DetourNode.h

//
// Copyright (c) 2009-2010 Mikko Mononen memon@inside.org
//
// This software is provided 'as-is', without any express or implied
// warranty.  In no event will the authors be held liable for any damages
// arising from the use of this software.
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would be
//    appreciated but is not required.
// 2. Altered source versions must be plainly marked as such, and must not be
//    misrepresented as being the original software.
// 3. This notice may not be removed or altered from any source distribution.
//
 
#ifndef DETOURNODE_H
#define DETOURNODE_H
 
#include "DetourNavMesh.h"
 
enum dtNodeFlags
{
    DT_NODE_OPEN = 0x01,
    DT_NODE_CLOSED = 0x02,
    DT_NODE_PARENT_DETACHED = 0x04, // parent of the node is not adjacent. Found using raycast.
};
 
typedef unsigned short dtNodeIndex;
static const dtNodeIndex DT_NULL_IDX = (dtNodeIndex)~0;
 
static const int DT_NODE_PARENT_BITS = 24;
static const int DT_NODE_STATE_BITS = 2;
struct dtNode
{
    float pos[3];                               
    float cost;                                 
    float total;                                
    unsigned int pidx : DT_NODE_PARENT_BITS;    
    unsigned int state : DT_NODE_STATE_BITS;    
    unsigned int flags : 3;                     
    dtPolyRef id;                               
};
 
static const int DT_MAX_STATES_PER_NODE = 1 << DT_NODE_STATE_BITS;  // number of extra states per node. See dtNode::state
 
class dtNodePool
{
public:
    dtNodePool(int maxNodes, int hashSize);
    ~dtNodePool();
    void clear();
 
    // Get a dtNode by ref and extra state information. If there is none then - allocate
    // There can be more than one node for the same polyRef but with different extra state information
    dtNode* getNode(dtPolyRef id, unsigned char state=0);   
    dtNode* findNode(dtPolyRef id, unsigned char state);
    unsigned int findNodes(dtPolyRef id, dtNode** nodes, const int maxNodes);
 
    inline unsigned int getNodeIdx(const dtNode* node) const
    {
        if (!node) return 0;
        return (unsigned int)(node - m_nodes) + 1;
    }
 
    inline dtNode* getNodeAtIdx(unsigned int idx)
    {
        if (!idx) return 0;
        return &m_nodes[idx - 1];
    }
 
    inline const dtNode* getNodeAtIdx(unsigned int idx) const
    {
        if (!idx) return 0;
        return &m_nodes[idx - 1];
    }
    
    inline int getMemUsed() const
    {
        return sizeof(*this) +
            sizeof(dtNode)*m_maxNodes +
            sizeof(dtNodeIndex)*m_maxNodes +
            sizeof(dtNodeIndex)*m_hashSize;
    }
    
    inline int getMaxNodes() const { return m_maxNodes; }
    
    inline int getHashSize() const { return m_hashSize; }
    inline dtNodeIndex getFirst(int bucket) const { return m_first[bucket]; }
    inline dtNodeIndex getNext(int i) const { return m_next[i]; }
    inline int getNodeCount() const { return m_nodeCount; }
    
private:
    // Explicitly disabled copy constructor and copy assignment operator.
    dtNodePool(const dtNodePool&);
    dtNodePool& operator=(const dtNodePool&);
    
    dtNode* m_nodes;
    dtNodeIndex* m_first;
    dtNodeIndex* m_next;
    const int m_maxNodes;
    const int m_hashSize;
    int m_nodeCount;
};
 
class dtNodeQueue
{
public:
    dtNodeQueue(int n);
    ~dtNodeQueue();
    
    inline void clear() { m_size = 0; }
    
    inline dtNode* top() { return m_heap[0]; }
    
    inline dtNode* pop()
    {
        dtNode* result = m_heap[0];
        m_size--;
        trickleDown(0, m_heap[m_size]);
        return result;
    }
    
    inline void push(dtNode* node)
    {
        m_size++;
        bubbleUp(m_size-1, node);
    }
    
    inline void modify(dtNode* node)
    {
        for (int i = 0; i < m_size; ++i)
        {
            if (m_heap[i] == node)
            {
                bubbleUp(i, node);
                return;
            }
        }
    }
    
    inline bool empty() const { return m_size == 0; }
    
    inline int getMemUsed() const
    {
        return sizeof(*this) +
        sizeof(dtNode*) * (m_capacity + 1);
    }
    
    inline int getCapacity() const { return m_capacity; }
    
private:
    // Explicitly disabled copy constructor and copy assignment operator.
    dtNodeQueue(const dtNodeQueue&);
    dtNodeQueue& operator=(const dtNodeQueue&);
 
    void bubbleUp(int i, dtNode* node);
    void trickleDown(int i, dtNode* node);
    
    dtNode** m_heap;
    const int m_capacity;
    int m_size;
};      
 
 
#endif // DETOURNODE_H