text: /** \file
   * \brief Declaration of interface for planar subgraph algorithms.
   *
   * \author Carsten Gutwenger
   *
   * \par License:
   * This file is part of the Open Graph Drawing Framework (OGDF).
   *
   * \par
   * Copyright (C)<br>
   * See README.md in the OGDF root directory for details.
   *
   * \par
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * Version 2 or 3 as published by the Free Software Foundation;
   * see the file LICENSE.txt included in the packaging of this file
   * for details.
   *
   * \par
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * \par
   * You should have received a copy of the GNU General Public
   * License along with this program; if not, see
   * http://www.gnu.org/copyleft/gpl.html
   */
  
  #pragma once
  
  #include <ogdf/basic/GraphCopy.h>
  #include <ogdf/basic/Module.h>
  #include <ogdf/basic/Logger.h>
  #include <ogdf/basic/Timeouter.h>
  #include <ogdf/basic/Thread.h>
  
  
  namespace ogdf {
  
  /**
   * \brief Interface for planar subgraph algorithms.
   *
   * \see PlanarizationLayout, PlanarizationGridLayout
   */
  template<typename TCost>
  class PlanarSubgraphModule : public Module, public Timeouter {
  
  	unsigned int m_maxThreads;	//!< The maximal number of used threads.
  
  public:
  	//! Initializes a planar subgraph module (default constructor).
  	PlanarSubgraphModule() {
  #ifdef OGDF_MEMORY_POOL_NTS
  		m_maxThreads = 1;
  #else
  		m_maxThreads = max(1u, Thread::hardware_concurrency());
  #endif
  	}
  
  
  	/**
  	 * \brief Returns the set of edges \p delEdges which have to be deleted to obtain the planar subgraph.
  	 * @param G is the input graph.
  	 * @param cost are the costs of edges.
  	 * @param preferredEdges are edges that should be contained in the planar subgraph.
  	 * @param delEdges is the set of edges that need to be deleted to obtain the planar subgraph.
  	 * @param preferredImplyPlanar indicates that the edges \p preferredEdges induce a planar graph.
  	 */
  	ReturnType call(const Graph &G,
  		const EdgeArray<TCost> &cost,
  		const List<edge> &preferredEdges,
  		List<edge> &delEdges,
  		bool preferredImplyPlanar = false)
  	{
  		return doCall(G,preferredEdges,delEdges,&cost,preferredImplyPlanar);
  	}
  
  
  	/**
  	 * \brief Returns the set of edges \p delEdges which have to be deleted to obtain the planar subgraph.
  	 * @param G is the input graph.
  	 * @param preferredEdges are edges that should be contained in the planar subgraph.
  	 * @param delEdges is the set of edges that need to be deleted to obtain the planar subgraph.
  	 * @param preferredImplyPlanar indicates that the edges \p preferredEdges induce a planar graph.
  	 */
  	ReturnType call(const Graph &G,
  		const List<edge> &preferredEdges,
  		List<edge> &delEdges,
  		bool preferredImplyPlanar = false)
  	{
  		return doCall(G,preferredEdges,delEdges,nullptr,preferredImplyPlanar);
  	}
  
  
  	/**
  	 * \brief Returns the set of edges \p delEdges which have to be deleted to obtain the planar subgraph.
  	 * @param G is the input graph.
  	 * @param cost are the costs of edges.
  	 * @param delEdges is the set of edges that need to be deleted to obtain the planar subgraph.
  	 */
  	ReturnType call(const Graph &G, const EdgeArray<TCost> &cost, List<edge> &delEdges) {
  		List<edge> preferredEdges;
  		return doCall(G,preferredEdges,delEdges, &cost);
  	}
  
  	/**
  	 * \brief Returns the set of edges \p delEdges which have to be deleted to obtain the planar subgraph.
  	 * @param G is the input graph.
  	 * @param delEdges is the set of edges that need to be deleted to obtain the planar subgraph.
  	 */
  	ReturnType call(const Graph &G, List<edge> &delEdges) {
  		List<edge> preferredEdges;
  		return doCall(G,preferredEdges,delEdges);
  	}
  
  
  	//! Returns the set of edges \p delEdges which have to be deleted to obtain the planar subgraph.
  	ReturnType operator()(const Graph &G,
  		const List<edge> &preferredEdges,
  		List<edge> &delEdges,
  		bool preferredImplyPlanar = false)
  	{
  		return call(G,preferredEdges,delEdges,preferredImplyPlanar);
  	}
  
  	//! Returns the set of edges \p delEdges which have to be deleted to obtain the planar subgraph.
  	ReturnType operator()(const Graph &G, List<edge> &delEdges) {
  		return call(G,delEdges);
  	}
  
  
  	/**
  	 * \brief Makes \p GC planar by deleting edges.
  	 * @param GC is a copy of the input graph.
  	 * @param preferredEdges are edges in \p GC that should be contained in the planar subgraph.
  	 * @param delOrigEdges is the set of original edges whose copy has been deleted in \p GC.
  	 * @param preferredImplyPlanar indicates that the edges \p preferredEdges induce a planar graph.
  	 */
  	ReturnType callAndDelete(GraphCopy &GC,
  		const List<edge> &preferredEdges,
  		List<edge> &delOrigEdges,
  		bool preferredImplyPlanar = false)
  	{
  		List<edge> delEdges;
  		ReturnType retValue = call(GC, preferredEdges, delEdges, preferredImplyPlanar);
  		if(isSolution(retValue)) {
  			for (edge eCopy : delEdges) {
  				delOrigEdges.pushBack(GC.original(eCopy));
  				GC.delEdge(eCopy);
  			}
  		}
  		return retValue;
  	}
  
  	/**
  	 * \brief Makes \p G planar by deleting edges.
  	 * @param GC is a copy of the input graph.
  	 * @param delOrigEdges is the set of original edges whose copy has been deleted in \p GC.
  	 */
  	ReturnType callAndDelete(GraphCopy &GC, List<edge> &delOrigEdges) {
  		List<edge> preferredEdges;
  		return callAndDelete(GC,preferredEdges,delOrigEdges);
  	}
  
  	//! Returns a new instance of the planar subgraph module with the same option settings.
  	virtual PlanarSubgraphModule *clone() const = 0;
  
  	//! Returns the maximal number of used threads.
  	unsigned int maxThreads() const { return m_maxThreads; }
  
  	//! Sets the maximal number of used threads to \p n.
  	void maxThreads(unsigned int n) {
  #ifndef OGDF_MEMORY_POOL_NTS
  		m_maxThreads = n;
  #endif
  	}
  
  protected:
  	// computes set of edges delEdges, which have to be deleted
  	// in order to get a planar subgraph; edges in preferredEdges
  	// should be contained in planar subgraph
  	// must be implemented by derived classes!
  	/**
  	 * \brief Computes the set of edges \p delEdges which have to be deleted to obtain the planar subgraph.
  	 *
  	 * This is the actual algorithm call and needs to be implemented
  	 * by derived classes.
  	 * @param G is the input graph.
  	 * @param preferredEdges are edges that should be contained in the planar subgraph.
  	 * @param delEdges is the set of edges that need to be deleted to obtain the planar subgraph.
  	 * @param pCost is apointer to an edge array containing the edge costs; this pointer
  	 *        can be 0 if no costs are given (all edges have cost 1).
  	 * @param preferredImplyPlanar indicates that the edges \p preferredEdges induce a planar graph.
  	 */
  	virtual ReturnType doCall(const Graph &G,
  		const List<edge> &preferredEdges,
  		List<edge> &delEdges,
  		const EdgeArray<TCost>  *pCost = nullptr,
  		bool preferredImplyPlanar = false) = 0;
  
  	OGDF_MALLOC_NEW_DELETE
  };
  
  }
  