1 | #ifndef _ViewCellBsp_H__
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2 | #define _ViewCellBsp_H__
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3 |
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4 | #include "Mesh.h"
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5 | #include "Containers.h"
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6 | #include "Polygon3.h"
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7 | #include <stack>
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8 | #include "Statistics.h"
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9 | #include "VssRay.h"
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10 | #include "ViewCell.h"
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11 |
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12 | namespace GtpVisibilityPreprocessor {
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13 |
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14 | class ViewCellLeaf;
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15 | //class BspViewCell;
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16 | class Plane3;
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17 | class BspTree;
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18 | class BspInterior;
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19 | //class Polygon3;
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20 | class AxisAlignedBox3;
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21 | class Ray;
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22 | class ViewCellsStatistics;
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23 | class ViewCellsManager;
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24 | class ViewCellsTree;
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25 | class ViewCell;
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26 | class ViewCellLeaf;
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27 |
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28 | class BspNodeGeometry
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29 | {
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30 | public:
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31 | BspNodeGeometry()
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32 | {};
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33 |
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34 | /** copy constructor copying the polygon array.
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35 | The polygons are deeply copied.
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36 | */
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37 | BspNodeGeometry(const BspNodeGeometry &rhs);
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38 | /** This operator uses a deep copy to copy the polygons.
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39 | */
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40 | BspNodeGeometry& operator=(const BspNodeGeometry& p);
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41 |
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42 | /** Builds node geometry using this polygons.
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43 | @NOTE The polygons are NOT duplicated, only
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44 | a shallow copy is used.
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45 | */
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46 | BspNodeGeometry(const PolygonContainer &polys);
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47 |
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48 | ~BspNodeGeometry();
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49 |
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50 | /** Returns accumulated area of all polygons.
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51 | */
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52 | float GetArea() const;
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53 | /** Returns volume of this node geometry.
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54 | */
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55 | float GetVolume() const;
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56 |
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57 | /** Computes new front and back geometry based on the old cell
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58 | geometry and a new split plane
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59 | @returns true if the geometry is actually split by this plane
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60 | */
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61 | bool SplitGeometry(BspNodeGeometry &front,
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62 | BspNodeGeometry &back,
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63 | const Plane3 &splitPlane,
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64 | const AxisAlignedBox3 &box,
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65 | const float epsilon) const;
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66 |
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67 | /** Computes the intersection of the box with the node geometry.
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68 | */
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69 | int ComputeIntersection(const AxisAlignedBox3 &box) const;
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70 |
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71 | /** Computes bounding box of the geometry.
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72 | */
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73 | void GetBoundingBox(AxisAlignedBox3 &box) const;
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74 |
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75 | /** Returns
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76 | 1 of geometry in front of plane
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77 | 0 if plane intersects geometry,
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78 | -1 if geometry in back of plane
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79 | */
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80 | int Side(const Plane3 &plane, const float eps = 0.0f) const;
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81 |
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82 | /** Splits the polygon and returns the part of the polygon inside of the node geometry.
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83 | */
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84 | Polygon3 *SplitPolygon(Polygon3 *poly, const float epsilon) const;
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85 |
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86 | /** Computes mass center of bsp node geometry.
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87 | */
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88 | Vector3 CenterOfMass() const;
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89 |
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90 | bool Valid() const;
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91 |
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92 |
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93 | friend ostream &operator<<(ostream &s, const BspNodeGeometry &a)
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94 | {
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95 | PolygonContainer::const_iterator it, it_end = a.mPolys.end();
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96 |
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97 | for (it = a.mPolys.begin(); it != it_end; ++ it)
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98 | s << *(*it) << endl;
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99 | return s << endl;
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100 | }
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101 |
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102 | int Size() const;
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103 | const PolygonContainer &GetPolys();
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104 |
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105 | /** Adds polygon and plane equation to this geometry.
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106 | */
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107 | void Add(Polygon3 *p, const Plane3 &plane);
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108 |
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109 | /** Adds node geometry to mesh.
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110 | @note the mesh vertices will not be connected
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111 | */
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112 | friend void IncludeNodeGeomInMesh(const BspNodeGeometry &geom, Mesh &mesh);
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113 |
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114 | protected:
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115 | /** The polygons the geometry consists of.
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116 | */
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117 | PolygonContainer mPolys;
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118 |
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119 | /** The corresponding set of planes for the polygons.
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120 | Need this because of precision issues.
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121 | */
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122 | vector<Plane3> mPlanes;
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123 | };
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124 |
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125 |
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126 | /** Data structure used for optimized ray casting.
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127 | */
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128 | struct BspRayTraversalData
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129 | {
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130 | BspNode *mNode;
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131 | Vector3 mExitPoint;
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132 | float mMaxT;
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133 |
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134 | BspRayTraversalData() {}
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135 |
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136 | BspRayTraversalData(BspNode *n, const Vector3 &extp, const float maxt):
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137 | mNode(n), mExitPoint(extp), mMaxT(maxt)
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138 | {}
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139 |
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140 | BspRayTraversalData(BspNode *n, const Vector3 &extp):
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141 | mNode(n), mExitPoint(extp)
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142 | {}
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143 | };
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144 |
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145 | /** Data used for passing ray data down the tree.
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146 | */
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147 | struct BoundedRay
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148 | {
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149 | Ray *mRay;
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150 | float mMinT;
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151 | float mMaxT;
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152 |
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153 | BoundedRay(): mMinT(0), mMaxT(1e6), mRay(NULL)
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154 | {}
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155 | BoundedRay(Ray *r, float minT, float maxT):
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156 | mRay(r), mMinT(minT), mMaxT(maxT)
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157 | {}
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158 | };
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159 |
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160 | typedef vector<BoundedRay *> BoundedRayContainer;
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161 |
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162 | class BspTreeStatistics: public StatisticsBase
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163 | {
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164 | public:
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165 | // total number of nodes
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166 | int nodes;
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167 | // number of splits
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168 | int splits[3];
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169 |
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170 | // totals number of rays
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171 | int rays;
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172 | // maximal reached depth
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173 | int maxDepth;
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174 | // minimal depth
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175 | int minDepth;
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176 |
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177 | // max depth nodes
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178 | int maxDepthNodes;
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179 | // minimum depth nodes
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180 | int minDepthNodes;
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181 | // max depth nodes
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182 | int minPvsNodes;
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183 | // nodes with minimum PVS
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184 | int minRaysNodes;
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185 | // max ray contribution nodes
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186 | int maxRayContribNodes;
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187 | // minimum area nodes
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188 | int minProbabilityNodes;
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189 | /// nodes termination because of max cost ratio;
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190 | int maxCostNodes;
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191 | // max number of rays per node
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192 | int maxObjectRefs;
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193 | // accumulated depth (used to compute average)
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194 | int accumDepth;
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195 | // number of initial polygons
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196 | int polys;
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197 | /// samples contributing to pvs
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198 | int contributingSamples;
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199 | /// sample contributions to pvs
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200 | int sampleContributions;
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201 | /// largest pvs
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202 | int maxPvs;
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203 | /// number of invalid leaves
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204 | int invalidLeaves;
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205 | /// polygon splits
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206 | int polySplits;
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207 | /// accumulated number of rays refs
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208 | int accumRays;
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209 | int pvs;
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210 |
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211 | // Constructor
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212 | BspTreeStatistics()
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213 | {
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214 | Reset();
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215 | }
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216 |
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217 | int Nodes() const {return nodes;}
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218 | int Interior() const { return nodes / 2; }
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219 | int Leaves() const { return (nodes / 2) + 1; }
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220 |
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221 | // TODO: computation wrong
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222 | double AvgDepth() const { return accumDepth / (double)Leaves();};
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223 | double AvgRays() const { return accumRays / (double)Leaves();};
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224 |
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225 | void Reset()
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226 | {
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227 | nodes = 0;
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228 | for (int i = 0; i < 3; ++ i)
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229 | splits[i] = 0;
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230 |
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231 | maxDepth = 0;
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232 | minDepth = 99999;
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233 | polys = 0;
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234 | accumDepth = 0;
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235 | pvs = 0;
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236 | maxDepthNodes = 0;
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237 | minPvsNodes = 0;
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238 | minRaysNodes = 0;
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239 | maxRayContribNodes = 0;
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240 | minProbabilityNodes = 0;
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241 | maxCostNodes = 0;
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242 |
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243 | contributingSamples = 0;
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244 | sampleContributions = 0;
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245 |
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246 | maxPvs = 0;
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247 | invalidLeaves = 0;
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248 | polySplits = 0;
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249 | accumRays = 0;
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250 | }
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251 |
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252 | void Print(ostream &app) const;
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253 |
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254 | friend ostream &operator<<(ostream &s, const BspTreeStatistics &stat)
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255 | {
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256 | stat.Print(s);
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257 | return s;
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258 | }
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259 | };
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260 |
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261 |
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262 | /**
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263 | BspNode abstract class serving for interior and leaf node implementation
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264 | */
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265 | class BspNode
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266 | {
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267 | friend class BspTree;
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268 |
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269 | public:
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270 | BspNode();
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271 | virtual ~BspNode(){};
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272 | BspNode(BspInterior *parent);
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273 |
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274 | /** Determines whether this node is a leaf or not
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275 | @return true if leaf
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276 | */
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277 | virtual bool IsLeaf() const = 0;
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278 |
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279 | /** Determines whether this node is a root
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280 | @return true if root
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281 | */
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282 | virtual bool IsRoot() const;
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283 |
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284 | /** Returns parent node.
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285 | */
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286 | BspInterior *GetParent();
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287 |
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288 | /** Sets parent node.
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289 | */
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290 | void SetParent(BspInterior *parent);
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291 |
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292 | /** Returns true if this node is a sibling of node n.
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293 | */
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294 | bool IsSibling(BspNode *n) const;
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295 |
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296 | /** returns depth of the node.
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297 | */
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298 | int GetDepth() const;
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299 |
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300 | /** returns true if the whole subtree is valid
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301 | */
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302 | bool TreeValid() const;
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303 |
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304 | void SetTreeValid(const bool v);
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305 |
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306 | //-- mailing options
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307 |
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308 | void Mail() { mMailbox = sMailId; }
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309 | static void NewMail() { ++ sMailId; }
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310 | bool Mailed() const { return mMailbox == sMailId; }
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311 |
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312 | static int sMailId;
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313 | int mMailbox;
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314 |
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315 | int mTimeStamp;
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316 |
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317 | protected:
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318 |
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319 | /// if this sub tree is a completely valid view space region
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320 | bool mTreeValid;
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321 | /// parent of this node
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322 | BspInterior *mParent;
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323 | };
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324 |
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325 |
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326 | /** BSP interior node implementation
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327 | */
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328 | class BspInterior: public BspNode
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329 | {
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330 | friend class BspTree;
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331 | public:
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332 | /** Standard contructor taking split plane as argument.
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333 | */
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334 | BspInterior(const Plane3 &plane);
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335 | ~BspInterior();
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336 | /** @return false since it is an interior node
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337 | */
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338 | bool IsLeaf() const;
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339 |
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340 | BspNode *GetBack();
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341 | BspNode *GetFront();
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342 |
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343 | /** Returns split plane.
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344 | */
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345 | Plane3 GetPlane() const;
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346 |
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347 | /** Replace front or back child with new child.
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348 | */
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349 | void ReplaceChildLink(BspNode *oldChild, BspNode *newChild);
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350 | /** Replace front and back child.
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351 | */
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352 | void SetupChildLinks(BspNode *b, BspNode *f);
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353 |
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354 | friend ostream &operator<<(ostream &s, const BspInterior &A)
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355 | {
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356 | return s << A.mPlane;
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357 | }
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358 |
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359 | protected:
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360 |
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361 | /// Splitting plane corresponding to this node
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362 | Plane3 mPlane;
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363 |
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364 | /// back node
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365 | BspNode *mBack;
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366 | /// front node
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367 | BspNode *mFront;
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368 | };
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369 |
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370 |
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371 | /** BSP leaf node implementation.
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372 | */
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373 | class BspLeaf: public BspNode
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374 | {
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375 | friend class BspTree;
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376 |
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377 | public:
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378 | BspLeaf();
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379 | BspLeaf(ViewCellLeaf *viewCell);
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380 | BspLeaf(BspInterior *parent);
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381 | BspLeaf(BspInterior *parent, ViewCellLeaf *viewCell);
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382 |
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383 | ~BspLeaf();
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384 |
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385 | /** @return true since it is an interior node
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386 | */
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387 | bool IsLeaf() const;
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388 |
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389 | /** Returns pointer of view cell.
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390 | */
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391 | ViewCellLeaf *GetViewCell() const;
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392 |
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393 | /** Sets pointer to view cell.
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394 | */
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395 | void SetViewCell(ViewCellLeaf *viewCell);
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396 |
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397 | /// Rays piercing this leaf.
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398 | VssRayContainer mVssRays;
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399 |
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400 | /// leaf pvs
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401 | ObjectPvs *mPvs;
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402 |
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403 | /// Probability that the view point lies in this leaf
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404 | float mProbability;
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405 |
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406 | protected:
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407 |
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408 | /// if NULL this does not correspond to feasible viewcell
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409 | ViewCellLeaf *mViewCell;
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410 | };
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411 |
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412 | /** Implementation of the view cell BSP tree.
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413 | */
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414 | class BspTree
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415 | {
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416 | friend class ViewCellsParseHandlers;
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417 |
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418 | public:
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419 |
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420 | /** Additional data which is passed down the BSP tree during traversal.
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421 | */
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422 | struct BspTraversalData
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423 | {
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424 | /// the current node
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425 | BspNode *mNode;
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426 | /// polygonal data for splitting
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427 | PolygonContainer *mPolygons;
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428 | /// current depth
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429 | int mDepth;
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430 | /// the view cell associated with this subdivsion
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431 | ViewCellLeaf *mViewCell;
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432 | /// rays piercing this node
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433 | BoundedRayContainer *mRays;
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434 | /// probability of current node
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435 | float mProbability;
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436 | /// geometry of node as induced by planes
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437 | BspNodeGeometry *mGeometry;
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438 |
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439 | /// pvs size
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440 | int mPvs;
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441 |
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442 | /** Returns average ray contribution.
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443 | */
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444 | float GetAvgRayContribution() const
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445 | {
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446 | return (float)mPvs / ((float)mRays->size() + Limits::Small);
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447 | }
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448 |
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449 |
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450 | BspTraversalData():
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451 | mNode(NULL),
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452 | mPolygons(NULL),
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453 | mDepth(0),
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454 | mViewCell(NULL),
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455 | mRays(NULL),
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456 | mPvs(0),
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457 | mProbability(0.0),
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458 | mGeometry(NULL)
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459 | {}
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460 |
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461 | BspTraversalData(BspNode *node,
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462 | PolygonContainer *polys,
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463 | const int depth,
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464 | ViewCellLeaf *viewCell,
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465 | BoundedRayContainer *rays,
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466 | int pvs,
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467 | float p,
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468 | BspNodeGeometry *cell):
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469 | mNode(node),
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470 | mPolygons(polys),
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471 | mDepth(depth),
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472 | mViewCell(viewCell),
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473 | mRays(rays),
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474 | mPvs(pvs),
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475 | mProbability(p),
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476 | mGeometry(cell)
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477 | {}
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478 |
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479 |
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480 | float GetCost() const
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481 | {
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482 | #if 0
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483 | return mPvs * mProbability;
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484 | #endif
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485 | #if 0
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486 | return (float) (-mDepth); // for regular grid
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487 | #endif
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488 | #if 1
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489 | return (float) mDepth; // depth first
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490 | #endif
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491 | #if 0
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492 | return mProbability;
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493 | #endif
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494 | #if 0
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495 | return (float)mPvs;
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496 | #endif
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497 | #if 0
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498 | return (float)mRays->size();
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499 | #endif
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500 | }
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501 |
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502 | friend bool operator<(const BspTraversalData &a, const BspTraversalData &b)
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503 | {
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504 | return a.GetCost() < b.GetCost();
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505 | }
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506 | };
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507 |
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508 | //typedef std::stack<BspTraversalData> BspTraversalStack;
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509 | typedef std::priority_queue<BspTraversalData> BspTraversalStack;
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510 |
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511 | /** Default constructor reading the environment file and
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512 | creating an empty tree.
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513 | */
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514 | BspTree();
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515 | /** Destroys tree and nodes.
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516 | */
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517 | ~BspTree();
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518 |
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519 | /** Returns detailed statistics of the BSP tree.
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520 | */
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521 | const BspTreeStatistics &GetStatistics() const;
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522 |
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523 | /** Constructs tree using the given list of view cells.
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524 | For this type of construction we filter all view cells down the
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525 | tree. If there is no polygon left, the last split plane
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526 | decides inside or outside of the viewcell. A pointer to the
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527 | appropriate view cell is stored within each leaf.
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528 | Many leafs can point to the same viewcell.
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529 | */
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530 | void Construct(const ViewCellContainer &viewCells);
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531 |
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532 | /** Constructs tree using the given list of objects.
|
---|
533 | @note the objects are not taken as view cells, but the view cells are
|
---|
534 | constructed from the subdivision: Each leaf is taken as one viewcell.
|
---|
535 | @param objects list of objects
|
---|
536 | */
|
---|
537 | void Construct(const ObjectContainer &objects);
|
---|
538 |
|
---|
539 | void Construct(const ObjectContainer &objects,
|
---|
540 | const RayContainer &sampleRays,
|
---|
541 | AxisAlignedBox3 *forcedBoundingBox);
|
---|
542 |
|
---|
543 | /** Constructs the tree from a given set of rays.
|
---|
544 | @param sampleRays the set of sample rays the construction is based on
|
---|
545 | @param viewCells if not NULL, new view cells are
|
---|
546 | created in the leafs and stored in the conatainer
|
---|
547 | */
|
---|
548 | void Construct(const RayContainer &sampleRays,
|
---|
549 | AxisAlignedBox3 *forcedBoundingBox);
|
---|
550 |
|
---|
551 | /** Returns list of BSP leaves.
|
---|
552 | */
|
---|
553 | void CollectLeaves(vector<BspLeaf *> &leaves) const;
|
---|
554 |
|
---|
555 | /** Returns box which bounds the whole tree.
|
---|
556 | */
|
---|
557 | AxisAlignedBox3 GetBoundingBox()const;
|
---|
558 |
|
---|
559 | /** Returns root of BSP tree.
|
---|
560 | */
|
---|
561 | BspNode *GetRoot() const;
|
---|
562 |
|
---|
563 |
|
---|
564 | //bool Export(const string filename);
|
---|
565 |
|
---|
566 | /** Collects the leaf view cells of the tree
|
---|
567 | @param viewCells returns the view cells
|
---|
568 | */
|
---|
569 | void CollectViewCells(ViewCellContainer &viewCells) const;
|
---|
570 |
|
---|
571 | /** A ray is cast possible intersecting the tree.
|
---|
572 | @param the ray that is cast.
|
---|
573 | @returns the number of intersections with objects stored in the tree.
|
---|
574 | */
|
---|
575 | int _CastRay(Ray &ray);
|
---|
576 |
|
---|
577 |
|
---|
578 | int CastLineSegment(const Vector3 &origin,
|
---|
579 | const Vector3 &termination,
|
---|
580 | ViewCellContainer &viewcells
|
---|
581 | );
|
---|
582 |
|
---|
583 | ViewCell *GetViewCell(const Vector3 &point);
|
---|
584 |
|
---|
585 | /// bsp tree construction types
|
---|
586 | enum {FROM_INPUT_VIEW_CELLS, FROM_SCENE_GEOMETRY, FROM_SAMPLES};
|
---|
587 |
|
---|
588 | /** Returns statistics.
|
---|
589 | */
|
---|
590 | BspTreeStatistics &GetStat();
|
---|
591 |
|
---|
592 | /** finds neighbouring leaves of this tree node.
|
---|
593 | */
|
---|
594 | int FindNeighbors(BspNode *n, vector<BspLeaf *> &neighbors,
|
---|
595 | const bool onlyUnmailed) const;
|
---|
596 |
|
---|
597 | /** Constructs geometry of view cell returning a BSP node geometry type.
|
---|
598 | */
|
---|
599 | void ConstructGeometry(BspNode *n, BspNodeGeometry &cell) const;
|
---|
600 |
|
---|
601 | /** Construct geometry of view cell.
|
---|
602 | */
|
---|
603 | void ConstructGeometry(ViewCell* vc, BspNodeGeometry &geom) const;
|
---|
604 |
|
---|
605 |
|
---|
606 | /** Sets pointer to view cells manager.
|
---|
607 | */
|
---|
608 | void SetViewCellsManager(ViewCellsManager *vcm);
|
---|
609 |
|
---|
610 | /** Returns random leaf of BSP tree.
|
---|
611 | @param halfspace defines the halfspace from which the leaf is taken.
|
---|
612 | */
|
---|
613 | BspLeaf *GetRandomLeaf(const Plane3 &halfspace);
|
---|
614 |
|
---|
615 | /** Returns random leaf of BSP tree.
|
---|
616 | @param onlyUnmailed if only unmailed leaves should be returned.
|
---|
617 | */
|
---|
618 | BspLeaf *GetRandomLeaf(const bool onlyUnmailed = false);
|
---|
619 |
|
---|
620 |
|
---|
621 | /** Returns epsilon of this tree.
|
---|
622 | */
|
---|
623 | float GetEpsilon() const;
|
---|
624 |
|
---|
625 | int CollectMergeCandidates(const vector<BspLeaf *> leaves,
|
---|
626 | vector<MergeCandidate> &candidates);
|
---|
627 |
|
---|
628 | int CollectMergeCandidates(const VssRayContainer &rays,
|
---|
629 | vector<MergeCandidate> &candidates);
|
---|
630 |
|
---|
631 | /** Exports Bsp tree to file.
|
---|
632 | */
|
---|
633 | bool Export(ofstream &stream);
|
---|
634 |
|
---|
635 |
|
---|
636 | /** Returns view cell corresponding to
|
---|
637 | the invalid view space. If it does not exist, it is created.
|
---|
638 | */
|
---|
639 | BspViewCell *GetOutOfBoundsCell();
|
---|
640 |
|
---|
641 | ViewCellsTree *mViewCellsTree;
|
---|
642 |
|
---|
643 | protected:
|
---|
644 |
|
---|
645 | // --------------------------------------------------------------
|
---|
646 | // For sorting objects
|
---|
647 | // --------------------------------------------------------------
|
---|
648 | struct SortableEntry
|
---|
649 | {
|
---|
650 | enum {POLY_MIN, POLY_MAX};
|
---|
651 |
|
---|
652 | int type;
|
---|
653 | float value;
|
---|
654 | Polygon3 *poly;
|
---|
655 | SortableEntry() {}
|
---|
656 | SortableEntry(const int t, const float v, Polygon3 *poly):
|
---|
657 | type(t), value(v), poly(poly) {}
|
---|
658 |
|
---|
659 | bool operator<(const SortableEntry &b) const
|
---|
660 | {
|
---|
661 | return value < b.value;
|
---|
662 | }
|
---|
663 | };
|
---|
664 |
|
---|
665 | void ExportNode(BspNode *node, ofstream &stream);
|
---|
666 |
|
---|
667 | /** Evaluates tree stats in the BSP tree leafs.
|
---|
668 | */
|
---|
669 | void EvaluateLeafStats(const BspTraversalData &data);
|
---|
670 |
|
---|
671 | /** Subdivides node with respect to the traversal data.
|
---|
672 | @param tStack current traversal stack
|
---|
673 | @param tData traversal data also holding node to be subdivided
|
---|
674 | @returns new root of the subtree
|
---|
675 | */
|
---|
676 | BspNode *Subdivide(BspTraversalStack &tStack, BspTraversalData &tData);
|
---|
677 |
|
---|
678 | /** Constructs the tree from the given list of polygons and rays.
|
---|
679 | @param polys stores set of polygons on which subdivision may be based
|
---|
680 | @param rays storesset of rays on which subdivision may be based
|
---|
681 | */
|
---|
682 | void Construct(PolygonContainer *polys, BoundedRayContainer *rays);
|
---|
683 |
|
---|
684 | /** Selects the best possible splitting plane.
|
---|
685 | @param leaf the leaf to be split
|
---|
686 | @param polys the polygon list on which the split decition is based
|
---|
687 | @param rays ray container on which selection may be based
|
---|
688 | @note the polygons can be reordered in the process
|
---|
689 | @returns the split plane
|
---|
690 | */
|
---|
691 | Plane3 SelectPlane(BspLeaf *leaf,
|
---|
692 | BspTraversalData &data);
|
---|
693 |
|
---|
694 | /** Evaluates the contribution of the candidate split plane.
|
---|
695 |
|
---|
696 | @param candidatePlane the candidate split plane
|
---|
697 | @param polys the polygons the split can be based on
|
---|
698 | @param rays the rays the split can be based on
|
---|
699 |
|
---|
700 | @returns the cost of the candidate split plane
|
---|
701 | */
|
---|
702 | float SplitPlaneCost(const Plane3 &candidatePlane,
|
---|
703 | BspTraversalData &data) const;
|
---|
704 |
|
---|
705 | /** Strategies where the effect of the split plane is tested
|
---|
706 | on all input rays.
|
---|
707 | @returns the cost of the candidate split plane
|
---|
708 | */
|
---|
709 | float SplitPlaneCost(const Plane3 &candidatePlane,
|
---|
710 | const PolygonContainer &polys) const;
|
---|
711 |
|
---|
712 | /** Strategies where the effect of the split plane is tested
|
---|
713 | on all input rays.
|
---|
714 |
|
---|
715 | @returns the cost of the candidate split plane
|
---|
716 | */
|
---|
717 | float SplitPlaneCost(const Plane3 &candidatePlane,
|
---|
718 | const BoundedRayContainer &rays,
|
---|
719 | const int pvs,
|
---|
720 | const float probability,
|
---|
721 | const BspNodeGeometry &cell) const;
|
---|
722 |
|
---|
723 | /** Filters next view cell down the tree and inserts it into the appropriate leaves
|
---|
724 | (i.e., possibly more than one leaf).
|
---|
725 | */
|
---|
726 | void InsertViewCell(ViewCellLeaf *viewCell);
|
---|
727 | /** Inserts polygons down the tree. The polygons are filtered until a leaf is reached,
|
---|
728 | then further subdivided.
|
---|
729 | */
|
---|
730 | void InsertPolygons(PolygonContainer *polys);
|
---|
731 |
|
---|
732 | /** Subdivide leaf.
|
---|
733 | @param leaf the leaf to be subdivided
|
---|
734 |
|
---|
735 | @param polys the polygons to be split
|
---|
736 | @param frontPolys returns the polygons in front of the split plane
|
---|
737 | @param backPolys returns the polygons in the back of the split plane
|
---|
738 |
|
---|
739 | @param rays the polygons to be filtered
|
---|
740 | @param frontRays returns the polygons in front of the split plane
|
---|
741 | @param backRays returns the polygons in the back of the split plane
|
---|
742 |
|
---|
743 | @returns the root of the subdivision
|
---|
744 | */
|
---|
745 |
|
---|
746 | BspInterior *SubdivideNode(BspTraversalData &tData,
|
---|
747 | BspTraversalData &frontData,
|
---|
748 | BspTraversalData &backData,
|
---|
749 | PolygonContainer &coincident);
|
---|
750 |
|
---|
751 | /** Filters polygons down the tree.
|
---|
752 | @param node the current BSP node
|
---|
753 | @param polys the polygons to be filtered
|
---|
754 | @param frontPolys returns the polygons in front of the split plane
|
---|
755 | @param backPolys returns the polygons in the back of the split plane
|
---|
756 | */
|
---|
757 | void FilterPolygons(BspInterior *node,
|
---|
758 | PolygonContainer *polys,
|
---|
759 | PolygonContainer *frontPolys,
|
---|
760 | PolygonContainer *backPolys);
|
---|
761 |
|
---|
762 | /** Take 3 ray endpoints, where two are minimum and one a maximum
|
---|
763 | point or the other way round.
|
---|
764 | */
|
---|
765 | Plane3 ChooseCandidatePlane(const BoundedRayContainer &rays) const;
|
---|
766 |
|
---|
767 | /** Take plane normal as plane normal and the midpoint of the ray.
|
---|
768 | PROBLEM: does not resemble any point where visibility is likely to change
|
---|
769 | */
|
---|
770 | Plane3 ChooseCandidatePlane2(const BoundedRayContainer &rays) const;
|
---|
771 |
|
---|
772 | /** Fit the plane between the two lines so that the plane has equal shortest
|
---|
773 | distance to both lines.
|
---|
774 | */
|
---|
775 | Plane3 ChooseCandidatePlane3(const BoundedRayContainer &rays) const;
|
---|
776 |
|
---|
777 | /** Selects the split plane in order to construct a tree with
|
---|
778 | certain characteristics (e.g., balanced tree, least splits,
|
---|
779 | 2.5d aligned)
|
---|
780 | @param polygons container of polygons
|
---|
781 | @param rays bundle of rays on which the split can be based
|
---|
782 | */
|
---|
783 | Plane3 SelectPlaneHeuristics(BspLeaf *leaf,
|
---|
784 | BspTraversalData &data);
|
---|
785 |
|
---|
786 | /** Extracts the meshes of the objects and adds them to polygons.
|
---|
787 | Adds object aabb to the aabb of the tree.
|
---|
788 | @param maxPolys the maximal number of objects to be stored as polygons
|
---|
789 | @returns the number of polygons
|
---|
790 | */
|
---|
791 | int AddToPolygonSoup(const ObjectContainer &objects,
|
---|
792 | PolygonContainer &polys,
|
---|
793 | int maxObjects = 0,
|
---|
794 | bool addToBbox = true);
|
---|
795 |
|
---|
796 | /** Extracts the meshes of the view cells and and adds them to polygons.
|
---|
797 | Adds view cell aabb to the aabb of the tree.
|
---|
798 | @param maxPolys the maximal number of objects to be stored as polygons
|
---|
799 | @returns the number of polygons
|
---|
800 | */
|
---|
801 | int AddToPolygonSoup(const ViewCellContainer &viewCells,
|
---|
802 | PolygonContainer &polys,
|
---|
803 | int maxObjects = 0);
|
---|
804 |
|
---|
805 | /** Extract polygons of this mesh and add to polygon container.
|
---|
806 | @param mesh the mesh that drives the polygon construction
|
---|
807 | @param parent the parent intersectable this polygon is constructed from
|
---|
808 | @returns number of polygons
|
---|
809 | */
|
---|
810 | int AddMeshToPolygons(Mesh *mesh, PolygonContainer &polys, MeshInstance *parent);
|
---|
811 |
|
---|
812 | /** Helper function which extracts a view cell on the front and the back
|
---|
813 | of the split plane.
|
---|
814 | @param backViewCell returns view cell on the back of the split plane
|
---|
815 | @param frontViewCell returns a view cell on the front of the split plane
|
---|
816 | @param coincident container of polygons coincident to the split plane
|
---|
817 | @param splitPlane the split plane which decides about back and front
|
---|
818 | @param extractBack if a back view cell is extracted
|
---|
819 | @param extractFront if a front view cell is extracted
|
---|
820 | */
|
---|
821 | void ExtractViewCells(BspTraversalData &frontData,
|
---|
822 | BspTraversalData &backData,
|
---|
823 | const PolygonContainer &coincident,
|
---|
824 | const Plane3 &splitPlane) const;
|
---|
825 |
|
---|
826 | /** Computes best cost ratio for the suface area heuristics for axis aligned
|
---|
827 | splits. This heuristics minimizes the cost for ray traversal.
|
---|
828 | @param polys the polygons guiding the ratio computation
|
---|
829 | @param box the bounding box of the leaf
|
---|
830 | @param axis the current split axis
|
---|
831 | @param position returns the split position
|
---|
832 | @param objectsBack the number of objects in the back of the split plane
|
---|
833 | @param objectsFront the number of objects in the front of the split plane
|
---|
834 | */
|
---|
835 | float BestCostRatio(const PolygonContainer &polys,
|
---|
836 | const AxisAlignedBox3 &box,
|
---|
837 | const int axis,
|
---|
838 | float &position,
|
---|
839 | int &objectsBack,
|
---|
840 | int &objectsFront) const;
|
---|
841 |
|
---|
842 | /** Sorts split candidates for surface area heuristics for axis aligned splits.
|
---|
843 | @param polys the input for choosing split candidates
|
---|
844 | @param axis the current split axis
|
---|
845 | @param splitCandidates returns sorted list of split candidates
|
---|
846 | */
|
---|
847 | void SortSplitCandidates(const PolygonContainer &polys,
|
---|
848 | const int axis,
|
---|
849 | vector<SortableEntry> &splitCandidates) const;
|
---|
850 |
|
---|
851 | /** Selects an axis aligned split plane.
|
---|
852 | Returns true if split is valied
|
---|
853 | */
|
---|
854 | bool SelectAxisAlignedPlane(Plane3 &plane, const PolygonContainer &polys) const;
|
---|
855 |
|
---|
856 | /** Subdivides the rays into front and back rays according to the split plane.
|
---|
857 |
|
---|
858 | @param plane the split plane
|
---|
859 | @param rays contains the rays to be split. The rays are
|
---|
860 | distributed into front and back rays.
|
---|
861 | @param frontRays returns rays on the front side of the plane
|
---|
862 | @param backRays returns rays on the back side of the plane
|
---|
863 |
|
---|
864 | @returns the number of splits
|
---|
865 | */
|
---|
866 | int SplitRays(const Plane3 &plane,
|
---|
867 | BoundedRayContainer &rays,
|
---|
868 | BoundedRayContainer &frontRays,
|
---|
869 | BoundedRayContainer &backRays);
|
---|
870 |
|
---|
871 |
|
---|
872 | /** Extracts the split planes representing the space bounded by node n.
|
---|
873 | */
|
---|
874 | void ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const;
|
---|
875 |
|
---|
876 | /** Adds the object to the pvs of the front and back leaf with a given classification.
|
---|
877 |
|
---|
878 | @param obj the object to be added
|
---|
879 | @param cf the ray classification regarding the split plane
|
---|
880 | @param frontPvs returns the PVS of the front partition
|
---|
881 | @param backPvs returns the PVS of the back partition
|
---|
882 |
|
---|
883 | */
|
---|
884 | void AddObjToPvs(Intersectable *obj, const int cf, int &frontPvs, int &backPvs) const;
|
---|
885 |
|
---|
886 | /** Computes PVS size induced by the rays.
|
---|
887 | */
|
---|
888 | int ComputePvsSize(const BoundedRayContainer &rays) const;
|
---|
889 |
|
---|
890 | /** Returns true if tree can be terminated.
|
---|
891 | */
|
---|
892 | inline bool TerminationCriteriaMet(const BspTraversalData &data) const;
|
---|
893 |
|
---|
894 | /** Computes accumulated ray lenght of this rays.
|
---|
895 | */
|
---|
896 | float AccumulatedRayLength(BoundedRayContainer &rays) const;
|
---|
897 |
|
---|
898 | /** Splits polygons with respect to the split plane.
|
---|
899 | @param polys the polygons to be split. the polygons are consumed and
|
---|
900 | distributed to the containers frontPolys, backPolys, coincident.
|
---|
901 | @param frontPolys returns the polygons in the front of the split plane
|
---|
902 | @param backPolys returns the polygons in the back of the split plane
|
---|
903 | @param coincident returns the polygons coincident to the split plane
|
---|
904 |
|
---|
905 | @returns the number of splits
|
---|
906 | */
|
---|
907 | int SplitPolygons(const Plane3 &plane,
|
---|
908 | PolygonContainer &polys,
|
---|
909 | PolygonContainer &frontPolys,
|
---|
910 | PolygonContainer &backPolys,
|
---|
911 | PolygonContainer &coincident) const;
|
---|
912 |
|
---|
913 | /** Adds ray sample contributions to the PVS.
|
---|
914 | @param sampleContributions the number contributions of the samples
|
---|
915 | @param contributingSampels the number of contributing rays
|
---|
916 |
|
---|
917 | */
|
---|
918 | void AddToPvs(BspLeaf *leaf,
|
---|
919 | const BoundedRayContainer &rays,
|
---|
920 | int &sampleContributions,
|
---|
921 | int &contributingSamples);
|
---|
922 |
|
---|
923 | /** Preprocesses polygons and throws out all polygons which
|
---|
924 | are coincident to the view space box faces:
|
---|
925 | These polygons can can be problematic for bsp because they create
|
---|
926 | bad view cells.
|
---|
927 | */
|
---|
928 | void PreprocessPolygons(PolygonContainer &polys);
|
---|
929 |
|
---|
930 | /** Returns view cell corresponding to the invalid view space.
|
---|
931 | If it does not exist, it is created.
|
---|
932 | */
|
---|
933 | BspViewCell *GetOrCreateOutOfBoundsCell();
|
---|
934 |
|
---|
935 | /// Pointer to the root of the tree.
|
---|
936 | BspNode *mRoot;
|
---|
937 |
|
---|
938 | /// Stores statistics during traversal.
|
---|
939 | BspTreeStatistics mStat;
|
---|
940 |
|
---|
941 | /// Strategies for choosing next split plane.
|
---|
942 | enum {NO_STRATEGY = 0,
|
---|
943 | RANDOM_POLYGON = 1,
|
---|
944 | AXIS_ALIGNED = 2,
|
---|
945 | LEAST_SPLITS = 4,
|
---|
946 | BALANCED_POLYS = 8,
|
---|
947 | BALANCED_VIEW_CELLS = 16,
|
---|
948 | LARGEST_POLY_AREA = 32,
|
---|
949 | VERTICAL_AXIS = 64,
|
---|
950 | BLOCKED_RAYS = 128,
|
---|
951 | LEAST_RAY_SPLITS = 256,
|
---|
952 | BALANCED_RAYS = 512,
|
---|
953 | PVS = 1024
|
---|
954 | };
|
---|
955 |
|
---|
956 | /// box around the whole view domain
|
---|
957 | AxisAlignedBox3 mBox;
|
---|
958 |
|
---|
959 | /// view cell corresponding to unbounded space
|
---|
960 | BspViewCell *mOutOfBoundsCell;
|
---|
961 |
|
---|
962 | /// if view cells should be generated or the given view cells should be used.
|
---|
963 | bool mGenerateViewCells;
|
---|
964 |
|
---|
965 | /// maximal number of polygons before subdivision termination
|
---|
966 | int mTermMinPolys;
|
---|
967 | /// maximal number of rays before subdivision termination
|
---|
968 | int mTermMinRays;
|
---|
969 | /// maximal possible depth
|
---|
970 | int mTermMaxDepth;
|
---|
971 | /// mininum area
|
---|
972 | float mTermMinProbability;
|
---|
973 | /// mininum PVS
|
---|
974 | int mTermMinPvs;
|
---|
975 |
|
---|
976 | /// minimal number of polygons for axis aligned split
|
---|
977 | int mTermMinPolysForAxisAligned;
|
---|
978 | /// minimal number of rays for axis aligned split
|
---|
979 | int mTermMinRaysForAxisAligned;
|
---|
980 | /// minimal number of objects for axis aligned split
|
---|
981 | int mTermMinObjectsForAxisAligned;
|
---|
982 | /// maximal contribution per ray
|
---|
983 | float mTermMaxRayContribution;
|
---|
984 | /// minimal accumulated ray length
|
---|
985 | float mTermMinAccRayLength;
|
---|
986 |
|
---|
987 |
|
---|
988 | /// strategy to get the best split plane
|
---|
989 | int mSplitPlaneStrategy;
|
---|
990 | /// number of candidates evaluated for the next split plane
|
---|
991 | int mMaxPolyCandidates;
|
---|
992 | /// number of candidates for split planes evaluated using the rays
|
---|
993 | int mMaxRayCandidates;
|
---|
994 | /// maximum tests for split plane evaluation with a single candidate
|
---|
995 | int mMaxTests;
|
---|
996 |
|
---|
997 | float mCtDivCi;
|
---|
998 |
|
---|
999 | /// axis aligned split criteria
|
---|
1000 | float mAxisAlignedCtDivCi;
|
---|
1001 | float mSplitBorder;
|
---|
1002 | float mMaxCostRatio;
|
---|
1003 |
|
---|
1004 | // factors guiding the split plane heuristics
|
---|
1005 | float mVerticalSplitsFactor;
|
---|
1006 | float mLargestPolyAreaFactor;
|
---|
1007 | float mBlockedRaysFactor;
|
---|
1008 | float mLeastRaySplitsFactor;
|
---|
1009 | float mBalancedRaysFactor;
|
---|
1010 | float mPvsFactor;
|
---|
1011 | float mLeastSplitsFactor;
|
---|
1012 | float mBalancedPolysFactor;
|
---|
1013 | float mBalancedViewCellsFactor;
|
---|
1014 |
|
---|
1015 | /// if area or accumulated ray lenght should be used for PVS heuristics
|
---|
1016 | bool mUseAreaForPvs;
|
---|
1017 |
|
---|
1018 | int mMaxViewCells;
|
---|
1019 |
|
---|
1020 | /// epsilon where two points are still considered equal
|
---|
1021 | float mEpsilon;
|
---|
1022 |
|
---|
1023 | ViewCellsManager *mViewCellsManager;
|
---|
1024 |
|
---|
1025 | int mTimeStamp;
|
---|
1026 |
|
---|
1027 | float mTotalCost;
|
---|
1028 | int mTotalPvsSize;
|
---|
1029 |
|
---|
1030 | //int mSplits;
|
---|
1031 | ofstream mSubdivisionStats;
|
---|
1032 |
|
---|
1033 | private:
|
---|
1034 |
|
---|
1035 | /** Evaluates split plane classification with respect to the plane's
|
---|
1036 | contribution for a balanced tree.
|
---|
1037 | */
|
---|
1038 | static const float sLeastPolySplitsTable[4];
|
---|
1039 | /** Evaluates split plane classification with respect to the plane's
|
---|
1040 | contribution for a minimum number splits in the tree.
|
---|
1041 | */
|
---|
1042 | static const float sBalancedPolysTable[4];
|
---|
1043 | /** Evaluates split plane classification with respect to the plane's
|
---|
1044 | contribution for a minimum number of ray splits.
|
---|
1045 | */
|
---|
1046 | static const float sLeastRaySplitsTable[5];
|
---|
1047 | /** Evaluates split plane classification with respect to the plane's
|
---|
1048 | contribution for balanced rays.
|
---|
1049 | */
|
---|
1050 | static const float sBalancedRaysTable[5];
|
---|
1051 |
|
---|
1052 | /// Generates unique ids for PVS criterium
|
---|
1053 | static void GenerateUniqueIdsForPvs();
|
---|
1054 |
|
---|
1055 | //-- unique ids for PVS criterium
|
---|
1056 | static int sFrontId;
|
---|
1057 | static int sBackId;
|
---|
1058 | static int sFrontAndBackId;
|
---|
1059 | };
|
---|
1060 |
|
---|
1061 |
|
---|
1062 | struct BspIntersection
|
---|
1063 | {
|
---|
1064 | // the point of intersection
|
---|
1065 | float mT;
|
---|
1066 |
|
---|
1067 | BspLeaf *mLeaf;
|
---|
1068 |
|
---|
1069 | BspIntersection(const float t, BspLeaf *l):
|
---|
1070 | mT(t), mLeaf(l) {}
|
---|
1071 |
|
---|
1072 | BspIntersection() {}
|
---|
1073 |
|
---|
1074 | bool operator<(const BspIntersection &b) const
|
---|
1075 | {
|
---|
1076 | return mT < b.mT;
|
---|
1077 | }
|
---|
1078 | };
|
---|
1079 |
|
---|
1080 | /** struct storing the view cell intersections.
|
---|
1081 | */
|
---|
1082 | struct BspRay
|
---|
1083 | {
|
---|
1084 | VssRay *vssRay;
|
---|
1085 |
|
---|
1086 | std::vector<BspIntersection> intersections;
|
---|
1087 |
|
---|
1088 | BspRay(VssRay *ray): vssRay(ray) {}
|
---|
1089 | };
|
---|
1090 |
|
---|
1091 | }
|
---|
1092 |
|
---|
1093 | #endif
|
---|