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inkscape/share/extensions/voronoi_diagram.py
Daniel Baumann 02d935e272
Adding upstream version 1.4.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
2025-06-22 23:40:13 +02:00

310 lines
11 KiB
Python

#!/usr/bin/env python3
# coding=utf-8
#
# Copyright (C) 2011 Vincent Nivoliers and contributors
#
# Contributors
# ~suv, <suv-sf@users.sf.net>
# - Voronoi Diagram algorithm and C code by Steven Fortune, 1987, http://ect.bell-labs.com/who/sjf/
# - Python translation to file voronoi.py by Bill Simons, 2005, http://www.oxfish.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
#
"""
Create Voronoi diagram from seeds (midpoints of selected objects)
"""
import random
import inkex
from inkex import Group, Rectangle, PathElement, Vector2d as Point
import voronoi
class Voronoi(inkex.EffectExtension):
"""Extension to create a Voronoi diagram."""
def add_arguments(self, pars):
pars.add_argument("--tab")
pars.add_argument(
"--diagram-type",
default="Voronoi",
dest="diagramType",
choices=["Voronoi", "Delaunay", "Both"],
help="Defines the type of the diagram",
)
pars.add_argument(
"--clip-box",
choices=["Page", "Automatic from seeds"],
default="Page",
dest="clip_box",
help="Defines the bounding box of the Voronoi diagram",
)
pars.add_argument(
"--show-clip-box",
type=inkex.Boolean,
default=False,
dest="showClipBox",
help="Set this to true to write the bounding box",
)
pars.add_argument(
"--delaunay-fill-options",
default="delaunay-no-fill",
dest="delaunayFillOptions",
help="Set the Delaunay triangles color options",
)
def dot(self, x, y):
"""Clipping a line by a bounding box"""
return x[0] * y[0] + x[1] * y[1]
def intersect_line_segment(self, line, vt1, vt2):
"""Get the line intersection of the two verticies"""
sc1 = self.dot(line, vt1) - line[2]
sc2 = self.dot(line, vt2) - line[2]
if sc1 * sc2 > 0:
return 0, 0, False
tmp = self.dot(line, vt1) - self.dot(line, vt2)
if tmp == 0:
return 0, 0, False
und = (line[2] - self.dot(line, vt2)) / tmp
vt0 = 1 - und
return und * vt1[0] + vt0 * vt2[0], und * vt1[1] + vt0 * vt2[1], True
def clip_edge(self, vertices, lines, edge, bbox):
# bounding box corners
bbc = [
(bbox[0], bbox[2]),
(bbox[1], bbox[2]),
(bbox[1], bbox[3]),
(bbox[0], bbox[3]),
]
# record intersections of the line with bounding box edges
if edge[0] >= len(lines):
return []
line = lines[edge[0]]
interpoints = []
for i in range(4):
pnt = self.intersect_line_segment(line, bbc[i], bbc[(i + 1) % 4])
if pnt[2]:
interpoints.append(pnt)
# if the edge has no intersection, return empty intersection
if len(interpoints) < 2:
return []
if len(interpoints) > 2: # happens when the edge crosses the corner of the box
interpoints = list(set(interpoints)) # remove doubles
# points of the edge
vt1 = vertices[edge[1]]
interpoints.append((vt1[0], vt1[1], False))
vt2 = vertices[edge[2]]
interpoints.append((vt2[0], vt2[1], False))
# sorting the points in the widest range to get them in order on the line
minx = interpoints[0][0]
miny = interpoints[0][1]
maxx = interpoints[0][0]
maxy = interpoints[0][1]
for point in interpoints:
minx = min(point[0], minx)
maxx = max(point[0], maxx)
miny = min(point[1], miny)
maxy = max(point[1], maxy)
if (maxx - minx) > (maxy - miny):
interpoints.sort()
else:
interpoints.sort(key=lambda pt: pt[1])
start = []
inside = False # true when the part of the line studied is in the clip box
start_write = False # true when the part of the line is in the edge segment
for point in interpoints:
if point[2]: # The point is a bounding box intersection
if inside:
if start_write:
return [[start[0], start[1]], [point[0], point[1]]]
return []
else:
if start_write:
start = point
inside = not inside
else: # The point is a segment endpoint
if start_write:
if inside:
# a vertex ends the line inside the bounding box
return [[start[0], start[1]], [point[0], point[1]]]
return []
else:
if inside:
start = point
start_write = not start_write
def effect(self):
# Check that elements have been selected
if not self.svg.selection:
inkex.errormsg(_("Please select objects!"))
return
linestyle = {
"stroke": "#000000",
"stroke-width": str(self.svg.to_dimensionless("1px")),
"fill": "none",
"stroke-linecap": "round",
"stroke-linejoin": "round",
}
facestyle = {
"stroke": "#000000",
"stroke-width": str(self.svg.to_dimensionless("1px")),
"fill": "none",
"stroke-linecap": "round",
"stroke-linejoin": "round",
}
parent_group = self.svg.selection.first().getparent()
trans = parent_group.composed_transform()
invtrans = None
if trans:
invtrans = -trans
# Recovery of the selected objects
pts = []
nodes = []
seeds = []
fills = []
for node in self.svg.selection.values():
nodes.append(node)
bbox = node.bounding_box()
if bbox:
center_x, center_y = bbox.center
point = [center_x, center_y]
if trans:
point = trans.apply_to_point(point)
pts.append(Point(*point))
if self.options.delaunayFillOptions != "delaunay-no-fill":
fills.append(node.style.get("fill", "none"))
seeds.append(Point(center_x, center_y))
# Creation of groups to store the result
if self.options.diagramType != "Delaunay":
# Voronoi
group_voronoi = parent_group.add(Group())
group_voronoi.set("inkscape:label", "Voronoi")
if invtrans:
group_voronoi.transform @= invtrans
if self.options.diagramType != "Voronoi":
# Delaunay
group_delaunay = parent_group.add(Group())
group_delaunay.set("inkscape:label", "Delaunay")
# Clipping box handling
if self.options.diagramType != "Delaunay":
# Clipping bounding box creation
group_bbox = sum([node.bounding_box() for node in nodes], None)
# Clipbox is the box to which the Voronoi diagram is restricted
if self.options.clip_box == "Page":
width = self.svg.viewbox_width
height = self.svg.viewbox_height
clip_box = (0, width, 0, height)
else:
clip_box = (
group_bbox.left,
group_bbox.right,
group_bbox.top,
group_bbox.bottom,
)
# Safebox adds points so that no Voronoi edge in clip_box is infinite
safe_box = (
2 * clip_box[0] - clip_box[1],
2 * clip_box[1] - clip_box[0],
2 * clip_box[2] - clip_box[3],
2 * clip_box[3] - clip_box[2],
)
pts.append(Point(safe_box[0], safe_box[2]))
pts.append(Point(safe_box[1], safe_box[2]))
pts.append(Point(safe_box[1], safe_box[3]))
pts.append(Point(safe_box[0], safe_box[3]))
if self.options.showClipBox:
# Add the clip box to the drawing
rect = group_voronoi.add(Rectangle())
rect.set("x", str(clip_box[0]))
rect.set("y", str(clip_box[2]))
rect.set("width", str(clip_box[1] - clip_box[0]))
rect.set("height", str(clip_box[3] - clip_box[2]))
rect.style = linestyle
# Voronoi diagram generation
if self.options.diagramType != "Delaunay":
vertices, lines, edges = voronoi.computeVoronoiDiagram(pts)
for edge in edges:
vindex1, vindex2 = edge[1:]
if (vindex1 < 0) or (vindex2 < 0):
continue # infinite lines have no need to be handled in the clipped box
else:
segment = self.clip_edge(vertices, lines, edge, clip_box)
# segment = [vertices[vindex1],vertices[vindex2]] # deactivate clipping
if len(segment) > 1:
x1, y1 = segment[0]
x2, y2 = segment[1]
cmds = [["M", [x1, y1]], ["L", [x2, y2]]]
path = group_voronoi.add(PathElement())
path.set("d", str(inkex.Path(cmds)))
path.style = linestyle
if self.options.diagramType != "Voronoi":
triangles = voronoi.computeDelaunayTriangulation(seeds)
i = 0
if self.options.delaunayFillOptions == "delaunay-fill":
random.seed("inkscape")
for triangle in triangles:
pt1 = seeds[triangle[0]]
pt2 = seeds[triangle[1]]
pt3 = seeds[triangle[2]]
cmds = [
["M", [pt1.x, pt1.y]],
["L", [pt2.x, pt2.y]],
["L", [pt3.x, pt3.y]],
["Z", []],
]
if (
self.options.delaunayFillOptions == "delaunay-fill"
or self.options.delaunayFillOptions == "delaunay-fill-random"
):
facestyle = {
"stroke": fills[triangle[random.randrange(0, 2)]],
"stroke-width": str(self.svg.to_dimensionless("0.005px")),
"fill": fills[triangle[random.randrange(0, 2)]],
"stroke-linecap": "round",
"stroke-linejoin": "round",
}
path = group_delaunay.add(PathElement())
path.set("d", str(inkex.Path(cmds)))
path.style = facestyle
i += 1
if __name__ == "__main__":
Voronoi().run()