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