Return the counterclockwise angle in the range (-π, π) between the positive X axis and the line intersecting a and b.
resulting angle
vecAngle([0, 0], [-1, 0]); // returns π Copy
vecAngle([0, 0], [-1, 0]); // returns π
Return the counterclockwise angle in the range (-π, π) between the positive X axis and the line intersecting a and b.