grid_polar.py revision 9fefe969c78790b255996a6fa8ebe02c403761ba
#!/usr/bin/env python
'''
Copyright (C) 2007 John Beard john.j.beard@gmail.com
##This extension allows you to draw a polar grid in Inkscape.
##There is a wide range of options including subdivision and labels.
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
'''
import inkex
import simplestyle, sys
from math import *
def draw_SVG_circle(r, cx, cy, width, fill, name, parent):
style = { 'stroke': '#000000', 'stroke-width':str(width), 'fill': fill }
circ_attribs = {'style':simplestyle.formatStyle(style),
'cx':str(cx), 'cy':str(cy),
'r':str(r),
inkex.addNS('label','inkscape'):name}
circle = inkex.etree.SubElement(parent, inkex.addNS('circle','svg'), circ_attribs )
def draw_SVG_line(x1, y1, x2, y2, width, name, parent):
style = { 'stroke': '#000000', 'stroke-width':str(width), 'fill': 'none' }
line_attribs = {'style':simplestyle.formatStyle(style),
inkex.addNS('label','inkscape'):name,
'd':'M '+str(x1)+','+str(y1)+' L '+str(x2)+','+str(y2)}
inkex.etree.SubElement(parent, inkex.addNS('path','svg'), line_attribs )
def draw_SVG_label_centred(x, y, string, font_size, name, parent):
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_attribs = {'style':simplestyle.formatStyle(style),
inkex.addNS('label','inkscape'):name,
'x':str(x), 'y':str(y)}
label = inkex.etree.SubElement(parent, inkex.addNS('text','svg'), label_attribs)
label.text = string
class Grid_Polar(inkex.Effect):
def __init__(self):
inkex.Effect.__init__(self)
self.OptionParser.add_option("--r_divs",
action="store", type="int",
dest="r_divs", default=5,
help="Circular Divisions")
self.OptionParser.add_option("--dr",
action="store", type="float",
dest="dr", default=50,
help="Circular Division Spacing")
self.OptionParser.add_option("--r_subdivs",
action="store", type="int",
dest="r_subdivs", default=3,
help="Circular Subdivisions per Major division")
self.OptionParser.add_option("--r_log",
action="store", type="inkbool",
dest="r_log", default=False,
help="Logarithmic subdivisions if true")
self.OptionParser.add_option("--r_divs_th",
action="store", type="float",
dest="r_divs_th", default=2,
help="Major Circular Division Line thickness")
self.OptionParser.add_option("--r_subdivs_th",
action="store", type="float",
dest="r_subdivs_th", default=1,
help="Minor Circular Division Line thickness")
self.OptionParser.add_option("--a_divs",
action="store", type="int",
dest="a_divs", default=24,
help="Angle Divisions")
self.OptionParser.add_option("--a_divs_cent",
action="store", type="int",
dest="a_divs_cent", default=4,
help="Angle Divisions at Centre")
self.OptionParser.add_option("--a_subdivs",
action="store", type="int",
dest="a_subdivs", default=1,
help="Angcular Subdivisions per Major division")
self.OptionParser.add_option("--a_subdivs_cent",
action="store", type="int",
dest="a_subdivs_cent", default=1,
help="Angular Subdivisions end 'n' major circular divisions before the centre")
self.OptionParser.add_option("--a_divs_th",
action="store", type="float",
dest="a_divs_th", default=2,
help="Major Angular Division Line thickness")
self.OptionParser.add_option("--a_subdivs_th",
action="store", type="float",
dest="a_subdivs_th", default=1,
help="Minor Angular Division Line thickness")
self.OptionParser.add_option("--c_dot_dia",
action="store", type="float",
dest="c_dot_dia", default=5.0,
help="Diameter of Centre Dot")
self.OptionParser.add_option("--a_labels",
action="store", type="string",
dest="a_labels", default='deg',
help="The kind of labels to apply")
self.OptionParser.add_option("--a_label_size",
action="store", type="int",
dest="a_label_size", default=18,
help="The nominal pixel size of the circumferential labels")
self.OptionParser.add_option("--a_label_outset",
action="store", type="float",
dest="a_label_outset", default=24,
help="The radial outset of the circumferential labels")
def effect(self):
# Embed grid in group
#Put in in the centre of the current view
t = 'translate(' + str( self.view_center[0] ) + ',' + str( self.view_center[1] ) + ')'
g_attribs = {inkex.addNS('label','inkscape'):'Grid_Polar:R' +
str( self.options.r_divs )+':A'+str( self.options.a_divs ),
'transform':t }
grid = inkex.etree.SubElement(self.current_layer, 'g', g_attribs)
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_SVG_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_SVG_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_SVG_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_SVG_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_SVG_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_SVG_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 divison
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_SVG_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_SVG_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_SVG_label_centred(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)
e = Grid_Polar()
e.affect()