#!/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=1, 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='deg', 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()