Added Geoff Michel's osgpick and osgUtil::PickVisitor code.

include/osgUtil/PickVisitor

@@ -0,0 +1,65 @@
+/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2003 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.
+*/
+// PickIntersectVisitor == Pick visitor - used for screen based picking
+// based on osgUtil::IntersectVisitor BUT
+// traversing into Projection Nodes using the modified projections.
+// also supplies high level intersector for 'what is under a pixel in a sceneview'
+// GWM Feb 2003.
+
+
+#ifndef OSGUTIL_PICKINTERSECTVISITOR
+#define OSGUTIL_PICKINTERSECTVISITOR 1
+
+#include <osgUtil/IntersectVisitor>
+#include <osgUtil/SceneView>
+
+namespace osgUtil {
+
+// PickIntersectVisitor simplifies picking - routines take x,y mouse pixel & detect hits
+class OSGUTIL_EXPORT PickIntersectVisitor : public IntersectVisitor {
+public:
+	PickIntersectVisitor() { 
+		setNodeMaskOverride(0xffffffff); // need to make the visitor override the nodemask to visit invisible actions
+	}
+	~PickIntersectVisitor() {  }
+	HitList& getHits(osgUtil::SceneView *, int x, int y);
+	HitList& PickIntersectVisitor::getIntersections(osg::Node *scene, osg::Vec3 nr, osg::Vec3 fr);
+private:
+	osg::ref_ptr<osg::LineSegment> _lineSegment;
+    friend class osgUtil::IntersectVisitor;
+};
+
+// PickVisitor traverses whole scene and checks below all Projection nodes
+class OSGUTIL_EXPORT PickVisitor : public osg::NodeVisitor {
+public:
+	PickVisitor() { 
+		xp=yp=0;    
+		setNodeMaskOverride(0xffffffff); // need to make the visitor override the nodemask to visit invisible actions
+		setTraversalMode(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN);
+	}
+	~PickVisitor() { }
+    virtual void apply(osg::Projection& pr);
+	osgUtil::IntersectVisitor::HitList& getHits(osg::Node *nd, const osg::Matrix &projm, const float x, const float y);
+	osgUtil::IntersectVisitor::HitList& getHits(osgUtil::SceneView *, double x, double y);
+	osgUtil::IntersectVisitor::HitList & getHits(osg::Node *nd, const osg::Vec3 near_point, const osg::Vec3 far_point);
+	osgUtil::IntersectVisitor::HitList& getHits(void);
+	inline void setxy(float xpt, float ypt) { xp=xpt; yp=ypt; }
+	inline bool hits() { return _PIVsegHitList.size()>0;}
+private:
+	PickIntersectVisitor _piv;
+	float xp, yp; // start point in viewport fraction coordiantes
+    osgUtil::IntersectVisitor::HitList       _PIVsegHitList;
+};
+}// namespace osgUtil
+
+#endif // match OSGUTIL_PICKINTERSECTVISITOR