I modified TXPPagedLOD::traverse to prevent the terrain from inappropriately
unloading the higher level of detail tiles. It wasn't updating the frame number
of the tile or the range it was traversing, causing
PagedLOD::removeExpiredChildren to always consider the range expired.
Working from version 2.9.8.
~Laura
#include "TileMapper.h"
#include "TXPPagedLOD.h"
#include <algorithm>
using namespace txp;
TXPPagedLOD::TXPPagedLOD():
osg::PagedLOD()
{
}
TXPPagedLOD::TXPPagedLOD(const TXPPagedLOD& plod,const osg::CopyOp& copyop):
osg::PagedLOD(plod,copyop),
_tileIdentifier(plod._tileIdentifier)
{
}
TXPPagedLOD::~TXPPagedLOD()
{
}
void TXPPagedLOD::traverse(osg::NodeVisitor& nv)
{
//TileMapper* tileMapper = dynamic_cast<TileMapper*>(nv.getUserData());
//Modified by Brad Anderegg (May-27-08) because the black listing process
appears to make tiles switch lods
//when they clearly shouldnt, in the worst cases a tile will page out that
is right in front of you.
bool forceUseOfFirstChild = /*tileMapper ?
(tileMapper->isNodeBlackListed(this)) :*/ false;
double timeStamp =
nv.getFrameStamp()?nv.getFrameStamp()->getReferenceTime():0.0;
bool updateTimeStamp = nv.getVisitorType()==osg::NodeVisitor::CULL_VISITOR;
int frameNumber = nv.getFrameStamp()?nv.getFrameStamp()->getFrameNumber():0;
// 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());
}
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):
{
float distance = nv.getDistanceToEyePoint(getCenter(),true);
int lastChildTraversed = -1;
bool needToLoadChild = false;
unsigned maxRangeSize = _rangeList.size();
if (maxRangeSize!=0 && forceUseOfFirstChild)
maxRangeSize=1;
for(unsigned int i=0;i<maxRangeSize;++i)
{
if (forceUseOfFirstChild ||
(_rangeList[i].first<=distance &&
distance<_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;
}
}
}
if (needToLoadChild)
{
unsigned int numChildren = _children.size();
//std::cout<<"PagedLOD::traverse() - falling back "<<std::endl;
// select the last valid child.
if (numChildren>0 && ((int)numChildren-1)!=lastChildTraversed)
{
//std::cout<<" to child "<<numChildren-1<<std::endl;
if (updateTimeStamp)
_perRangeDataList[numChildren-1]._timeStamp=timeStamp;
_children[numChildren-1]->accept(nv);
}
// now request the loading of the next unload child.
if (nv.getDatabaseRequestHandler() &&
numChildren<_perRangeDataList.size())
{
// compute priority from where abouts in the required range
the distance falls.
float priority =
(_rangeList[numChildren].second-distance)/(_rangeList[numChildren].second-_rangeList[numChildren].first);
// modify the priority according to the child's priority
offset and scale.
priority = _perRangeDataList[numChildren]._priorityOffset +
priority * _perRangeDataList[numChildren]._priorityScale;
//std::cout<<" requesting child
"<<_fileNameList[numChildren]<<" priotity = "<<priority<<std::endl;
nv.getDatabaseRequestHandler()->requestNodeFile(_perRangeDataList[numChildren]._filename,
this,
priority,
nv.getFrameStamp(),
_perRangeDataList[numChildren]._databaseRequest);
}
}
break;
}
default:
break;
}
}
osg::BoundingSphere TXPPagedLOD::computeBound() const
{
// Force calculation of entire bounding sphere; this will include any
// externally-referenced models which are attached to the tile.
// If this is not done, then externally referenced models will disappear
// when the tile they are attached to leaves the view volume.
osg::BoundingSphere result = osg::Group::computeBound();
if (_centerMode==USER_DEFINED_CENTER && _radius>=0.0f)
{
float tempRadius = osg::maximum( _radius, result.radius() );
result = osg::BoundingSphere(_userDefinedCenter,tempRadius);
}
return result;
}
_______________________________________________
osg-submissions mailing list
[email protected]
http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org
