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

src/osgUtil/GNUmakefile

@@ -9,6 +9,7 @@ CXXFILES = \
 	DisplayRequirementsVisitor.cpp\
 	InsertImpostorsVisitor.cpp\
 	IntersectVisitor.cpp\
+	PickVisitor.cpp\
 	Optimizer.cpp\
 	RenderBin.cpp\
 	RenderGraph.cpp\

src/osgUtil/PickVisitor.cpp

@@ -0,0 +1,116 @@
+/* -*-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.
+*/
+
+
+#include <osgUtil/PickVisitor>
+#include <osgUtil/SceneView>
+#include <osg/Projection>
+
+using namespace osg;
+using namespace osgUtil;
+
+osgUtil::IntersectVisitor::HitList & PickIntersectVisitor::getHits(osgUtil::SceneView *scv, int x, int y)
+{ // High level get intersection with sceneview using a ray from x,y on the screen
+	int x0,y0,width,height;
+	scv->getViewport(x0, y0, width, height);
+//	setxy(-1+2*(float)(x-x0)/(float)width,	1-2*(float)(y-y0)/(float)height);
+	// sets xp,yp as pixels scaled to a mapping of (-1,1, -1,1); needed for Projection from x,y pixels
+    osg::Vec3 near_point,far_point;
+	 // get ends of line segment perpendicular to screen:
+    if (!scv->projectWindowXYIntoObject(x,height-y,near_point,far_point))
+    {
+        osg::notify(osg::NOTICE) << "PickIntersect failed to calculate intersection ray."<< std::endl;
+        return getHitList(NULL); // empty;
+    }
+
+	return getIntersections(scv->getSceneData(),near_point,far_point);
+}
+
+osgUtil::IntersectVisitor::HitList & PickIntersectVisitor::getIntersections(osg::Node *scene,
+	osg::Vec3 near_point,osg::Vec3 far_point)
+{	// option for non-sceneView users: you need to get the screen perp line and call getIntersections
+	// if you are using Projection nodes you should also call setxy to define the xp,yp positions for use with
+	// the ray transformed by Projection
+	_lineSegment = new osg::LineSegment;
+	_lineSegment->set(near_point,far_point); // make a line segment
+    addLineSegment(_lineSegment.get());
+	
+	scene->accept(*this);
+	return getHitList(_lineSegment.get());
+}
+
+// pickvisitor - top level; test main scenegraph than traverse to lower Projections
+osgUtil::IntersectVisitor::HitList & PickVisitor::getHits(osg::Node *nd, const osg::Vec3 near_point, const osg::Vec3 far_point)
+{ // High level get intersection with sceneview using a ray from x,y on the screen
+	// sets xp,yp as pixels scaled to a mapping of (-1,1, -1,1); needed for Projection from x,y pixels
+    
+	// first get the standard hits in un-projected nodes
+	_PIVsegHitList=_piv.getIntersections(nd,near_point,far_point); // fill hitlist
+
+	// then get hits in projection nodes
+	traverse(*(nd)); // check for projection nodes
+	return _PIVsegHitList;
+}
+osgUtil::IntersectVisitor::HitList & PickVisitor::getHits(osgUtil::SceneView *scv, const double x, const double y)
+{ // High level get intersection with sceneview using a ray from x,y on the screen
+	int x0,y0,width,height;
+	scv->getViewport(x0, y0, width, height);
+	setxy(-1+2*(float)(x-x0)/(float)width,	1-2*(float)(y-y0)/(float)height);
+	// sets xp,yp as pixels scaled to a mapping of (-1,1, -1,1); needed for Projection from x,y pixels
+    osg::Vec3 near_point,far_point;
+	 // get ends of line segment perpendicular to screen:
+    if (!scv->projectWindowXYIntoObject(x,height-y,near_point,far_point))
+    {
+        osg::notify(osg::NOTICE) << "PickIntersect failed to calculate intersection ray."<< std::endl;
+        return _piv.getHitList(NULL); // empty;
+    }
+	osg::Node *nd=scv->getSceneData();
+	getHits(nd, near_point,far_point);
+	return _PIVsegHitList;
+}
+osgUtil::IntersectVisitor::HitList & PickVisitor::getHits(void)
+{ // High level return current intersections
+	return _PIVsegHitList;
+}
+osgUtil::IntersectVisitor::HitList& PickVisitor::getHits(osg::Node *scene, 
+		const osg::Matrix &projm, const float x, const float y)
+{ // utility for non=sceneview viewers
+	// x,y are values returned by 
+	osg::Matrix inverseMVPW;
+	inverseMVPW.invert(projm);
+	double ix=0.5+0.5*x, iy=0.5-0.5*y; // for this purpose, range from 0-1
+	osg::Vec3 near_point = osg::Vec3(ix,iy,0.0f)*inverseMVPW;
+	osg::Vec3 far_point = osg::Vec3(ix,iy,1.0f)*inverseMVPW;
+	setxy(x,-y);	
+	getHits(scene,near_point,far_point);
+	return _PIVsegHitList;
+}
+void PickVisitor::apply(osg::Projection& pr)
+{ // stack the intersect rays, transform to new projection, traverse
+	// Assumes that the Projection is an absolute projection
+	osg::Matrix mt=osg::Matrix::inverse(pr.getMatrix());
+	osg::Vec3 npt=osg::Vec3(xp,yp,1) * mt, farpt=osg::Vec3(xp,yp,-1) * mt;
+
+	// traversing the nodes children, using the projection direction
+	for (unsigned int i=0; i<pr.getNumChildren(); i++) {
+		osg::Node *nodech=pr.getChild(i);
+		osgUtil::IntersectVisitor::HitList &hli=_piv.getIntersections(nodech,npt, farpt);
+		for(osgUtil::IntersectVisitor::HitList::iterator hitr=hli.begin();
+			hitr!=hli.end();
+			++hitr) { // add the projection hits to the scene hits.
+				// This is why _lineSegment is retained as a member of PickIntersectVisitor
+			_PIVsegHitList.push_back(*hitr);
+		}
+		traverse(*nodech);
+    }
+}