// Copyright (c) 2000 Max-Planck-Institute Saarbruecken (Germany). // All rights reserved. // // This file is part of CGAL (www.cgal.org). // // $URL: https://github.com/CGAL/cgal/blob/v5.2/Partition_2/include/CGAL/Partition_2/Circulator_pair.h $ // $Id: Circulator_pair.h 0779373 2020-03-26T13:31:46+01:00 Sébastien Loriot // SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial // // // Author(s) : Susan Hert #ifndef CGAL_CIRC_PAIR_H #define CGAL_CIRC_PAIR_H #include #include namespace CGAL { // // "before" always means a point between front and back in the indicated // direction // // "after" always means a point just beyond the range of [front,back] // template class Circ_pair { public: Circ_pair(BidirectionalCirculator back, BidirectionalCirculator front) : _front(front), _back(back), _direction(COUNTERCLOCKWISE) {} Circ_pair(BidirectionalCirculator back, BidirectionalCirculator front, Orientation dir) : _front(front), _back(back), _direction(dir) {} Circ_pair(BidirectionalCirculator front_and_back, Orientation dir) : _front(front_and_back), _back(front_and_back), _direction(dir) {} void initialize(BidirectionalCirculator new_back_and_front) { _back = _front = new_back_and_front; } void push_back(BidirectionalCirculator new_back) { _back = new_back; } void pop_back() { _back = before_back(); } void push_front(BidirectionalCirculator new_front) { _front = new_front; } void pop_front() { _front = before_front(); } BidirectionalCirculator front() const { return _front; } BidirectionalCirculator back() const { return _back; } Orientation direction() const { return _direction; } void set_direction(Orientation direction) { _direction = direction; } void change_dir() { if (_direction == CLOCKWISE) _direction = COUNTERCLOCKWISE; else _direction = CLOCKWISE; } BidirectionalCirculator before_back() { BidirectionalCirculator temp = _back; if (_direction == COUNTERCLOCKWISE) return ++temp; else return --temp; } BidirectionalCirculator after_back() { BidirectionalCirculator temp = _back; if (_direction == COUNTERCLOCKWISE) return --temp; else return ++temp; } BidirectionalCirculator before_front() { BidirectionalCirculator temp = _front; if (_direction == COUNTERCLOCKWISE) return --temp; else return ++temp; } BidirectionalCirculator after_front() { BidirectionalCirculator temp = _front; if (_direction == COUNTERCLOCKWISE) return ++temp; else return --temp; } private: BidirectionalCirculator _front, _back; Orientation _direction; }; } #endif // CGAL_CIRC_PAIR_H