[235] | 1 | #include "Polygon3.h"
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| 2 | #include "Mesh.h"
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[268] | 3 | #include "ViewCellBsp.h" // TODO: erase this |
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[308] | 4 | #include "Mesh.h" |
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[295] | 5 | #include "AxisAlignedBox3.h" |
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[314] | 6 | #include "Ray.h" |
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[286] | 7 | |
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[329] | 8 | float Polygon3::sSideTolerance = 0.002f; |
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| 9 | float Polygon3::sSideToleranceSqrt = 0.000004f; |
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| 10 | |
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[319] | 11 | Polygon3::Polygon3(): |
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| 12 | mMaterial(NULL), mParent(NULL), mPiercingRays(NULL) |
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[235] | 13 | {} |
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| 14 | |
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[319] | 15 | Polygon3::Polygon3(const VertexContainer &vertices): |
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| 16 | mVertices(vertices), mMaterial(NULL), mParent(NULL), mPiercingRays(NULL) |
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[235] | 17 | {} |
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| 18 | |
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[319] | 19 | Polygon3::Polygon3(MeshInstance *parent): |
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[329] | 20 | mMaterial(NULL), mParent(parent), mPiercingRays(NULL) |
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[312] | 21 | {} |
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| 22 | |
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[329] | 23 | Polygon3::Polygon3(Face *face, Mesh *parentMesh): |
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| 24 | mMaterial(NULL), mParent(NULL), mPiercingRays(NULL) |
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[264] | 25 | { |
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| 26 | VertexIndexContainer::iterator it = face->mVertexIndices.begin(); |
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| 27 | for (; it != face->mVertexIndices.end(); ++it) |
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[235] | 28 | { |
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[286] | 29 | mVertices.push_back(parentMesh->mVertices[*it]); |
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| 30 | mMaterial = parentMesh->mMaterial; |
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[235] | 31 | } |
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| 32 | } |
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| 33 | |
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[319] | 34 | Polygon3::~Polygon3() |
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| 35 | { |
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| 36 | DEL_PTR(mPiercingRays); |
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| 37 | } |
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| 38 | |
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[238] | 39 | Plane3 Polygon3::GetSupportingPlane() const |
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[235] | 40 | { |
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| 41 | return Plane3(mVertices[0], mVertices[1], mVertices[2]); |
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| 42 | } |
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| 43 | |
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[306] | 44 | Vector3 Polygon3::GetNormal() const
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| 45 | {
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[321] | 46 | return Normalize(CrossProd(mVertices[2] - mVertices[1],
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| 47 | mVertices[0] - mVertices[1]));
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[306] | 48 | } |
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| 49 | |
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[312] | 50 | void Polygon3::Split(const Plane3 &partition, |
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| 51 | Polygon3 &front, |
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| 52 | Polygon3 &back, |
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| 53 | VertexContainer &splitPts) |
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[235] | 54 | { |
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[289] | 55 | Vector3 ptA = mVertices.back(); |
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[235] | 56 | |
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[329] | 57 | int sideA = partition.Side(ptA, sSideTolerance); |
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[235] | 58 | |
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| 59 | VertexContainer::const_iterator it; |
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[312] | 60 | |
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[318] | 61 | bool foundSplit = false; |
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[235] | 62 | // find line - plane intersections |
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| 63 | for (it = mVertices.begin(); it != mVertices.end(); ++ it) |
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| 64 | { |
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[289] | 65 | Vector3 ptB = *it; |
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[329] | 66 | int sideB = partition.Side(ptB, sSideTolerance); |
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[239] | 67 | |
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[235] | 68 | // vertices on different sides => split |
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[237] | 69 | if (sideB > 0)
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| 70 | {
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| 71 | if (sideA < 0)
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| 72 | { |
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| 73 | //-- plane - line intersection |
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[312] | 74 | Vector3 splitPt = partition.FindIntersection(ptA, ptB); |
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[294] | 75 | |
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[312] | 76 | // test if split point not too close to previous split point |
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[318] | 77 | if (!foundSplit || |
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[329] | 78 | (SqrDistance(splitPt, splitPts.back()) > sSideToleranceSqrt)) |
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[289] | 79 | { |
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| 80 | // add vertex to both polygons |
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[312] | 81 | front.mVertices.push_back(splitPt); |
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| 82 | back.mVertices.push_back(splitPt); |
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| 83 | |
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| 84 | splitPts.push_back(splitPt); |
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[318] | 85 | foundSplit = true; |
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[289] | 86 | } |
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[237] | 87 | } |
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[312] | 88 | front.mVertices.push_back(ptB); |
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[237] | 89 | } |
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| 90 | else if (sideB < 0)
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| 91 | {
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| 92 | if (sideA > 0)
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[235] | 93 | { |
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[237] | 94 | //-- plane - line intersection |
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[312] | 95 | Vector3 splitPt = partition.FindIntersection(ptA, ptB); |
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| 96 | // test if split point not too close to other split point |
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| 97 | // test if split point not too close to previous split point |
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[318] | 98 | if (!foundSplit || |
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[329] | 99 | (SqrDistance(splitPt, splitPts.back()) > sSideToleranceSqrt)) |
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[289] | 100 | { |
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| 101 | // add vertex to both polygons |
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[312] | 102 | front.mVertices.push_back(splitPt); |
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| 103 | back.mVertices.push_back(splitPt); |
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[237] | 104 | |
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[312] | 105 | splitPts.push_back(splitPt); |
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[318] | 106 | foundSplit = true; |
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[294] | 107 | } |
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[235] | 108 | } |
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[312] | 109 | back.mVertices.push_back(ptB); |
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[235] | 110 | } |
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[237] | 111 | else |
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[235] | 112 | { |
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[237] | 113 | // vertex on plane => add vertex to both polygons |
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[312] | 114 | front.mVertices.push_back(ptB); |
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| 115 | back.mVertices.push_back(ptB); |
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[235] | 116 | } |
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[237] | 117 | |
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[235] | 118 | ptA = ptB; |
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| 119 | sideA = sideB; |
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| 120 | } |
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| 121 | } |
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| 122 | |
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[298] | 123 | float Polygon3::GetArea() const |
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| 124 | { |
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[306] | 125 | Vector3 v = CrossProd(mVertices.back(), mVertices.front());
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| 126 |
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| 127 | for (int i=0; i < mVertices.size() - 1; ++i)
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| 128 | v += CrossProd(mVertices[i], mVertices[i+1]);
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| 129 |
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| 130 | //Debug << "area2: " << 0.5f * fabs(DotProd(GetNormal(), v)) << endl; |
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| 131 | return 0.5f * fabs(DotProd(GetNormal(), v)); |
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[298] | 132 | } |
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| 133 | |
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[238] | 134 | int Polygon3::Side(const Plane3 &plane) const |
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[235] | 135 | { |
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[238] | 136 | int classification = ClassifyPlane(plane); |
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| 137 | |
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[327] | 138 | if (classification == Plane3::BACK_SIDE) |
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[238] | 139 | return -1; |
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[327] | 140 | else if (classification == Plane3::FRONT_SIDE) |
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[238] | 141 | return 1; |
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| 142 | |
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| 143 | return 0; |
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| 144 | } |
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| 145 | |
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| 146 | int Polygon3::ClassifyPlane(const Plane3 &plane) const |
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| 147 | { |
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[235] | 148 | VertexContainer::const_iterator it; |
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| 149 | |
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| 150 | bool onFrontSide = false; |
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| 151 | bool onBackSide = false; |
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[297] | 152 | |
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[265] | 153 | int count = 0; |
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[238] | 154 | // find possible line-plane intersections |
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[235] | 155 | for (it = mVertices.begin(); it != mVertices.end(); ++ it) |
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| 156 | { |
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[329] | 157 | int side = plane.Side(*it, sSideTolerance); |
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[294] | 158 | |
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[235] | 159 | if (side > 0) |
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| 160 | onFrontSide = true; |
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| 161 | else if (side < 0) |
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| 162 | onBackSide = true; |
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[265] | 163 | |
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[264] | 164 | //TODO: check if split goes through vertex |
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| 165 | if (onFrontSide && onBackSide) // split |
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[235] | 166 | { |
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[327] | 167 | return Plane3::SPLIT; |
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[235] | 168 | } |
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[265] | 169 | // 3 vertices enough to decide coincident |
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[321] | 170 | else if (((++ count) >= 3) && !onFrontSide && !onBackSide) |
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| 171 | { |
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[327] | 172 | return Plane3::COINCIDENT; |
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[321] | 173 | } |
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[235] | 174 | } |
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| 175 | |
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| 176 | if (onBackSide) |
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| 177 | { |
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[327] | 178 | return Plane3::BACK_SIDE; |
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[235] | 179 | } |
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| 180 | else if (onFrontSide) |
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| 181 | { |
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[327] | 182 | return Plane3::FRONT_SIDE; |
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[235] | 183 | } |
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[322] | 184 | |
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[327] | 185 | return Plane3::COINCIDENT; // plane and polygon are coincident |
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[235] | 186 | } |
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| 187 |
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[256] | 188 | |
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| 189 | Vector3 |
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| 190 | Polygon3::Center() const |
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| 191 | { |
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| 192 | int i; |
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| 193 | Vector3 sum = mVertices[0]; |
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| 194 | for (i=1; i < mVertices.size(); i++) |
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| 195 | sum += mVertices[i]; |
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| 196 | |
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[289] | 197 | return sum/(float)i; |
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[256] | 198 | } |
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| 199 | |
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| 200 | |
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| 201 | void |
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| 202 | Polygon3::Scale(const float scale) |
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| 203 | { |
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| 204 | int i; |
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| 205 | Vector3 center = Center(); |
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| 206 | for (i=0; i < mVertices.size(); i++) { |
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| 207 | mVertices[i] = center + scale*(mVertices[i] - center); |
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| 208 | } |
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| 209 | } |
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[289] | 210 | |
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[299] | 211 | bool Polygon3::Valid() const |
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[289] | 212 | { |
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| 213 | if (mVertices.size() < 3) |
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| 214 | return false; |
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| 215 | |
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[299] | 216 | #if 1 |
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| 217 | // check if area exceeds certain size |
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| 218 | if (AREA_LIMIT > GetArea()) |
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[301] | 219 | { |
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| 220 | //Debug << "area too small: " << GetArea() << endl; |
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[299] | 221 | return false; |
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[301] | 222 | } |
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[299] | 223 | #else |
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[289] | 224 | Vector3 vtx = mVertices.back(); |
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| 225 | VertexContainer::const_iterator it, it_end = mVertices.end(); |
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| 226 | |
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| 227 | for (it = mVertices.begin(); it != it_end; ++it) |
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| 228 | { |
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| 229 | if (!(SqrDistance(vtx, *it) > SIDE_TOLERANCE_SQRD)) |
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| 230 | { |
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| 231 | Debug << "Malformed vertices:\n" << *this << endl; |
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| 232 | return false; |
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| 233 | } |
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| 234 | vtx = *it; |
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| 235 | } |
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[299] | 236 | #endif |
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[289] | 237 | return true; |
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| 238 | } |
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[295] | 239 | |
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| 240 | void Polygon3::IncludeInBox(const PolygonContainer &polys, AxisAlignedBox3 &box) |
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| 241 | { |
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| 242 | PolygonContainer::const_iterator it, it_end = polys.end(); |
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| 243 | |
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| 244 | for (it = polys.begin(); it != it_end; ++ it) |
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| 245 | box.Include(*(*it)); |
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[314] | 246 | } |
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| 247 |
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| 248 | // int_lineseg returns 1 if the given line segment intersects a 2D
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| 249 | // ray travelling in the positive X direction. This is used in the
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| 250 | // Jordan curve computation for polygon intersection.
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| 251 | inline int
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| 252 | int_lineseg(float px,
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| 253 | float py,
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| 254 | float u1,
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| 255 | float v1,
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| 256 | float u2,
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| 257 | float v2)
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| 258 | {
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| 259 | float t;
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| 260 | float ydiff;
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| 261 |
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| 262 | u1 -= px; u2 -= px; // translate line
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| 263 | v1 -= py; v2 -= py;
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| 264 |
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| 265 | if ((v1 > 0 && v2 > 0) ||
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| 266 | (v1 < 0 && v2 < 0) ||
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| 267 | (u1 < 0 && u2 < 0))
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| 268 | return 0;
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| 269 |
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| 270 | if (u1 > 0 && u2 > 0)
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| 271 | return 1;
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| 272 |
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| 273 | ydiff = v2 - v1;
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| 274 |
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| 275 | if (fabs(ydiff) < Limits::Small)
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| 276 | { // denominator near 0
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| 277 | if (((fabs(v1) > Limits::Small) || (u1 > 0) || (u2 > 0)))
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| 278 | return 0;
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| 279 | return 1;
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| 280 | }
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| 281 |
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| 282 | t = -v1 / ydiff; // Compute parameter
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| 283 |
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| 284 | return (u1 + t * (u2 - u1)) > 0;
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| 285 | }
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| 286 |
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| 287 | int Polygon3::CastRay(const Ray &ray, float &t, const float nearestT)
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| 288 | {
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| 289 | Plane3 plane = GetSupportingPlane();
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| 290 | float dot = DotProd(plane.mNormal, ray.GetDir());
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| 291 |
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| 292 | // Watch for near-zero denominator
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| 293 | // ONLY single sided polygons!!!!!
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| 294 | if (dot > -Limits::Small)
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| 295 | // if (fabs(dot) < Limits::Small)
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| 296 | return Ray::NO_INTERSECTION;
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| 297 |
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| 298 | t = (-plane.mD - DotProd(plane.mNormal, ray.GetLoc())) / dot;
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| 299 |
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| 300 | if (t <= Limits::Small)
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| 301 | return Ray::INTERSECTION_OUT_OF_LIMITS;
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| 302 |
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| 303 | if (t >= nearestT) {
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| 304 | return Ray::INTERSECTION_OUT_OF_LIMITS; // no intersection was found
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| 305 | }
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| 306 |
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| 307 | int count = 0;
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| 308 | float u, v, u1, v1, u2, v2;
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| 309 | int i;
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| 310 |
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| 311 | int paxis = plane.mNormal.DrivingAxis();
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| 312 |
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| 313 | // Project the intersection point onto the coordinate plane
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| 314 | // specified by which.
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| 315 | ray.Extrap(t).ExtractVerts(&u, &v, paxis);
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| 316 |
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| 317 | int size = (int)mVertices.size();
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| 318 |
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| 319 | mVertices.back().ExtractVerts(&u1, &v1, paxis );
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| 320 |
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| 321 | if (0 && size <= 4)
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| 322 | {
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| 323 | // assume a convex face
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| 324 | for (i = 0; i < size; i++)
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| 325 | {
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| 326 | mVertices[i].ExtractVerts(&u2, &v2, paxis);
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| 327 |
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| 328 | // line u1, v1, u2, v2
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| 329 |
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| 330 | if ((v2 - v1)*(u1 - u) > (u2 - u1)*(v1 - v))
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| 331 | return Ray::NO_INTERSECTION;
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| 332 |
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| 333 | u1 = u2;
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| 334 | v1 = v2;
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| 335 | }
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| 336 |
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| 337 | return Ray::INTERSECTION;
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| 338 | }
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| 339 |
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| 340 | // We're stuck with the Jordan curve computation. Count number
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| 341 | // of intersections between the line segments the polygon comprises
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| 342 | // with a ray originating at the point of intersection and
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| 343 | // travelling in the positive X direction.
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| 344 | for (i = 0; i < size; i++)
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| 345 | {
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| 346 | mVertices[i].ExtractVerts(&u2, &v2, paxis);
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| 347 |
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| 348 | count += (int_lineseg(u, v, u1, v1, u2, v2) != 0);
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| 349 |
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| 350 | u1 = u2;
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| 351 | v1 = v2;
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| 352 | }
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| 353 |
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| 354 | // We hit polygon if number of intersections is odd.
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| 355 | return (count & 1) ? Ray::INTERSECTION : Ray::NO_INTERSECTION;
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| 356 | }
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| 357 |
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[319] | 358 | RayContainer *Polygon3::GetPiercingRays()
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| 359 | {
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| 360 | if (!mPiercingRays)
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| 361 | mPiercingRays = new RayContainer();
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| 362 | return mPiercingRays;
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| 363 | }
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| 364 |
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| 365 | void Polygon3::AddPiercingRay(Ray *ray)
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| 366 | {
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[329] | 367 | GetPiercingRays()->push_back(ray);
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[319] | 368 | } |
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