// // OctreeSendThread.cpp // assignment-client/src/octree // // Created by Brad Hefta-Gaub on 8/21/13. // Copyright 2013 High Fidelity, Inc. // // Distributed under the Apache License, Version 2.0. // See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html // #include #include #include #include #include "OctreeSendThread.h" #include "OctreeServer.h" #include "OctreeServerConsts.h" quint64 startSceneSleepTime = 0; quint64 endSceneSleepTime = 0; OctreeSendThread::OctreeSendThread(const SharedAssignmentPointer& myAssignment, const SharedNodePointer& node) : _myAssignment(myAssignment), _myServer(static_cast(myAssignment.data())), _node(node), _nodeUUID(node->getUUID()), _packetData(), _nodeMissingCount(0), _isShuttingDown(false) { QString safeServerName("Octree"); if (_myServer) { safeServerName = _myServer->getMyServerName(); } qDebug() << qPrintable(safeServerName) << "server [" << _myServer << "]: client connected " "- starting sending thread [" << this << "]"; OctreeServer::clientConnected(); } OctreeSendThread::~OctreeSendThread() { QString safeServerName("Octree"); if (_myServer) { safeServerName = _myServer->getMyServerName(); } qDebug() << qPrintable(safeServerName) << "server [" << _myServer << "]: client disconnected " "- ending sending thread [" << this << "]"; OctreeServer::clientDisconnected(); OctreeServer::stopTrackingThread(this); _node.clear(); _myAssignment.clear(); } void OctreeSendThread::setIsShuttingDown() { _isShuttingDown = true; } bool OctreeSendThread::process() { if (_isShuttingDown) { return false; // exit early if we're shutting down } // check that our server and assignment is still valid if (!_myServer || !_myAssignment) { return false; // exit early if it's not, it means the server is shutting down } OctreeServer::didProcess(this); quint64 start = usecTimestampNow(); // don't do any send processing until the initial load of the octree is complete... if (_myServer->isInitialLoadComplete()) { if (_node) { _nodeMissingCount = 0; OctreeQueryNode* nodeData = static_cast(_node->getLinkedData()); // Sometimes the node data has not yet been linked, in which case we can't really do anything if (nodeData && !nodeData->isShuttingDown()) { bool viewFrustumChanged = nodeData->updateCurrentViewFrustum(); packetDistributor(nodeData, viewFrustumChanged); } } } if (_isShuttingDown) { return false; // exit early if we're shutting down } // Only sleep if we're still running and we got the lock last time we tried, otherwise try to get the lock asap if (isStillRunning()) { // dynamically sleep until we need to fire off the next set of octree elements int elapsed = (usecTimestampNow() - start); int usecToSleep = OCTREE_SEND_INTERVAL_USECS - elapsed; if (usecToSleep > 0) { PerformanceWarning warn(false,"OctreeSendThread... usleep()",false,&_usleepTime,&_usleepCalls); usleep(usecToSleep); } else { const int MIN_USEC_TO_SLEEP = 1; usleep(MIN_USEC_TO_SLEEP); } } return isStillRunning(); // keep running till they terminate us } quint64 OctreeSendThread::_usleepTime = 0; quint64 OctreeSendThread::_usleepCalls = 0; quint64 OctreeSendThread::_totalBytes = 0; quint64 OctreeSendThread::_totalWastedBytes = 0; quint64 OctreeSendThread::_totalPackets = 0; int OctreeSendThread::handlePacketSend(OctreeQueryNode* nodeData, int& trueBytesSent, int& truePacketsSent) { OctreeServer::didHandlePacketSend(this); // if we're shutting down, then exit early if (nodeData->isShuttingDown()) { return 0; } bool debug = _myServer->wantsDebugSending(); quint64 now = usecTimestampNow(); bool packetSent = false; // did we send a packet? int packetsSent = 0; // Here's where we check to see if this packet is a duplicate of the last packet. If it is, we will silently // obscure the packet and not send it. This allows the callers and upper level logic to not need to know about // this rate control savings. if (nodeData->shouldSuppressDuplicatePacket()) { nodeData->resetOctreePacket(); // we still need to reset it though! return packetsSent; // without sending... } // If we've got a stats message ready to send, then see if we can piggyback them together if (nodeData->stats.isReadyToSend() && !nodeData->isShuttingDown()) { // Send the stats message to the client unsigned char* statsMessage = nodeData->stats.getStatsMessage(); int statsMessageLength = nodeData->stats.getStatsMessageLength(); int piggyBackSize = nodeData->getPacketLength() + statsMessageLength; // If the size of the stats message and the voxel message will fit in a packet, then piggyback them if (piggyBackSize < MAX_PACKET_SIZE) { // copy voxel message to back of stats message memcpy(statsMessage + statsMessageLength, nodeData->getPacket(), nodeData->getPacketLength()); statsMessageLength += nodeData->getPacketLength(); // since a stats message is only included on end of scene, don't consider any of these bytes "wasted", since // there was nothing else to send. int thisWastedBytes = 0; _totalWastedBytes += thisWastedBytes; _totalBytes += nodeData->getPacketLength(); _totalPackets++; if (debug) { const unsigned char* messageData = nodeData->getPacket(); int numBytesPacketHeader = numBytesForPacketHeader(reinterpret_cast(messageData)); const unsigned char* dataAt = messageData + numBytesPacketHeader; dataAt += sizeof(OCTREE_PACKET_FLAGS); OCTREE_PACKET_SEQUENCE sequence = (*(OCTREE_PACKET_SEQUENCE*)dataAt); dataAt += sizeof(OCTREE_PACKET_SEQUENCE); OCTREE_PACKET_SENT_TIME timestamp = (*(OCTREE_PACKET_SENT_TIME*)dataAt); dataAt += sizeof(OCTREE_PACKET_SENT_TIME); qDebug() << "Adding stats to packet at " << now << " [" << _totalPackets <<"]: sequence: " << sequence << " timestamp: " << timestamp << " statsMessageLength: " << statsMessageLength << " original size: " << nodeData->getPacketLength() << " [" << _totalBytes << "] wasted bytes:" << thisWastedBytes << " [" << _totalWastedBytes << "]"; } // actually send it OctreeServer::didCallWriteDatagram(this); NodeList::getInstance()->writeDatagram((char*) statsMessage, statsMessageLength, _node); packetSent = true; } else { // not enough room in the packet, send two packets OctreeServer::didCallWriteDatagram(this); NodeList::getInstance()->writeDatagram((char*) statsMessage, statsMessageLength, _node); // since a stats message is only included on end of scene, don't consider any of these bytes "wasted", since // there was nothing else to send. int thisWastedBytes = 0; _totalWastedBytes += thisWastedBytes; _totalBytes += statsMessageLength; _totalPackets++; if (debug) { const unsigned char* messageData = nodeData->getPacket(); int numBytesPacketHeader = numBytesForPacketHeader(reinterpret_cast(messageData)); const unsigned char* dataAt = messageData + numBytesPacketHeader; dataAt += sizeof(OCTREE_PACKET_FLAGS); OCTREE_PACKET_SEQUENCE sequence = (*(OCTREE_PACKET_SEQUENCE*)dataAt); dataAt += sizeof(OCTREE_PACKET_SEQUENCE); OCTREE_PACKET_SENT_TIME timestamp = (*(OCTREE_PACKET_SENT_TIME*)dataAt); dataAt += sizeof(OCTREE_PACKET_SENT_TIME); qDebug() << "Sending separate stats packet at " << now << " [" << _totalPackets <<"]: sequence: " << sequence << " timestamp: " << timestamp << " size: " << statsMessageLength << " [" << _totalBytes << "] wasted bytes:" << thisWastedBytes << " [" << _totalWastedBytes << "]"; } trueBytesSent += statsMessageLength; truePacketsSent++; packetsSent++; OctreeServer::didCallWriteDatagram(this); NodeList::getInstance()->writeDatagram((char*)nodeData->getPacket(), nodeData->getPacketLength(), _node); packetSent = true; thisWastedBytes = MAX_PACKET_SIZE - nodeData->getPacketLength(); _totalWastedBytes += thisWastedBytes; _totalBytes += nodeData->getPacketLength(); _totalPackets++; if (debug) { const unsigned char* messageData = nodeData->getPacket(); int numBytesPacketHeader = numBytesForPacketHeader(reinterpret_cast(messageData)); const unsigned char* dataAt = messageData + numBytesPacketHeader; dataAt += sizeof(OCTREE_PACKET_FLAGS); OCTREE_PACKET_SEQUENCE sequence = (*(OCTREE_PACKET_SEQUENCE*)dataAt); dataAt += sizeof(OCTREE_PACKET_SEQUENCE); OCTREE_PACKET_SENT_TIME timestamp = (*(OCTREE_PACKET_SENT_TIME*)dataAt); dataAt += sizeof(OCTREE_PACKET_SENT_TIME); qDebug() << "Sending packet at " << now << " [" << _totalPackets <<"]: sequence: " << sequence << " timestamp: " << timestamp << " size: " << nodeData->getPacketLength() << " [" << _totalBytes << "] wasted bytes:" << thisWastedBytes << " [" << _totalWastedBytes << "]"; } } nodeData->stats.markAsSent(); } else { // If there's actually a packet waiting, then send it. if (nodeData->isPacketWaiting() && !nodeData->isShuttingDown()) { // just send the voxel packet OctreeServer::didCallWriteDatagram(this); NodeList::getInstance()->writeDatagram((char*)nodeData->getPacket(), nodeData->getPacketLength(), _node); packetSent = true; int thisWastedBytes = MAX_PACKET_SIZE - nodeData->getPacketLength(); _totalWastedBytes += thisWastedBytes; _totalBytes += nodeData->getPacketLength(); _totalPackets++; if (debug) { const unsigned char* messageData = nodeData->getPacket(); int numBytesPacketHeader = numBytesForPacketHeader(reinterpret_cast(messageData)); const unsigned char* dataAt = messageData + numBytesPacketHeader; dataAt += sizeof(OCTREE_PACKET_FLAGS); OCTREE_PACKET_SEQUENCE sequence = (*(OCTREE_PACKET_SEQUENCE*)dataAt); dataAt += sizeof(OCTREE_PACKET_SEQUENCE); OCTREE_PACKET_SENT_TIME timestamp = (*(OCTREE_PACKET_SENT_TIME*)dataAt); dataAt += sizeof(OCTREE_PACKET_SENT_TIME); qDebug() << "Sending packet at " << now << " [" << _totalPackets <<"]: sequence: " << sequence << " timestamp: " << timestamp << " size: " << nodeData->getPacketLength() << " [" << _totalBytes << "] wasted bytes:" << thisWastedBytes << " [" << _totalWastedBytes << "]"; } } } // remember to track our stats if (packetSent) { nodeData->stats.packetSent(nodeData->getPacketLength()); trueBytesSent += nodeData->getPacketLength(); truePacketsSent++; packetsSent++; nodeData->octreePacketSent(); nodeData->resetOctreePacket(); } return packetsSent; } /// Version of voxel distributor that sends the deepest LOD level at once int OctreeSendThread::packetDistributor(OctreeQueryNode* nodeData, bool viewFrustumChanged) { OctreeServer::didPacketDistributor(this); // if shutting down, exit early if (nodeData->isShuttingDown()) { return 0; } // calculate max number of packets that can be sent during this interval int clientMaxPacketsPerInterval = std::max(1, (nodeData->getMaxOctreePacketsPerSecond() / INTERVALS_PER_SECOND)); int maxPacketsPerInterval = std::min(clientMaxPacketsPerInterval, _myServer->getPacketsPerClientPerInterval()); int truePacketsSent = 0; int trueBytesSent = 0; int packetsSentThisInterval = 0; bool isFullScene = ((!viewFrustumChanged || !nodeData->getWantDelta()) && nodeData->getViewFrustumJustStoppedChanging()) || nodeData->hasLodChanged(); bool somethingToSend = true; // assume we have something // FOR NOW... node tells us if it wants to receive only view frustum deltas bool wantDelta = viewFrustumChanged && nodeData->getWantDelta(); // If our packet already has content in it, then we must use the color choice of the waiting packet. // If we're starting a fresh packet, then... // If we're moving, and the client asked for low res, then we force monochrome, otherwise, use // the clients requested color state. bool wantColor = nodeData->getWantColor(); bool wantCompression = nodeData->getWantCompression(); // If we have a packet waiting, and our desired want color, doesn't match the current waiting packets color // then let's just send that waiting packet. if (!nodeData->getCurrentPacketFormatMatches()) { if (nodeData->isPacketWaiting()) { packetsSentThisInterval += handlePacketSend(nodeData, trueBytesSent, truePacketsSent); } else { nodeData->resetOctreePacket(); } int targetSize = MAX_OCTREE_PACKET_DATA_SIZE; if (wantCompression) { targetSize = nodeData->getAvailable() - sizeof(OCTREE_PACKET_INTERNAL_SECTION_SIZE); } _packetData.changeSettings(wantCompression, targetSize); } const ViewFrustum* lastViewFrustum = wantDelta ? &nodeData->getLastKnownViewFrustum() : NULL; // If the current view frustum has changed OR we have nothing to send, then search against // the current view frustum for things to send. if (viewFrustumChanged || nodeData->nodeBag.isEmpty()) { // if our view has changed, we need to reset these things... if (viewFrustumChanged) { if (nodeData->moveShouldDump() || nodeData->hasLodChanged()) { nodeData->dumpOutOfView(); } nodeData->map.erase(); } if (!viewFrustumChanged && !nodeData->getWantDelta()) { // only set our last sent time if we weren't resetting due to frustum change quint64 now = usecTimestampNow(); nodeData->setLastTimeBagEmpty(now); } // track completed scenes and send out the stats packet accordingly nodeData->stats.sceneCompleted(); nodeData->setLastRootTimestamp(_myServer->getOctree()->getRoot()->getLastChanged()); // TODO: add these to stats page //::endSceneSleepTime = _usleepTime; //unsigned long sleepTime = ::endSceneSleepTime - ::startSceneSleepTime; //unsigned long encodeTime = nodeData->stats.getTotalEncodeTime(); //unsigned long elapsedTime = nodeData->stats.getElapsedTime(); int packetsJustSent = handlePacketSend(nodeData, trueBytesSent, truePacketsSent); packetsSentThisInterval += packetsJustSent; // If we're starting a full scene, then definitely we want to empty the nodeBag if (isFullScene) { nodeData->nodeBag.deleteAll(); } // TODO: add these to stats page //::startSceneSleepTime = _usleepTime; // start tracking our stats nodeData->stats.sceneStarted(isFullScene, viewFrustumChanged, _myServer->getOctree()->getRoot(), _myServer->getJurisdiction()); // This is the start of "resending" the scene. bool dontRestartSceneOnMove = false; // this is experimental if (dontRestartSceneOnMove) { if (nodeData->nodeBag.isEmpty()) { nodeData->nodeBag.insert(_myServer->getOctree()->getRoot()); // only in case of empty } } else { nodeData->nodeBag.insert(_myServer->getOctree()->getRoot()); // original behavior, reset on move or empty } } // If we have something in our nodeBag, then turn them into packets and send them out... if (!nodeData->nodeBag.isEmpty()) { int bytesWritten = 0; quint64 start = usecTimestampNow(); // TODO: add these to stats page //quint64 startCompressTimeMsecs = OctreePacketData::getCompressContentTime() / 1000; //quint64 startCompressCalls = OctreePacketData::getCompressContentCalls(); int extraPackingAttempts = 0; bool completedScene = false; while (somethingToSend && packetsSentThisInterval < maxPacketsPerInterval && !nodeData->isShuttingDown()) { float lockWaitElapsedUsec = OctreeServer::SKIP_TIME; float encodeElapsedUsec = OctreeServer::SKIP_TIME; float compressAndWriteElapsedUsec = OctreeServer::SKIP_TIME; float packetSendingElapsedUsec = OctreeServer::SKIP_TIME; quint64 startInside = usecTimestampNow(); bool lastNodeDidntFit = false; // assume each node fits if (!nodeData->nodeBag.isEmpty()) { OctreeElement* subTree = nodeData->nodeBag.extract(); /* TODO: Looking for a way to prevent locking and encoding a tree that is not // going to result in any packets being sent... // // If our node is root, and the root hasn't changed, and our view hasn't changed, // and we've already seen at least one duplicate packet, then we probably don't need // to lock the tree and encode, because the result should be that no bytes will be // encoded, and this will be a duplicate packet from the last one we sent... OctreeElement* root = _myServer->getOctree()->getRoot(); bool skipEncode = false; if ( (subTree == root) && (nodeData->getLastRootTimestamp() == root->getLastChanged()) && !viewFrustumChanged && (nodeData->getDuplicatePacketCount() > 0) ) { qDebug() << "is root, root not changed, view not changed, already seen a duplicate!" << "Can we skip it?"; skipEncode = true; } */ bool wantOcclusionCulling = nodeData->getWantOcclusionCulling(); CoverageMap* coverageMap = wantOcclusionCulling ? &nodeData->map : IGNORE_COVERAGE_MAP; float voxelSizeScale = nodeData->getOctreeSizeScale(); int boundaryLevelAdjustClient = nodeData->getBoundaryLevelAdjust(); int boundaryLevelAdjust = boundaryLevelAdjustClient + (viewFrustumChanged && nodeData->getWantLowResMoving() ? LOW_RES_MOVING_ADJUST : NO_BOUNDARY_ADJUST); EncodeBitstreamParams params(INT_MAX, &nodeData->getCurrentViewFrustum(), wantColor, WANT_EXISTS_BITS, DONT_CHOP, wantDelta, lastViewFrustum, wantOcclusionCulling, coverageMap, boundaryLevelAdjust, voxelSizeScale, nodeData->getLastTimeBagEmpty(), isFullScene, &nodeData->stats, _myServer->getJurisdiction()); // TODO: should this include the lock time or not? This stat is sent down to the client, // it seems like it may be a good idea to include the lock time as part of the encode time // are reported to client. Since you can encode without the lock nodeData->stats.encodeStarted(); quint64 lockWaitStart = usecTimestampNow(); _myServer->getOctree()->lockForRead(); quint64 lockWaitEnd = usecTimestampNow(); lockWaitElapsedUsec = (float)(lockWaitEnd - lockWaitStart); quint64 encodeStart = usecTimestampNow(); bytesWritten = _myServer->getOctree()->encodeTreeBitstream(subTree, &_packetData, nodeData->nodeBag, params); quint64 encodeEnd = usecTimestampNow(); encodeElapsedUsec = (float)(encodeEnd - encodeStart); // If after calling encodeTreeBitstream() there are no nodes left to send, then we know we've // sent the entire scene. We want to know this below so we'll actually write this content into // the packet and send it completedScene = nodeData->nodeBag.isEmpty(); // if we're trying to fill a full size packet, then we use this logic to determine if we have a DIDNT_FIT case. if (_packetData.getTargetSize() == MAX_OCTREE_PACKET_DATA_SIZE) { if (_packetData.hasContent() && bytesWritten == 0 && params.stopReason == EncodeBitstreamParams::DIDNT_FIT) { lastNodeDidntFit = true; } } else { // in compressed mode and we are trying to pack more... and we don't care if the _packetData has // content or not... because in this case even if we were unable to pack any data, we want to drop // below to our sendNow logic, but we do want to track that we attempted to pack extra extraPackingAttempts++; if (bytesWritten == 0 && params.stopReason == EncodeBitstreamParams::DIDNT_FIT) { lastNodeDidntFit = true; } } nodeData->stats.encodeStopped(); _myServer->getOctree()->unlock(); } else { // If the bag was empty then we didn't even attempt to encode, and so we know the bytesWritten were 0 bytesWritten = 0; somethingToSend = false; // this will cause us to drop out of the loop... } // If the last node didn't fit, but we're in compressed mode, then we actually want to see if we can fit a // little bit more in this packet. To do this we write into the packet, but don't send it yet, we'll // keep attempting to write in compressed mode to add more compressed segments // We only consider sending anything if there is something in the _packetData to send... But // if bytesWritten == 0 it means either the subTree couldn't fit or we had an empty bag... Both cases // mean we should send the previous packet contents and reset it. if (completedScene || lastNodeDidntFit) { if (_packetData.hasContent()) { quint64 compressAndWriteStart = usecTimestampNow(); // if for some reason the finalized size is greater than our available size, then probably the "compressed" // form actually inflated beyond our padding, and in this case we will send the current packet, then // write to out new packet... unsigned int writtenSize = _packetData.getFinalizedSize() + (nodeData->getCurrentPacketIsCompressed() ? sizeof(OCTREE_PACKET_INTERNAL_SECTION_SIZE) : 0); if (writtenSize > nodeData->getAvailable()) { packetsSentThisInterval += handlePacketSend(nodeData, trueBytesSent, truePacketsSent); } nodeData->writeToPacket(_packetData.getFinalizedData(), _packetData.getFinalizedSize()); extraPackingAttempts = 0; quint64 compressAndWriteEnd = usecTimestampNow(); compressAndWriteElapsedUsec = (float)(compressAndWriteEnd - compressAndWriteStart); } // If we're not running compressed, then we know we can just send now. Or if we're running compressed, but // the packet doesn't have enough space to bother attempting to pack more... bool sendNow = true; if (nodeData->getCurrentPacketIsCompressed() && nodeData->getAvailable() >= MINIMUM_ATTEMPT_MORE_PACKING && extraPackingAttempts <= REASONABLE_NUMBER_OF_PACKING_ATTEMPTS) { sendNow = false; // try to pack more } int targetSize = MAX_OCTREE_PACKET_DATA_SIZE; if (sendNow) { quint64 packetSendingStart = usecTimestampNow(); packetsSentThisInterval += handlePacketSend(nodeData, trueBytesSent, truePacketsSent); quint64 packetSendingEnd = usecTimestampNow(); packetSendingElapsedUsec = (float)(packetSendingEnd - packetSendingStart); if (wantCompression) { targetSize = nodeData->getAvailable() - sizeof(OCTREE_PACKET_INTERNAL_SECTION_SIZE); } } else { // If we're in compressed mode, then we want to see if we have room for more in this wire packet. // but we've finalized the _packetData, so we want to start a new section, we will do that by // resetting the packet settings with the max uncompressed size of our current available space // in the wire packet. We also include room for our section header, and a little bit of padding // to account for the fact that whenc compressing small amounts of data, we sometimes end up with // a larger compressed size then uncompressed size targetSize = nodeData->getAvailable() - sizeof(OCTREE_PACKET_INTERNAL_SECTION_SIZE) - COMPRESS_PADDING; } _packetData.changeSettings(nodeData->getWantCompression(), targetSize); // will do reset } OctreeServer::trackTreeWaitTime(lockWaitElapsedUsec); OctreeServer::trackEncodeTime(encodeElapsedUsec); OctreeServer::trackCompressAndWriteTime(compressAndWriteElapsedUsec); OctreeServer::trackPacketSendingTime(packetSendingElapsedUsec); quint64 endInside = usecTimestampNow(); quint64 elapsedInsideUsecs = endInside - startInside; OctreeServer::trackInsideTime((float)elapsedInsideUsecs); } // Here's where we can/should allow the server to send other data... // send the environment packet // TODO: should we turn this into a while loop to better handle sending multiple special packets if (_myServer->hasSpecialPacketToSend(_node) && !nodeData->isShuttingDown()) { int specialPacketsSent; trueBytesSent += _myServer->sendSpecialPacket(_node, nodeData, specialPacketsSent); nodeData->resetOctreePacket(); // because nodeData's _sequenceNumber has changed truePacketsSent += specialPacketsSent; packetsSentThisInterval += specialPacketsSent; } // Re-send packets that were nacked by the client while (nodeData->hasNextNackedPacket() && packetsSentThisInterval < maxPacketsPerInterval) { const QByteArray* packet = nodeData->getNextNackedPacket(); if (packet) { NodeList::getInstance()->writeDatagram(*packet, _node); truePacketsSent++; packetsSentThisInterval++; _totalBytes += packet->size(); _totalPackets++; _totalWastedBytes += MAX_PACKET_SIZE - packet->size(); } } quint64 end = usecTimestampNow(); int elapsedmsec = (end - start)/USECS_PER_MSEC; OctreeServer::trackLoopTime(elapsedmsec); // TODO: add these to stats page //quint64 endCompressCalls = OctreePacketData::getCompressContentCalls(); //int elapsedCompressCalls = endCompressCalls - startCompressCalls; //quint64 endCompressTimeMsecs = OctreePacketData::getCompressContentTime() / 1000; //int elapsedCompressTimeMsecs = endCompressTimeMsecs - startCompressTimeMsecs; // if after sending packets we've emptied our bag, then we want to remember that we've sent all // the voxels from the current view frustum if (nodeData->nodeBag.isEmpty()) { nodeData->updateLastKnownViewFrustum(); nodeData->setViewSent(true); nodeData->map.erase(); // It would be nice if we could save this, and only reset it when the view frustum changes } } // end if bag wasn't empty, and so we sent stuff... return truePacketsSent; }