Point3D Line3D::intersect_coplanar(Line3D another) {
Point3D line_a_origpt = orig_pt();
Vector3D line_a_versor = versor();
Point3D line_b_origpt = another.orig_pt();
Vector3D line_b_versor = another.versor();
// creates a triplet of coplanar, non-coincident points
double delta_distance = 100.0;
Vector3D displ_vector_a = line_a_versor.scale(delta_distance);
Vector3D displ_vector_b = line_b_versor.scale(delta_distance);
Point3D point_a = Point3D(line_a_origpt.x(), line_a_origpt.y(), line_a_origpt.z());
Point3D point_b = displ_vector_b.move_pt(point_a);
Point3D point_c = displ_vector_a.move_pt(point_a);
CartesianPlane colinear_plane = CartesianPlane(point_a, point_b, point_c);
//code inspired to: http://geomalgorithms.com/a05-_intersect-1.html#intersect2D_2Segments()
Vector3D w_vect = Vector3D( line_a_origpt, line_b_origpt );
Vector3D vers_a_perp = colinear_plane.perp_versor_in_plane(line_a_versor);
double factor_numerator = - vers_a_perp.scalar_prod(w_vect);
double factor_denominator = vers_a_perp.scalar_prod(line_b_versor);
double factor_scaling = factor_numerator / factor_denominator;
Point3D intersection_pt3d = line_b_versor.scale(factor_scaling).move_pt(line_b_origpt);
return intersection_pt3d;
};
bool Line3D::iscoincident(Line3D another) {
if (not isparallel(another)) {
return false; };
Point3D orig_pt_a = orig_pt();
Point3D orig_pt_b = another.orig_pt();
if (orig_pt_a.is_coincident(orig_pt_b)) {
return true; }
else {
Vector3D test_line = Vector3D(orig_pt_a, orig_pt_b);
if (test_line.isodirection(versor())) {
return true;}
else {
return false;}
}
};
