is_ccw_xy

compas.geometry.is_ccw_xy(a, b, c, colinear=False)[source]

Determine if c is on the left of ab when looking from a to b, and assuming that all points lie in the XY plane.

Parameters:
a[float, float, float] | compas.geometry.Point

Base point defined by XY(Z) coordinates.

b[float, float, float] | compas.geometry.Point

First end point defined by XY(Z) coordinates.

c[float, float, float] | compas.geometry.Point

Second end point defined by XY(Z) coordinates.

colinearbool, optional

If True, colinear points will return a positive result.

Returns:
bool

True if ccw. False otherwise.

See also

is_colinear_xy

References

For more info, see [1].

[1]

Marsh, C. Computational Geometry in Python: From Theory to Application. Available at: https://www.toptal.com/python/computational-geometry-in-python-from-theory-to-implementation

Examples

>>> print(is_ccw_xy([0, 0, 0], [0, 1, 0], [-1, 0, 0]))
True

>>> print(is_ccw_xy([0, 0, 0], [0, 1, 0], [+1, 0, 0]))
False

>>> print(is_ccw_xy([0, 0, 0], [1, 0, 0], [2, 0, 0]))
False

>>> print(is_ccw_xy([0, 0, 0], [1, 0, 0], [2, 0, 0], True))
True