Added beginnings of osgUtil::PlaneIntersector and osgSim::ElevationSlice

include/osgSim/ElevationSlice

@@ -0,0 +1,98 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield 
+ *
+ * This library is open source and may be redistributed and/or modified under  
+ * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or 
+ * (at your option) any later version.  The full license is in LICENSE file
+ * included with this distribution, and on the openscenegraph.org website.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
+ * OpenSceneGraph Public License for more details.
+*/
+
+#ifndef OSGSIM_ELEVATIONSLICE
+#define OSGSIM_ELEVATIONSLICE 1
+
+#include <osgUtil/IntersectionVisitor>
+
+// include so we can get access to the DatabaseCacheReadCallback
+#include <osgSim/LineOfSight>
+
+namespace osgSim {
+
+/** Helper class for setting up and aquiring height above terrain intersections with terrain.*/
+class OSGSIM_EXPORT ElevationSlice
+{
+    public :
+
+    
+        ElevationSlice();
+        
+        /** Set the start point of the slice.*/        
+        void setStartPoint(const osg::Vec3d& startPoint) { _startPoint = startPoint; }
+
+        /** Get the start point of the slice.*/        
+        const osg::Vec3d& getStartPoint() const { return _startPoint; }
+        
+        /** Set the end point of the slice.*/        
+        void setEndPoint(const osg::Vec3d& endPoint) { _endPoint = endPoint; }
+
+        /** Get the end point of the slice.*/        
+        const osg::Vec3d& getEndPoint() const { return _endPoint; }
+
+        
+        typedef std::vector<osg::Vec3d> Vec3dList;
+        
+        /** Get the intersections in the form of a vector of Vec3d. */
+        const Vec3dList& getIntersections() const  { return _intersections; }
+
+        typedef std::pair<double,double> DistanceHeight;
+        typedef std::vector<DistanceHeight> DistanceHeightList;
+        
+        /** Get the intersections in the form a vector of pair<double,double> representing distance along the slice and height. */
+        const DistanceHeightList& getDistanceHeightIntersections() const { return _distanceHeightIntersections; }
+        
+       
+        /** Compute the intersections with the specified scene graph, the results are stored in vectors of Vec3d.
+          * Note, if the topmost node is a CoordinateSystemNode then the input points are assumed to be geocentric,
+          * with the up vector defined by the EllipsoidModel attached to the CoordinateSystemNode.
+          * If the topmost node is not a CoordinateSystemNode then a local coordinates frame is assumed, with a local up vector. */
+        void computeIntersections(osg::Node* scene);
+
+        /** Compute the vertical distance between the specified scene graph and a single HAT point. .*/
+        static Vec3dList computeElevationSlice(osg::Node* scene, const osg::Vec3d& startPoint, const osg::Vec3d& endPoint);
+        
+        
+        /** Clear the database cache.*/
+        void clearDatabaseCache() { if (_dcrc.valid()) _dcrc->clearDatabaseCache(); }
+
+        /** Set the ReadCallback that does the reading of external PagedLOD models, and caching of loaded subgraphs.
+          * Note, if you have mulitple LineOfSight or ElevationSlice objects in use at one time then you should share a single
+          * DatabaseCacheReadCallback between all of them. */
+        void setDatabaseCacheReadCallback(DatabaseCacheReadCallback* dcrc);
+
+        /** Get the ReadCallback that does the reading of external PagedLOD models, and caching of loaded subgraphs.*/
+        DatabaseCacheReadCallback* getDatabaseCacheReadCallback() { return _dcrc.get(); }
+        
+        /** Get the IntersectionVistor that does the intersection traversal over the scene.
+          * Note, if you want to customized the traversal then you can use the IntersectionVisitor's method to alter its behavior. */
+        osgUtil::IntersectionVisitor& getIntersectionVisitor() { return _intersectionVisitor; }
+
+    protected :
+    
+    
+        osg::Vec3d                              _startPoint;
+        osg::Vec3d                              _endPoint;
+        Vec3dList                               _intersections;
+        DistanceHeightList                      _distanceHeightIntersections;
+        
+        osg::ref_ptr<DatabaseCacheReadCallback> _dcrc;
+        osgUtil::IntersectionVisitor            _intersectionVisitor;
+
+
+};
+
+}
+
+#endif

include/osgUtil/IntersectionVisitor

@@ -215,6 +215,67 @@ class OSGUTIL_EXPORT PolytopeIntersector : public Intersector
     
 };
 
+/** Concrent class for implementing polytope intersections with the scene graph.
+  * To be used in conjunction with IntersectionVisitor. */
+class OSGUTIL_EXPORT PlaneIntersector : public Intersector
+{
+    public:
+    
+        /** Construct a PolytopeIntersector using speified polytope in MODEL coordinates.*/
+        PlaneIntersector(const osg::Plane& plane, const osg::Polytope& boundingPolytope=osg::Polytope());
+        
+        /** Construct a PolytopeIntersector using speified polytope in specified coordinate frame.*/
+        PlaneIntersector(CoordinateFrame cf, const osg::Plane& plane, const osg::Polytope& boundingPolytope=osg::Polytope());
+
+        struct Intersection
+        {
+            Intersection() {}
+        
+            bool operator < (const Intersection& rhs) const
+            {
+                if (nodePath < rhs.nodePath) return true;
+                if (rhs.nodePath < nodePath ) return false;
+                return (drawable < rhs.drawable);
+            }
+
+            osg::NodePath                   nodePath;
+            osg::ref_ptr<osg::Drawable>     drawable;
+        };
+        
+        typedef std::set<Intersection> Intersections;
+        
+        inline void insertIntersection(const Intersection& intersection) { getIntersections().insert(intersection); }
+
+        inline Intersections& getIntersections() { return _parent ? _parent->_intersections : _intersections; }
+
+        inline Intersection getFirstIntersection() { Intersections& intersections = getIntersections(); return intersections.empty() ? Intersection() : *(intersections.begin()); }
+
+    public:
+
+        virtual Intersector* clone(osgUtil::IntersectionVisitor& iv);
+        
+        virtual bool enter(const osg::Node& node);
+        
+        virtual void leave();
+        
+        virtual void intersect(osgUtil::IntersectionVisitor& iv, osg::Drawable* drawable);
+        
+        virtual void reset();
+
+        virtual bool containsIntersections() { return !_intersections.empty(); }
+
+    protected:
+
+        PlaneIntersector*   _parent;
+
+        osg::Plane          _plane;
+        osg::Polytope       _polytope;
+        
+        Intersections       _intersections;
+    
+};
+
+
 /** Concrent class for passing multiple intersectors through the scene graph.
   * To be used in conjunction with IntersectionVisitor. */
 class OSGUTIL_EXPORT IntersectorGroup : public Intersector