Merge pull request #31 from andersgb/acos-roundoff-fix

Arc parsing round-off fix
pull/36/merge
Andy Port 2017-12-25 23:55:26 -05:00 committed by GitHub
commit 50d7db0352
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2 changed files with 33 additions and 2 deletions

View File

@ -1300,10 +1300,13 @@ class Arc(object):
# delta is the angular distance of the arc (w.r.t the circle)
# theta is the angle between the positive x'-axis and the start point
# on the circle
u1_real_rounded = u1.real
if u1.real > 1 or u1.real < -1:
u1_real_rounded = round(u1.real)
if u1.imag > 0:
self.theta = degrees(acos(u1.real))
self.theta = degrees(acos(u1_real_rounded))
elif u1.imag < 0:
self.theta = -degrees(acos(u1.real))
self.theta = -degrees(acos(u1_real_rounded))
else:
if u1.real > 0: # start is on pos u_x axis
self.theta = 0

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@ -137,3 +137,31 @@ class TestParser(unittest.TestCase):
def test_errors(self):
self.assertRaises(ValueError, parse_path, 'M 100 100 L 200 200 Z 100 200')
def test_roundoff(self):
"""Paths with arc segments may have floating point round-off issues"""
path1 = parse_path("""
M160.172,102.95
L159.922,102.95
A0.025,0.025 0 0,1 159.897,102.925
L159.897,102.675
A0.025,0.025 0 0,1 159.922,102.65
L160.172,102.65
A0.025,0.025 0 0,1 160.197,102.675
L160.197,102.925
A0.025,0.025 0 0,1 160.172,102.95""")
path2 = Path(Line(start=(160.172 + 102.95j), end=(159.922 + 102.95j)),
Arc(start=(159.922 + 102.95j), radius=(0.025 + 0.025j), rotation=0.0,
large_arc=False, sweep=True, end=(159.897 + 102.925j)),
Line(start=(159.897 + 102.925j), end=(159.897 + 102.675j)),
Arc(start=(159.897 + 102.675j), radius=(0.025 + 0.025j), rotation=0.0,
large_arc=False, sweep=True, end=(159.922 + 102.65j)),
Line(start=(159.922 + 102.65j), end=(160.172 + 102.65j)),
Arc(start=(160.172 + 102.65j), radius=(0.025 + 0.025j), rotation=0.0,
large_arc=False, sweep=True, end=(160.197 + 102.675j)),
Line(start=(160.197 + 102.675j), end=(160.197 + 102.925j)),
Arc(start=(160.197 + 102.925j), radius=(0.025 + 0.025j), rotation=0.0,
large_arc=False, sweep=True, end=(160.172 + 102.95j)))
self.assertEqual(path1, path2)