void DiInstanceBatch::DefragmentBatchDoCull( InstancedModelVec &usedEntities )
{
auto itor = usedEntities.begin();
auto end = usedEntities.end();
DiVec3 vMinPos = DiVec3::ZERO, firstPos = DiVec3::ZERO;
DiInstancedModelPtr first;
if( !usedEntities.empty() )
{
first = *usedEntities.begin();
firstPos= first->GetDerivedPosition();
vMinPos = first->GetDerivedPosition();
}
while( itor != end )
{
const DiVec3 &vPos = (*itor)->GetDerivedPosition();
vMinPos.x = DiMath::Min( vMinPos.x, vPos.x );
vMinPos.y = DiMath::Min( vMinPos.y, vPos.y );
vMinPos.z = DiMath::Min( vMinPos.z, vPos.z );
if( vMinPos.squaredDistance( vPos ) < vMinPos.squaredDistance( firstPos ) )
{
firstPos = vPos;
}
++itor;
}
while( !usedEntities.empty() && mInstancedModels.size() < mInstancesPerBatch )
{
auto closest = usedEntities.begin();
auto it = usedEntities.begin();
auto e = usedEntities.end();
DiVec3 closestPos;
closestPos = (*closest)->GetDerivedPosition();
while( it != e )
{
const DiVec3 &vPos = (*it)->GetDerivedPosition();
if( firstPos.squaredDistance( vPos ) < firstPos.squaredDistance( closestPos ) )
{
closest = it;
closestPos = vPos;
}
++it;
}
mInstancedModels.push_back( *closest );
*closest = *(usedEntities.end() - 1);
usedEntities.pop_back();
}
}
