115 lines
5.3 KiB
Python
115 lines
5.3 KiB
Python
#!/usr/bin/env python3
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"""
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Extension for InkScape 1.0
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Author: Mario Voigt / FabLab Chemnitz
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Mail: mario.voigt@stadtfabrikanten.org
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Date: 01.06.2021
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Last patch: 02.06.2021
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License: GNU GPL v3
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Splits a path at value t=0..1 (t=0.5 means 50%) or at a defined length with unit.
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Applies independently for each sub path in selection. Use 'Path > Reverse' to change the cutting direction.
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"""
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import copy
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import inkex
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from inkex import bezier, CubicSuperPath, PathElement, Path
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from inkex.bezier import csplength
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class SplitAndBreakBezierAtT(inkex.EffectExtension):
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def breakContours(self, element, breakelements = None):
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''' this does the same as "CTRL + SHIFT + K" '''
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if breakelements == None:
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breakelements = []
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if element.tag == inkex.addNS('path','svg'):
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parent = element.getparent()
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idx = parent.index(element)
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idSuffix = 0
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raw = element.path.to_arrays()
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subPaths, prev = [], 0
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for i in range(len(raw)): #breaks compound paths into sub paths
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if raw[i][0] == 'M' and i != 0:
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subPaths.append(raw[prev:i])
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prev = i
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subPaths.append(raw[prev:])
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for subpath in subPaths:
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replacedelement = copy.copy(element)
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oldId = replacedelement.get('id')
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csp = CubicSuperPath(subpath)
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if len(subpath) > 1 and csp[0][0] != csp[0][1]: #avoids pointy paths like M "31.4794 57.6024 Z"
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replacedelement.set('d', csp)
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replacedelement.set('id', oldId + str(idSuffix))
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parent.insert(idx, replacedelement)
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idSuffix += 1
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breakelements.append(replacedelement)
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parent.remove(element)
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for child in element.getchildren():
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self.breakContours(child, breakelements)
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return breakelements
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def add_arguments(self, pars):
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pars.add_argument('--tab')
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pars.add_argument('--split_select', default="t")
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pars.add_argument('--unit', default="mm")
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pars.add_argument('--target_length', type=float, default=0.5)
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pars.add_argument('--target_t', type=float, default=0.5)
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def effect(self):
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breakApartElements = None
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for element in self.svg.selection.filter(PathElement):
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breakApartElements = self.breakContours(element, breakApartElements)
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if breakApartElements is not None:
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for element in breakApartElements:
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csp = element.path.to_superpath()
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slengths, totalLength = csplength(csp)
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if totalLength == 0:
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inkex.utils.debug("{} is invalid: zero length (path d='{}'). Skipping ...".format(element.get('id'), element.path))
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continue
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if self.options.split_select == "t":
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length_at_target_t = self.options.target_t * totalLength
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elif self.options.split_select == "length":
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length_at_target_t = self.svg.unittouu(str(self.options.target_length) + self.options.unit)
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if length_at_target_t > totalLength:
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inkex.utils.debug("Entered length is larger than length of {}. Skipping ...".format(element.get('id')))
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continue
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self.options.target_t = length_at_target_t / totalLength #override
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new = []
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lengthSum = 0
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segOfTOccurence = None
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for seg in csp:
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new.append([seg[0][:]])
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for i in range(1,len(seg)):
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segLength = bezier.cspseglength(new[-1][-1], seg[i])
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lengthSum += segLength
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current_t = lengthSum / totalLength
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#insert a new breaking node in case we are at the desired t parameter
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if current_t >= self.options.target_t:
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if segOfTOccurence is None:
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segOfTOccurence = i
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t_dist = 1 - ((lengthSum - length_at_target_t) / segLength)
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result = bezier.cspbezsplitatlength(new[-1][-1], seg[i], t_dist)
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better_result = [[list(el) for el in elements] for elements in result]
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new[-1][-1], nxt, seg[i] = better_result
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new[-1].append(nxt[:])
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new[-1].append(seg[i])
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newpath = CubicSuperPath(new).to_path(curves_only=True).to_arrays()
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#insert the splitting at the occurence (we add "m 0,0") to break the path
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newpath.insert(segOfTOccurence + 1, ['m', [0, 0]])
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element.path = Path(newpath)
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breakAparts = self.breakContours(element)
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#print the breaking point coordinate
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#for step, (x, y) in enumerate(breakAparts[1].path.end_points):
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# self.msg("x={},y={}".format(x, y))
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# break
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else:
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inkex.utils.debug("Selection seems to be empty!")
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return
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if __name__ == '__main__':
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SplitAndBreakBezierAtT().run() |