ContinuousSpace.get_heading returns wrong result sometimes in toroidal space mode

[senden9]

Describe the bug
ContinuousSpace.get_heading returns wrong result when going over the middle line and toroidal space is enabled.

Expected behavior
Heading from (51, 51) to (49, 49) should return (-2, -2).

To Reproduce

import numpy as np
from mesa import space

cspace = space.ContinuousSpace(100, 100, True)
print(cspace.get_heading((51, 51), (49, 49)))

Prints (98.0, 98.0). So it goes 180 Degree in the wrong direction.

If I shift the points down I get the right results:

import numpy as np
from mesa import space

cspace = space.ContinuousSpace(100, 100, True)
print(cspace.get_heading((11, 11), (9, 9)))

Prints (-2.0, -2.0). So the correct result.

[catherinedevlin]

Confirmed that the bug is still present in v1.2.1.

[rht]

Fixed by #1686.