def test_angles():
arc = ConstructionArc(radius=1, start_angle=30, end_angle=60)
assert tuple(arc.angles(2)) == (30, 60)
assert tuple(arc.angles(3)) == (30, 45, 60)
arc.start_angle = 180
arc.end_angle = 0
assert tuple(arc.angles(2)) == (180, 0)
assert tuple(arc.angles(3)) == (180, 270, 0)
arc.start_angle = -90
arc.end_angle = -180
assert tuple(arc.angles(2)) == (270, 180)
assert tuple(arc.angles(4)) == (270, 0, 90, 180)
def from_arc(cls,
arc: ConstructionArc,
start_width: float,
end_width: float,
segments: int = 64) -> 'CurvedTrace':
"""
Create curved trace from an arc.
Args:
arc: :class:`~ezdxf.math.ConstructionArc` object
start_width: start width
end_width: end width
segments: count of segments for full circle (360 degree) approximation, partial arcs have proportional
less segments, but at least 3
Raises:
ValueError: if arc.radius <= 0
"""
if arc.radius <= 0:
raise ValueError(f'Invalid radius: {arc.radius}.')
curve_trace = cls()
count = max(math.ceil(arc.angle_span / 360.0 * segments), 3) + 1
center = Vec2(arc.center)
for point, width in zip(arc.vertices(arc.angles(count)),
linspace(start_width, end_width, count)):
curve_trace._append(point, point - center, width)
return curve_trace