#!/usr/bin/env python
'''
Copyright (C) 2009 Michel Chatelain.
Copyright (C) 2007 Tavmjong Bah, tavmjong@free.fr
Copyright (C) 2006 Georg Wiora, xorx@quarkbox.de
Copyright (C) 2006 Johan Engelen, johan@shouraizou.nl
Copyright (C) 2005 Aaron Spike, aaron@ekips.org
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
Changes:
* This program is derived by Michel Chatelain from funcplot.py. His changes are in the Public Domain.
* Michel Chatelain, 17-18 janvier 2009, a partir de funcplot.py
* 20 janvier 2009 : adaptation a la version 0.46 a partir de la nouvelle version de funcplot.py
'''
import inkex, simplepath, simplestyle
from math import *
from random import *
def drawfunction(t_start, t_end, xleft, xright, ybottom, ytop, samples, width, height, left, bottom,
fx = "cos(3*t)", fy = "sin(5*t)", times2pi = False, isoscale = True, drawaxis = True):
if times2pi == True:
t_start = 2 * pi * t_start
t_end = 2 * pi * t_end
# coords and scales based on the source rect
scalex = width / (xright - xleft)
xoff = left
coordx = lambda x: (x - xleft) * scalex + xoff #convert x-value to coordinate
scaley = height / (ytop - ybottom)
yoff = bottom
coordy = lambda y: (ybottom - y) * scaley + yoff #convert y-value to coordinate
# Check for isotropic scaling and use smaller of the two scales, correct ranges
if isoscale:
if scaley<scalex:
# compute zero location
xzero = coordx(0)
# set scale
scalex = scaley
# correct x-offset
xleft = (left-xzero)/scalex
xright = (left+width-xzero)/scalex
else :
# compute zero location
yzero = coordy(0)
# set scale
scaley = scalex
# correct x-offset
ybottom = (yzero-bottom)/scaley
ytop = (bottom+height-yzero)/scaley
# functions specified by the user
if fx != "":
f1 = eval('lambda t: ' + fx.strip('"'))
if fy != "":
f2 = eval('lambda t: ' + fy.strip('"'))
# step is increment of t
step = (t_end - t_start) / (samples-1)
third = step / 3.0
ds = step * 0.001 # Step used in calculating derivatives
a = [] # path array
# add axis
if drawaxis :
# check for visibility of x-axis
if ybottom<=0 and ytop>=0:
# xaxis
a.append(['M ',[left, coordy(0)]])
a.append([' l ',[width, 0]])
# check for visibility of y-axis
if xleft<=0 and xright>=0:
# xaxis
a.append([' M ',[coordx(0),bottom]])
a.append([' l ',[0, -height]])
# initialize functions and derivatives for 0;
# they are carried over from one iteration to the next, to avoid extra function calculations.
x0 = f1(t_start)
y0 = f2(t_start)
# numerical derivatives, using 0.001*step as the small differential
t1 = t_start + ds # Second point AFTER first point (Good for first point)
x1 = f1(t1)
y1 = f2(t1)
dx0 = (x1 - x0)/ds
dy0 = (y1 - y0)/ds
# Start curve
a.append([' M ',[coordx(x0), coordy(y0)]]) # initial moveto
for i in range(int(samples-1)):
t1 = (i+1) * step + t_start
t2 = t1 - ds # Second point BEFORE first point (Good for last point)
x1 = f1(t1)
x2 = f1(t2)
y1 = f2(t1)
y2 = f2(t2)
# numerical derivatives
dx1 = (x1 - x2)/ds
dy1 = (y1 - y2)/ds
# create curve
a.append([' C ',
[coordx(x0 + (dx0 * third)), coordy(y0 + (dy0 * third)),
coordx(x1 - (dx1 * third)), coordy(y1 - (dy1 * third)),
coordx(x1), coordy(y1)]
])
t0 = t1 # Next segment's start is this segments end
x0 = x1
y0 = y1
dx0 = dx1 # Assume the functions are smooth everywhere, so carry over the derivatives too
dy0 = dy1
return a
class ParamCurves(inkex.Effect):
def __init__(self):
inkex.Effect.__init__(self)
self.OptionParser.add_option("--t_start",
action="store", type="float",
dest="t_start", default=0.0,
help="Start t-value")
self.OptionParser.add_option("--t_end",
action="store", type="float",
dest="t_end", default=1.0,
help="End t-value")
self.OptionParser.add_option("--times2pi",
action="store", type="inkbool",
dest="times2pi", default=True,
help="Multiply t-range by 2*pi")
self.OptionParser.add_option("--xleft",
action="store", type="float",
dest="xleft", default=-1.0,
help="x-value of rectangle's left")
self.OptionParser.add_option("--xright",
action="store", type="float",
dest="xright", default=1.0,
help="x-value of rectangle's right")
self.OptionParser.add_option("--ybottom",
action="store", type="float",
dest="ybottom", default=-1.0,
help="y-value of rectangle's bottom")
self.OptionParser.add_option("--ytop",
action="store", type="float",
dest="ytop", default=1.0,
help="y-value of rectangle's top")
self.OptionParser.add_option("-s", "--samples",
action="store", type="int",
dest="samples", default=8,
help="Samples")
self.OptionParser.add_option("--fofx",
action="store", type="string",
dest="fofx", default="cos(3*t)",
help="fx(t) for plotting")
self.OptionParser.add_option("--fofy",
action="store", type="string",
dest="fofy", default="sin(5*t)",
help="fy(t) for plotting")
self.OptionParser.add_option("--remove",
action="store", type="inkbool",
dest="remove", default=True,
help="If True, source rectangle is removed")
self.OptionParser.add_option("--isoscale",
action="store", type="inkbool",
dest="isoscale", default=True,
help="If True, isotropic scaling is used")
self.OptionParser.add_option("--drawaxis",
action="store", type="inkbool",
dest="drawaxis", default=True,
help="If True, axis are drawn")
self.OptionParser.add_option("--tab",
action="store", type="string",
dest="tab", default="sampling",
help="The selected UI-tab when OK was pressed")
self.OptionParser.add_option("--paramcurvesuse",
action="store", type="string",
dest="paramcurvesuse", default="",
help="dummy")
self.OptionParser.add_option("--pythonfunctions",
action="store", type="string",
dest="pythonfunctions", default="",
help="dummy")
def effect(self):
for id, node in self.selected.iteritems():
if node.tag == inkex.addNS('rect','svg'):
# create new path with basic dimensions of selected rectangle
newpath = inkex.etree.Element(inkex.addNS('path','svg'))
x = float(node.get('x'))
y = float(node.get('y'))
w = float(node.get('width'))
h = float(node.get('height'))
#copy attributes of rect
s = node.get('style')
if s:
newpath.set('style', s)
t = node.get('transform')
if t:
newpath.set('transform', t)
# top and bottom were exchanged
newpath.set('d', simplepath.formatPath(
drawfunction(self.options.t_start,
self.options.t_end,
self.options.xleft,
self.options.xright,
self.options.ybottom,
self.options.ytop,
self.options.samples,
w,h,x,y+h,
self.options.fofx,
self.options.fofy,
self.options.times2pi,
self.options.isoscale,
self.options.drawaxis)))
newpath.set('title', self.options.fofx + " " + self.options.fofy)
#newpath.set('desc', '!func;' + self.options.fofx + ';' + self.options.fofy + ';'
# + `self.options.t_start` + ';'
# + `self.options.t_end` + ';'
# + `self.options.samples`)
# add path into SVG structure
node.getparent().append(newpath)
# option wether to remove the rectangle or not.
if self.options.remove:
node.getparent().remove(node)
if __name__ == '__main__':
e = ParamCurves()
e.affect()
# vim: expandtab shiftwidth=4 tabstop=8 softtabstop=4 fileencoding=utf-8 textwidth=99
