[167] | 1 | #include "Ray.h"
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[162] | 2 | #include "Mesh.h"
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[170] | 3 | #include "MeshKdTree.h"
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[162] | 4 |
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| 5 | int MeshInstance::mailID = 21843194198;
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| 6 |
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| 7 | void
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| 8 | Mesh::Preprocess()
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| 9 | {
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| 10 | mBoundingBox.Initialize();
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| 11 |
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| 12 | VertexContainer::const_iterator vi = mVertices.begin();
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| 13 | for (; vi != mVertices.end(); vi++) {
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| 14 | mBoundingBox.Include(*vi);
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| 15 | }
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| 16 |
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| 17 | mIsConvex = false;
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[170] | 18 |
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| 19 | if (mFaces.size() > 2*MeshKdTree::mTermMinCost) {
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| 20 | mKdTree = new MeshKdTree(this);
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| 21 | MeshKdLeaf *root = (MeshKdLeaf *)mKdTree->GetRoot();
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| 22 | for (int i = 0; i < mFaces.size(); i++)
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| 23 | root->mFaces.push_back(i);
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| 24 | cout<<"KD";
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| 25 | mKdTree->Construct();
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| 26 | }
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[162] | 27 | }
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| 28 |
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[170] | 29 | AxisAlignedBox3
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| 30 | Mesh::GetFaceBox(const int faceIndex)
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| 31 | {
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| 32 | Face *face = mFaces[faceIndex];
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| 33 | AxisAlignedBox3 box;
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| 34 | box.SetMin( mVertices[face->mVertexIndices[0]] );
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| 35 | box.SetMax(box.Min());
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| 36 | for (int i = 1; i < face->mVertexIndices.size(); i++) {
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| 37 | box.Include(mVertices[face->mVertexIndices[i]]);
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| 38 | }
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| 39 | return box;
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| 40 | }
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[162] | 41 |
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| 42 | int
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[170] | 43 | Mesh::CastRayToFace(
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| 44 | const int faceIndex,
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| 45 | Ray &ray,
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| 46 | float &nearestT,
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| 47 | int &nearestFace,
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| 48 | MeshInstance *instance
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| 49 | )
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| 50 | {
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| 51 | float t;
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| 52 | int hit = 0;
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| 53 | if (RayFaceIntersection(faceIndex, ray, t, nearestT) == Ray::INTERSECTION) {
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| 54 | switch (ray.GetType()) {
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| 55 | case Ray::GLOBAL_RAY:
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| 56 | ray.intersections.push_back(Ray::RayIntersection(t, instance, faceIndex));
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| 57 | hit++;
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| 58 | break;
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| 59 | case Ray::LOCAL_RAY:
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| 60 | nearestT = t;
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| 61 | nearestFace = faceIndex;
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| 62 | hit++;
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| 63 | break;
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| 64 | }
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| 65 | }
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| 66 | return hit;
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| 67 | }
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| 68 |
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| 69 | int
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[162] | 70 | Mesh::CastRay(
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| 71 | Ray &ray,
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| 72 | MeshInstance *instance
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| 73 | )
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| 74 | {
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[170] | 75 | if (mKdTree) {
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| 76 | return mKdTree->CastRay(ray, instance);
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| 77 | }
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| 78 |
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[162] | 79 | int faceIndex = 0;
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| 80 | int hits = 0;
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| 81 | float nearestT = MAX_FLOAT;
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[170] | 82 | int nearestFace = -1;
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| 83 |
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[162] | 84 | if (ray.GetType() == Ray::LOCAL_RAY && ray.intersections.size())
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| 85 | nearestT = ray.intersections[0].mT;
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| 86 |
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| 87 | for ( ;
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| 88 | faceIndex < mFaces.size();
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| 89 | faceIndex++) {
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[170] | 90 | hits += CastRayToFace(faceIndex, ray, nearestT, nearestFace, instance);
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| 91 | if (mIsConvex && nearestFace != -1)
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| 92 | break;
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[162] | 93 | }
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| 94 |
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| 95 | if ( hits && ray.GetType() == Ray::LOCAL_RAY ) {
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| 96 | if (ray.intersections.size())
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| 97 | ray.intersections[0] = Ray::RayIntersection(nearestT, instance, nearestFace);
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| 98 | else
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| 99 | ray.intersections.push_back(Ray::RayIntersection(nearestT, instance, nearestFace));
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| 100 | }
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| 101 |
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| 102 | return hits;
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| 103 | }
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| 104 |
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[170] | 105 | int
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| 106 | Mesh::CastRayToSelectedFaces(
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| 107 | Ray &ray,
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| 108 | const vector<int> &faces,
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| 109 | MeshInstance *instance
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| 110 | )
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| 111 | {
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| 112 | vector<int>::const_iterator fi;
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| 113 | int faceIndex = 0;
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| 114 | int hits = 0;
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| 115 | float nearestT = MAX_FLOAT;
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| 116 | int nearestFace = -1;
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[162] | 117 |
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[170] | 118 | if (ray.GetType() == Ray::LOCAL_RAY && ray.intersections.size())
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| 119 | nearestT = ray.intersections[0].mT;
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| 120 |
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| 121 | for ( fi = faces.begin();
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| 122 | fi != faces.end();
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| 123 | fi++) {
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| 124 | hits += CastRayToFace(*fi, ray, nearestT, nearestFace, instance);
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| 125 | if (mIsConvex && nearestFace != -1)
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| 126 | break;
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| 127 | }
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| 128 |
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| 129 | if ( hits && ray.GetType() == Ray::LOCAL_RAY ) {
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| 130 | if (ray.intersections.size())
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| 131 | ray.intersections[0] = Ray::RayIntersection(nearestT, instance, nearestFace);
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| 132 | else
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| 133 | ray.intersections.push_back(Ray::RayIntersection(nearestT, instance, nearestFace));
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| 134 | }
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| 135 |
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| 136 | return hits;
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| 137 | }
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| 138 |
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| 139 |
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[162] | 140 | // int_lineseg returns 1 if the given line segment intersects a 2D
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| 141 | // ray travelling in the positive X direction. This is used in the
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| 142 | // Jordan curve computation for polygon intersection.
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| 143 | inline int
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| 144 | int_lineseg(float px,
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| 145 | float py,
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| 146 | float u1,
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| 147 | float v1,
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| 148 | float u2,
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| 149 | float v2)
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| 150 | {
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| 151 | float t;
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| 152 | float ydiff;
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| 153 |
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| 154 | u1 -= px; u2 -= px; // translate line
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| 155 | v1 -= py; v2 -= py;
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| 156 |
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| 157 | if ((v1 > 0 && v2 > 0) ||
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| 158 | (v1 < 0 && v2 < 0) ||
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| 159 | (u1 < 0 && u2 < 0))
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| 160 | return 0;
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| 161 |
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| 162 | if (u1 > 0 && u2 > 0)
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| 163 | return 1;
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| 164 |
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| 165 | ydiff = v2 - v1;
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| 166 | if (fabs(ydiff) < Limits::Small) { // denominator near 0
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| 167 | if (((fabs(v1) > Limits::Small) ||
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| 168 | (u1 > 0) || (u2 > 0)))
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| 169 | return 0;
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| 170 | return 1;
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| 171 | }
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| 172 |
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| 173 | t = -v1 / ydiff; // Compute parameter
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| 174 |
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| 175 | return (u1 + t * (u2 - u1)) > 0;
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| 176 | }
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| 177 |
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| 178 |
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| 179 |
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| 180 | // intersection with the polygonal face of the mesh
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| 181 | int
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| 182 | Mesh::RayFaceIntersection(const int faceIndex,
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| 183 | const Ray &ray,
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| 184 | float &t,
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| 185 | const float nearestT
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| 186 | )
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| 187 | {
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| 188 | Face *face = mFaces[faceIndex];
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| 189 |
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| 190 | Plane3 plane = GetFacePlane(faceIndex);
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| 191 | float dot = DotProd(plane.mNormal, ray.GetDir());
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| 192 |
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| 193 | // Watch for near-zero denominator
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| 194 | // ONLY single sided polygons!!!!!
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| 195 | if (dot > -Limits::Small)
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| 196 | // if (fabs(dot) < Limits::Small)
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| 197 | return Ray::NO_INTERSECTION;
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| 198 |
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| 199 | t = (-plane.mD - DotProd(plane.mNormal, ray.GetLoc())) / dot;
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| 200 |
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| 201 | if (t <= Limits::Small)
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| 202 | return Ray::INTERSECTION_OUT_OF_LIMITS;
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| 203 |
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| 204 | if (t >= nearestT) {
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| 205 | return Ray::INTERSECTION_OUT_OF_LIMITS; // no intersection was found
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| 206 | }
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| 207 |
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| 208 | int count = 0;
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| 209 | float u, v, u1, v1, u2, v2;
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| 210 | int i;
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| 211 |
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| 212 | int paxis = plane.mNormal.DrivingAxis();
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| 213 |
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| 214 | // Project the intersection point onto the coordinate plane
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| 215 | // specified by which.
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| 216 | ray.Extrap(t).ExtractVerts(&u, &v, paxis);
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| 217 |
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| 218 |
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[170] | 219 | int size = face->mVertexIndices.size();
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| 220 |
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| 221 | mVertices[face->mVertexIndices[size - 1]].
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[162] | 222 | ExtractVerts(&u1, &v1, paxis );
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[170] | 223 |
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| 224 | if (0 && size <= 4) {
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[162] | 225 | // assume a convex face
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[170] | 226 | for (i = 0; i < size; i++) {
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[162] | 227 | mVertices[face->mVertexIndices[i]].ExtractVerts(&u2, &v2, paxis);
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| 228 | // line u1, v1, u2, v2
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| 229 | if ((v2 - v1)*(u1 - u) > (u2 - u1)*(v1 - v))
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| 230 | return Ray::NO_INTERSECTION;
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| 231 | u1 = u2;
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| 232 | v1 = v2;
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| 233 | }
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| 234 |
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| 235 | return Ray::INTERSECTION;
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| 236 | }
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| 237 |
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| 238 | // We're stuck with the Jordan curve computation. Count number
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| 239 | // of intersections between the line segments the polygon comprises
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| 240 | // with a ray originating at the point of intersection and
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| 241 | // travelling in the positive X direction.
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[170] | 242 | for (i = 0; i < size; i++) {
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[162] | 243 | mVertices[face->mVertexIndices[i]].ExtractVerts(&u2, &v2, paxis);
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| 244 | count += (int_lineseg(u, v, u1, v1, u2, v2) != 0);
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| 245 | u1 = u2;
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| 246 | v1 = v2;
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| 247 | }
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| 248 |
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| 249 | // We hit polygon if number of intersections is odd.
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| 250 | return (count & 1) ? Ray::INTERSECTION : Ray::NO_INTERSECTION;
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| 251 | }
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| 252 |
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| 253 |
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| 254 | int
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| 255 | MeshInstance::CastRay(
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| 256 | Ray &ray
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| 257 | )
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| 258 | {
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| 259 | int res = mMesh->CastRay(ray, this);
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| 260 | return res;
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| 261 | }
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| 262 |
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[170] | 263 | int
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| 264 | MeshInstance::CastRay(
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| 265 | Ray &ray,
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| 266 | const vector<int> &faces
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| 267 | )
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| 268 | {
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| 269 | return mMesh->CastRayToSelectedFaces(ray, faces, this);
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| 270 | }
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[162] | 271 |
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[170] | 272 |
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[162] | 273 | Plane3
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| 274 | Mesh::GetFacePlane(const int faceIndex)
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| 275 | {
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| 276 | Face *face = mFaces[faceIndex];
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| 277 | return Plane3(mVertices[face->mVertexIndices[0]],
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| 278 | mVertices[face->mVertexIndices[1]],
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| 279 | mVertices[face->mVertexIndices[2]]);
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| 280 | }
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| 281 |
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| 282 | int
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| 283 | MeshTransformedInstance::CastRay(
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| 284 | Ray &ray
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| 285 | )
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| 286 | {
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| 287 | ray.ApplyTransform(Invert(mWorldTransform));
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| 288 | int res = mMesh->CastRay(ray, this);
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| 289 | ray.ApplyTransform(mWorldTransform);
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| 290 |
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| 291 | return res;
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| 292 | }
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[170] | 293 |
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