C++ NodeVisitor::getDistanceToViewPoint方法代码示例

void
TileNode::load(osg::NodeVisitor& nv)
{
    // Access the context:
    EngineContext* context = static_cast<EngineContext*>( nv.getUserData() );

    // Create a new load request on demand:
    if ( !_loadRequest.valid() )
    {
        Threading::ScopedMutexLock lock(_mutex);
        if ( !_loadRequest.valid() )
        {
            _loadRequest = new LoadTileData( this, context );
            _loadRequest->setName( _key.str() );
            _loadRequest->setTileKey( _key );
        }
    }

    // Prioritize by LOD. (negated because lower order gets priority)
    float priority = - (float)getTileKey().getLOD();

    if ( context->getOptions().highResolutionFirst() == true )
        priority = -priority;

    // then sort by distance within each LOD.
    float distance = nv.getDistanceToViewPoint( getBound().center(), true );
    priority = 10.0f*priority - log10(distance);

    // testing intermediate loading idea...
    //if ( getTileKey().getLOD() == 5 )
    //    priority += 100.0f;

    // Submit to the loader.
    context->getLoader()->load( _loadRequest.get(), priority, nv );
}

void ElevationLOD::traverse( osg::NodeVisitor& nv)
{
    if (nv.getVisitorType()   == osg::NodeVisitor::CULL_VISITOR &&
        nv.getTraversalMode() == osg::NodeVisitor::TRAVERSE_ACTIVE_CHILDREN )
    {
        bool rangeOK     = true;
        bool altitudeOK  = true;

        // first test the range:
        if ( _minRange.isSet() || _maxRange.isSet() )
        {
            float range = nv.getDistanceToViewPoint( getBound().center(), true );
            rangeOK =
                (!_minRange.isSet() || (range >= *_minRange)) &&
                (!_maxRange.isSet() || (range <= *_maxRange));
        }

        if ( rangeOK )
        {
            if ( _minElevation.isSet() || _maxElevation.isSet() )
            {
                double alt;

                // first see if we have a precalculated elevation:
                osgUtil::CullVisitor* cv = Culling::asCullVisitor(nv);

                osg::Vec3d eye = cv->getViewPoint();

                if ( _srs && !_srs->isProjected() )
                {
                    GeoPoint mapPoint;
                    mapPoint.fromWorld( _srs.get(), eye );
                    alt = mapPoint.z();
                }
                else
                {
                    alt = eye.z();
                }

                // account for the LOD scale
                alt *= cv->getLODScale();

                altitudeOK =
                    (!_minElevation.isSet() || (alt >= *_minElevation)) &&
                    (!_maxElevation.isSet() || (alt <= *_maxElevation));
            }

            if ( altitudeOK )
            {
                std::for_each(_children.begin(),_children.end(),osg::NodeAcceptOp(nv));
            }
        }
    }
    else
    {
        osg::Group::traverse( nv );
    }
}

void
HTMNode::traverse(osg::NodeVisitor& nv)
{
    if ( nv.getVisitorType() == nv.CULL_VISITOR )
    {
        //OE_INFO << getName() << std::endl;
#if 0
        if ( _isLeaf )
        {
            if (_settings._debugFrame != nv.getFrameStamp()->getFrameNumber())
            {
                OE_NOTICE << "Frame " << _settings._debugFrame << ": " << _settings._debugCount << std::endl;
                _settings._debugCount = 0;
                _settings._debugFrame = nv.getFrameStamp()->getFrameNumber();
            }
            _settings._debugCount += getNumChildren();
        }
#endif

        const osg::BoundingSphere& bs = getBound();

        float range = nv.getDistanceToViewPoint(bs.center(), true);
        bool inRange = false;

        if (_settings._maxRange.isSet() == false)
        {
            inRange = range < (bs.radius() * _settings._rangeFactor.get());
        }
        else
        {
            inRange = range < (bs.radius() + _settings._maxRange.get());
        }

        if ( inRange )
        {
            osg::Group::traverse( nv );
            
            if (_debug.valid() && _isLeaf)
            {
                _debug->accept(nv);
            }
        }
        else if (_debug.valid())
        {
            _debug->accept(nv);
        }
    }
    else
    {
        if (_debug.valid())
        {
            _debug->accept(nv);
        }

        osg::Group::traverse( nv );        
    }
}

void
TileGroup::traverse(osg::NodeVisitor& nv)
{
    if ( nv.getTraversalMode() == nv.TRAVERSE_ACTIVE_CHILDREN )
    {
        float range = 0.0f;
        if ( nv.getVisitorType() == nv.CULL_VISITOR )
        {
            range = nv.getDistanceToViewPoint( getBound().center(), true );
        }

        // if all four subtiles have reported that they are upsampling, 
        // don't use any of them.
        if ( _traverseSubtiles && _numSubtilesUpsampling == 4 )
        {
            _traverseSubtiles = false;
        }

        // if we are out of subtile range, or we're in range but the subtiles are
        // not all loaded yet, or we are skipping subtiles, draw the current tile.
        if ( range > _subtileRange || _numSubtilesLoaded < 4 || !_traverseSubtiles )
        {
            _tilenode->accept( nv );
        }

        // if we're in range, traverse the subtiles.
        if ( _traverseSubtiles && range <= _subtileRange )
        {
            for( unsigned q=0; q<4; ++q )
            {
                getChild(1+q)->accept( nv );
            }

            // update the TileNode so it knows what frame we're in.
            if ( nv.getFrameStamp() )
            {
              _tilenode->setLastTraversalFrame( nv.getFrameStamp()->getFrameNumber() );
            }
        }
    }
    else
    {
        osg::Group::traverse( nv );
    }
}

void
TileNode::load(osg::NodeVisitor& nv)
{
    // Access the context:
    EngineContext* context = VisitorData::fetch<EngineContext>(nv, ENGINE_CONTEXT_TAG);

    // Create a new load request on demand:
    if ( !_loadRequest.valid() )
    {
        Threading::ScopedMutexLock lock(_mutex);
        if ( !_loadRequest.valid() )
        {
            _loadRequest = new LoadTileData( this, context );
            _loadRequest->setName( _key.str() );
            _loadRequest->setTileKey( _key );
        }
    }

    
    // Construct the load PRIORITY: 0=lowest, 1=highest.
    
    const SelectionInfo& si = context->getSelectionInfo();
    int lod     = getTileKey().getLOD();
    int numLods = si.numLods();
    
    // LOD priority is in the range [0..numLods]
    float lodPriority = (float)lod;
    if ( context->getOptions().highResolutionFirst() == false )
        lodPriority = (float)(numLods - lod);

    float distance = nv.getDistanceToViewPoint(getBound().center(), true);

    // dist priority uis in the range [0..1]
    float distPriority = 1.0 - distance/si.visParameters(0)._visibilityRange;

    // add thenm together, and you get tiles sorted first by lodPriority (because of
    // the biggest range), and second by distance.
    float priority = lodPriority + distPriority;

    // normalize the composite priority to [0..1].
    priority /= (float)(numLods+1);

    // Submit to the loader.
    context->getLoader()->load( _loadRequest.get(), priority, nv );
}

void LOD::traverse(osg::NodeVisitor& nv)
{
    if(_dirty_copy)
    {
        osg::Group* prnt =  getParent(0);
        for(unsigned i =0;i<prnt->getNumChildren();++i)
        {
            auto chld = prnt->getChild(i);
            if (!dynamic_cast<avLod::LOD*>(chld))
                addChild(chld);
        }
        _dirty_copy =false;
    }
    switch(nv.getTraversalMode())
    {
        //case(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN):
        //    std::for_each(_children.begin(),_children.end(),NodeAcceptOp(nv));
        //    break;
        case(osg::NodeVisitor::TRAVERSE_ACTIVE_CHILDREN):
        {
            float required_range = 0;
            if (_rangeMode==DISTANCE_FROM_EYE_POINT)
            {
                required_range = nv.getDistanceToViewPoint(getCenter(),true);
            }
            else
            {
                osg::CullStack* cullStack = dynamic_cast<osg::CullStack*>(&nv);
                if (cullStack && cullStack->getLODScale())
                {
                    required_range = cullStack->clampedPixelSize(getBound()) / cullStack->getLODScale();
                }
                else
                {
                    // fallback to selecting the highest res tile by
                    // finding out the max range
                    for(unsigned int i=0;i<_rangeList.size();++i)
                    {
                        required_range = osg::maximum(required_range,_rangeList[i].first);
                    }
                }
            }

            unsigned int numChildren = _children.size();
            if (_rangeList.size()<numChildren) numChildren=_rangeList.size();

            for(unsigned int i=0;i<numChildren;++i)
            {
                if (_rangeList[i].first<=required_range && required_range<_rangeList[i].second)
                {
                    _children[i]->setNodeMask(/*0xffffffff*/REFLECTION_MASK);// accept(nv);
                }
                else
                {
                    _children[i]->setNodeMask(0);
                }
            }
           break;
        }
        default:
            break;
    }
}

// MOST of this is copied and pasted from OSG's osg::PagedLOD::traverse,
// except where otherwise noted with an "osgEarth" comment.
void
TilePagedLOD::traverse(osg::NodeVisitor& nv)
{
    // set the frame number of the traversal so that external nodes can find out how active this
    // node is.
    if (nv.getFrameStamp() &&
        nv.getVisitorType()==osg::NodeVisitor::CULL_VISITOR)
    {
        setFrameNumberOfLastTraversal(nv.getFrameStamp()->getFrameNumber());
        
        // osgEarth: update our progress tracker to prevent tile cancelation.
        if (_progress.valid())
        {
            _progress->update( nv.getFrameStamp()->getFrameNumber() );
        }
    }

    double timeStamp = nv.getFrameStamp()?nv.getFrameStamp()->getReferenceTime():0.0;
    unsigned int frameNumber = nv.getFrameStamp()?nv.getFrameStamp()->getFrameNumber():0;
    bool updateTimeStamp = nv.getVisitorType()==osg::NodeVisitor::CULL_VISITOR;

    switch(nv.getTraversalMode())
    {
    case(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN):
            std::for_each(_children.begin(),_children.end(),osg::NodeAcceptOp(nv));
            break;
        case(osg::NodeVisitor::TRAVERSE_ACTIVE_CHILDREN):
        {
            osg::ref_ptr<MPTerrainEngineNode> engine;
            MPTerrainEngineNode::getEngineByUID( _engineUID, engine );
            if (!engine.valid())
                return;

            // Compute the required range.
            float required_range = -1.0;
            if (engine->getComputeRangeCallback())
            {                
                required_range = (*engine->getComputeRangeCallback())(this, nv);
            }            

            // If we don't have a callback or it return a negative number fallback on the original calculation.
            if (required_range < 0.0)
            {
                if (_rangeMode==DISTANCE_FROM_EYE_POINT)
                {
                    required_range = nv.getDistanceToViewPoint(getCenter(),true);

                    if (_rangeFactor.isSet())
                        required_range /= _rangeFactor.get();
                }
                else
                {
                    osg::CullStack* cullStack = dynamic_cast<osg::CullStack*>(&nv);
                    if (cullStack && cullStack->getLODScale()>0.0f)
                    {
                        required_range = cullStack->clampedPixelSize(getBound()) / cullStack->getLODScale();
                    }
                    else
                    {
                        // fallback to selecting the highest res tile by
                        // finding out the max range
                        for(unsigned int i=0;i<_rangeList.size();++i)
                        {
                            required_range = osg::maximum(required_range,_rangeList[i].first);
                        }
                    }
                }
            }

            int lastChildTraversed = -1;
            bool needToLoadChild = false;
            for(unsigned int i=0;i<_rangeList.size();++i)
            {
                if (_rangeList[i].first<=required_range && required_range<_rangeList[i].second)
                {
                    if (i<_children.size())
                    {
                        if (updateTimeStamp)
                        {
                            _perRangeDataList[i]._timeStamp=timeStamp;
                            _perRangeDataList[i]._frameNumber=frameNumber;
                        }

                        _children[i]->accept(nv);
                        lastChildTraversed = (int)i;
                    }
                    else
                    {
                        needToLoadChild = true;
                    }
                }
            }

#ifdef INHERIT_VIEWPOINT_CAMERAS_CANNOT_SUBDIVIDE
            // Prevents an INHERIT_VIEWPOINT camera from invoking tile subdivision
            if (needToLoadChild)
            {
                osgUtil::CullVisitor* cv = dynamic_cast<osgUtil::CullVisitor*>(&nv);
//.........这里部分代码省略.........