%02x%02x' % (r, g, b), 'fill')
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s['fill-opacity'] = 255
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if self.options.stroke_type == 'random':
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for s in styles:
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r = random.randint(0, 255)
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g = random.randint(0, 255)
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b = random.randint(0, 255)
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s.set_color('#%02x%02x%02x' % (r, g, b), 'stroke')
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s['stroke-opacity'] = 255
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# Return the list of styles.
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return [str(s) for s in styles]
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def _create_polygons(self, triangles):
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'Render triangles as SVG polygons.'
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styles = self._create_styles(len(triangles))
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group = self.svg.get_current_layer().add(Group())
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for tri, style in zip(triangles, styles):
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tri_str = ' '.join(['%.10g %.10g' % (pt[0], pt[1]) for pt in tri])
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poly = Polygon()
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poly.set('points', tri_str)
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poly.style = style
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group.add(poly)
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def _create_lines(self, triangles):
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'Render triangles as individual SVG lines.'
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# First, find all unique lines.
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lines = set()
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for tri in triangles:
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if len(tri) != 3:
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sys.exit(inkex.utils.errormsg(_('Internal error: Encountered a non-triangle.')))
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for i, j in [(0, 1), (0, 2), (1, 2)]:
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xy1 = tuple(tri[i])
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xy2 = tuple(tri[j])
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if xy1 < xy2:
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lines.update([(xy1, xy2)])
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else:
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lines.update([(xy2, xy1)])
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# Then, create SVG line elements.
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styles = self._create_styles(len(lines))
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group = self.svg.get_current_layer().add(Group())
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for ([(x1, y1), (x2, y2)], style) in zip(lines, styles):
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line = Line()
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line.set('x1', x1)
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line.set('y1', y1)
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line.set('x2', x2)
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line.set('y2', y2)
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line.style = style
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group.add(line)
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def effect(self):
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'Triangulate a set of objects.'
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# Complain if the selection is empty.
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if len(self.svg.selection) == 0:
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return inkex.utils.errormsg(_('Please select at least one object.'))
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# Acquire a set of all points from all selected objects.
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all_points = set()
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warned_text = False
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for obj in self.svg.selection.values():
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if isinstance(obj, TextElement) and not warned_text:
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sys.stderr.write('Warning: Text elements are not currently supported. Ignoring all text in the selection.\n')
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warned_text = True
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all_points.update(self._path_points(obj.to_path_element()))
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# Use SciPy to perform the Delaunay triangulation.
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pts = np.array(list(all_points))
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if len(pts) == 0:
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return inkex.utils.errormsg(_('No points were found.'))
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qopts = self.options.qhull
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if self.options.joggling:
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qopts = 'QJ ' + qopts
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simplices = Delaunay(pts, furthest_site=self.options.furthest, qhull_options=qopts).simplices
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# Create either triangles or lines, as request. Either option uses the
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# style of the first object in the selection.
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triangles = []
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for s in simplices:
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try:
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triangles.append(pts[s])
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except IndexError:
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pass
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if self.options.elt_type == 'poly':
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self._create_polygons(triangles)
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elif self.options.elt_type == 'line':
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self._create_lines(triangles)
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else:
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return inkex.utils.errormsg(_('Internal error: unexpected element type "%s".') % self.options.elt_type)
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if __name__ == '__main__':
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DelaunayTriangulation().run()
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