def signed_angle_between(from_v: Vec2, to_v: Vec2, return_neg: bool = False):
"""
考虑符号的矢量夹角
Args:
from_v: 起始矢量
to_v: 终止矢量
returnNegative: 是否返回负值，默认FALSE
Returns:
float: 返回夹角弧度值，逆时针为正, 值域[0,2pi]
"""
res = arctan2(to_v.normalize().y,
to_v.normalize().x) - arctan2(from_v.normalize().y,
from_v.normalize().x)
if return_neg:
return res
else:
if res < 0:
return 2 * pi + res
else:
return res
def _append(self, point: Vec2, normal: Vec2, width: float) -> None:
"""
Add a curve trace station (like a vertex) at location `point`.
Args:
point: 2D curve location (vertex), z-axis of 3D vertices is ignored.
normal: curve normal
width: width of station
"""
if _NULLVEC2.isclose(normal):
normal = _NULLVEC2
else:
normal = normal.normalize(width / 2)
self._stations.append(CurveStation(point + normal, point - normal))