[235] | 1 | #include "Polygon3.h"
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| 2 | #include "Mesh.h"
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[372] | 3 | #include "Mesh.h"
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| 4 | #include "AxisAlignedBox3.h"
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| 5 | #include "Ray.h"
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| 6 |
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| 7 | Polygon3::Polygon3():
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| 8 | mMaterial(NULL), mParent(NULL), mPiercingRays(0)
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| 9 | {}
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| 10 |
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| 11 | Polygon3::Polygon3(const VertexContainer &vertices):
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| 12 | mVertices(vertices), mMaterial(NULL), mParent(NULL), mPiercingRays(0)
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| 13 | {}
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| 14 |
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| 15 | Polygon3::Polygon3(MeshInstance *parent):
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| 16 | mMaterial(NULL), mParent(parent), mPiercingRays(0)
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| 17 | {}
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| 18 |
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| 19 | Polygon3::Polygon3(Face *face, Mesh *parentMesh):
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| 20 | mMaterial(NULL), mParent(NULL), mPiercingRays(0)
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| 21 | {
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| 22 | VertexIndexContainer::iterator it = face->mVertexIndices.begin();
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| 23 | for (; it != face->mVertexIndices.end(); ++it)
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| 24 | {
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| 25 | mVertices.push_back(parentMesh->mVertices[*it]);
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| 26 | mMaterial = parentMesh->mMaterial;
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| 27 | }
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| 28 | }
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| 29 |
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| 30 | Plane3 Polygon3::GetSupportingPlane() const
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| 31 | {
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| 32 | return Plane3(mVertices[0], mVertices[1], mVertices[2]);
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| 33 | }
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| 34 |
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[306] | 35 | Vector3 Polygon3::GetNormal() const
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| 36 | {
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[321] | 37 | return Normalize(CrossProd(mVertices[2] - mVertices[1],
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| 38 | mVertices[0] - mVertices[1]));
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[372] | 39 | }
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| 40 |
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| 41 | void Polygon3::Split(const Plane3 &partition,
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| 42 | Polygon3 &front,
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[448] | 43 | Polygon3 &back,
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| 44 | const float epsilon)
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[372] | 45 | {
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| 46 | Vector3 ptA = mVertices.back();
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| 47 |
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[448] | 48 | int sideA = partition.Side(ptA, epsilon);
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[372] | 49 |
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| 50 | VertexContainer::const_iterator it;
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| 51 |
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[436] | 52 | Vector3 lastSplit;
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| 53 |
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[372] | 54 | bool foundSplit = false;
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[448] | 55 |
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| 56 | //-- find line - plane intersections
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[372] | 57 | for (it = mVertices.begin(); it != mVertices.end(); ++ it)
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| 58 | {
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| 59 | Vector3 ptB = *it;
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[448] | 60 | int sideB = partition.Side(ptB, epsilon);
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[372] | 61 |
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| 62 | // vertices on different sides => split
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[237] | 63 | if (sideB > 0)
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| 64 | {
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| 65 | if (sideA < 0)
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[372] | 66 | {
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| 67 | //-- plane - line intersection
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| 68 | Vector3 splitPt = partition.FindIntersection(ptA, ptB);
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| 69 |
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| 70 | // test if split point not too close to previous split point
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[448] | 71 | if (!foundSplit || (!EpsilonEqualV3(splitPt, lastSplit, epsilon)))
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[372] | 72 | {
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| 73 | // add vertex to both polygons
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| 74 | front.mVertices.push_back(splitPt);
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| 75 | back.mVertices.push_back(splitPt);
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| 76 |
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[436] | 77 | lastSplit = splitPt;
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[372] | 78 | foundSplit = true;
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| 79 | }
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| 80 | }
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| 81 | front.mVertices.push_back(ptB);
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| 82 | }
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[237] | 83 | else if (sideB < 0)
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| 84 | {
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| 85 | if (sideA > 0)
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[372] | 86 | {
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| 87 | //-- plane - line intersection
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| 88 | Vector3 splitPt = partition.FindIntersection(ptA, ptB);
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| 89 | // test if split point not too close to other split point
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| 90 | // test if split point not too close to previous split point
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[448] | 91 | if (!foundSplit || (!EpsilonEqualV3(splitPt, lastSplit, epsilon)))
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[372] | 92 | {
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| 93 | // add vertex to both polygons
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| 94 | front.mVertices.push_back(splitPt);
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| 95 | back.mVertices.push_back(splitPt);
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| 96 |
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[436] | 97 | lastSplit = splitPt;
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[372] | 98 | foundSplit = true;
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| 99 | }
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| 100 | }
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| 101 | back.mVertices.push_back(ptB);
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| 102 | }
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| 103 | else
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| 104 | {
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| 105 | // vertex on plane => add vertex to both polygons
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| 106 | front.mVertices.push_back(ptB);
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| 107 | back.mVertices.push_back(ptB);
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| 108 | }
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| 109 |
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| 110 | ptA = ptB;
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| 111 | sideA = sideB;
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| 112 | }
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| 113 | }
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| 114 |
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| 115 | float Polygon3::GetArea() const
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| 116 | {
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[306] | 117 | Vector3 v = CrossProd(mVertices.back(), mVertices.front());
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| 118 |
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| 119 | for (int i=0; i < mVertices.size() - 1; ++i)
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| 120 | v += CrossProd(mVertices[i], mVertices[i+1]);
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| 121 |
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[372] | 122 | //Debug << "area2: " << 0.5f * fabs(DotProd(GetNormal(), v)) << endl;
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| 123 | return 0.5f * fabs(DotProd(GetNormal(), v));
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| 124 | }
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[235] | 125 |
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[448] | 126 | int Polygon3::Side(const Plane3 &plane,
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| 127 | const float epsilon) const
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[372] | 128 | {
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[448] | 129 | int classification = ClassifyPlane(plane, epsilon);
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[372] | 130 |
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| 131 | if (classification == BACK_SIDE)
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| 132 | return -1;
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| 133 | else if (classification == FRONT_SIDE)
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| 134 | return 1;
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[314] | 135 |
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[372] | 136 | return 0;
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| 137 | }
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| 138 |
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[448] | 139 | int Polygon3::ClassifyPlane(const Plane3 &plane,
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| 140 | const float epsilon) const
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[372] | 141 | {
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| 142 | VertexContainer::const_iterator it;
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| 143 |
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| 144 | bool onFrontSide = false;
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| 145 | bool onBackSide = false;
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| 146 |
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| 147 | int count = 0;
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| 148 | // find possible line-plane intersections
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| 149 | for (it = mVertices.begin(); it != mVertices.end(); ++ it)
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| 150 | {
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[448] | 151 | const int side = plane.Side(*it, epsilon);
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[372] | 152 |
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| 153 | if (side > 0)
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| 154 | onFrontSide = true;
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| 155 | else if (side < 0)
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| 156 | onBackSide = true;
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| 157 |
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| 158 | //TODO: check if split goes through vertex
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| 159 | if (onFrontSide && onBackSide) // split
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| 160 | {
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| 161 | return SPLIT;
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| 162 | }
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| 163 | // 3 vertices enough to decide coincident
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| 164 | else if (((++ count) >= 3) && !onFrontSide && !onBackSide)
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| 165 | {
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| 166 | return COINCIDENT;
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| 167 | }
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| 168 | }
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| 169 |
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| 170 | if (onBackSide)
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| 171 | {
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| 172 | return BACK_SIDE;
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| 173 | }
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| 174 | else if (onFrontSide)
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| 175 | {
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| 176 | return FRONT_SIDE;
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| 177 | }
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| 178 |
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| 179 | return COINCIDENT; // plane and polygon are coincident
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| 180 | }
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| 181 |
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[448] | 182 | /*int Polygon3::ClassifyPlane(const Plane3 &plane) const
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[404] | 183 | {
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[448] | 184 | return ClassifyPlane(plane, Limits::Small);
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| 185 | }*/
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[372] | 186 |
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[404] | 187 |
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[372] | 188 | Vector3
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| 189 | Polygon3::Center() const
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| 190 | {
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| 191 | int i;
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| 192 | Vector3 sum = mVertices[0];
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| 193 | for (i=1; i < mVertices.size(); i++)
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| 194 | sum += mVertices[i];
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| 195 |
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| 196 | return sum/(float)i;
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| 197 | }
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| 198 |
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| 199 |
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| 200 | void
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| 201 | Polygon3::Scale(const float scale)
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| 202 | {
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| 203 | int i;
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| 204 | Vector3 center = Center();
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| 205 | for (i=0; i < mVertices.size(); i++) {
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| 206 | mVertices[i] = center + scale*(mVertices[i] - center);
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| 207 | }
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| 208 | }
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| 209 |
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[448] | 210 | bool Polygon3::Valid(const float epsilon) const
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[372] | 211 | {
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| 212 | if (mVertices.size() < 3)
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| 213 | return false;
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| 214 |
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| 215 | #if 1
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| 216 | // check if area exceeds certain size
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| 217 | if (AREA_LIMIT > GetArea())
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| 218 | {
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| 219 | //Debug << "area too small: " << GetArea() << endl;
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| 220 | return false;
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| 221 | }
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| 222 | #else
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| 223 | Vector3 vtx = mVertices.back();
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| 224 | VertexContainer::const_iterator it, it_end = mVertices.end();
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| 225 |
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| 226 | for (it = mVertices.begin(); it != it_end; ++it)
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| 227 | {
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[448] | 228 | if (!(EpsilonEqual(vtx, *it)))
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[372] | 229 | {
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[448] | 230 | //Debug << "Malformed vertices:\n" << *this << endl;
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[372] | 231 | return false;
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| 232 | }
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| 233 | vtx = *it;
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| 234 | }
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| 235 | #endif
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| 236 | return true;
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| 237 | }
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| 238 |
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| 239 | void Polygon3::IncludeInBox(const PolygonContainer &polys, AxisAlignedBox3 &box)
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| 240 | {
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| 241 | PolygonContainer::const_iterator it, it_end = polys.end();
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| 242 |
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| 243 | for (it = polys.begin(); it != it_end; ++ it)
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| 244 | box.Include(*(*it));
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| 245 | }
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| 246 |
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[314] | 247 | // int_lineseg returns 1 if the given line segment intersects a 2D
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| 248 | // ray travelling in the positive X direction. This is used in the
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| 249 | // Jordan curve computation for polygon intersection.
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| 250 | inline int
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| 251 | int_lineseg(float px,
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| 252 | float py,
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| 253 | float u1,
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| 254 | float v1,
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| 255 | float u2,
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| 256 | float v2)
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| 257 | {
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| 258 | float t;
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| 259 | float ydiff;
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| 260 |
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| 261 | u1 -= px; u2 -= px; // translate line
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| 262 | v1 -= py; v2 -= py;
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| 263 |
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| 264 | if ((v1 > 0 && v2 > 0) ||
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| 265 | (v1 < 0 && v2 < 0) ||
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| 266 | (u1 < 0 && u2 < 0))
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| 267 | return 0;
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| 268 |
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| 269 | if (u1 > 0 && u2 > 0)
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| 270 | return 1;
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| 271 |
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| 272 | ydiff = v2 - v1;
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| 273 |
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| 274 | if (fabs(ydiff) < Limits::Small)
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| 275 | { // denominator near 0
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| 276 | if (((fabs(v1) > Limits::Small) || (u1 > 0) || (u2 > 0)))
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| 277 | return 0;
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| 278 | return 1;
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| 279 | }
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| 280 |
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| 281 | t = -v1 / ydiff; // Compute parameter
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| 282 |
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| 283 | return (u1 + t * (u2 - u1)) > 0;
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| 284 | }
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| 285 |
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| 286 | int Polygon3::CastRay(const Ray &ray, float &t, const float nearestT)
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| 287 | {
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| 288 | Plane3 plane = GetSupportingPlane();
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| 289 | float dot = DotProd(plane.mNormal, ray.GetDir());
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| 290 |
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| 291 | // Watch for near-zero denominator
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| 292 | // ONLY single sided polygons!!!!!
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| 293 | if (dot > -Limits::Small)
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| 294 | // if (fabs(dot) < Limits::Small)
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| 295 | return Ray::NO_INTERSECTION;
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| 296 |
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| 297 | t = (-plane.mD - DotProd(plane.mNormal, ray.GetLoc())) / dot;
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| 298 |
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| 299 | if (t <= Limits::Small)
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| 300 | return Ray::INTERSECTION_OUT_OF_LIMITS;
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| 301 |
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| 302 | if (t >= nearestT) {
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| 303 | return Ray::INTERSECTION_OUT_OF_LIMITS; // no intersection was found
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| 304 | }
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| 305 |
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| 306 | int count = 0;
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| 307 | float u, v, u1, v1, u2, v2;
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| 308 | int i;
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| 309 |
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| 310 | int paxis = plane.mNormal.DrivingAxis();
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| 311 |
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| 312 | // Project the intersection point onto the coordinate plane
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| 313 | // specified by which.
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| 314 | ray.Extrap(t).ExtractVerts(&u, &v, paxis);
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| 315 |
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| 316 | int size = (int)mVertices.size();
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| 317 |
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| 318 | mVertices.back().ExtractVerts(&u1, &v1, paxis );
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| 319 |
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| 320 | if (0 && size <= 4)
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| 321 | {
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| 322 | // assume a convex face
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| 323 | for (i = 0; i < size; i++)
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| 324 | {
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| 325 | mVertices[i].ExtractVerts(&u2, &v2, paxis);
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| 326 |
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| 327 | // line u1, v1, u2, v2
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| 328 |
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| 329 | if ((v2 - v1)*(u1 - u) > (u2 - u1)*(v1 - v))
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| 330 | return Ray::NO_INTERSECTION;
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| 331 |
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| 332 | u1 = u2;
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| 333 | v1 = v2;
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| 334 | }
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| 335 |
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| 336 | return Ray::INTERSECTION;
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| 337 | }
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| 338 |
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| 339 | // We're stuck with the Jordan curve computation. Count number
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| 340 | // of intersections between the line segments the polygon comprises
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| 341 | // with a ray originating at the point of intersection and
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| 342 | // travelling in the positive X direction.
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| 343 | for (i = 0; i < size; i++)
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| 344 | {
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| 345 | mVertices[i].ExtractVerts(&u2, &v2, paxis);
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| 346 |
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| 347 | count += (int_lineseg(u, v, u1, v1, u2, v2) != 0);
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| 348 |
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| 349 | u1 = u2;
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| 350 | v1 = v2;
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| 351 | }
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| 352 |
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| 353 | // We hit polygon if number of intersections is odd.
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| 354 | return (count & 1) ? Ray::INTERSECTION : Ray::NO_INTERSECTION;
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| 355 | }
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| 356 |
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[372] | 357 | void Polygon3::InheritRays(Polygon3 &front_piece,
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| 358 | Polygon3 &back_piece) const
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| 359 | {
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| 360 | if (mPiercingRays.empty())
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| 361 | return;
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| 362 |
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| 363 | RayContainer::const_iterator it,
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| 364 | it_end = mPiercingRays.end();
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| 365 |
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| 366 | for (it = mPiercingRays.begin(); it != it_end; ++ it)
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| 367 | {
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| 368 | switch((*it)->GetId())
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| 369 | {
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| 370 | case Ray::BACK:
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| 371 | back_piece.mPiercingRays.push_back(*it);
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| 372 | break;
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| 373 | case Ray::FRONT:
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| 374 | front_piece.mPiercingRays.push_back(*it);
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| 375 | break;
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| 376 | case Ray::FRONT_BACK:
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| 377 | back_piece.mPiercingRays.push_back(*it);
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| 378 | break;
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| 379 | case Ray::BACK_FRONT:
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| 380 | front_piece.mPiercingRays.push_back(*it);
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| 381 | break;
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| 382 | default:
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| 383 | break;
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| 384 | }
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| 385 | }
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| 386 | }
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| 387 |
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[448] | 388 | int Polygon3::ClassifyPlane(const PolygonContainer &polys,
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| 389 | const Plane3 &plane,
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| 390 | const float epsilon)
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[372] | 391 | {
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| 392 | PolygonContainer::const_iterator it;
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| 393 |
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| 394 | bool onFrontSide = false;
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| 395 | bool onBackSide = false;
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| 396 |
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| 397 | // find intersections
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| 398 | for (it = polys.begin(); it != polys.end(); ++ it)
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| 399 | {
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[448] | 400 | const int cf = (*it)->ClassifyPlane(plane, epsilon);
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[372] | 401 |
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| 402 | if (cf == FRONT_SIDE)
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| 403 | onFrontSide = true;
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| 404 | else if (cf == BACK_SIDE)
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| 405 | onBackSide = true;
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| 406 |
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| 407 | if ((cf == SPLIT) || (cf == COINCIDENT) || (onFrontSide && onBackSide))
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| 408 | {
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| 409 | return SPLIT;
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| 410 | }
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| 411 | }
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| 412 |
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| 413 | if (onBackSide)
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| 414 | {
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| 415 | return BACK_SIDE;
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| 416 | }
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| 417 | else if (onFrontSide)
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| 418 | {
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| 419 | return FRONT_SIDE;
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| 420 | }
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| 421 |
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| 422 | return SPLIT;
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| 423 | }
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| 424 |
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[375] | 425 | int Polygon3::ParentObjectsSize(const PolygonContainer &polys)
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[372] | 426 | {
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| 427 | int count = 0;
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| 428 |
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| 429 | PolygonContainer::const_iterator it, it_end = polys.end();
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| 430 |
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| 431 | MeshInstance::NewMail();
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| 432 |
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| 433 | for (it = polys.begin(); it != it_end; ++ it)
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| 434 | {
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| 435 | if ((*it)->mParent && !(*it)->mParent->Mailed())
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| 436 | {
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| 437 | ++ count;
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| 438 | (*it)->mParent->Mail();
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| 439 | }
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| 440 | }
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| 441 | return count;
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[384] | 442 | }
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| 443 |
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| 444 | float Polygon3::GetArea(const PolygonContainer &cell)
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| 445 | {
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| 446 | float area = 0;
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| 447 | PolygonContainer::const_iterator pit;
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| 448 |
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| 449 | for (pit = cell.begin(); pit != cell.end(); ++ pit)
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[448] | 450 | {
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| 451 | if ((*pit)->mVertices.size() < 3)
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| 452 | Debug << "ERROR" << endl;
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| 453 |
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[384] | 454 | area += (*pit)->GetArea();
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[448] | 455 | }
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[396] | 456 |
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[384] | 457 | return area;
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[396] | 458 | }
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| 459 |
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| 460 |
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| 461 | Polygon3 *Polygon3::CreateReversePolygon() const
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| 462 | {
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| 463 | Polygon3 *revPoly = new Polygon3();
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| 464 |
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| 465 | VertexContainer::const_reverse_iterator rit,
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| 466 | rit_end = mVertices.rend();
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| 467 |
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| 468 | for(rit = mVertices.rbegin(); rit != rit_end; ++ rit)
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[448] | 469 | revPoly->mVertices.push_back(*rit);
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| 470 |
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| 471 | return revPoly;
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[319] | 472 | } |
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