+class FGSceneryIntersect : public osg::NodeVisitor {
+public:
+ FGSceneryIntersect(const SGLineSegmentd& lineSegment,
+ const osg::Node* skipNode) :
+ osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ACTIVE_CHILDREN),
+ _lineSegment(lineSegment),
+ _skipNode(skipNode),
+ _material(0),
+ _haveHit(false)
+ { }
+
+ bool getHaveHit() const
+ { return _haveHit; }
+ const SGLineSegmentd& getLineSegment() const
+ { return _lineSegment; }
+ const SGMaterial* getMaterial() const
+ { return _material; }
+
+ virtual void apply(osg::Node& node)
+ {
+ if (&node == _skipNode)
+ return;
+ if (!testBoundingSphere(node.getBound()))
+ return;
+
+ addBoundingVolume(node);
+ }
+
+ virtual void apply(osg::Group& group)
+ {
+ if (&group == _skipNode)
+ return;
+ if (!testBoundingSphere(group.getBound()))
+ return;
+
+ traverse(group);
+ addBoundingVolume(group);
+ }
+
+ virtual void apply(osg::Transform& transform)
+ { handleTransform(transform); }
+ virtual void apply(osg::Camera& camera)
+ {
+ if (camera.getRenderOrder() != osg::Camera::NESTED_RENDER)
+ return;
+ handleTransform(camera);
+ }
+ virtual void apply(osg::CameraView& transform)
+ { handleTransform(transform); }
+ virtual void apply(osg::MatrixTransform& transform)
+ { handleTransform(transform); }
+ virtual void apply(osg::PositionAttitudeTransform& transform)
+ { handleTransform(transform); }
+
+private:
+ void handleTransform(osg::Transform& transform)
+ {
+ if (&transform == _skipNode)
+ return;
+ // Hmm, may be this needs to be refined somehow ...
+ if (transform.getReferenceFrame() != osg::Transform::RELATIVE_RF)
+ return;
+
+ if (!testBoundingSphere(transform.getBound()))
+ return;
+
+ osg::Matrix inverseMatrix;
+ if (!transform.computeWorldToLocalMatrix(inverseMatrix, this))
+ return;
+ osg::Matrix matrix;
+ if (!transform.computeLocalToWorldMatrix(matrix, this))
+ return;
+
+ SGLineSegmentd lineSegment = _lineSegment;
+ bool haveHit = _haveHit;
+ const SGMaterial* material = _material;
+
+ _haveHit = false;
+ _lineSegment = lineSegment.transform(SGMatrixd(inverseMatrix.ptr()));
+
+ addBoundingVolume(transform);
+ traverse(transform);
+
+ if (_haveHit) {
+ _lineSegment = _lineSegment.transform(SGMatrixd(matrix.ptr()));
+ } else {
+ _lineSegment = lineSegment;
+ _material = material;
+ _haveHit = haveHit;
+ }
+ }
+
+ simgear::BVHNode* getNodeBoundingVolume(osg::Node& node)
+ {
+ SGSceneUserData* userData = SGSceneUserData::getSceneUserData(&node);
+ if (!userData)
+ return 0;
+ return userData->getBVHNode();
+ }
+ void addBoundingVolume(osg::Node& node)
+ {
+ simgear::BVHNode* bvNode = getNodeBoundingVolume(node);
+ if (!bvNode)
+ return;
+
+ // Find ground intersection on the bvh nodes
+ simgear::BVHLineSegmentVisitor lineSegmentVisitor(_lineSegment,
+ 0/*startTime*/);
+ bvNode->accept(lineSegmentVisitor);
+ if (!lineSegmentVisitor.empty()) {
+ _lineSegment = lineSegmentVisitor.getLineSegment();
+ _material = lineSegmentVisitor.getMaterial();
+ _haveHit = true;
+ }
+ }
+
+ bool testBoundingSphere(const osg::BoundingSphere& bound) const
+ {
+ if (!bound.valid())
+ return false;
+
+ SGSphered sphere(toVec3d(toSG(bound._center)), bound._radius);
+ return intersects(_lineSegment, sphere);
+ }
+
+ SGLineSegmentd _lineSegment;
+ const osg::Node* _skipNode;
+
+ const SGMaterial* _material;
+ bool _haveHit;
+};
+