This function is based on the idea that the cross product between v1 and v2 is
norm(v1) * norm(v2) * sin(alpha) where
alpha is the angle between the vectors. By going through each line segment as a vector and
taking the cross product,
we see if sin(alpha) is mostly positive or negative. Positive here meaning the vectors
are turning right, negative meaning they are turning left.
Array of line segments to check, note that they have to define a polygon by defining a
closed shape (ie. the last line must end where the first line starts.).
This function is based on the idea that the cross product between v1 and v2 is norm(v1) * norm(v2) * sin(alpha) where alpha is the angle between the vectors. By going through each line segment as a vector and taking the cross product, we see if sin(alpha) is mostly positive or negative. Positive here meaning the vectors are turning right, negative meaning they are turning left.