// Copyright (c) 2006,2007,2009,2010,2011 Tel-Aviv University (Israel). // All rights reserved. // // This file is part of CGAL (www.cgal.org). // You can redistribute it and/or modify it under the terms of the GNU // General Public License as published by the Free Software Foundation, // either version 3 of the License, or (at your option) any later version. // // Licensees holding a valid commercial license may use this file in // accordance with the commercial license agreement provided with the software. // // This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE // WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. // // $URL$ // $Id$ // // // Author(s) : Ron Wein // Efi Fogel #ifndef CGAL_ARR_CURVE_DATA_TRAITS_2_H #define CGAL_ARR_CURVE_DATA_TRAITS_2_H /*! \file * Definition of the Arr_curve_data_traits_2<> class template. */ #include #include #include #include #include namespace CGAL { /*! \class * A generic traits class for maintaining an arrangement of curves that have * an extra data field. This traits class is templated with an ordinary traits * class, which is also used as a based traits class to inherit from. * It can attach data objects to Curve_2 and to X_monotone_curve_2 objects * (possibly of two different types). * The data field is updated when the curves are converted from Curve_2 to * X_monotone_curve_2, and when the X_monotone_curve_2 curves are split. * When two x-monotone curves overlap, the data field to be associated with * the overlapping subcurve is obtained from the merge functor. * All other functors are inherited from the base ordinary traits class. */ template , class CurveData_ = XMonotoneCurveData_, class Convert_ = _Default_convert_func > class Arr_curve_data_traits_2 : public Traits_ { public: typedef Traits_ Base_traits_2; typedef XMonotoneCurveData_ X_monotone_curve_data; typedef Merge_ Merge; typedef CurveData_ Curve_data; typedef Convert_ Convert; typedef typename Base_traits_2::Curve_2 Base_curve_2; typedef typename Base_traits_2::X_monotone_curve_2 Base_x_monotone_curve_2; typedef typename Base_traits_2::Point_2 Point_2; typedef typename Base_traits_2::Has_left_category Has_left_category; typedef typename Base_traits_2::Has_merge_category Base_has_merge_category; typedef Tag_true Has_merge_category; typedef typename Base_traits_2::Has_do_intersect_category Has_do_intersect_category; typedef typename internal::Arr_complete_left_side_category< Base_traits_2 >::Category Left_side_category; typedef typename internal::Arr_complete_bottom_side_category< Base_traits_2 >::Category Bottom_side_category; typedef typename internal::Arr_complete_top_side_category< Base_traits_2 >::Category Top_side_category; typedef typename internal::Arr_complete_right_side_category< Base_traits_2 >::Category Right_side_category; // Representation of a curve with an addtional data field: typedef _Curve_data_ex Curve_2; // Representation of an x-monotone curve with an addtional data field: typedef _Curve_data_ex X_monotone_curve_2; typedef typename Base_traits_2::Multiplicity Multiplicity; public: /// \name Construction. //@{ /*! Default constructor. */ Arr_curve_data_traits_2 () {} /*! Constructor from a base-traits class. */ Arr_curve_data_traits_2 (const Base_traits_2 & traits) : Base_traits_2 (traits) {} //@} /// \name Overriden functors. //@{ class Make_x_monotone_2 { private: const Base_traits_2 * base; public: /*! Constructor. */ Make_x_monotone_2 (const Base_traits_2 * _base) : base (_base) {} /*! * Cut the given curve into x-monotone subcurves and insert them to the * given output iterator. As segments are always x_monotone, only one * x-monotone curve will be contained in the iterator. * \param cv The curve. * \param oi The output iterator, whose value-type is X_monotone_curve_2. * \return The past-the-end iterator. */ template OutputIterator operator() (const Curve_2& cv, OutputIterator oi) const { // Make the original curve x-monotone. std::list base_objects; base->make_x_monotone_2_object() (cv, std::back_inserter (base_objects)); // Attach the data to each of the resulting x-monotone curves. typename std::list::const_iterator it; const Base_x_monotone_curve_2 *base_x_curve; X_monotone_curve_data xdata = Convert()(cv.data()); for (it = base_objects.begin(); it != base_objects.end(); ++it) { base_x_curve = object_cast (&(*it)); if (base_x_curve != NULL) { // Current object is an x-monotone curve: Attach data to it. *oi = make_object (X_monotone_curve_2 (*base_x_curve, xdata)); } else { // Current object is an isolated point: Leave it as is. CGAL_assertion (object_cast (&(*it)) != NULL); *oi = *it; } ++oi; } return (oi); } }; /*! Get a Make_x_monotone_2 functor object. */ Make_x_monotone_2 make_x_monotone_2_object () const { return Make_x_monotone_2 (this); } class Split_2 { private: const Base_traits_2 * base; public: /*! Constructor. */ Split_2 (const Base_traits_2 * _base) : base (_base) {} /*! * Split a given x-monotone curve at a given point into two sub-curves. * \param cv The curve to split * \param p The split point. * \param c1 Output: The left resulting subcurve (p is its right endpoint). * \param c2 Output: The right resulting subcurve (p is its left endpoint). * \pre p lies on cv but is not one of its end-points. */ void operator() (const X_monotone_curve_2& cv, const Point_2 & p, X_monotone_curve_2& c1, X_monotone_curve_2& c2) const { // Split the original curve. base->split_2_object() (cv, p, c1, c2); // Attach data to the split curves. c1.set_data (cv.data()); c2.set_data (cv.data()); return; } }; /*! Get a Split_2 functor object. */ Split_2 split_2_object () const { return Split_2 (this); } class Intersect_2 { private: const Base_traits_2 * base; public: /*! Constructor. */ Intersect_2 (const Base_traits_2 * _base) : base (_base) {} /*! * Find the intersections of the two given curves and insert them to the * given output iterator. As two segments may itersect only once, only a * single will be contained in the iterator. * \param cv1 The first curve. * \param cv2 The second curve. * \param oi The output iterator. * \return The past-the-end iterator. */ template OutputIterator operator() (const X_monotone_curve_2& cv1, const X_monotone_curve_2& cv2, OutputIterator oi) const { // Use the base functor to obtain all intersection objects. std::list base_objects; base->intersect_2_object() (cv1, cv2, std::back_inserter (base_objects)); // Stop if the list is empty: if (base_objects.empty()) return (oi); // Go over all intersection objects and prepare the output. typename std::list::const_iterator it; const Base_x_monotone_curve_2 *base_cv; for (it = base_objects.begin(); it != base_objects.end(); ++it) { if ((base_cv = object_cast (&(*it))) != NULL) { // The current intersection object is an overlapping x-monotone // curve: Merge the data fields of both intersecting curves and // associate the result with the overlapping curve. X_monotone_curve_2 cv (*base_cv, Merge() (cv1.data(), cv2.data())); *oi = make_object (cv); } else { // The current intersection object is an intersection point: // Copy it as is. *oi = *it; } ++oi; } return (oi); } }; /*! Get an Intersect_2 functor object. */ Intersect_2 intersect_2_object () const { return Intersect_2 (this); } class Are_mergeable_2 { private: const Base_traits_2 * base; public: /*! Constructor. */ Are_mergeable_2 (const Base_traits_2 * _base) : base (_base) {} /*! * Check whether it is possible to merge two given x-monotone curves. * \param cv1 The first curve. * \param cv2 The second curve. * \return (true) if the two curves are mergeable; (false) otherwise. */ bool operator() (const X_monotone_curve_2& cv1, const X_monotone_curve_2& cv2) const { return (_are_mergeable_base_imp (cv1, cv2, Base_has_merge_category())); } private: /*! * Implementation of the base predicate in case the HasMerge tag is true. */ bool _are_mergeable_base_imp (const X_monotone_curve_2& cv1, const X_monotone_curve_2& cv2, Tag_true) const { // In case the two base curves are not mergeable, the extended curves // are not mergeable as well. if (! (base->are_mergeable_2_object() (cv1, cv2))) return (false); // In case the two base curves are mergeable, check that they have the // same data fields. return (cv1.data() == cv2.data()); } /*! * Implementation of the base predicate in case the HasMerge tag is false. */ bool _are_mergeable_base_imp (const X_monotone_curve_2& , const X_monotone_curve_2& , Tag_false) const { // Curve merging is not supported: return (false); } }; /*! Get an Are_mergeable_2 functor object. */ Are_mergeable_2 are_mergeable_2_object () const { return Are_mergeable_2 (this); } /*! \class Merge_2 * A functor that merges two x-monotone arcs into one. */ class Merge_2 { private: const Base_traits_2 * base; public: /*! Constructor. */ Merge_2 (const Base_traits_2 * _base) : base (_base) {} /*! * Merge two given x-monotone curves into a single curve (segment). * \param cv1 The first curve. * \param cv2 The second curve. * \param c Output: The merged curve. * \pre The two curves are mergeable. */ void operator() (const X_monotone_curve_2& cv1, const X_monotone_curve_2& cv2, X_monotone_curve_2& c) const { // The function is implemented based on the base Has_merge category. _merge_imp (cv1, cv2, c, Base_has_merge_category()); } private: /*! * Implementation of the operator() in case the HasMerge tag is true. */ void _merge_imp (const X_monotone_curve_2& cv1, const X_monotone_curve_2& cv2, X_monotone_curve_2& c, Tag_true) const { // Merge the two base curve. Base_x_monotone_curve_2 base_cv; base->merge_2_object() (cv1, cv2, base_cv); // Attach data from one of the curves. CGAL_precondition (cv1.data() == cv2.data()); c = X_monotone_curve_2 (base_cv, cv1.data()); return; } /*! * Implementation of the operator() in case the HasMerge tag is false. */ void _merge_imp (const X_monotone_curve_2& , const X_monotone_curve_2& , X_monotone_curve_2& , Tag_false) const { // This function should never be called! CGAL_error_msg("Merging curves is not supported."); } }; /*! Get a Merge_2 functor object. */ Merge_2 merge_2_object () const { return Merge_2 (this); } class Construct_x_monotone_curve_2 { private: const Base_traits_2 * base; public: /*! Constructor. */ Construct_x_monotone_curve_2 (const Base_traits_2 * _base) : base (_base) {} /*! * Return an x-monotone curve connecting the two given endpoints. * \param p The first point. * \param q The second point. * \pre p and q must not be the same. * \return An x-monotone curve connecting p and q. */ X_monotone_curve_2 operator() (const Point_2& p, const Point_2& q) const { Base_x_monotone_curve_2 base_cv = base->construct_x_monotone_curve_2_object() (p, q); return (X_monotone_curve_2 (base_cv, X_monotone_curve_data())); } }; /*! Get a Construct_x_monotone_curve_2 functor object. */ Construct_x_monotone_curve_2 construct_x_monotone_curve_2_object () const { return Construct_x_monotone_curve_2 (this); } //@} }; } //namespace CGAL #endif