109 lines
4.7 KiB
Python
109 lines
4.7 KiB
Python
|
#!/usr/bin/env python3
|
||
|
|
|
||
|
|
from __future__ import print_function
|
||
|
|
import sys
|
||
|
|
import math
|
||
|
|
import inkex
|
||
|
|
from inkex.paths import CubicSuperPath
|
||
|
|
inkex.localization.localize
|
||
|
|
|
||
|
|
class TransformExponential(inkex.Effect):
|
||
|
|
def __init__(self):
|
||
|
|
inkex.Effect.__init__(self)
|
||
|
|
#self.arg_parser.add_argument('-a', '--axis', default='x', help='distortion axis. Valid values are "x", "y", or "xy". Default is "x"')
|
||
|
|
self.arg_parser.add_argument('-x', '--exponent', type=float, default=1.3, help='distortion factor. 1=no distortion, default 1.3')
|
||
|
|
self.arg_parser.add_argument('-p', '--padding_perc', type=float, default=0, help='pad at origin. Padding 100% runs the exponential curve through [0.5 .. 1.0] -- default 0% runs through [0.0 .. 1.0]')
|
||
|
|
|
||
|
|
def x_exp(self, bbox, x):
|
||
|
|
""" reference implementation ignoring padding. unused. """
|
||
|
|
xmin = bbox[0] # maps to 0
|
||
|
|
xmax = bbox[1] # maps to 1
|
||
|
|
w = xmax-xmin # maps to 1
|
||
|
|
# convert world to math coordinates
|
||
|
|
xm = (x-xmin)/w
|
||
|
|
# apply function with properties f(1.0) == 1.0 and f(0.0) == 0.0
|
||
|
|
xm = xm**self.options.exponent # oh, parabola or logarithm?
|
||
|
|
# convert back from math to world coordinates.
|
||
|
|
return x*w + xmin
|
||
|
|
|
||
|
|
def x_exp_p(self, bbox, x):
|
||
|
|
""" parabola mapping with padding
|
||
|
|
CAUTION: the properties f(1.0) == 1.0 and f(0.0) == 0.0
|
||
|
|
do not really hold, as our x does not run the full range [0.0 .. 1.0]
|
||
|
|
FIXME: if you expect some c**xm here, instead of xm**c, think about c==1 ...
|
||
|
|
"""
|
||
|
|
xmin = bbox[0] # maps to 0 when padding=0,
|
||
|
|
xmax = bbox[1] # maps to 1
|
||
|
|
xzero = xmin - (xmax-xmin)*self.options.padding_perc*0.01 # maps to 0, after applying padding
|
||
|
|
w = xmax - xzero
|
||
|
|
w = w * (1+self.options.padding_perc*0.01)
|
||
|
|
# convert world to math coordinates
|
||
|
|
xm = (x-xzero)/w
|
||
|
|
# apply function with properties f(1.0) == 1.0 and f(0.0) == 0.0
|
||
|
|
xm = xm**self.options.exponent # oh, parabola or logarithm?
|
||
|
|
return xm
|
||
|
|
|
||
|
|
def x_exp_p_inplace(self, bbox, xm):
|
||
|
|
""" back from mat to world coordinates, retaining xmin and xmax
|
||
|
|
|
||
|
|
Algorithm: (pre)compute a linear mapping function by explicitly
|
||
|
|
running x_exp_p for the two points xmin and xmax.
|
||
|
|
Then use the resulting linear function to map back any xm into world coordinates x.
|
||
|
|
|
||
|
|
An obvious speedup by factor 3 is waiting for you here.
|
||
|
|
"""
|
||
|
|
|
||
|
|
xmin = bbox[0]
|
||
|
|
xmax = bbox[1]
|
||
|
|
## assert that xmin maps to xmin and xmax maps to xmax, whatever x_exp_p() does to us.
|
||
|
|
f_xmin = self.x_exp_p(bbox, xmin)
|
||
|
|
f_xmax = self.x_exp_p(bbox, xmax)
|
||
|
|
f_x = self.x_exp_p(bbox, xm)
|
||
|
|
x = (f_x - f_xmin) * (xmax-xmin) / (f_xmax-f_xmin) + xmin
|
||
|
|
return x
|
||
|
|
|
||
|
|
def computeBBox(self, pts):
|
||
|
|
""" 'improved' version of simplepath.computeBBox, this one includes b-spline handles."""
|
||
|
|
xmin = None
|
||
|
|
xmax = None
|
||
|
|
ymin = None
|
||
|
|
ymax = None
|
||
|
|
for p in pts:
|
||
|
|
for pp in p:
|
||
|
|
for ppp in pp:
|
||
|
|
if xmin is None: xmin = ppp[0]
|
||
|
|
if xmax is None: xmax = ppp[0]
|
||
|
|
if ymin is None: ymin = ppp[1]
|
||
|
|
if ymax is None: ymax = ppp[1]
|
||
|
|
|
||
|
|
if xmin > ppp[0]: xmin = ppp[0]
|
||
|
|
if xmax < ppp[0]: xmax = ppp[0]
|
||
|
|
if ymin > ppp[1]: ymin = ppp[1]
|
||
|
|
if ymax < ppp[1]: ymax = ppp[1]
|
||
|
|
return (xmin, xmax, ymin, ymax)
|
||
|
|
|
||
|
|
def effect(self):
|
||
|
|
|
||
|
|
if len(self.svg.selected) == 0:
|
||
|
|
inkex.errormsg(_("Please select an object to perform the " +
|
||
|
|
"exponential-distort transformation on."))
|
||
|
|
return
|
||
|
|
|
||
|
|
for id, node in self.svg.selected.items():
|
||
|
|
type = node.get("{http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd}type", "path")
|
||
|
|
if node.tag != '{http://www.w3.org/2000/svg}path' or type != 'path':
|
||
|
|
inkex.errormsg(node.tag + " is not a path. Type="+type+". Please use 'Path->Object to Path' first.")
|
||
|
|
else:
|
||
|
|
pts = CubicSuperPath(node.get('d'))
|
||
|
|
bbox = self.computeBBox(pts)
|
||
|
|
## bbox (60.0, 160.0, 77.0, 197.0)
|
||
|
|
## pts [[[[60.0, 77.0], [60.0, 77.0], [60.0, 77.0]], [[60.0, 197.0], [60.0, 197.0], [60.0, 197.0]], [[70.0, 197.0], ...
|
||
|
|
for p in pts:
|
||
|
|
for pp in p:
|
||
|
|
for ppp in pp:
|
||
|
|
ppp[0] = self.x_exp_p_inplace(bbox, ppp[0])
|
||
|
|
|
||
|
|
node.set('d', str(pts))
|
||
|
|
|
||
|
|
if __name__ == '__main__':
|
||
|
|
TransformExponential().run()
|