Point is feasible or not in DP process

[bryanibit]

I don't know the rule for choosing infeasible or feasible points in DP process as shown in function 'graphSearchDp(PathOptimizationNS::ReferencePath *)' of file named reference_path_smoother.cpp.

if ((ref_curvature < 0 && cur_l < ref_r) || (ref_curvature > 0 && cur_l > ref_r)
                || dp_point.dis_to_obs_ < search_threshold) {
                dp_point.is_feasible_ = false;
            }
            if (i == 0 && dp_point.lateral_index_ != start_lateral_index) dp_point.is_feasible_ = false;
            if (i == 0 && dp_point.lateral_index_ == start_lateral_index) {
                dp_point.is_feasible_ = true;
                dp_point.dir_ = start_state_.z;
                dp_point.cost_ = 0.0;
            }

Could you please explain that for me? Thank you so much!!