83 lines
2.6 KiB
Python
83 lines
2.6 KiB
Python
# Copyright (C) 2018 Michael Matthews
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#
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# This file is part of CutCraft.
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#
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# CutCraft is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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#
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# CutCraft is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with CutCraft. If not, see <http://www.gnu.org/licenses/>.
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from .point import Point
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from math import sqrt
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def isclose(a, b, rel_tol=1e-09, abs_tol=0.0):
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# Required as Inkscape does not include math.isclose().
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return abs(a-b) <= max(rel_tol * max(abs(a), abs(b)), abs_tol)
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class Line(object):
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""" Line class defined by start and end Points. """
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def __init__(self, point1, point2):
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self.pts = (point1, point2)
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self.x = [point1.x, point2.x]
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self.y = [point1.y, point2.y]
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return
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def _line(self):
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# Convert line segment into a line equation (infinite length).
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p1 = self.pts[0]
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p2 = self.pts[1]
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A = (p1.y - p2.y)
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B = (p2.x - p1.x)
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C = (p1.x*p2.y - p2.x*p1.y)
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return A, B, -C
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def intersection(self, other):
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# Find the intersection of the lines (infinite length - not segments)
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L1 = self._line()
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L2 = other._line()
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D = L1[0] * L2[1] - L1[1] * L2[0]
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Dx = L1[2] * L2[1] - L1[1] * L2[2]
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Dy = L1[0] * L2[2] - L1[2] * L2[0]
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if D != 0:
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x = Dx / D
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y = Dy / D
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return Point(x, y)
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else:
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return None
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def normal(self):
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# Return the unit normal
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dx = self.x[1] - self.x[0]
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dy = self.y[1] - self.y[0]
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d = sqrt(dx*dx + dy*dy)
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return dx/d, -dy/d
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def addkerf(self, kerf):
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nx, ny = self.normal()
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offset = Point(ny*kerf, nx*kerf)
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self.pts = (self.pts[0] + offset, self.pts[1] + offset)
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self.x = [self.pts[0].x, self.pts[1].x]
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self.y = [self.pts[0].y, self.pts[1].y]
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def __eq__(self, other):
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return (self.pts == other.pts)
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def __ne__(self, other):
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return (self.pts != other.pts)
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def __repr__(self):
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return "Line(" + repr(self.pts[0]) + ", " + repr(self.pts[1]) + ")"
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def __str__(self):
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return "(" + str(self.pts[0]) + ", " + str(self.pts[1]) + ")"
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