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#!/usr/bin/env python
# coding=utf-8
#
# Copyright (C) 2007 John Beard john.j.beard@gmail.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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
"""
This extension allows you to draw a polar grid in Inkscape.
There is a wide range of options including subdivision and labels.
"""
from math import cos, log, pi, sin
import inkex
from inkex import Group, Circle, TextElement
def draw_circle(r, cx, cy, width, fill, name, parent):
"""Draw an SVG circle"""
circle = parent.add(Circle(cx=str(cx), cy=str(cy), r=str(r)))
circle.style = {"stroke": "#000000", "stroke-width": str(width), "fill": fill}
circle.label = name
def draw_line(x1, y1, x2, y2, width, name, parent):
"""Draw an SVG line"""
line = parent.add(inkex.PathElement())
line.style = {"stroke": "#000000", "stroke-width": str(width), "fill": "none"}
line.path = "M {},{} L {},{}".format(x1, y1, x2, y2)
line.label = name
def draw_label(x, y, string, font_size, name, parent):
"""Draw a centered label"""
label = parent.add(TextElement(x=str(x), y=str(y)))
label.style = {
"text-align": "center",
"vertical-align": "top",
"text-anchor": "middle",
"font-size": str(font_size) + "px",
"fill-opacity": "1.0",
"stroke": "none",
"font-weight": "normal",
"font-style": "normal",
"fill": "#000000",
}
label.text = string
label.label = name
class GridPolar(inkex.GenerateExtension):
def add_arguments(self, pars):
pars.add_argument("--tab")
pars.add_argument("--r_divs", type=int, default=5, help="Circular Divisions")
pars.add_argument(
"--dr", type=float, default=50, help="Circular Division Spacing"
)
pars.add_argument(
"--r_subdivs", type=int, default=3, help="Subdivisions per Major div"
)
pars.add_argument(
"--r_log", type=inkex.Boolean, default=False, help="Logarithmic subdiv"
)
pars.add_argument(
"--r_divs_th", type=float, default=2, help="Major Line thickness"
)
pars.add_argument(
"--r_subdivs_th", type=float, default=1, help="Minor Line thickness"
)
pars.add_argument("--a_divs", type=int, default=24, help="Angle Divisions")
pars.add_argument(
"--a_divs_cent", type=int, default=4, help="Angle Divisions at Centre"
)
pars.add_argument(
"--a_subdivs", type=int, default=1, help="Angcular Subdivisions"
)
pars.add_argument(
"--a_subdivs_cent", type=int, default=2, help="Angular Subdivisions end"
)
pars.add_argument(
"--a_divs_th", type=float, default=2, help="Major Angular thickness"
)
pars.add_argument(
"--a_subdivs_th", type=float, default=1, help="Minor Angular thickness"
)
pars.add_argument(
"--c_dot_dia", type=float, default=5.0, help="Diameter of Centre Dot"
)
pars.add_argument(
"--a_labels", default="none", help="The kind of labels to apply"
)
pars.add_argument(
"--a_label_size", type=int, default=18, help="Pixel size of the labels"
)
pars.add_argument(
"--a_label_outset", type=float, default=24, help="Label Radial outset"
)
def generate(self):
self.options.dr = self.svg.unittouu(str(self.options.dr) + "px")
self.options.r_divs_th = self.svg.unittouu(str(self.options.r_divs_th) + "px")
self.options.r_subdivs_th = self.svg.unittouu(
str(self.options.r_subdivs_th) + "px"
)
self.options.a_divs_th = self.svg.unittouu(str(self.options.a_divs_th) + "px")
self.options.a_subdivs_th = self.svg.unittouu(
str(self.options.a_subdivs_th) + "px"
)
self.options.c_dot_dia = self.svg.unittouu(str(self.options.c_dot_dia) + "px")
self.options.a_label_size = self.svg.unittouu(
str(self.options.a_label_size) + "px"
)
self.options.a_label_outset = self.svg.unittouu(
str(self.options.a_label_outset) + "px"
)
# Embed grid in group
grid = Group.new("GridPolar:R{0.r_divs}:A{0.a_divs}".format(self.options))
(pos_x, pos_y) = self.svg.namedview.center
grid.transform.add_translate(pos_x, pos_y)
dr = self.options.dr # Distance between neighbouring circles
dtheta = (
2 * pi / self.options.a_divs_cent
) # Angular change between adjacent radial lines at centre
rmax = self.options.r_divs * dr
# Create SVG circles
for i in range(1, self.options.r_divs + 1):
draw_circle(
i * dr,
0,
0, # major div circles
self.options.r_divs_th,
"none",
"MajorDivCircle" + str(i) + ":R" + str(i * dr),
grid,
)
if self.options.r_log: # logarithmic subdivisions
for j in range(2, self.options.r_subdivs):
draw_circle(
i * dr
- (1 - log(j, self.options.r_subdivs))
* dr, # minor div circles
0,
0,
self.options.r_subdivs_th,
"none",
"MinorDivCircle" + str(i) + ":Log" + str(j),
grid,
)
else: # linear subdivs
for j in range(1, self.options.r_subdivs):
draw_circle(
i * dr - j * dr / self.options.r_subdivs, # minor div circles
0,
0,
self.options.r_subdivs_th,
"none",
"MinorDivCircle" + str(i) + ":R" + str(i * dr),
grid,
)
if (
self.options.a_divs == self.options.a_divs_cent
): # the lines can go from the centre to the edge
for i in range(0, self.options.a_divs):
draw_line(
0,
0,
rmax * sin(i * dtheta),
rmax * cos(i * dtheta),
self.options.a_divs_th,
"RadialGridline" + str(i),
grid,
)
else: # we need separate lines
for i in range(
0, self.options.a_divs_cent
): # lines that go to the first circle
draw_line(
0,
0,
dr * sin(i * dtheta),
dr * cos(i * dtheta),
self.options.a_divs_th,
"RadialGridline" + str(i),
grid,
)
dtheta = (
2 * pi / self.options.a_divs
) # work out the angle change for outer lines
for i in range(
0, self.options.a_divs
): # lines that go from there to the edge
draw_line(
dr * sin(i * dtheta + pi / 2.0),
dr * cos(i * dtheta + pi / 2.0),
rmax * sin(i * dtheta + pi / 2.0),
rmax * cos(i * dtheta + pi / 2.0),
self.options.a_divs_th,
"RadialGridline" + str(i),
grid,
)
if self.options.a_subdivs > 1: # draw angular subdivs
for i in range(0, self.options.a_divs): # for each major division
for j in range(1, self.options.a_subdivs): # draw the subdivisions
angle = (
i * dtheta - j * dtheta / self.options.a_subdivs + pi / 2.0
) # the angle of the subdivion line
draw_line(
dr * self.options.a_subdivs_cent * sin(angle),
dr * self.options.a_subdivs_cent * cos(angle),
rmax * sin(angle),
rmax * cos(angle),
self.options.a_subdivs_th,
"RadialMinorGridline" + str(i),
grid,
)
if self.options.c_dot_dia != 0: # if a non-zero diameter, draw the centre dot
draw_circle(
self.options.c_dot_dia / 2.0, 0, 0, 0, "#000000", "CentreDot", grid
)
if self.options.a_labels == "deg":
label_radius = rmax + self.options.a_label_outset # radius of label centres
label_size = self.options.a_label_size
numeral_size = (
0.73 * label_size
) # numerals appear to be 0.73 the height of the nominal pixel size of the font in "Sans"
for i in range(
0, self.options.a_divs
): # self.options.a_divs): #radial line labels
draw_label(
sin(i * dtheta + pi / 2.0)
* label_radius, # 0 at the RHS, mathematical style
cos(i * dtheta + pi / 2.0) * label_radius
+ numeral_size / 2.0, # centre the text vertically
str(i * 360 / self.options.a_divs),
label_size,
"Label" + str(i),
grid,
)
return grid
if __name__ == "__main__":
GridPolar().run()
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