1 files changed, 831 insertions, 91 deletions

diff --git a/indra/newview/llvocache.cpp b/indra/newview/llvocache.cpp
index 7db19c5c1b..aa3594638a 100755
--- a/indra/newview/llvocache.cpp
+++ b/indra/newview/llvocache.cpp
@@ -29,6 +29,19 @@
 #include "llerror.h"
 #include "llregionhandle.h"
 #include "llviewercontrol.h"
+#include "llviewerobjectlist.h"
+#include "lldrawable.h"
+#include "llviewerregion.h"
+#include "pipeline.h"
+#include "llagentcamera.h"
+
+//static variables
+U32 LLVOCacheEntry::sMinFrameRange = 0;
+F32 LLVOCacheEntry::sNearRadius = 1.0f;
+F32 LLVOCacheEntry::sRearFarRadius = 1.0f;
+F32 LLVOCacheEntry::sFrontPixelThreshold = 1.0f;
+F32 LLVOCacheEntry::sRearPixelThreshold = 1.0f;
+BOOL LLVOCachePartition::sNeedsOcclusionCheck = FALSE;
 
 BOOL check_read(LLAPRFile* apr_file, void* src, S32 n_bytes) 
 {
@@ -46,12 +59,19 @@ BOOL check_write(LLAPRFile* apr_file, void* src, S32 n_bytes)
 //---------------------------------------------------------------------------
 
 LLVOCacheEntry::LLVOCacheEntry(U32 local_id, U32 crc, LLDataPackerBinaryBuffer &dp)
-	:
+:	LLTrace::MemTrackable<LLVOCacheEntry, 16>("LLVOCacheEntry"),
+	LLViewerOctreeEntryData(LLViewerOctreeEntry::LLVOCACHEENTRY),
 	mLocalID(local_id),
 	mCRC(crc),
+	mUpdateFlags(-1),
 	mHitCount(0),
 	mDupeCount(0),
-	mCRCChangeCount(0)
+	mCRCChangeCount(0),
+	mState(INACTIVE),
+	mSceneContrib(0.f),
+	mValid(TRUE),
+	mParentID(0),
+	mBSphereRadius(-1.0f)
 {
 	mBuffer = new U8[dp.getBufferSize()];
 	mDP.assignBuffer(mBuffer, dp.getBufferSize());
@@ -59,24 +79,40 @@ LLVOCacheEntry::LLVOCacheEntry(U32 local_id, U32 crc, LLDataPackerBinaryBuffer &
 }
 
 LLVOCacheEntry::LLVOCacheEntry()
-	:
+:	LLTrace::MemTrackable<LLVOCacheEntry, 16>("LLVOCacheEntry"),
+	LLViewerOctreeEntryData(LLViewerOctreeEntry::LLVOCACHEENTRY),
 	mLocalID(0),
 	mCRC(0),
+	mUpdateFlags(-1),
 	mHitCount(0),
 	mDupeCount(0),
 	mCRCChangeCount(0),
-	mBuffer(NULL)
+	mBuffer(NULL),
+	mState(INACTIVE),
+	mSceneContrib(0.f),
+	mValid(TRUE),
+	mParentID(0),
+	mBSphereRadius(-1.0f)
 {
 	mDP.assignBuffer(mBuffer, 0);
 }
 
 LLVOCacheEntry::LLVOCacheEntry(LLAPRFile* apr_file)
-	: mBuffer(NULL)
+:	LLTrace::MemTrackable<LLVOCacheEntry, 16>("LLVOCacheEntry"),
+	LLViewerOctreeEntryData(LLViewerOctreeEntry::LLVOCACHEENTRY), 
+	mBuffer(NULL),
+	mUpdateFlags(-1),
+	mState(INACTIVE),
+	mSceneContrib(0.f),
+	mValid(FALSE),
+	mParentID(0),
+	mBSphereRadius(-1.0f)
 {
 	S32 size = -1;
 	BOOL success;
 
 	mDP.assignBuffer(mBuffer, 0);
+	
 	success = check_read(apr_file, &mLocalID, sizeof(U32));
 	if(success)
 	{
@@ -104,7 +140,7 @@ LLVOCacheEntry::LLVOCacheEntry(LLAPRFile* apr_file)
 			// We've got a bogus size, skip reading it.
 			// We won't bother seeking, because the rest of this file
 			// is likely bogus, and will be tossed anyway.
-			llwarns << "Bogus cache entry, size " << size << ", aborting!" << llendl;
+			LL_WARNS() << "Bogus cache entry, size " << size << ", aborting!" << LL_ENDL;
 			success = FALSE;
 		}
 	}
@@ -132,6 +168,8 @@ LLVOCacheEntry::LLVOCacheEntry(LLAPRFile* apr_file)
 		mDupeCount = 0;
 		mCRCChangeCount = 0;
 		mBuffer = NULL;
+		mEntry = NULL;
+		mState = INACTIVE;
 	}
 }
 
@@ -140,37 +178,131 @@ LLVOCacheEntry::~LLVOCacheEntry()
 	mDP.freeBuffer();
 }
 
-
-// New CRC means the object has changed.
-void LLVOCacheEntry::assignCRC(U32 crc, LLDataPackerBinaryBuffer &dp)
+void LLVOCacheEntry::updateEntry(U32 crc, LLDataPackerBinaryBuffer &dp)
 {
-	if (  (mCRC != crc)
-		||(mDP.getBufferSize() == 0))
+	if(mCRC != crc)
 	{
 		mCRC = crc;
-		mHitCount = 0;
 		mCRCChangeCount++;
+	}
+
+	mDP.freeBuffer();
+
+	llassert_always(dp.getBufferSize() > 0);
+	mBuffer = new U8[dp.getBufferSize()];
+	mDP.assignBuffer(mBuffer, dp.getBufferSize());
+	mDP = dp;
+}
+
+//virtual 
+void LLVOCacheEntry::setOctreeEntry(LLViewerOctreeEntry* entry)
+{
+	if(!entry && mDP.getBufferSize() > 0)
+	{
+		LLUUID fullid;
+		LLViewerObject::unpackUUID(&mDP, fullid, "ID");
+		
+		LLViewerObject* obj = gObjectList.findObject(fullid);
+		if(obj && obj->mDrawable)
+		{
+			entry = obj->mDrawable->getEntry();
+		}
+	}
+
+	LLViewerOctreeEntryData::setOctreeEntry(entry);
+}
+
+void LLVOCacheEntry::setState(U32 state)
+{
+	if(state > LOW_BITS) //special states
+	{
+		mState |= (HIGH_BITS & state);
+		return;
+	}
+
+	//
+	//otherwise LOW_BITS states
+	//
+	clearState(LOW_BITS);
+	mState |= (LOW_BITS & state);
+
+	if(getState() == ACTIVE)
+	{
+		const S32 MIN_INTERVAL = 64 + sMinFrameRange;
+		U32 last_visible = getVisible();
+		
+		setVisible();
+
+		U32 cur_visible = getVisible();
+		if(cur_visible - last_visible > MIN_INTERVAL ||
+			cur_visible < MIN_INTERVAL)
+		{
+			mLastCameraUpdated = 0; //reset
+		}
+		else
+		{
+			mLastCameraUpdated = LLViewerRegion::sLastCameraUpdated;
+		}
+	}
+}
+
+void LLVOCacheEntry::addChild(LLVOCacheEntry* entry)
+{
+	llassert(entry != NULL);
+	llassert(entry->getParentID() == mLocalID);
+	llassert(entry->getEntry() != NULL);
+
+	if(!entry || !entry->getEntry() || entry->getParentID() != mLocalID)
+	{
+		return;
+	}
+	
+	mChildrenList.insert(entry);
+
+	//update parent bbox
+	if(getEntry() != NULL && isState(INACTIVE))
+	{
+		updateParentBoundingInfo(entry);
+		resetVisible();
+	}
+}
+	
+void LLVOCacheEntry::removeChild(LLVOCacheEntry* entry)
+{
+	entry->setParentID(0);
+
+	vocache_entry_set_t::iterator iter = mChildrenList.find(entry);
+	if(iter != mChildrenList.end())
+	{
+		mChildrenList.erase(iter);
+	}
+}
 
-		mDP.freeBuffer();
-		mBuffer = new U8[dp.getBufferSize()];
-		mDP.assignBuffer(mBuffer, dp.getBufferSize());
-		mDP = dp;
+//remove the first child, and return it.
+LLVOCacheEntry* LLVOCacheEntry::getChild()
+{
+	LLVOCacheEntry* child = NULL;
+	vocache_entry_set_t::iterator iter = mChildrenList.begin();
+	if(iter != mChildrenList.end())
+	{
+		child = *iter;
+		mChildrenList.erase(iter);
 	}
+
+	return child;
 }
 
-LLDataPackerBinaryBuffer *LLVOCacheEntry::getDP(U32 crc)
+LLDataPackerBinaryBuffer *LLVOCacheEntry::getDP()
 {
-	if (  (mCRC != crc)
-		||(mDP.getBufferSize() == 0))
+	if (mDP.getBufferSize() == 0)
 	{
-		//llinfos << "Not getting cache entry, invalid!" << llendl;
+		//LL_INFOS() << "Not getting cache entry, invalid!" << LL_ENDL;
 		return NULL;
 	}
-	mHitCount++;
+	
 	return &mDP;
 }
 
-
 void LLVOCacheEntry::recordHit()
 {
 	mHitCount++;
@@ -179,12 +311,12 @@ void LLVOCacheEntry::recordHit()
 
 void LLVOCacheEntry::dump() const
 {
-	llinfos << "local " << mLocalID
+	LL_INFOS() << "local " << mLocalID
 		<< " crc " << mCRC
 		<< " hits " << mHitCount
 		<< " dupes " << mDupeCount
 		<< " change " << mCRCChangeCount
-		<< llendl;
+		<< LL_ENDL;
 }
 
 BOOL LLVOCacheEntry::writeToFile(LLAPRFile* apr_file) const
@@ -221,49 +353,643 @@ BOOL LLVOCacheEntry::writeToFile(LLAPRFile* apr_file) const
 	return success ;
 }
 
+//static 
+void LLVOCacheEntry::updateDebugSettings()
+{
+	//the number of frames invisible objects stay in memory
+	static LLCachedControl<U32> inv_obj_time(gSavedSettings,"NonvisibleObjectsInMemoryTime");
+	sMinFrameRange = inv_obj_time - 1; //make 0 to be the maximum 
+
+	//min radius: all objects within this radius remain loaded in memory
+	static LLCachedControl<F32> min_radius(gSavedSettings,"SceneLoadMinRadius");
+	sNearRadius = llmin((F32)min_radius, gAgentCamera.mDrawDistance); //can not exceed the draw distance
+	sNearRadius = llmax(sNearRadius, 1.f); //minimum value is 1.0m
+
+	//objects within the view frustum whose visible area is greater than this threshold will be loaded
+	static LLCachedControl<F32> front_pixel_threshold(gSavedSettings,"SceneLoadFrontPixelThreshold");
+	sFrontPixelThreshold = front_pixel_threshold;
+
+	//objects out of the view frustum whose visible area is greater than this threshold will remain loaded
+	static LLCachedControl<F32> rear_pixel_threshold(gSavedSettings,"SceneLoadRearPixelThreshold");
+	sRearPixelThreshold = rear_pixel_threshold;
+	sRearPixelThreshold = llmax(sRearPixelThreshold, sFrontPixelThreshold); //can not be smaller than sFrontPixelThreshold.
+
+	// a percentage of draw distance beyond which all objects outside of view frustum will be unloaded, regardless of pixel threshold
+	static LLCachedControl<F32> rear_max_radius_frac(gSavedSettings,"SceneLoadRearMaxRadiusFraction");
+	sRearFarRadius = llmax(rear_max_radius_frac * gAgentCamera.mDrawDistance / 100.f, 1.0f); //minimum value is 1.0m
+	sRearFarRadius = llmax(sRearFarRadius, (F32)min_radius); //can not be less than "SceneLoadMinRadius".
+	sRearFarRadius = llmin(sRearFarRadius, gAgentCamera.mDrawDistance); //can not be more than the draw distance.
+}
+
+//static 
+F32 LLVOCacheEntry::getSquaredPixelThreshold(bool is_front)
+{
+	F32 threshold;
+	if(is_front)
+	{
+		threshold = sFrontPixelThreshold;
+	}
+	else
+	{
+		threshold = sRearPixelThreshold;
+	}
+
+	//object projected area threshold
+	F32 pixel_meter_ratio = LLViewerCamera::getInstance()->getPixelMeterRatio();
+	F32 projection_threshold = pixel_meter_ratio > 0.f ? threshold / pixel_meter_ratio : 0.f;
+	projection_threshold *= projection_threshold;
+
+	return projection_threshold;
+}
+
+bool LLVOCacheEntry::isAnyVisible(const LLVector4a& camera_origin, const LLVector4a& local_camera_origin, F32 dist_threshold)
+{
+	LLOcclusionCullingGroup* group = (LLOcclusionCullingGroup*)getGroup();
+	if(!group)
+	{
+		return false;
+	}
+
+	//any visible
+	bool vis = group->isAnyRecentlyVisible();
+
+	//not ready to remove
+	if(!vis)
+	{
+		S32 cur_vis = llmax(group->getAnyVisible(), (S32)getVisible());
+		vis = (cur_vis + sMinFrameRange > LLViewerOctreeEntryData::getCurrentFrame());
+	}
+
+	//within the back sphere
+	if(!vis && !mParentID && !group->isOcclusionState(LLOcclusionCullingGroup::OCCLUDED))
+	{
+		LLVector4a lookAt;
+
+		if(mBSphereRadius > 0.f)
+		{
+			lookAt.setSub(mBSphereCenter, local_camera_origin);		
+			dist_threshold += mBSphereRadius;
+		}
+		else
+		{
+			lookAt.setSub(getPositionGroup(), camera_origin);
+			dist_threshold += getBinRadius();
+		}
+
+		vis = (lookAt.dot3(lookAt).getF32() < dist_threshold * dist_threshold);
+	}
+
+	return vis;
+}
+
+void LLVOCacheEntry::calcSceneContribution(const LLVector4a& camera_origin, bool needs_update, U32 last_update, F32 max_dist)
+{
+	if(!needs_update && getVisible() >= last_update)
+	{
+		return; //no need to update
+	}
+
+	LLVector4a lookAt;
+	lookAt.setSub(getPositionGroup(), camera_origin);
+	F32 distance = lookAt.getLength3().getF32();
+	distance -= sNearRadius;
+
+	if(distance <= 0.f)
+	{
+		//nearby objects, set a large number
+		const F32 LARGE_SCENE_CONTRIBUTION = 1000.f; //a large number to force to load the object.
+		mSceneContrib = LARGE_SCENE_CONTRIBUTION;
+	}
+	else
+	{
+		F32 rad = getBinRadius();
+		max_dist += rad;
+
+		if(distance + sNearRadius < max_dist)
+		{
+			mSceneContrib = (rad * rad) / distance;		
+		}
+		else
+		{
+			mSceneContrib = 0.f; //out of draw distance, not to load
+		}
+	}
+
+	setVisible();
+}
+
+void LLVOCacheEntry::saveBoundingSphere()
+{
+	mBSphereCenter = getPositionGroup();
+	mBSphereRadius = getBinRadius();
+}
+
+void LLVOCacheEntry::setBoundingInfo(const LLVector3& pos, const LLVector3& scale)
+{
+	LLVector4a center, newMin, newMax;
+	center.load3(pos.mV);
+	LLVector4a size;
+	size.load3(scale.mV);
+	newMin.setSub(center, size);
+	newMax.setAdd(center, size);
+	
+	setPositionGroup(center);
+	setSpatialExtents(newMin, newMax);
+
+	if(getNumOfChildren() > 0) //has children
+	{
+		updateParentBoundingInfo();
+	}
+	else
+	{
+		setBinRadius(llmin(size.getLength3().getF32() * 4.f, 256.f));
+	}
+}
+
+//make the parent bounding box to include all children
+void LLVOCacheEntry::updateParentBoundingInfo()
+{
+	if(mChildrenList.empty())
+	{
+		return;
+	}
+
+	for(vocache_entry_set_t::iterator iter = mChildrenList.begin(); iter != mChildrenList.end(); ++iter)
+	{
+		updateParentBoundingInfo(*iter);
+	}
+	resetVisible();
+}
+
+//make the parent bounding box to include this child
+void LLVOCacheEntry::updateParentBoundingInfo(const LLVOCacheEntry* child)
+{
+	const LLVector4a* child_exts = child->getSpatialExtents();
+	LLVector4a newMin, newMax;
+	newMin = child_exts[0];
+	newMax = child_exts[1];
+	
+	//move to regional space.
+	{
+		const LLVector4a& parent_pos = getPositionGroup();
+		newMin.add(parent_pos);
+		newMax.add(parent_pos);
+	}
+
+	//update parent's bbox(min, max)
+	const LLVector4a* parent_exts = getSpatialExtents();
+	update_min_max(newMin, newMax, parent_exts[0]);
+	update_min_max(newMin, newMax, parent_exts[1]);
+	for(S32 i = 0; i < 4; i++)
+	{
+		llclamp(newMin[i], 0.f, 256.f);
+		llclamp(newMax[i], 0.f, 256.f);
+	}
+	setSpatialExtents(newMin, newMax);
+
+	//update parent's bbox center
+	LLVector4a center;
+	center.setAdd(newMin, newMax);
+	center.mul(0.5f);
+	setPositionGroup(center);	
+
+	//update parent's bbox size vector
+	LLVector4a size;
+	size.setSub(newMax, newMin);
+	size.mul(0.5f);
+	setBinRadius(llmin(size.getLength3().getF32() * 4.f, 256.f));
+}
 //-------------------------------------------------------------------
-//LLVOCache
+//LLVOCachePartition
 //-------------------------------------------------------------------
-// Format string used to construct filename for the object cache
-static const char OBJECT_CACHE_FILENAME[] = "objects_%d_%d.slc";
+LLVOCacheGroup::~LLVOCacheGroup()
+{
+	for(S32 i = 0; i < LLViewerCamera::NUM_CAMERAS; i++)
+	{
+		if(mOcclusionState[i] & ACTIVE_OCCLUSION)
+		{
+			((LLVOCachePartition*)mSpatialPartition)->removeOccluder(this);
+			break;
+		}
+	}
+}
 
-const U32 MAX_NUM_OBJECT_ENTRIES = 128 ;
-const U32 MIN_ENTRIES_TO_PURGE = 16 ;
-const U32 INVALID_TIME = 0 ;
-const char* object_cache_dirname = "objectcache";
-const char* header_filename = "object.cache";
+//virtual
+void LLVOCacheGroup::handleChildAddition(const OctreeNode* parent, OctreeNode* child)
+{
+	if (child->getListenerCount() == 0)
+	{
+		new LLVOCacheGroup(child, mSpatialPartition);
+	}
+	else
+	{
+		OCT_ERRS << "LLVOCacheGroup redundancy detected." << LL_ENDL;
+	}
 
-LLVOCache* LLVOCache::sInstance = NULL;
+	unbound();
+	
+	((LLViewerOctreeGroup*)child->getListener(0))->unbound();
+}
 
-//static 
-LLVOCache* LLVOCache::getInstance() 
-{	
-	if(!sInstance)
+LLVOCachePartition::LLVOCachePartition(LLViewerRegion* regionp)
+:	LLTrace::MemTrackable<LLVOCachePartition>("LLVOCachePartition")
+{
+	mLODPeriod = 16;
+	mRegionp = regionp;
+	mPartitionType = LLViewerRegion::PARTITION_VO_CACHE;
+	mBackSlectionEnabled = -1;
+	mIdleHash = 0;
+	
+	for(S32 i = 0; i < LLViewerCamera::NUM_CAMERAS; i++)
 	{
-		sInstance = new LLVOCache() ;
+		mCulledTime[i] = 0;	
 	}
-	return sInstance ;
+	mCullHistory = -1;
+
+	new LLVOCacheGroup(mOctree, this);
 }
 
-//static 
-BOOL LLVOCache::hasInstance() 
+void LLVOCachePartition::addEntry(LLViewerOctreeEntry* entry)
 {
-	return sInstance != NULL ;
+	llassert(entry->hasVOCacheEntry());
+
+	mOctree->insert(entry);
 }
+	
+void LLVOCachePartition::removeEntry(LLViewerOctreeEntry* entry)
+{
+	entry->getVOCacheEntry()->setGroup(NULL);
 
-//static 
-void LLVOCache::destroyClass() 
+	llassert(!entry->getGroup());
+}
+	
+class LLVOCacheOctreeCull : public LLViewerOctreeCull
 {
-	if(sInstance)
+public:
+	LLVOCacheOctreeCull(LLCamera* camera, LLViewerRegion* regionp, 
+		const LLVector3& shift, bool use_object_cache_occlusion, F32 pixel_threshold, LLVOCachePartition* part) 
+		: LLViewerOctreeCull(camera), 
+		  mRegionp(regionp),
+		  mPartition(part),
+		  mPixelThreshold(pixel_threshold)
 	{
-		delete sInstance ;
-		sInstance = NULL ;
+		mLocalShift = shift;
+		mUseObjectCacheOcclusion = use_object_cache_occlusion;
+		mNearRadius = LLVOCacheEntry::sNearRadius;
 	}
+
+	virtual bool earlyFail(LLViewerOctreeGroup* base_group)
+	{
+		if( mUseObjectCacheOcclusion &&
+			base_group->getOctreeNode()->getParent()) //never occlusion cull the root node
+		{
+			LLOcclusionCullingGroup* group = (LLOcclusionCullingGroup*)base_group;
+			if(group->needsUpdate())
+			{
+				//needs to issue new occlusion culling check, perform view culling check first.
+				return false;
+			}
+
+			group->checkOcclusion();
+
+			if (group->isOcclusionState(LLOcclusionCullingGroup::OCCLUDED))
+			{
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	virtual S32 frustumCheck(const LLViewerOctreeGroup* group)
+	{
+#if 0
+		S32 res = AABBInRegionFrustumGroupBounds(group);
+#else	
+		S32 res = AABBInRegionFrustumNoFarClipGroupBounds(group);
+		if (res != 0)
+		{
+			res = llmin(res, AABBRegionSphereIntersectGroupExtents(group, mLocalShift));
+		}
+#endif
+
+		return res;
+	}
+
+	virtual S32 frustumCheckObjects(const LLViewerOctreeGroup* group)
+	{
+#if 0
+		S32 res = AABBInRegionFrustumObjectBounds(group);
+#else
+		S32 res = AABBInRegionFrustumNoFarClipObjectBounds(group);
+		if (res != 0)
+		{
+			res = llmin(res, AABBRegionSphereIntersectObjectExtents(group, mLocalShift));
+		}
+#endif
+
+		if(res != 0)
+		{
+			//check if the objects projection large enough
+			const LLVector4a* exts = group->getObjectExtents();
+			res = checkProjectionArea(exts[0], exts[1], mLocalShift, mPixelThreshold, mNearRadius);
+		}
+
+		return res;
+	}
+
+	virtual void processGroup(LLViewerOctreeGroup* base_group)
+	{
+		if( !mUseObjectCacheOcclusion ||
+			!base_group->getOctreeNode()->getParent())
+		{ 
+			//no occlusion check
+			if(mRegionp->addVisibleGroup(base_group))
+			{
+				base_group->setVisible();
+			}
+			return;
+		}
+
+		LLOcclusionCullingGroup* group = (LLOcclusionCullingGroup*)base_group;
+		if(group->needsUpdate() || !group->isRecentlyVisible())//needs to issue new occlusion culling check.
+		{
+			mPartition->addOccluders(group);
+			group->setVisible();
+			return ; //wait for occlusion culling result
+		}
+
+		if(group->isOcclusionState(LLOcclusionCullingGroup::QUERY_PENDING) || 
+			group->isOcclusionState(LLOcclusionCullingGroup::ACTIVE_OCCLUSION))
+		{
+			//keep waiting
+			group->setVisible();
+		}
+		else
+		{
+			if(mRegionp->addVisibleGroup(base_group))
+			{
+				base_group->setVisible();
+			}
+		}
+	}
+
+private:
+	LLVOCachePartition* mPartition;
+	LLViewerRegion*     mRegionp;
+	LLVector3           mLocalShift; //shift vector from agent space to local region space.
+	F32                 mPixelThreshold;
+	F32                 mNearRadius;
+	bool                mUseObjectCacheOcclusion;
+};
+
+//select objects behind camera
+class LLVOCacheOctreeBackCull : public LLViewerOctreeCull
+{
+public:
+	LLVOCacheOctreeBackCull(LLCamera* camera, const LLVector3& shift, LLViewerRegion* regionp, F32 pixel_threshold, bool use_occlusion) 
+		: LLViewerOctreeCull(camera), mRegionp(regionp), mPixelThreshold(pixel_threshold), mUseObjectCacheOcclusion(use_occlusion)
+	{
+		mLocalShift = shift;
+		mSphereRadius = LLVOCacheEntry::sRearFarRadius;
+	}
+	
+	virtual bool earlyFail(LLViewerOctreeGroup* base_group)
+	{
+		if( mUseObjectCacheOcclusion &&
+			base_group->getOctreeNode()->getParent()) //never occlusion cull the root node
+		{
+			LLOcclusionCullingGroup* group = (LLOcclusionCullingGroup*)base_group;
+
+			if (group->getOcclusionState() > 0) //occlusion state is not clear.
+			{
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	virtual S32 frustumCheck(const LLViewerOctreeGroup* group)
+	{			
+		const LLVector4a* exts = group->getExtents();
+		return backSphereCheck(exts[0], exts[1]);
+	}
+
+	virtual S32 frustumCheckObjects(const LLViewerOctreeGroup* group)
+	{
+		const LLVector4a* exts = group->getObjectExtents();
+		if(backSphereCheck(exts[0], exts[1]))
+		{
+			//check if the objects projection large enough
+			const LLVector4a* exts = group->getObjectExtents();
+			return checkProjectionArea(exts[0], exts[1], mLocalShift, mPixelThreshold, mSphereRadius);
+		}
+		return false;
+	}
+
+	virtual void processGroup(LLViewerOctreeGroup* base_group)
+	{
+		mRegionp->addVisibleGroup(base_group);
+		return;
+	}
+
+private:
+	//a sphere around the camera origin, including objects behind camera.
+	S32 backSphereCheck(const LLVector4a& min, const LLVector4a& max)
+	{
+		return AABBSphereIntersect(min, max, mCamera->getOrigin() - mLocalShift, mSphereRadius);
+	}
+
+private:
+	F32              mSphereRadius;
+	LLViewerRegion*  mRegionp;
+	LLVector3        mLocalShift; //shift vector from agent space to local region space.
+	F32              mPixelThreshold;
+	bool             mUseObjectCacheOcclusion;
+};
+
+void LLVOCachePartition::selectBackObjects(LLCamera &camera, F32 pixel_threshold, bool use_occlusion)
+{
+	if(LLViewerCamera::sCurCameraID != LLViewerCamera::CAMERA_WORLD)
+	{
+		return;
+	}
+
+	if(mBackSlectionEnabled < 0)
+	{
+		mBackSlectionEnabled = LLVOCacheEntry::sMinFrameRange - 1;
+		mBackSlectionEnabled = llmax(mBackSlectionEnabled, (S32)1);
+	}
+
+	if(!mBackSlectionEnabled)
+	{
+		return;
+	}
+
+	//localize the camera
+	LLVector3 region_agent = mRegionp->getOriginAgent();
+	
+	LLVOCacheOctreeBackCull culler(&camera, region_agent, mRegionp, pixel_threshold, use_occlusion);
+	culler.traverse(mOctree);
+
+	mBackSlectionEnabled--;
+	if(!mRegionp->getNumOfVisibleGroups())
+	{
+		mBackSlectionEnabled = 0;
+	}
+
+	return;
+}
+
+S32 LLVOCachePartition::cull(LLCamera &camera, bool do_occlusion)
+{
+	static LLCachedControl<bool> use_object_cache_occlusion(gSavedSettings,"UseObjectCacheOcclusion");
+	
+	if(!LLViewerRegion::sVOCacheCullingEnabled)
+	{
+		return 0;
+	}
+	if(mRegionp->isPaused())
+	{
+		return 0;
+	}
+
+	((LLViewerOctreeGroup*)mOctree->getListener(0))->rebound();
+
+	if(LLViewerCamera::sCurCameraID != LLViewerCamera::CAMERA_WORLD)
+	{
+		return 0; //no need for those cameras.
+	}
+
+	if(mCulledTime[LLViewerCamera::sCurCameraID] == LLViewerOctreeEntryData::getCurrentFrame())
+	{
+		return 0; //already culled
+	}
+	mCulledTime[LLViewerCamera::sCurCameraID] = LLViewerOctreeEntryData::getCurrentFrame();
+
+	if(!mCullHistory && LLViewerRegion::isViewerCameraStatic())
+	{
+		U32 seed = llmax(mLODPeriod >> 1, (U32)4);
+		if(LLViewerCamera::sCurCameraID == LLViewerCamera::CAMERA_WORLD)
+		{
+			if(!(LLViewerOctreeEntryData::getCurrentFrame() % seed))
+			{
+				mIdleHash = (mIdleHash + 1) % seed;
+			}
+		}
+		if(LLViewerOctreeEntryData::getCurrentFrame() % seed != mIdleHash)
+		{
+			mFrontCull = FALSE;
+
+			//process back objects selection
+			selectBackObjects(camera, LLVOCacheEntry::getSquaredPixelThreshold(mFrontCull), 
+				do_occlusion && use_object_cache_occlusion);
+			return 0; //nothing changed, reduce frequency of culling
+		}
+	}
+	else
+	{
+		mBackSlectionEnabled = -1; //reset it.
+	}
+
+	//localize the camera
+	LLVector3 region_agent = mRegionp->getOriginAgent();
+	camera.calcRegionFrustumPlanes(region_agent, gAgentCamera.mDrawDistance);
+
+	mFrontCull = TRUE;
+	LLVOCacheOctreeCull culler(&camera, mRegionp, region_agent, do_occlusion && use_object_cache_occlusion, 
+		LLVOCacheEntry::getSquaredPixelThreshold(mFrontCull), this);
+	culler.traverse(mOctree);	
+
+	if(!sNeedsOcclusionCheck)
+	{
+		sNeedsOcclusionCheck = !mOccludedGroups.empty();
+	}
+	return 1;
+}
+
+void LLVOCachePartition::setCullHistory(BOOL has_new_object)
+{
+	mCullHistory <<= 1;
+	mCullHistory |= has_new_object;
 }
 
+void LLVOCachePartition::addOccluders(LLViewerOctreeGroup* gp)
+{
+	LLVOCacheGroup* group = (LLVOCacheGroup*)gp;
+
+	if(!group->isOcclusionState(LLOcclusionCullingGroup::ACTIVE_OCCLUSION))
+	{
+		group->setOcclusionState(LLOcclusionCullingGroup::ACTIVE_OCCLUSION);
+		mOccludedGroups.insert(group);
+	}
+}
+
+void LLVOCachePartition::processOccluders(LLCamera* camera)
+{
+	if(mOccludedGroups.empty())
+	{
+		return;
+	}
+	if(LLViewerCamera::sCurCameraID != LLViewerCamera::CAMERA_WORLD)
+	{
+		return; //no need for those cameras.
+	}
+
+	LLVector3 region_agent = mRegionp->getOriginAgent();
+	LLVector4a shift(region_agent[0], region_agent[1], region_agent[2]);
+	for(std::set<LLVOCacheGroup*>::iterator iter = mOccludedGroups.begin(); iter != mOccludedGroups.end(); ++iter)
+	{
+		LLVOCacheGroup* group = *iter;
+		if(group->isOcclusionState(LLOcclusionCullingGroup::ACTIVE_OCCLUSION))
+		{
+			group->doOcclusion(camera, &shift);
+			group->clearOcclusionState(LLOcclusionCullingGroup::ACTIVE_OCCLUSION);
+		}
+	}	
+}
+
+void LLVOCachePartition::resetOccluders()
+{
+	if(mOccludedGroups.empty())
+	{
+		return;
+	}
+
+	for(std::set<LLVOCacheGroup*>::iterator iter = mOccludedGroups.begin(); iter != mOccludedGroups.end(); ++iter)
+	{
+		LLVOCacheGroup* group = *iter;
+		group->clearOcclusionState(LLOcclusionCullingGroup::ACTIVE_OCCLUSION);
+	}	
+	mOccludedGroups.clear();
+	sNeedsOcclusionCheck = FALSE;
+}
+
+void LLVOCachePartition::removeOccluder(LLVOCacheGroup* group)
+{
+	if(mOccludedGroups.empty())
+	{
+		return;
+	}
+	mOccludedGroups.erase(group);
+}
+//-------------------------------------------------------------------
+//LLVOCache
+//-------------------------------------------------------------------
+// Format string used to construct filename for the object cache
+static const char OBJECT_CACHE_FILENAME[] = "objects_%d_%d.slc";
+
+const U32 MAX_NUM_OBJECT_ENTRIES = 128 ;
+const U32 MIN_ENTRIES_TO_PURGE = 16 ;
+const U32 INVALID_TIME = 0 ;
+const char* object_cache_dirname = "objectcache";
+const char* header_filename = "object.cache";
+
+
 LLVOCache::LLVOCache():
-	mInitialized(FALSE),
-	mReadOnly(TRUE),
+	mInitialized(false),
+	mReadOnly(true),
 	mNumEntries(0),
 	mCacheSize(1)
 {
@@ -291,16 +1017,16 @@ void LLVOCache::initCache(ELLPath location, U32 size, U32 cache_version)
 {
 	if(!mEnabled)
 	{
-		llwarns << "Not initializing cache: Cache is currently disabled." << llendl;
+		LL_WARNS() << "Not initializing cache: Cache is currently disabled." << LL_ENDL;
 		return ;
 	}
 
 	if(mInitialized)
 	{
-		llwarns << "Cache already initialized." << llendl;
+		LL_WARNS() << "Cache already initialized." << LL_ENDL;
 		return ;
 	}
-	mInitialized = TRUE ;
+	mInitialized = true;
 
 	setDirNames(location);
 	if (!mReadOnly)
@@ -325,39 +1051,48 @@ void LLVOCache::initCache(ELLPath location, U32 size, U32 cache_version)
 	}	
 }
 	
-void LLVOCache::removeCache(ELLPath location) 
+void LLVOCache::removeCache(ELLPath location, bool started) 
 {
+	if(started)
+	{
+		removeCache();
+		return;
+	}
+
 	if(mReadOnly)
 	{
-		llwarns << "Not removing cache at " << location << ": Cache is currently in read-only mode." << llendl;
+		LL_WARNS() << "Not removing cache at " << location << ": Cache is currently in read-only mode." << LL_ENDL;
 		return ;
-	}
+	}	
 
-	llinfos << "about to remove the object cache due to settings." << llendl ;
+	LL_INFOS() << "about to remove the object cache due to settings." << LL_ENDL ;
 
 	std::string mask = "*";
 	std::string cache_dir = gDirUtilp->getExpandedFilename(location, object_cache_dirname);
-	llinfos << "Removing cache at " << cache_dir << llendl;
+	LL_INFOS() << "Removing cache at " << cache_dir << LL_ENDL;
 	gDirUtilp->deleteFilesInDir(cache_dir, mask); //delete all files
 	LLFile::rmdir(cache_dir);
 
 	clearCacheInMemory();
-	mInitialized = FALSE ;
+	mInitialized = false;
 }
 
 void LLVOCache::removeCache() 
 {
-	llassert_always(mInitialized) ;
+	if(!mInitialized)
+	{
+		//OK to remove cache even it is not initialized.
+		LL_WARNS() << "Object cache is not initialized yet." << LL_ENDL;
+	}
+
 	if(mReadOnly)
 	{
-		llwarns << "Not clearing object cache: Cache is currently in read-only mode." << llendl;
+		LL_WARNS() << "Not clearing object cache: Cache is currently in read-only mode." << LL_ENDL;
 		return ;
 	}
 
-	llinfos << "about to remove the object cache due to some error." << llendl ;
-
 	std::string mask = "*";
-	llinfos << "Removing cache at " << mObjectCacheDirName << llendl;
+	LL_INFOS() << "Removing object cache at " << mObjectCacheDirName << LL_ENDL;
 	gDirUtilp->deleteFilesInDir(mObjectCacheDirName, mask); 
 
 	clearCacheInMemory() ;
@@ -366,23 +1101,23 @@ void LLVOCache::removeCache()
 
 void LLVOCache::removeEntry(HeaderEntryInfo* entry) 
 {
-	llassert_always(mInitialized) ;
+	llassert_always(mInitialized);
 	if(mReadOnly)
 	{
-		return ;
+		return;
 	}
 	if(!entry)
 	{
-		return ;
+		return;
 	}
 
-	header_entry_queue_t::iterator iter = mHeaderEntryQueue.find(entry) ;
+	header_entry_queue_t::iterator iter = mHeaderEntryQueue.find(entry);
 	if(iter != mHeaderEntryQueue.end())
 	{		
-		mHandleEntryMap.erase(entry->mHandle) ;		
-		mHeaderEntryQueue.erase(iter) ;
-		removeFromCache(entry) ;
-		delete entry ;
+		mHandleEntryMap.erase(entry->mHandle);		
+		mHeaderEntryQueue.erase(iter);
+		removeFromCache(entry);
+		delete entry;
 
 		mNumEntries = mHandleEntryMap.size() ;
 	}
@@ -429,7 +1164,7 @@ void LLVOCache::removeFromCache(HeaderEntryInfo* entry)
 {
 	if(mReadOnly)
 	{
-		llwarns << "Not removing cache for handle " << entry->mHandle << ": Cache is currently in read-only mode." << llendl;
+		LL_WARNS() << "Not removing cache for handle " << entry->mHandle << ": Cache is currently in read-only mode." << LL_ENDL;
 		return ;
 	}
 
@@ -444,7 +1179,7 @@ void LLVOCache::readCacheHeader()
 {
 	if(!mEnabled)
 	{
-		llwarns << "Not reading cache header: Cache is currently disabled." << llendl;
+		LL_WARNS() << "Not reading cache header: Cache is currently disabled." << LL_ENDL;
 		return;
 	}
 
@@ -474,7 +1209,7 @@ void LLVOCache::readCacheHeader()
 								
 				if(!success) //failed
 				{
-					llwarns << "Error reading cache header entry. (entry_index=" << mNumEntries << ")" << llendl;
+					LL_WARNS() << "Error reading cache header entry. (entry_index=" << mNumEntries << ")" << LL_ENDL;
 					delete entry ;
 					entry = NULL ;
 					break ;
@@ -502,7 +1237,7 @@ void LLVOCache::readCacheHeader()
 		//for(header_entry_queue_t::iterator iter = mHeaderEntryQueue.begin() ; success && iter != mHeaderEntryQueue.end(); ++iter)
 		//{
 		//	getObjectCacheFilename((*iter)->mHandle, name) ;
-		//	llinfos << name << llendl ;
+		//	LL_INFOS() << name << LL_ENDL ;
 		//}
 		//-----------
 	}
@@ -527,13 +1262,13 @@ void LLVOCache::writeCacheHeader()
 {
 	if (!mEnabled)
 	{
-		llwarns << "Not writing cache header: Cache is currently disabled." << llendl;
+		LL_WARNS() << "Not writing cache header: Cache is currently disabled." << LL_ENDL;
 		return;
 	}
 
 	if(mReadOnly)
 	{
-		llwarns << "Not writing cache header: Cache is currently in read-only mode." << llendl;
+		LL_WARNS() << "Not writing cache header: Cache is currently in read-only mode." << LL_ENDL;
 		return;
 	}
 
@@ -587,7 +1322,7 @@ void LLVOCache::readFromCache(U64 handle, const LLUUID& id, LLVOCacheEntry::voca
 {
 	if(!mEnabled)
 	{
-		llwarns << "Not reading cache for handle " << handle << "): Cache is currently disabled." << llendl;
+		LL_WARNS() << "Not reading cache for handle " << handle << "): Cache is currently disabled." << LL_ENDL;
 		return ;
 	}
 	llassert_always(mInitialized);
@@ -595,7 +1330,7 @@ void LLVOCache::readFromCache(U64 handle, const LLUUID& id, LLVOCacheEntry::voca
 	handle_entry_map_t::iterator iter = mHandleEntryMap.find(handle) ;
 	if(iter == mHandleEntryMap.end()) //no cache
 	{
-		llwarns << "No handle map entry for " << handle << llendl;
+		LL_WARNS() << "No handle map entry for " << handle << LL_ENDL;
 		return ;
 	}
 
@@ -612,7 +1347,7 @@ void LLVOCache::readFromCache(U64 handle, const LLUUID& id, LLVOCacheEntry::voca
 		{		
 			if(cache_id != id)
 			{
-				llinfos << "Cache ID doesn't match for this region, discarding"<< llendl;
+				LL_INFOS() << "Cache ID doesn't match for this region, discarding"<< LL_ENDL;
 				success = false ;
 			}
 
@@ -623,13 +1358,12 @@ void LLVOCache::readFromCache(U64 handle, const LLUUID& id, LLVOCacheEntry::voca
 	
 				if(success)
 				{
-					for (S32 i = 0; i < num_entries; i++)
+					for (S32 i = 0; i < num_entries && apr_file.eof() != APR_EOF; i++)
 					{
-						LLVOCacheEntry* entry = new LLVOCacheEntry(&apr_file);
+						LLPointer<LLVOCacheEntry> entry = new LLVOCacheEntry(&apr_file);
 						if (!entry->getLocalID())
 						{
-							llwarns << "Aborting cache file load for " << filename << ", cache file corruption!" << llendl;
-							delete entry ;
+							LL_WARNS() << "Aborting cache file load for " << filename << ", cache file corruption!" << LL_ENDL;
 							success = false ;
 							break ;
 						}
@@ -665,18 +1399,18 @@ void LLVOCache::purgeEntries(U32 size)
 	mNumEntries = mHandleEntryMap.size() ;
 }
 
-void LLVOCache::writeToCache(U64 handle, const LLUUID& id, const LLVOCacheEntry::vocache_entry_map_t& cache_entry_map, BOOL dirty_cache) 
+void LLVOCache::writeToCache(U64 handle, const LLUUID& id, const LLVOCacheEntry::vocache_entry_map_t& cache_entry_map, BOOL dirty_cache, bool removal_enabled) 
 {
 	if(!mEnabled)
 	{
-		llwarns << "Not writing cache for handle " << handle << "): Cache is currently disabled." << llendl;
+		LL_WARNS() << "Not writing cache for handle " << handle << "): Cache is currently disabled." << LL_ENDL;
 		return ;
 	}
 	llassert_always(mInitialized);
 
 	if(mReadOnly)
 	{
-		llwarns << "Not writing cache for handle " << handle << "): Cache is currently in read-only mode." << llendl;
+		LL_WARNS() << "Not writing cache for handle " << handle << "): Cache is currently in read-only mode." << LL_ENDL;
 		return ;
 	}	
 
@@ -711,13 +1445,13 @@ void LLVOCache::writeToCache(U64 handle, const LLUUID& id, const LLVOCacheEntry:
 	//update cache header
 	if(!updateEntry(entry))
 	{
-		llwarns << "Failed to update cache header index " << entry->mIndex << ". handle = " << handle << llendl;
+		LL_WARNS() << "Failed to update cache header index " << entry->mIndex << ". handle = " << handle << LL_ENDL;
 		return ; //update failed.
 	}
 
 	if(!dirty_cache)
 	{
-		llwarns << "Skipping write to cache for handle " << handle << ": cache not dirty" << llendl;
+		LL_WARNS() << "Skipping write to cache for handle " << handle << ": cache not dirty" << LL_ENDL;
 		return ; //nothing changed, no need to update.
 	}
 
@@ -738,7 +1472,14 @@ void LLVOCache::writeToCache(U64 handle, const LLUUID& id, const LLVOCacheEntry:
 	
 			for (LLVOCacheEntry::vocache_entry_map_t::const_iterator iter = cache_entry_map.begin(); success && iter != cache_entry_map.end(); ++iter)
 			{
-				success = iter->second->writeToFile(&apr_file) ;
+				if(!removal_enabled || iter->second->isValid())
+				{
+					success = iter->second->writeToFile(&apr_file) ;
+					if(!success)
+					{
+						break;
+					}
+				}
 			}
 		}
 	}
@@ -746,7 +1487,6 @@ void LLVOCache::writeToCache(U64 handle, const LLUUID& id, const LLVOCacheEntry:
 	if(!success)
 	{
 		removeEntry(entry) ;
-
 	}
 
 	return ;