![[tokkee]](http://tokkee.org/images/avatar.png){kind=avatar}
index aa438e12142ea72d57451244e869c2246f483d2b..c74e7d71e53347186dd231c1b4697b52b8ed207a 100755 (executable)
--- a/share/extensions/wavy.py
+++ b/share/extensions/wavy.py
from random import *
def drawwave(samples, periods, width, height, left, top,
- fx = "sin(x)", fpx = "cos(x)", fponum = True):
-
- # step is the distance between nodes on x
- step = 2*pi / samples
- third = step / 3.0
-
- # coords and scales based on the source rect
- xoff = left
- yoff = top + (height / 2)
- scalex = width / (2*pi * periods)
- scaley = height / 2
- procx = lambda x: x * scalex + xoff
- procy = lambda y: y * scaley + yoff
-
- # functions specified by the user
- if fx != "":
- f = eval('lambda x: ' + fx)
- if fpx != "":
- fp = eval('lambda x: ' + fpx)
-
- # initialize function and derivative for 0;
- # they are carried over from one iteration to the next, to avoid extra function calculations
- y0 = f(0)
- if fponum == True: # numerical derivative, using 0.001*step as the small differential
- d0 = (f(0 + 0.001*step) - y0)/(0.001*step)
- else: # derivative given by the user
- d0 = fp(0)
-
- a = [] # path array
- a.append(['M',[procx(0.0), procy(y0)]]) # initial moveto
-
- for i in range(int(samples * periods)):
- x = i * step
- y1 = f(x + step)
- if fponum == True: # numerical derivative
- d1 = (y1 - f(x + step - 0.001*step))/(0.001*step)
- else: # derivative given by the user
- d1 = fp(x + step)
- # create curve
- a.append(['C',[procx(x + third), procy(y0 + (d0 * third)),
- procx(x + (step - third)), procy(y1 - (d1 * third)),
- procx(x + step), procy(y1)]])
- y0 = y1 # next segment's y0 is this segment's y1
- d0 = d1 # we assume the function is smooth everywhere, so carry over the derivative too
-
- return a
+ fx = "sin(x)", fpx = "cos(x)", fponum = True):
+
+ # step is the distance between nodes on x
+ step = 2*pi / samples
+ third = step / 3.0
+
+ # coords and scales based on the source rect
+ xoff = left
+ yoff = top + (height / 2)
+ scalex = width / (2*pi * periods)
+ scaley = height / 2
+ procx = lambda x: x * scalex + xoff
+ procy = lambda y: y * scaley + yoff
+
+ # functions specified by the user
+ if fx != "":
+ f = eval('lambda x: ' + fx)
+ if fpx != "":
+ fp = eval('lambda x: ' + fpx)
+
+ # initialize function and derivative for 0;
+ # they are carried over from one iteration to the next, to avoid extra function calculations
+ y0 = f(0)
+ if fponum == True: # numerical derivative, using 0.001*step as the small differential
+ d0 = (f(0 + 0.001*step) - y0)/(0.001*step)
+ else: # derivative given by the user
+ d0 = fp(0)
+
+ a = [] # path array
+ a.append(['M',[procx(0.0), procy(y0)]]) # initial moveto
+
+ for i in range(int(samples * periods)):
+ x = i * step
+ y1 = f(x + step)
+ if fponum == True: # numerical derivative
+ d1 = (y1 - f(x + step - 0.001*step))/(0.001*step)
+ else: # derivative given by the user
+ d1 = fp(x + step)
+ # create curve
+ a.append(['C',[procx(x + third), procy(y0 + (d0 * third)),
+ procx(x + (step - third)), procy(y1 - (d1 * third)),
+ procx(x + step), procy(y1)]])
+ y0 = y1 # next segment's y0 is this segment's y1
+ d0 = d1 # we assume the function is smooth everywhere, so carry over the derivative too
+
+ return a
class Wavy(inkex.Effect):
- def __init__(self):
- inkex.Effect.__init__(self)
- self.OptionParser.add_option("-p", "--periods",
- action="store", type="float",
- dest="periods", default=4.0,
- help="Periods (2*Pi each)")
- self.OptionParser.add_option("-s", "--samples",
- action="store", type="int",
- dest="samples", default=8,
- help="Samples per period")
- self.OptionParser.add_option("--fofx",
- action="store", type="string",
- dest="fofx", default="sin(x)",
- help="f(x) for plotting")
- self.OptionParser.add_option("--fponum",
- action="store", type="inkbool",
- dest="fponum", default=True,
- help="Calculate the first derivative numerically")
- self.OptionParser.add_option("--fpofx",
- action="store", type="string",
- dest="fpofx", default="cos(x)",
- help="f'(x) for plotting")
- def effect(self):
- for id, node in self.selected.iteritems():
- if node.tagName == 'rect':
- new = self.document.createElement('svg:path')
- x = float(node.attributes.getNamedItem('x').value)
- y = float(node.attributes.getNamedItem('y').value)
- w = float(node.attributes.getNamedItem('width').value)
- h = float(node.attributes.getNamedItem('height').value)
-
- s = node.attributes.getNamedItem('style').value
- new.setAttribute('style', s)
- try:
- t = node.attributes.getNamedItem('transform').value
- new.setAttribute('transform', t)
- except AttributeError:
- pass
- new.setAttribute('d', simplepath.formatPath(
- drawwave(self.options.samples,
- self.options.periods,
- w,h,x,y,
- self.options.fofx,
- self.options.fpofx,
- self.options.fponum)))
- node.parentNode.appendChild(new)
- node.parentNode.removeChild(node)
+ def __init__(self):
+ inkex.Effect.__init__(self)
+ self.OptionParser.add_option("-p", "--periods",
+ action="store", type="float",
+ dest="periods", default=4.0,
+ help="Periods (2*Pi each)")
+ self.OptionParser.add_option("-s", "--samples",
+ action="store", type="int",
+ dest="samples", default=8,
+ help="Samples per period")
+ self.OptionParser.add_option("--fofx",
+ action="store", type="string",
+ dest="fofx", default="sin(x)",
+ help="f(x) for plotting")
+ self.OptionParser.add_option("--fponum",
+ action="store", type="inkbool",
+ dest="fponum", default=True,
+ help="Calculate the first derivative numerically")
+ self.OptionParser.add_option("--fpofx",
+ action="store", type="string",
+ dest="fpofx", default="cos(x)",
+ help="f'(x) for plotting")
+ def effect(self):
+ for id, node in self.selected.iteritems():
+ if node.tagName == 'rect':
+ new = self.document.createElement('svg:path')
+ x = float(node.attributes.getNamedItem('x').value)
+ y = float(node.attributes.getNamedItem('y').value)
+ w = float(node.attributes.getNamedItem('width').value)
+ h = float(node.attributes.getNamedItem('height').value)
+
+ s = node.attributes.getNamedItem('style').value
+ new.setAttribute('style', s)
+ try:
+ t = node.attributes.getNamedItem('transform').value
+ new.setAttribute('transform', t)
+ except AttributeError:
+ pass
+ new.setAttribute('d', simplepath.formatPath(
+ drawwave(self.options.samples,
+ self.options.periods,
+ w,h,x,y,
+ self.options.fofx,
+ self.options.fpofx,
+ self.options.fponum)))
+ node.parentNode.appendChild(new)
+ node.parentNode.removeChild(node)
e = Wavy()
e.affect()