From 2851429333216f0fee0a3084097050b5b8d1ee9c Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Tue, 8 Jul 2008 17:35:10 +0000
Subject: [PATCH] Added optional control of whether to use KdTrees for
 intersections

---
 include/osgUtil/IntersectionVisitor    | 17 ++++++++++++++---
 src/osgUtil/IntersectionVisitor.cpp    |  2 ++
 src/osgUtil/LineSegmentIntersector.cpp | 10 +++-------
 3 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/include/osgUtil/IntersectionVisitor b/include/osgUtil/IntersectionVisitor
index f169a520f..886ac73e9 100644
--- a/include/osgUtil/IntersectionVisitor
+++ b/include/osgUtil/IntersectionVisitor
@@ -46,11 +46,12 @@ class Intersector : public osg::Referenced
             _coordinateFrame(cf),
             _disabledCount(0) {}
     
+    
         void setCoordinateFrame(CoordinateFrame cf) { _coordinateFrame = cf; }
         
         CoordinateFrame getCoordinateFrame() const { return _coordinateFrame; }
-    
-
+        
+        
         virtual Intersector* clone(osgUtil::IntersectionVisitor& iv) = 0;
         
         virtual bool enter(const osg::Node& node) = 0;
@@ -72,7 +73,7 @@ class Intersector : public osg::Referenced
     protected:
     
         CoordinateFrame _coordinateFrame;
-        unsigned int _disabledCount;
+        unsigned int    _disabledCount;
 
 };
 
@@ -138,6 +139,7 @@ class OSGUTIL_EXPORT IntersectionVisitor : public osg::NodeVisitor
         
         virtual void reset();
 
+
         /** Set the intersector that will be used to intersect with the scene, and to store any hits that occur.*/
         void setIntersector(Intersector* intersector);
         
@@ -148,6 +150,13 @@ class OSGUTIL_EXPORT IntersectionVisitor : public osg::NodeVisitor
         const Intersector* getIntersector() const { return _intersectorStack.empty() ? 0 : _intersectorStack.front().get(); }
 
 
+        /** Set whether the intersectors should use KdTrees when they are found on the scene graph.*/
+        void setUseKdTreeWhenAvailable(bool useKdTrees) { _useKdTreesWhenAvailable; }
+        
+        /** Set whether the intersectors should use KdTrees.*/
+        bool getUseKdTreeWhenAvailable() const { return _useKdTreesWhenAvailable; }
+
+
         /** Set the read callback.*/
         void setReadCallback(ReadCallback* rc) { _readCallback = rc; }
 
@@ -201,6 +210,8 @@ class OSGUTIL_EXPORT IntersectionVisitor : public osg::NodeVisitor
 
         typedef std::list< osg::ref_ptr<Intersector> > IntersectorStack;
         IntersectorStack _intersectorStack;
+
+        bool _useKdTreesWhenAvailable;
         
         osg::ref_ptr<ReadCallback> _readCallback;
         
diff --git a/src/osgUtil/IntersectionVisitor.cpp b/src/osgUtil/IntersectionVisitor.cpp
index 9c4350eb6..010ddef8e 100644
--- a/src/osgUtil/IntersectionVisitor.cpp
+++ b/src/osgUtil/IntersectionVisitor.cpp
@@ -155,6 +155,8 @@ IntersectionVisitor::IntersectionVisitor(Intersector* intersector, ReadCallback*
     // override the default node visitor mode.
     setTraversalMode(osg::NodeVisitor::TRAVERSE_ACTIVE_CHILDREN);
     
+    _useKdTreesWhenAvailable = true;
+
     setIntersector(intersector);
     
     setReadCallback(readCallback);
diff --git a/src/osgUtil/LineSegmentIntersector.cpp b/src/osgUtil/LineSegmentIntersector.cpp
index 004385386..2caeb0a5f 100644
--- a/src/osgUtil/LineSegmentIntersector.cpp
+++ b/src/osgUtil/LineSegmentIntersector.cpp
@@ -299,8 +299,8 @@ void LineSegmentIntersector::intersect(osgUtil::IntersectionVisitor& iv, osg::Dr
     unsigned int numKdTreeHits = 0;
     unsigned int numConventionalHits = 0;
     
-    osg::KdTree* kdTree = dynamic_cast<osg::KdTree*>(drawable->getShape());
     osg::Vec3d kdTreeHit;
+    osg::KdTree* kdTree = iv.getUseKdTreeWhenAvailable() ? dynamic_cast<osg::KdTree*>(drawable->getShape()) : 0;
     if (kdTree)
     {
         osg::KdTree::LineSegmentIntersections intersections;
@@ -343,11 +343,7 @@ void LineSegmentIntersector::intersect(osgUtil::IntersectionVisitor& iv, osg::Dr
             }
         }
         
-        // return;
-    }
-    else
-    {
-        // osg::notify(osg::NOTICE)<<"Not KdTree available"<<std::endl;
+        return;
     }
 
     osg::Timer_t after_kdTree = osg::Timer::instance()->tick();
@@ -423,7 +419,7 @@ void LineSegmentIntersector::intersect(osgUtil::IntersectionVisitor& iv, osg::Dr
     double timeKdTree = osg::Timer::instance()->delta_m(before_kdTree, after_kdTree);
     double timeConventional = osg::Timer::instance()->delta_m(after_kdTree, after_conventional);
 
-#if 1
+#if 0
     if (kdTree)
     {
         osg::notify(osg::NOTICE)<<"KdTree       ("<<kdTreeHit<<") intersections = "<<numKdTreeHits<< " time = "<<timeKdTree<<std::endl;