1  /**
 2  * angle_between.scad
 3  *
 4  * @copyright Justin Lin, 2020
 5  * @license https://opensource.org/licenses/lgpl-3.0.html
 6  *
 7  * @see https://openhome.cc/eGossip/OpenSCAD/lib3x-angle_between.html
 8  *
 9  **/
10  
11  use <_impl/_angle_between_impl.scad>
12  
13  function angle_between(vt1, vt2, ccw = false) = 
14      !ccw ? acos((vt1 * vt2) / sqrt((vt1 * vt1) * (vt2 * vt2))) :
15      len(vt1) == 2 ? angle_between_ccw_2d(vt1, vt2) : 
16                      angle_between_ccw_3d(vt1, vt2);