[437] | 1 | #ifndef _VspBspTree_H__ |
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| 2 | #define _VspBspTree_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 "RayInfo.h" |
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| 11 | |
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| 12 | class ViewCell; |
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| 13 | class BspViewCell; |
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| 14 | class Plane3; |
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| 15 | class VspBspTree; |
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| 16 | class VspBspInterior; |
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| 17 | class VspBspNode; |
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| 18 | class AxisAlignedBox3; |
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| 19 | class Ray; |
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| 20 | |
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| 21 | class VspBspNodeGeometry |
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| 22 | { |
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| 23 | public: |
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| 24 | VspBspNodeGeometry() |
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| 25 | {}; |
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| 26 | |
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| 27 | ~VspBspNodeGeometry(); |
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| 28 | |
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| 29 | float GetArea() const; |
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| 30 | |
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| 31 | /** Computes new cell based on the old cell definition and a new split plane |
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| 32 | @param side indicates which side of the halfspace |
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| 33 | */ |
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| 34 | void SplitGeometry(VspBspNodeGeometry &front, |
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| 35 | VspBspNodeGeometry &back, |
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| 36 | const VspBspTree &tree, |
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| 37 | const Plane3 &splitPlane) const; |
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| 38 | |
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| 39 | Polygon3 *SplitPolygon(Polygon3 *poly, const VspBspTree &tree) const; |
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| 40 | |
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| 41 | PolygonContainer mPolys; |
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| 42 | }; |
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| 43 | |
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| 44 | /** Data structure used for optimized ray casting. |
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| 45 | */ |
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| 46 | struct VspBspRayTraversalData |
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| 47 | { |
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| 48 | VspBspNode *mNode; |
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| 49 | Vector3 mExitPoint; |
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| 50 | float mMaxT; |
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| 51 | |
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| 52 | VspBspRayTraversalData() {} |
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| 53 | |
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| 54 | VspBspRayTraversalData(VspBspNode *n, const Vector3 &extp, const float maxt): |
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| 55 | mNode(n), mExitPoint(extp), mMaxT(maxt) |
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| 56 | {} |
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| 57 | }; |
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| 58 | |
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| 59 | class VspBspTreeStatistics: public StatisticsBase |
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| 60 | { |
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| 61 | public: |
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| 62 | // total number of nodes |
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| 63 | int nodes; |
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| 64 | // number of splits |
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| 65 | int splits; |
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| 66 | // totals number of rays |
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| 67 | int rays; |
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| 68 | // maximal reached depth |
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| 69 | int maxDepth; |
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| 70 | // minimal depth |
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| 71 | int minDepth; |
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| 72 | |
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| 73 | // max depth nodes |
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| 74 | int maxDepthNodes; |
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| 75 | // minimum depth nodes
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| 76 | int minDepthNodes;
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| 77 | // max depth nodes
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| 78 | int minPvsNodes;
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| 79 | // nodes with minimum PVS
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| 80 | int minRaysNodes;
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| 81 | // max ray contribution nodes
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| 82 | int maxRayContribNodes;
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| 83 | // minimum area nodes
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| 84 | int minAreaNodes; |
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| 85 | |
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| 86 | // max number of rays per node |
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| 87 | int maxObjectRefs; |
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| 88 | // accumulated depth (used to compute average) |
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| 89 | int accumDepth; |
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| 90 | // number of initial polygons |
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| 91 | int polys; |
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| 92 | /// samples contributing to pvs |
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| 93 | int contributingSamples; |
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| 94 | /// sample contributions to pvs |
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| 95 | int sampleContributions; |
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| 96 | /// largest pvs |
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| 97 | int largestPvs; |
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| 98 | |
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| 99 | // Constructor |
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| 100 | VspBspTreeStatistics() |
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| 101 | { |
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| 102 | Reset(); |
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| 103 | } |
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| 104 | |
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| 105 | int Nodes() const {return nodes;} |
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| 106 | int Interior() const { return nodes / 2; } |
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| 107 | int Leaves() const { return (nodes / 2) + 1; } |
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| 108 | |
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| 109 | // TODO: computation wrong |
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| 110 | double AvgDepth() const { return accumDepth / (double)Leaves();}; |
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| 111 | |
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| 112 | void Reset() |
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| 113 | { |
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| 114 | nodes = 0; |
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| 115 | splits = 0; |
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| 116 | |
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| 117 | maxDepth = 0; |
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| 118 | minDepth = 99999; |
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| 119 | polys = 0; |
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| 120 | accumDepth = 0; |
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| 121 | |
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| 122 | maxDepthNodes = 0;
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| 123 | minPvsNodes = 0;
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| 124 | minRaysNodes = 0;
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| 125 | maxRayContribNodes = 0; |
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| 126 | minAreaNodes = 0; |
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| 127 | |
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| 128 | contributingSamples = 0; |
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| 129 | sampleContributions = 0; |
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| 130 | } |
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| 131 | |
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| 132 | void Print(ostream &app) const; |
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| 133 | |
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| 134 | friend ostream &operator<<(ostream &s, const VspBspTreeStatistics &stat) |
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| 135 | { |
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| 136 | stat.Print(s); |
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| 137 | return s; |
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| 138 | } |
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| 139 | }; |
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| 140 | |
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| 141 | class VspBspViewCellsStatistics: public StatisticsBase |
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| 142 | { |
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| 143 | public: |
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| 144 | |
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| 145 | /// number of view cells |
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| 146 | int viewCells; |
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| 147 | |
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| 148 | /// size of the PVS |
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| 149 | int pvs; |
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| 150 | |
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| 151 | /// largest PVS of all view cells |
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| 152 | int maxPvs; |
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| 153 | |
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| 154 | /// smallest PVS of all view cells |
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| 155 | int minPvs; |
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| 156 | |
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| 157 | /// view cells with empty PVS |
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| 158 | int emptyPvs; |
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| 159 | |
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| 160 | /// number of bsp leaves covering the view space |
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| 161 | int bspLeaves; |
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| 162 | |
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| 163 | /// largest number of leaves covered by one view cell |
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| 164 | int maxVspBspLeaves; |
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| 165 | |
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| 166 | // Constructor |
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| 167 | VspBspViewCellsStatistics() |
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| 168 | { |
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| 169 | Reset(); |
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| 170 | } |
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| 171 | |
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| 172 | double AvgVspBspLeaves() const {return (double)bspLeaves / (double)viewCells;}; |
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| 173 | double AvgPvs() const {return (double)pvs / (double)viewCells;}; |
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| 174 | |
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| 175 | void Reset() |
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| 176 | { |
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| 177 | viewCells = 0; |
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| 178 | pvs = 0; |
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| 179 | maxPvs = 0; |
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| 180 | |
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| 181 | minPvs = 999999; |
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| 182 | emptyPvs = 0; |
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| 183 | bspLeaves = 0; |
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| 184 | maxVspBspLeaves = 0; |
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| 185 | } |
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| 186 | |
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| 187 | void Print(ostream &app) const; |
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| 188 | |
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| 189 | friend ostream &operator<<(ostream &s, const VspBspViewCellsStatistics &stat) |
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| 190 | { |
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| 191 | stat.Print(s); |
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| 192 | return s; |
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| 193 | } |
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| 194 | }; |
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| 195 | |
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| 196 | /** |
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| 197 | VspBspNode abstract class serving for interior and leaf node implementation |
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| 198 | */ |
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| 199 | class VspBspNode |
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| 200 | { |
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| 201 | friend class VspBspTree; |
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| 202 | |
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| 203 | public: |
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| 204 | VspBspNode(); |
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| 205 | virtual ~VspBspNode(){}; |
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| 206 | VspBspNode(VspBspInterior *parent); |
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| 207 | |
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| 208 | /** Determines whether this node is a leaf or not |
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| 209 | @return true if leaf |
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| 210 | */ |
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| 211 | virtual bool IsLeaf() const = 0; |
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| 212 | |
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| 213 | /** Determines whether this node is a root |
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| 214 | @return true if root |
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| 215 | */ |
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| 216 | virtual bool IsRoot() const; |
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| 217 | |
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| 218 | /** Returns parent node. |
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| 219 | */ |
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| 220 | VspBspInterior *GetParent(); |
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| 221 | |
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| 222 | /** Sets parent node. |
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| 223 | */ |
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| 224 | void SetParent(VspBspInterior *parent); |
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| 225 | |
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| 226 | |
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| 227 | static int sMailId; |
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| 228 | int mMailbox; |
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| 229 | |
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| 230 | void Mail() { mMailbox = sMailId; } |
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| 231 | static void NewMail() { ++ sMailId; } |
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| 232 | bool Mailed() const { return mMailbox == sMailId; } |
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| 233 | |
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| 234 | protected: |
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| 235 | |
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| 236 | /// parent of this node |
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| 237 | VspBspInterior *mParent; |
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| 238 | }; |
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| 239 | |
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| 240 | /** BSP interior node implementation |
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| 241 | */ |
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| 242 | class VspBspInterior : public VspBspNode |
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| 243 | { |
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| 244 | friend class VspBspTree; |
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| 245 | public: |
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| 246 | /** Standard contructor taking split plane as argument. |
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| 247 | */ |
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| 248 | VspBspInterior(const Plane3 &plane); |
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| 249 | ~VspBspInterior(); |
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| 250 | /** @return false since it is an interior node |
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| 251 | */ |
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| 252 | bool IsLeaf() const; |
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| 253 | |
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| 254 | VspBspNode *GetBack(); |
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| 255 | VspBspNode *GetFront(); |
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| 256 | |
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| 257 | Plane3 *GetPlane(); |
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| 258 | |
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| 259 | void ReplaceChildLink(VspBspNode *oldChild, VspBspNode *newChild); |
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| 260 | void SetupChildLinks(VspBspNode *b, VspBspNode *f); |
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| 261 | |
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| 262 | /** Splits polygons with respect to the split plane. |
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| 263 | @param polys the polygons to be split. the polygons are consumed and |
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| 264 | distributed to the containers frontPolys, backPolys, coincident. |
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| 265 | @param frontPolys returns the polygons in the front of the split plane |
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| 266 | @param backPolys returns the polygons in the back of the split plane |
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| 267 | @param coincident returns the polygons coincident to the split plane |
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| 268 | |
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| 269 | @returns the number of splits |
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| 270 | */ |
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| 271 | int SplitPolygons(PolygonContainer &polys, |
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| 272 | PolygonContainer &frontPolys, |
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| 273 | PolygonContainer &backPolys, |
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| 274 | PolygonContainer &coincident); |
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| 275 | |
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| 276 | friend ostream &operator<<(ostream &s, const VspBspInterior &A) |
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| 277 | { |
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| 278 | return s << A.mPlane; |
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| 279 | } |
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| 280 | |
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| 281 | protected: |
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| 282 | |
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| 283 | /// Splitting plane corresponding to this node |
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| 284 | Plane3 mPlane; |
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| 285 | /// back node |
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| 286 | VspBspNode *mBack; |
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| 287 | /// front node |
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| 288 | VspBspNode *mFront; |
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| 289 | }; |
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| 290 | |
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| 291 | /** BSP leaf node implementation. |
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| 292 | */ |
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| 293 | class VspBspLeaf : public VspBspNode |
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| 294 | { |
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| 295 | friend class VspBspTree; |
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| 296 | |
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| 297 | public: |
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| 298 | VspBspLeaf(); |
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| 299 | VspBspLeaf(BspViewCell *viewCell); |
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| 300 | VspBspLeaf(VspBspInterior *parent); |
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| 301 | VspBspLeaf(VspBspInterior *parent, BspViewCell *viewCell); |
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| 302 | |
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| 303 | /** @return true since it is an interior node |
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| 304 | */ |
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| 305 | bool IsLeaf() const; |
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| 306 | |
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| 307 | /** Returns pointer of view cell. |
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| 308 | */ |
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| 309 | BspViewCell *GetViewCell() const; |
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| 310 | |
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| 311 | /** Sets pointer to view cell. |
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| 312 | */ |
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| 313 | void SetViewCell(BspViewCell *viewCell); |
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| 314 | |
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| 315 | /** Adds ray sample contributions to the PVS. |
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| 316 | @param sampleContributions the number contributions of the samples |
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| 317 | @param contributingSampels the number of contributing rays |
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| 318 | |
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| 319 | */ |
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| 320 | void AddToPvs(const RayInfoContainer &rays, |
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| 321 | int &sampleContributions, |
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| 322 | int &contributingSamples, |
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| 323 | bool storeLeavesWithRays = false); |
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| 324 | |
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| 325 | protected: |
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| 326 | |
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| 327 | /// if NULL this does not correspond to feasible viewcell |
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| 328 | BspViewCell *mViewCell; |
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| 329 | }; |
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| 330 | |
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[445] | 331 | /** |
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| 332 | This is a view space partitioning specialised BSPtree.
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| 333 | There are no polygon splits, but we split the sample rays.
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| 334 | The candidates for the next split plane are evaluated only
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| 335 | by checking the sampled visibility information.
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| 336 | The polygons are employed merely as candidates for the next split planes. |
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[437] | 337 | */ |
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| 338 | class VspBspTree |
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| 339 | { |
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| 340 | public: |
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| 341 | |
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| 342 | /** Additional data which is passed down the BSP tree during traversal. |
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| 343 | */ |
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| 344 | struct VspBspTraversalData |
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| 345 | { |
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| 346 | /// the current node |
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| 347 | VspBspNode *mNode; |
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| 348 | /// polygonal data for splitting |
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| 349 | PolygonContainer *mPolygons; |
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| 350 | /// current depth |
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| 351 | int mDepth; |
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| 352 | /// the view cell associated with this subdivsion |
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| 353 | ViewCell *mViewCell; |
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| 354 | /// rays piercing this node |
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| 355 | RayInfoContainer *mRays; |
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[442] | 356 | /// area of current node |
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| 357 | float mArea; |
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| 358 | /// geometry of current node induced by split planes |
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| 359 | VspBspNodeGeometry *mGeometry; |
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[437] | 360 | |
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| 361 | /// pvs size |
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| 362 | int mPvs; |
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| 363 | |
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| 364 | /** Returns average ray contribution. |
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| 365 | */ |
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| 366 | float GetAvgRayContribution() const |
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| 367 | { |
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| 368 | return (float)mPvs / ((float)mRays->size() + Limits::Small); |
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| 369 | } |
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| 370 | |
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| 371 | |
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| 372 | VspBspTraversalData(): |
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| 373 | mNode(NULL), |
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| 374 | mPolygons(NULL), |
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| 375 | mDepth(0), |
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| 376 | mViewCell(NULL), |
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| 377 | mRays(NULL), |
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[442] | 378 | mPvs(0), |
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| 379 | mArea(0.0), |
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| 380 | mGeometry(NULL) |
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[437] | 381 | {} |
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| 382 | |
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| 383 | VspBspTraversalData(VspBspNode *node, |
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| 384 | PolygonContainer *polys, |
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| 385 | const int depth, |
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| 386 | ViewCell *viewCell, |
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| 387 | RayInfoContainer *rays, |
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[442] | 388 | int pvs, |
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| 389 | float area, |
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| 390 | VspBspNodeGeometry *cell): |
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[437] | 391 | mNode(node), |
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| 392 | mPolygons(polys), |
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| 393 | mDepth(depth), |
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| 394 | mViewCell(viewCell), |
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| 395 | mRays(rays), |
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[442] | 396 | mPvs(pvs), |
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| 397 | mArea(area), |
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| 398 | mGeometry(cell) |
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[437] | 399 | {} |
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| 400 | }; |
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| 401 | |
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| 402 | typedef std::stack<VspBspTraversalData> VspBspTraversalStack; |
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| 403 | |
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| 404 | /** Default constructor creating an empty tree. |
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| 405 | */ |
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[442] | 406 | VspBspTree(); |
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[437] | 407 | |
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| 408 | ~VspBspTree(); |
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| 409 | |
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| 410 | const VspBspTreeStatistics &GetStatistics() const; |
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| 411 | |
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| 412 | |
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| 413 | /** Constructs the tree from a given set of rays. |
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| 414 | @param sampleRays the set of sample rays the construction is based on |
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| 415 | @param viewCells if not NULL, new view cells are |
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[445] | 416 | created in the leafs and stored in the container |
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[437] | 417 | */ |
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| 418 | void Construct(const VssRayContainer &sampleRays); |
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| 419 | |
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| 420 | /** Returns list of BSP leaves. |
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| 421 | */ |
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| 422 | void CollectLeaves(vector<VspBspLeaf *> &leaves) const; |
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| 423 | |
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| 424 | /** Returns box which bounds the whole tree. |
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| 425 | */ |
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| 426 | AxisAlignedBox3 GetBoundingBox()const; |
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| 427 | |
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| 428 | /** Returns root of BSP tree. |
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| 429 | */ |
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| 430 | VspBspNode *GetRoot() const; |
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| 431 | |
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| 432 | /** Exports VspBsp tree to file. |
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| 433 | */ |
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| 434 | bool Export(const string filename); |
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| 435 | |
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| 436 | /** Collects the leaf view cells of the tree |
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| 437 | @param viewCells returns the view cells |
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| 438 | */ |
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| 439 | void CollectViewCells(ViewCellContainer &viewCells) const; |
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| 440 | |
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| 441 | /** A ray is cast possible intersecting the tree. |
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| 442 | @param the ray that is cast. |
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| 443 | @returns the number of intersections with objects stored in the tree. |
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| 444 | */ |
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| 445 | int CastRay(Ray &ray); |
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| 446 | |
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| 447 | /// bsp tree construction types |
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| 448 | enum {FROM_INPUT_VIEW_CELLS, FROM_SCENE_GEOMETRY, FROM_SAMPLES}; |
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| 449 | |
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| 450 | /** Returns statistics. |
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| 451 | */ |
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| 452 | VspBspTreeStatistics &GetStat(); |
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| 453 | |
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| 454 | /** finds neighbouring leaves of this tree node. |
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| 455 | */ |
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| 456 | int FindNeighbors(VspBspNode *n, vector<VspBspLeaf *> &neighbors, |
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| 457 | const bool onlyUnmailed) const; |
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| 458 | |
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| 459 | /** Constructs geometry associated with the half space intersections |
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| 460 | leading to this node. |
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| 461 | */ |
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| 462 | void ConstructGeometry(VspBspNode *n, PolygonContainer &cell) const; |
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| 463 | |
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[443] | 464 | /** Constructs geometry associated with the half space intersections |
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| 465 | leading to this node. |
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| 466 | */ |
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| 467 | void ConstructGeometry(BspViewCell *vc, PolygonContainer &cell) const; |
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| 468 | |
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[437] | 469 | /** Construct geometry and stores it in a geometry node container. |
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| 470 | */ |
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| 471 | void ConstructGeometry(VspBspNode *n, VspBspNodeGeometry &cell) const; |
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| 472 | |
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| 473 | /** Returns random leaf of BSP tree. |
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| 474 | @param halfspace defines the halfspace from which the leaf is taken. |
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| 475 | */ |
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| 476 | VspBspLeaf *GetRandomLeaf(const Plane3 &halfspace); |
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| 477 | |
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| 478 | /** Returns random leaf of BSP tree. |
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| 479 | @param onlyUnmailed if only unmailed leaves should be returned. |
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| 480 | */ |
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| 481 | VspBspLeaf *GetRandomLeaf(const bool onlyUnmailed = false); |
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| 482 | |
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| 483 | /** Traverses tree and counts all view cells as well as their PVS size. |
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| 484 | */ |
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| 485 | void EvaluateViewCellsStats(VspBspViewCellsStatistics &stat) const; |
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| 486 | |
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| 487 | |
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[442] | 488 | /** Returns view cell corresponding to unbounded space. |
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| 489 | */ |
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| 490 | BspViewCell *GetRootCell() const; |
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| 491 | |
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[437] | 492 | protected: |
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| 493 | |
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| 494 | // -------------------------------------------------------------- |
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| 495 | // For sorting objects |
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| 496 | // -------------------------------------------------------------- |
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| 497 | struct SortableEntry |
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| 498 | { |
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| 499 | enum {POLY_MIN, POLY_MAX}; |
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| 500 | |
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| 501 | int type; |
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| 502 | float value; |
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| 503 | Polygon3 *poly; |
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| 504 | SortableEntry() {} |
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| 505 | SortableEntry(const int t, const float v, Polygon3 *poly): |
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| 506 | type(t), value(v), poly(poly) {} |
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| 507 | |
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| 508 | bool operator<(const SortableEntry &b) const |
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| 509 | { |
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| 510 | return value < b.value; |
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| 511 | } |
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| 512 | }; |
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| 513 | |
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| 514 | /** Evaluates tree stats in the BSP tree leafs. |
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| 515 | */ |
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| 516 | void EvaluateLeafStats(const VspBspTraversalData &data); |
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| 517 | |
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| 518 | /** Subdivides node with respect to the traversal data. |
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| 519 | @param tStack current traversal stack |
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| 520 | @param tData traversal data also holding node to be subdivided |
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| 521 | @returns new root of the subtree |
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| 522 | */ |
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| 523 | VspBspNode *Subdivide(VspBspTraversalStack &tStack, VspBspTraversalData &tData); |
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| 524 | |
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| 525 | /** Constructs the tree from the given list of polygons and rays. |
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| 526 | @param polys stores set of polygons on which subdivision may be based |
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| 527 | @param rays storesset of rays on which subdivision may be based |
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| 528 | */ |
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| 529 | void Construct(PolygonContainer *polys, RayInfoContainer *rays); |
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| 530 | |
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| 531 | /** Selects the best possible splitting plane. |
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| 532 | @param leaf the leaf to be split |
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| 533 | @param polys the polygon list on which the split decition is based |
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| 534 | @param rays ray container on which selection may be based |
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| 535 | @note the polygons can be reordered in the process |
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| 536 | @returns the split plane |
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| 537 | */ |
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| 538 | Plane3 SelectPlane(VspBspLeaf *leaf, |
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| 539 | VspBspTraversalData &data); |
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| 540 | |
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| 541 | |
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| 542 | /** Strategies where the effect of the split plane is tested |
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| 543 | on all input rays. |
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| 544 | |
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| 545 | @returns the cost of the candidate split plane |
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| 546 | */ |
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| 547 | float SplitPlaneCost(const Plane3 &candidatePlane, |
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| 548 | const VspBspTraversalData &data); |
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| 549 | |
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| 550 | |
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| 551 | |
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| 552 | /** Subdivide leaf. |
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| 553 | @param leaf the leaf to be subdivided |
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| 554 | |
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| 555 | @param polys the polygons to be split |
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| 556 | @param frontPolys returns the polygons in front of the split plane |
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| 557 | @param backPolys returns the polygons in the back of the split plane |
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| 558 | |
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| 559 | @param rays the polygons to be filtered |
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| 560 | @param frontRays returns the polygons in front of the split plane |
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| 561 | @param backRays returns the polygons in the back of the split plane |
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| 562 | |
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| 563 | @returns the root of the subdivision |
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| 564 | */ |
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| 565 | |
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| 566 | VspBspInterior *SubdivideNode(VspBspTraversalData &tData, |
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| 567 | VspBspTraversalData &frontData, |
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| 568 | VspBspTraversalData &backData, |
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| 569 | PolygonContainer &coincident); |
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| 570 | |
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| 571 | /** Selects the split plane in order to construct a tree with |
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| 572 | certain characteristics (e.g., balanced tree, least splits, |
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| 573 | 2.5d aligned) |
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| 574 | @param polygons container of polygons |
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| 575 | @param rays bundle of rays on which the split can be based |
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| 576 | */ |
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| 577 | Plane3 SelectPlaneHeuristics(VspBspLeaf *leaf, |
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| 578 | VspBspTraversalData &data); |
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| 579 | |
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| 580 | /** Extracts the meshes of the objects and adds them to polygons. |
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| 581 | Adds object aabb to the aabb of the tree. |
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| 582 | @param maxPolys the maximal number of objects to be stored as polygons |
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| 583 | @returns the number of polygons |
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| 584 | */ |
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| 585 | int AddToPolygonSoup(const ObjectContainer &objects, |
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| 586 | PolygonContainer &polys, |
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| 587 | int maxObjects = 0); |
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| 588 | |
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| 589 | /** Extracts the meshes of the view cells and and adds them to polygons. |
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| 590 | Adds view cell aabb to the aabb of the tree. |
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| 591 | @param maxPolys the maximal number of objects to be stored as polygons |
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| 592 | @returns the number of polygons |
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| 593 | */ |
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| 594 | int AddToPolygonSoup(const ViewCellContainer &viewCells, |
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| 595 | PolygonContainer &polys, |
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| 596 | int maxObjects = 0); |
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| 597 | |
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| 598 | /** Extract polygons of this mesh and add to polygon container. |
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| 599 | @param mesh the mesh that drives the polygon construction |
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| 600 | @param parent the parent intersectable this polygon is constructed from |
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| 601 | @returns number of polygons |
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| 602 | */ |
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| 603 | int AddMeshToPolygons(Mesh *mesh, PolygonContainer &polys, MeshInstance *parent); |
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| 604 | |
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| 605 | /** returns next candidate index and reorders polygons so no candidate is chosen two times |
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| 606 | @param the current candidate index |
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| 607 | @param max the range of candidates |
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| 608 | */ |
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| 609 | int GetNextCandidateIdx(int currentIdx, PolygonContainer &polys); |
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| 610 | |
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| 611 | /** Computes best cost ratio for the suface area heuristics for axis aligned |
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| 612 | splits. This heuristics minimizes the cost for ray traversal. |
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| 613 | @param polys the polygons guiding the ratio computation |
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| 614 | @param box the bounding box of the leaf |
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| 615 | @param axis the current split axis |
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| 616 | @param position returns the split position |
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| 617 | @param objectsBack the number of objects in the back of the split plane |
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| 618 | @param objectsFront the number of objects in the front of the split plane |
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| 619 | */ |
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| 620 | float BestCostRatio(const PolygonContainer &polys, |
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| 621 | const AxisAlignedBox3 &box, |
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| 622 | const int axis, |
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| 623 | float &position, |
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| 624 | int &objectsBack, |
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| 625 | int &objectsFront) const; |
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| 626 | |
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| 627 | /** Sorts split candidates for surface area heuristics for axis aligned splits. |
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| 628 | @param polys the input for choosing split candidates |
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| 629 | @param axis the current split axis |
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| 630 | @param splitCandidates returns sorted list of split candidates |
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| 631 | */ |
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| 632 | void SortSplitCandidates(const PolygonContainer &polys, |
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| 633 | const int axis, |
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| 634 | vector<SortableEntry> &splitCandidates) const; |
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| 635 | |
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| 636 | /** Selects an axis aligned split plane. |
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| 637 | Returns true if split is valied |
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| 638 | */ |
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| 639 | bool SelectAxisAlignedPlane(Plane3 &plane, const PolygonContainer &polys) const; |
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| 640 | |
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| 641 | /** Bounds ray and returns minT and maxT. |
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| 642 | @returns true if ray hits BSP tree bounding box |
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| 643 | */ |
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| 644 | bool BoundRay(const Ray &ray, float &minT, float &maxT) const; |
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| 645 | |
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| 646 | /** Subdivides the rays into front and back rays according to the split plane. |
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| 647 | |
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| 648 | @param plane the split plane |
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| 649 | @param rays contains the rays to be split. The rays are |
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| 650 | distributed into front and back rays. |
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| 651 | @param frontRays returns rays on the front side of the plane |
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| 652 | @param backRays returns rays on the back side of the plane |
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| 653 | |
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| 654 | @returns the number of splits |
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| 655 | */ |
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| 656 | int SplitRays(const Plane3 &plane, |
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| 657 | RayInfoContainer &rays, |
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| 658 | RayInfoContainer &frontRays, |
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| 659 | RayInfoContainer &backRays); |
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| 660 | |
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| 661 | |
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| 662 | /** Extracts the split planes representing the space bounded by node n. |
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| 663 | */ |
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| 664 | void ExtractHalfSpaces(VspBspNode *n, vector<Plane3> &halfSpaces) const; |
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| 665 | |
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| 666 | /** Adds the object to the pvs of the front and back leaf with a given classification. |
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| 667 | |
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| 668 | @param obj the object to be added |
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| 669 | @param cf the ray classification regarding the split plane |
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| 670 | @param frontPvs returns the PVS of the front partition |
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| 671 | @param backPvs returns the PVS of the back partition |
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| 672 | |
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| 673 | */ |
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| 674 | void AddObjToPvs(Intersectable *obj, const int cf, int &frontPvs, int &backPvs) const; |
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| 675 | |
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| 676 | /** Computes PVS size induced by the rays. |
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| 677 | */ |
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| 678 | int ComputePvsSize(const RayInfoContainer &rays) const; |
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| 679 | |
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| 680 | /** Returns true if tree can be terminated. |
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| 681 | */ |
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| 682 | inline bool TerminationCriteriaMet(const VspBspTraversalData &data) const; |
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| 683 | |
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| 684 | /** Computes accumulated ray lenght of this rays. |
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| 685 | */ |
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| 686 | float AccumulatedRayLength(const RayInfoContainer &rays) const; |
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| 687 | |
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| 688 | |
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| 689 | |
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| 690 | /// Pointer to the root of the tree |
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| 691 | VspBspNode *mRoot; |
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| 692 | |
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| 693 | VspBspTreeStatistics mStat; |
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| 694 | |
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| 695 | /// Strategies for choosing next split plane. |
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| 696 | enum {NO_STRATEGY = 0, |
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| 697 | RANDOM_POLYGON = 1, |
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| 698 | AXIS_ALIGNED = 2, |
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| 699 | LEAST_RAY_SPLITS = 256, |
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| 700 | BALANCED_RAYS = 512, |
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| 701 | PVS = 1024 |
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| 702 | }; |
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| 703 | |
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| 704 | /// box around the whole view domain |
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| 705 | AxisAlignedBox3 mBox; |
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| 706 | |
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| 707 | /// view cell corresponding to unbounded space |
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| 708 | BspViewCell *mRootCell; |
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| 709 | |
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| 710 | /// minimal number of rays before subdivision termination |
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| 711 | int mTermMinRays; |
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| 712 | /// maximal possible depth |
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| 713 | int mTermMaxDepth; |
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| 714 | /// mininum area |
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| 715 | float mTermMinArea; |
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| 716 | /// mininum PVS |
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| 717 | int mTermMinPvs; |
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| 718 | |
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| 719 | /// minimal number of rays for axis aligned split |
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| 720 | int mTermMinRaysForAxisAligned; |
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| 721 | /// minimal number of objects for axis aligned split |
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| 722 | int mTermMinObjectsForAxisAligned; |
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| 723 | /// maximal contribution per ray |
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| 724 | float mTermMaxRayContribution; |
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| 725 | /// minimal accumulated ray length |
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| 726 | float mTermMinAccRayLength; |
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| 727 | |
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| 728 | |
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| 729 | /// strategy to get the best split plane |
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| 730 | int mSplitPlaneStrategy; |
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| 731 | /// number of candidates evaluated for the next split plane |
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| 732 | int mMaxPolyCandidates; |
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| 733 | /// number of candidates for split planes evaluated using the rays |
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| 734 | int mMaxRayCandidates; |
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[445] | 735 | /// balancing factor for PVS criterium |
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[437] | 736 | float mCtDivCi; |
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| 737 | |
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[445] | 738 | //-- axis aligned split criteria |
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[437] | 739 | float mAaCtDivCi; |
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| 740 | float mSplitBorder; |
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| 741 | float mMaxCostRatio; |
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| 742 | |
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[445] | 743 | //-- factors guiding the split plane heuristics |
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[437] | 744 | float mLeastRaySplitsFactor; |
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| 745 | float mBalancedRaysFactor; |
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| 746 | float mPvsFactor; |
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| 747 | |
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| 748 | /// if area or accumulated ray lenght should be used for PVS heuristics |
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[442] | 749 | bool mPvsUseArea; |
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[437] | 750 | |
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| 751 | private: |
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| 752 | |
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| 753 | static const float sLeastRaySplitsTable[5]; |
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| 754 | /** Evaluates split plane classification with respect to the plane's |
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| 755 | contribution for balanced rays. |
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| 756 | */ |
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| 757 | static const float sBalancedRaysTable[5]; |
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| 758 | |
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| 759 | /// Generates unique ids for PVS criterium |
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| 760 | static void GenerateUniqueIdsForPvs(); |
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| 761 | |
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| 762 | //-- unique ids for PVS criterium |
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| 763 | static int sFrontId; |
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| 764 | static int sBackId; |
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| 765 | static int sFrontAndBackId; |
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| 766 | }; |
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| 767 | |
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| 768 | #endif |
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