breadthfirstsearchtraversal.h

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/*
* Copyright 2016 Autodesk, Inc. All rights reserved.
* Use of this software is subject to the terms of the Autodesk license agreement and any attachments or Appendices thereto provided at the time of installation or download,
* or which otherwise accompanies this software in either electronic or hard copy form, or which is signed by you and accepted by Autodesk.
*/

#pragma once

#include "gwnavruntime/querysystem/workingmemcontainers/workingmemdeque.h"
#include "gwnavruntime/querysystem/workingmemcontainers/workingmemarray.h"
#include "gwnavruntime/querysystem/workingmemcontainers/trianglestatusingrid.h"
#include "gwnavruntime/queries/utils/navmeshtraversalcommon.h"
#include "gwnavruntime/queries/utils/queryutils.h"
#include "gwnavruntime/navmesh/identifiers/navtriangleptr.h"

namespace Kaim
{

class NavMeshElementBlob;


template <class Visitor>
class BreadthFirstSearchTraversal
{
    KY_DEFINE_NEW_DELETE_OPERATORS(MemStat_Query)

public:
    BreadthFirstSearchTraversal(
        QueryUtils& queryUtils, const CellBox& cellBox, Visitor& visitor) :
            m_activeData(queryUtils.m_database->GetActiveData()),
            m_visitor(&visitor),
            m_openNodes(queryUtils.GetWorkingMemory()),
            m_triangleStatus(queryUtils.GetWorkingMemory(), cellBox),
            m_visitedNodes(nullptr) {}

    KY_INLINE void Clear()
    {
        m_openNodes.MakeEmpty();
        m_triangleStatus.MakeEmpty();
    }

    KY_INLINE bool IsInitialized() const { return m_openNodes.IsInitialized() && m_triangleStatus.IsInitialized(); }

    // the navTag of the startTriangle is not tested
    inline TraversalResult SetStartTriangle(const NavTriangleRawPtr& triangleRawPtr);

    TraversalResult AddTriangleIfNeverEncountered(const NavTriangleRawPtr& triangleRawPtr);

    TraversalResult Search();

    KY_INLINE void SetVisitedNodeContainer(WorkingMemArray<NavTriangleRawPtr>* visitedNodes) { m_visitedNodes = visitedNodes; }

public:
    ActiveData* m_activeData;

    Visitor* m_visitor; //< the visitor (= the "node analyser")

    WorkingMemDeque<NavTriangleRawPtr> m_openNodes; //< open nodes = nodes that are about to be analysed

    TriangleStatusInGrid m_triangleStatus; //< closed nodes = nodes that have been analysed
    WorkingMemArray<NavTriangleRawPtr>* m_visitedNodes; //< nodes that have been visited
};

template <class Visitor>
TraversalResult BreadthFirstSearchTraversal<Visitor>:: SetStartTriangle(const NavTriangleRawPtr& triangleRawPtr)
{
    if (m_visitor->ShouldVisitTriangle(triangleRawPtr) == false)
        return TraversalResult_DONE;

    if (m_openNodes.PushBack(triangleRawPtr) == KY_ERROR)
        return TraversalResult_LACK_OF_MEMORY_FOR_OPEN_NODES;

    bool unused;
    if (m_triangleStatus.IsInitialized() == false)
        return TraversalResult_LACK_OF_MEMORY_FOR_CLOSED_NODES;

    return m_triangleStatus.OpenNodeIfNew(*m_activeData, triangleRawPtr, unused);
}

template <class Visitor>
TraversalResult BreadthFirstSearchTraversal<Visitor>::Search()
{
    bool doesStoreVisited = m_visitedNodes != nullptr;

    NavTriangleRawPtr currentTrianglerRawPtr;

    while (!m_openNodes.IsEmpty())
    {
        m_openNodes.Front(currentTrianglerRawPtr);
        m_openNodes.PopFront();

        m_visitor->Visit(currentTrianglerRawPtr, m_triangleStatus);

        if (doesStoreVisited)
        {
            if (m_visitedNodes->PushBack(currentTrianglerRawPtr) == KY_ERROR)
                return TraversalResult_LACK_OF_MEMORY_FOR_VISITED_NODES;
        }

        if (m_visitor->IsSearchFinished())
            return TraversalResult_DONE;

        if (m_visitor->ShouldVisitNeighborTriangle(currentTrianglerRawPtr, 0))
        {
            const TraversalResult rc = AddTriangleIfNeverEncountered(m_visitor->GetNeighborTriangle(currentTrianglerRawPtr, 0));
            if (rc != TraversalResult_DONE)
                return rc;
        }

        if (m_visitor->ShouldVisitNeighborTriangle(currentTrianglerRawPtr, 1))
        {
            const TraversalResult rc = AddTriangleIfNeverEncountered(m_visitor->GetNeighborTriangle(currentTrianglerRawPtr, 1));
            if (rc != TraversalResult_DONE)
                return rc;
        }

        if (m_visitor->ShouldVisitNeighborTriangle(currentTrianglerRawPtr, 2))
        {
            const TraversalResult rc = AddTriangleIfNeverEncountered(m_visitor->GetNeighborTriangle(currentTrianglerRawPtr, 2));
            if (rc != TraversalResult_DONE)
                return rc;
        }
    }

    return TraversalResult_DONE;
}

template <class Visitor>
TraversalResult BreadthFirstSearchTraversal<Visitor>::AddTriangleIfNeverEncountered(const NavTriangleRawPtr& triangleRawPtr)
{
    bool nodeIsNew;
    TraversalResult result = m_triangleStatus.OpenNodeIfNew(*m_activeData, triangleRawPtr, nodeIsNew);
    if (result != TraversalResult_DONE)
        return result;

    if (nodeIsNew && m_openNodes.PushBack(triangleRawPtr) == KY_ERROR)
        return TraversalResult_LACK_OF_MEMORY_FOR_OPEN_NODES;

    return TraversalResult_DONE;
}

}