AStar.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program 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, either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

/*
 * Copyright (C) 2006-2010 - Frictional Games
 *
 * This file is part of HPL1 Engine.
 */

#ifndef HPL_A_STAR_H
#define HPL_A_STAR_H

#include "common/list.h"
#include "hpl1/engine/game/GameTypes.h"
#include "hpl1/engine/math/MathTypes.h"
#include "hpl1/engine/system/SystemTypes.h"

namespace hpl {

class cAINodeContainer;
class cAINode;

//--------------------------------------

typedef Hpl1::Std::set<cAINode *> tAINodeSet;
typedef tAINodeSet::iterator tAINodeSetIt;

//--------------------------------------

typedef Common::List<cAINode *> tAINodeList;
typedef tAINodeList::iterator tAINodeListIt;

//--------------------------------------

class cAStarNode {
public:
    cAStarNode(cAINode *apAINode);

    float mfCost;
    float mfDistance;

    cAStarNode *mpParent;
    cAINode *mpAINode;
};

class cAStarNodeCompare {
public:
    bool operator()(cAStarNode *apNodeA, cAStarNode *apNodeB) const;
};

typedef Hpl1::Std::set<cAStarNode *, cAStarNodeCompare> tAStarNodeSet;
typedef tAStarNodeSet::iterator tAStarNodeSetIt;

//--------------------------------------
class cAStarHandler;

class iAStarCallback {
public:
    virtual ~iAStarCallback() {}

    virtual bool CanAddNode(cAINode *apParentNode, cAINode *apChildNode) = 0;
};

//--------------------------------------

class cAStarHandler {
public:
    cAStarHandler(cAINodeContainer *apContainer);
    ~cAStarHandler();

    bool GetPath(const cVector3f &avStart, const cVector3f &avGoal, tAINodeList *apNodeList);

    void SetMaxIterations(int alX) { mlMaxIterations = alX; }

    void SetCallback(iAStarCallback *apCallback) { mpCallback = apCallback; }

private:
    void IterateAlgorithm();

    void AddOpenNode(cAINode *apAINode, cAStarNode *apParent, float afDistance);

    cAStarNode *GetBestNode();

    float Cost(float afDistance, cAINode *apAINode, cAStarNode *apParent);
    float Heuristic(const cVector3f &avStart, const cVector3f &avGoal);

    bool IsGoalNode(cAINode *apAINode);

    cVector3f mvGoal;

    cAStarNode *mpGoalNode;
    tAINodeSet m_setGoalNodes;

    cAINodeContainer *mpContainer;

    int mlMaxIterations;

    iAStarCallback *mpCallback;

    tAStarNodeSet m_setOpenList;
    tAStarNodeSet m_setClosedList;
};

} // namespace hpl

#endif // HPL_A_STAR_H