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mightyscape-1.1-deprecated/extensions/fablabchemnitz/x_agram/x_agram.py
2021-07-23 02:36:56 +02:00

145 lines
5.4 KiB
Python

#!/usr/bin/env python3
"""
X-agram
Create n-pointed star polygons (pentagram, hexagram, etc)
"""
import inkex
from math import *
from lxml import etree
def addPathCommand(a, cmd):
for x in cmd:
a.append(str(x))
class XAgram(inkex.EffectExtension):
def add_arguments(self, pars):
pars.add_argument('--tab')
pars.add_argument('--points', type=int, default=5, help='Number of points (or sides)')
pars.add_argument('--skip', type=int, default=2, help='Vertex increment when connecting points')
pars.add_argument('--rotate', type=float, default=0, help='Rotation angle (clockwise, in degrees)')
pars.add_argument('--inner_circle', type=inkex.Boolean, default=False, help='Connect points via inner circle')
pars.add_argument('--show_inner_circle', type=inkex.Boolean, default=True, help='Show inner circle')
pars.add_argument('--inner_ratio', type=int, default=50, help='Inner radius percentage (inner radius as a percentage of the outer radius)')
def effect(self):
layer = self.svg.get_current_layer();
if len(self.svg.selected) == 0:
inkex.errormsg('Please select a circle or ellipse.')
exit()
numValid = 0
for id, obj in self.svg.selected.items():
cx,cy, rx,ry = 0,0, 0,0
style = ''
isValid = False
if obj.tag == inkex.addNS('circle','svg'):
isValid = True
cx = float(obj.get('cx'))
cy = float(obj.get('cy'))
rx = float(obj.get('r'))
ry = rx
elif obj.tag == inkex.addNS('ellipse', 'svg'):
isValid = True
cx = float(obj.get('cx'))
cy = float(obj.get('cy'))
rx = float(obj.get('rx'))
ry = float(obj.get('ry'))
elif obj.tag == inkex.addNS('path', 'svg'):
if obj.get(inkex.addNS('type', 'sodipodi')) == 'arc':
isValid = True
cx = float(obj.get(inkex.addNS('cx', 'sodipodi')))
cy = float(obj.get(inkex.addNS('cy', 'sodipodi')))
rx = float(obj.get(inkex.addNS('rx', 'sodipodi')))
ry = float(obj.get(inkex.addNS('ry', 'sodipodi')))
if not isValid:
continue;
numValid += 1
style = obj.get('style')
transform = obj.get('transform')
isEllipse = False
if rx != ry:
isEllipse = True
sides = self.options.points
skip = self.options.skip
rotate = self.options.rotate
useInnerCircle = self.options.inner_circle
showInnerCircle = self.options.show_inner_circle
innerRatio = float(self.options.inner_ratio) / 100.0
if useInnerCircle and showInnerCircle:
if not isEllipse:
cin = etree.SubElement(layer, inkex.addNS('circle','svg'))
cin.set('r', str(rx * innerRatio))
else:
cin = etree.SubElement(layer, inkex.addNS('ellipse','svg'))
cin.set('rx', str(rx * innerRatio))
cin.set('ry', str(ry * innerRatio))
cin.set('cx', str(cx))
cin.set('cy', str(cy))
cin.set('style', style)
if transform:
cin.set('transform', transform)
tau = 2*pi
origin = -(tau / 4) + (rotate * pi / 180)
out_pts = []
in_pts = []
for i in range(sides):
# Outer points (on outer circle)
theta = (i * (tau / sides))
px = cx + rx * cos(origin + theta)
py = cy + ry * sin(origin + theta)
out_pts.append([px, py])
# Inner points (on inner circle)
theta = ((i + (skip / 2.0)) * (tau / sides))
px = cx + rx * innerRatio * cos(origin + theta)
py = cy + ry * innerRatio * sin(origin + theta)
in_pts.append([px, py])
pts = []
pt_done = {}
for i in range(sides):
if i in pt_done:
continue;
p1 = out_pts[i]
addPathCommand(pts, ['M', p1[0], p1[1]])
pt_done[i] = True
start_index = i
curr = start_index
next = (curr + skip) % sides
while next != start_index:
p = out_pts[next]
pt_done[next] = True
if useInnerCircle:
addPathCommand(pts, ['L', in_pts[curr][0], in_pts[curr][1]])
addPathCommand(pts, ['L', p[0], p[1]])
curr = next
next = (curr + skip) % sides
if useInnerCircle:
addPathCommand(pts, ['L', in_pts[curr][0], in_pts[curr][1]])
addPathCommand(pts, ['z'])
# Create star polygon as a single path.
l1 = etree.SubElement(layer, inkex.addNS('path','svg'))
l1.set('style', style)
if transform:
l1.set('transform', transform)
l1.set('d', ' '.join(pts))
if numValid == 0:
inkex.errormsg('Selection must contain a circle or ellipse.')
if __name__ == '__main__':
XAgram().run()