Angel 3.2
A 2D Game Prototyping Engine
Traversal.cpp
1 
2 // Copyright (C) 2008-2013, Shane Liesegang
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29 
30 #include "stdafx.h"
31 #include "../AI/Traversal.h"
32 
33 #include "../AI/SpatialGraph.h"
34 
35 void Traversal::StartTraversal( const Vector2& vStartPoint, int maxResults, int maxIterations )
36 {
37  _traversalInitialized = true;
38  _maxIterations = maxIterations;
39  _numIterations = 0;
40  _maxResults = maxResults;
41  ClearAllVisited();
42  _results.clear();
43  _nodesToVisit.clear();
44 
45  //Add start node
46  AddNodeToVisit(theSpatialGraph.GetGraph()->FindNode( vStartPoint ));
47 }
48 
49 bool Traversal::DoNextTraversal()
50 {
51  if( !_traversalInitialized )
52  return false;
53 
54  while( HasNodesToVist() )
55  {
56  //get next node
57  SpatialGraphKDNode* pNextNode = PopNextNode();
58 
59  EvaluateNode(pNextNode);
60 
61  if( _maxResults != -1 && (int)_results.size() >= _maxResults )
62  return false;
63 
64  _numIterations++;
65  if( _maxIterations != -1 && _numIterations >= _maxIterations )
66  return false;
67 
68  }
69 
70  return false;
71 }
72 
73 void Traversal::ExecuteFullTraversal()
74 {
75  while( DoNextTraversal() ) {}
76 }
77 
78 std::vector<Vector2>& Traversal::GetResults()
79 {
80  return _results;
81 }
82 
83 void Traversal::AddSuccessors( SpatialGraphKDNode* pCurrent)
84 {
85  for( unsigned int i = 0; i < pCurrent->NeighborLOS.size(); i++ )
86  {
87  if( pCurrent->NeighborLOS[i] )
88  {
89  SpatialGraphKDNode* pNeighbor = pCurrent->Neighbors[i];
90  if( WasVisited(pNeighbor) )
91  AddNodeToVisit( pNeighbor );
92  }
93  }
94 }
95 
96 void Traversal::AddNodeToVisit( SpatialGraphKDNode* pNode )
97 {
98  _nodesToVisit.push_back( pNode );
99  SetVisited(pNode);
100 }
101 
102 bool Traversal::HasNodesToVist()
103 {
104  return _nodesToVisit.size() > 0;
105 }
106 
107 SpatialGraphKDNode* Traversal::PopNextNode()
108 {
109  SpatialGraphKDNode* pNext = _nodesToVisit.back();
110  _nodesToVisit.pop_front();
111 
112  return pNext;
113 }
114 
115 void Traversal::SetVisited( SpatialGraphKDNode* pNode )
116 {
117  _visited[pNode] = 1;
118 }
119 
120 bool Traversal::WasVisited( SpatialGraphKDNode* pNode )
121 {
122  return _visited.find(pNode) != _visited.end();
123 }
124 
125 void Traversal::ClearAllVisited()
126 {
127  _visited.clear();
128 }
129