OpenSceneGraph/src/osgSim/VisibilityGroup.cpp
2012-03-21 17:36:20 +00:00

86 lines
2.8 KiB
C++

/* -*-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.
*/
#include <osgSim/VisibilityGroup>
#include <osgUtil/CullVisitor>
#include <osgUtil/IntersectVisitor>
using namespace osgSim;
using namespace osg;
VisibilityGroup::VisibilityGroup():
_volumeIntersectionMask(0xFFFFFFFF),
_segmentLength(0.f)
{
}
VisibilityGroup::VisibilityGroup(const VisibilityGroup& sw,const osg::CopyOp& copyop):
osg::Group(sw,copyop),
_volumeIntersectionMask(0xFFFFFFFF),
_segmentLength(0.f)
{
}
void VisibilityGroup::traverse(osg::NodeVisitor& nv)
{
if (nv.getTraversalMode()==osg::NodeVisitor::TRAVERSE_ACTIVE_CHILDREN && nv.getVisitorType() == osg::NodeVisitor::CULL_VISITOR)
{
// cast to cullvisitor
osgUtil::CullVisitor& cv = (osgUtil::CullVisitor&) nv;
// here we test if we are inside the visibilityvolume
// first get the eyepoint and in local coordinates
osg::Vec3 eye = cv.getEyeLocal();
osg::Vec3 look = cv.getLookVectorLocal();
// now scale the segment to the segment length - if 0 use the group bounding sphere radius
float length = _segmentLength;
if(length == 0.f)
length = 2.0f*getBound().radius();
look *= length;
osg::Vec3 center = eye + look;
osg::Vec3 seg = center - eye;
// perform the intersection using the given mask
osgUtil::IntersectVisitor iv;
osg::ref_ptr<osg::LineSegment> lineseg = new osg::LineSegment;
lineseg->set(eye, center);
iv.addLineSegment(lineseg.get());
iv.setTraversalMask(_volumeIntersectionMask);
if(_visibilityVolume.valid())
_visibilityVolume->accept(iv);
// now examine the hit record
if(iv.hits())
{
osgUtil::IntersectVisitor::HitList& hitList = iv.getHitList(lineseg.get());
if(!hitList.empty()) // we actually hit something
{
// OSG_INFO << "Hit obstruction"<< std::endl;
osg::Vec3 normal = hitList.front().getWorldIntersectNormal();
if((normal*seg) > 0.f ) // we are inside
Group::traverse(nv);
}
}
}
else
{
Group::traverse(nv);
}
}