mirror of https://github.com/OpenTTD/OpenTTD.git
161 lines
4.6 KiB
C++
161 lines
4.6 KiB
C++
/*
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* This file is part of OpenTTD.
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* OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
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* OpenTTD 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.
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* See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
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*/
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/** @file nodelist.hpp List of nodes used for the A-star pathfinder. */
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#ifndef NODELIST_HPP
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#define NODELIST_HPP
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#include "../../misc/array.hpp"
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#include "../../misc/hashtable.hpp"
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#include "../../misc/binaryheap.hpp"
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/**
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* Hash table based node list multi-container class.
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* Implements open list, closed list and priority queue for A-star
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* path finder.
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*/
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template <class Titem_, int Thash_bits_open_, int Thash_bits_closed_>
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class CNodeList_HashTableT {
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public:
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typedef Titem_ Titem; ///< Make #Titem_ visible from outside of class.
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typedef typename Titem_::Key Key; ///< Make Titem_::Key a property of this class.
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typedef SmallArray<Titem_, 65536, 256> CItemArray; ///< Type that we will use as item container.
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typedef CHashTableT<Titem_, Thash_bits_open_ > COpenList; ///< How pointers to open nodes will be stored.
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typedef CHashTableT<Titem_, Thash_bits_closed_> CClosedList; ///< How pointers to closed nodes will be stored.
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typedef CBinaryHeapT<Titem_> CPriorityQueue; ///< How the priority queue will be managed.
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protected:
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CItemArray m_arr; ///< Here we store full item data (Titem_).
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COpenList m_open; ///< Hash table of pointers to open item data.
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CClosedList m_closed; ///< Hash table of pointers to closed item data.
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CPriorityQueue m_open_queue; ///< Priority queue of pointers to open item data.
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Titem *m_new_node; ///< New open node under construction.
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public:
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/** default constructor */
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CNodeList_HashTableT() : m_open_queue(2048)
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{
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m_new_node = nullptr;
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}
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/** destructor */
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~CNodeList_HashTableT()
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{
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}
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/** return number of open nodes */
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inline int OpenCount()
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{
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return m_open.Count();
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}
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/** return number of closed nodes */
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inline int ClosedCount()
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{
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return m_closed.Count();
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}
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/** allocate new data item from m_arr */
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inline Titem_ *CreateNewNode()
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{
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if (m_new_node == nullptr) m_new_node = m_arr.AppendC();
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return m_new_node;
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}
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/** Notify the nodelist that we don't want to discard the given node. */
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inline void FoundBestNode(Titem_ &item)
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{
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/* for now it is enough to invalidate m_new_node if it is our given node */
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if (&item == m_new_node) {
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m_new_node = nullptr;
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}
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/* TODO: do we need to store best nodes found in some extra list/array? Probably not now. */
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}
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/** insert given item as open node (into m_open and m_open_queue) */
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inline void InsertOpenNode(Titem_ &item)
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{
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assert(m_closed.Find(item.GetKey()) == nullptr);
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m_open.Push(item);
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m_open_queue.Include(&item);
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if (&item == m_new_node) {
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m_new_node = nullptr;
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}
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}
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/** return the best open node */
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inline Titem_ *GetBestOpenNode()
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{
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if (!m_open_queue.IsEmpty()) {
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return m_open_queue.Begin();
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}
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return nullptr;
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}
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/** remove and return the best open node */
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inline Titem_ *PopBestOpenNode()
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{
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if (!m_open_queue.IsEmpty()) {
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Titem_ *item = m_open_queue.Shift();
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m_open.Pop(*item);
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return item;
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}
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return nullptr;
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}
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/** return the open node specified by a key or nullptr if not found */
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inline Titem_ *FindOpenNode(const Key &key)
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{
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Titem_ *item = m_open.Find(key);
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return item;
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}
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/** remove and return the open node specified by a key */
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inline Titem_ &PopOpenNode(const Key &key)
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{
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Titem_ &item = m_open.Pop(key);
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uint idxPop = m_open_queue.FindIndex(item);
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m_open_queue.Remove(idxPop);
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return item;
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}
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/** close node */
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inline void InsertClosedNode(Titem_ &item)
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{
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assert(m_open.Find(item.GetKey()) == nullptr);
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m_closed.Push(item);
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}
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/** return the closed node specified by a key or nullptr if not found */
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inline Titem_ *FindClosedNode(const Key &key)
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{
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Titem_ *item = m_closed.Find(key);
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return item;
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}
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/** The number of items. */
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inline int TotalCount()
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{
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return m_arr.Length();
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}
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/** Get a particular item. */
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inline Titem_ &ItemAt(int idx)
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{
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return m_arr[idx];
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}
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/** Helper for creating output of this array. */
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template <class D> void Dump(D &dmp) const
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{
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dmp.WriteStructT("m_arr", &m_arr);
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}
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};
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#endif /* NODELIST_HPP */
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