40 lines
984 B
Python
40 lines
984 B
Python
"""Calculate the perimeter of a glyph."""
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from __future__ import print_function, division, absolute_import
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from fontTools.misc.py23 import *
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from fontTools.pens.basePen import BasePen
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from fontTools.misc.bezierTools import splitCubicAtT
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import math
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def distance(p0, p1):
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return math.hypot(p0[0] - p1[0], p0[1] - p1[1])
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class PerimeterPen(BasePen):
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def __init__(self, tolerance=0.005, glyphset=None):
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BasePen.__init__(self, glyphset)
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self.value = 0
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self._mult = 1. + tolerance
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def _moveTo(self, p0):
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pass
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def _lineTo(self, p1):
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p0 = self._getCurrentPoint()
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self.value += distance(p0, p1)
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def _addCubic(self, p0, p1, p2, p3):
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arch = distance(p0, p3)
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box = distance(p0, p1) + distance(p1, p2) + distance(p2, p3)
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if arch * self._mult >= box:
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self.value += (arch + box) * .5
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else:
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for c in splitCubicAtT(p0, p1, p2, p3, .5):
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self._addCubic(*c)
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def _curveToOne(self, p1, p2, p3):
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p0 = self._getCurrentPoint()
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self._addCubic(p0, p1, p2, p3)
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