public void AngleSum2d_ReturnsCorrectly()
{
// arrange
Vector2[] polygon = new Vector2[] { Vector2.left, Vector2.up, Vector2.right, Vector2.down };
Vector2 pointInside = Vector2.zero;
Vector2 planarOutside = Vector2.up + Vector2.right;
// act
bool inside = Mathf.Approximately(Mathf.PI * 2, PMath.AngleSum2d(pointInside, polygon));
bool outside = Mathf.Approximately(Mathf.PI * 2, PMath.AngleSum2d(planarOutside, polygon));
// assert
Assert.IsTrue(inside);
Assert.IsFalse(outside);
}