From 34cebc36c75024e06c6410ffd5e6b46360615c30 Mon Sep 17 00:00:00 2001
From: ZappoMan <bradh@konamoxt.com>
Date: Thu, 11 Jul 2013 09:11:09 -0700
Subject: [PATCH] short circuit node recursion for delta sending

---
 libraries/voxels/src/VoxelTree.cpp | 26 +++++++++++++++++++-------
 voxel-server/src/VoxelNodeData.cpp |  7 +++++--
 voxel-server/src/VoxelNodeData.h   |  1 +
 voxel-server/src/main.cpp          |  4 +++-
 4 files changed, 28 insertions(+), 10 deletions(-)

diff --git a/libraries/voxels/src/VoxelTree.cpp b/libraries/voxels/src/VoxelTree.cpp
index 70bca504cb..3be28e9b93 100644
--- a/libraries/voxels/src/VoxelTree.cpp
+++ b/libraries/voxels/src/VoxelTree.cpp
@@ -1182,7 +1182,26 @@ int VoxelTree::encodeTreeBitstreamRecursion(VoxelNode* node, unsigned char* outp
         if (!node->isInView(*params.viewFrustum)) {
             return bytesAtThisLevel;
         }
+        
+        // Ok, we are in view, but if we're in delta mode, then we also want to make sure we weren't already in view
+        // because we don't send nodes from the previously know in view frustum.
+        bool wasInView = false;
+        
+        if (params.deltaViewFrustum && params.lastViewFrustum) {
+            ViewFrustum::location location = node->inFrustum(*params.lastViewFrustum);
+            
+            // If we're a leaf, then either intersect or inside is considered "formerly in view"
+            if (node->isLeaf()) {
+                wasInView = location != ViewFrustum::OUTSIDE;
+            } else {
+                wasInView = location == ViewFrustum::INSIDE;
+            }
+        }
 
+        // If we were in view, then bail out early!        
+        if (wasInView) {
+            return bytesAtThisLevel;
+        }            
 
         // If the user also asked for occlusion culling, check if this node is occluded, but only if it's not a leaf.
         // leaf occlusion is handled down below when we check child nodes
@@ -1200,16 +1219,9 @@ int VoxelTree::encodeTreeBitstreamRecursion(VoxelNode* node, unsigned char* outp
                 CoverageMapStorageResult result = params.map->checkMap(voxelPolygon, false);
                 delete voxelPolygon; // cleanup
                 if (result == OCCLUDED) {
-                    //node->printDebugDetails("upper section, non-Leaf is occluded!! node=");
-                    //args->nonLeavesOccluded++;
-
-                    //args->subtreeVoxelsSkipped += (subArgs.voxelsTouched - 1);
-                    //args->totalVoxels += (subArgs.voxelsTouched - 1);
-
                     return bytesAtThisLevel;
                 }
             } else {
-                //node->printDebugDetails("upper section, shadow Not in view node=");
                 // If this shadow wasn't "all in view" then we ignored it for occlusion culling, but
                 // we do need to clean up memory and proceed as normal...
                 delete voxelPolygon;
diff --git a/voxel-server/src/VoxelNodeData.cpp b/voxel-server/src/VoxelNodeData.cpp
index f2cce906cf..a9fc4a8620 100644
--- a/voxel-server/src/VoxelNodeData.cpp
+++ b/voxel-server/src/VoxelNodeData.cpp
@@ -17,7 +17,8 @@ VoxelNodeData::VoxelNodeData(Node* owningNode) :
     _voxelPacketAvailableBytes(MAX_VOXEL_PACKET_SIZE),
     _maxSearchLevel(1),
     _maxLevelReachedInLastSearch(1),
-    _lastTimeBagEmpty(0)
+    _lastTimeBagEmpty(0),
+    _viewFrustumChanging(false)
 {
     _voxelPacket = new unsigned char[MAX_VOXEL_PACKET_SIZE];
     _voxelPacketAt = _voxelPacket;
@@ -27,7 +28,8 @@ VoxelNodeData::VoxelNodeData(Node* owningNode) :
 
 
 void VoxelNodeData::resetVoxelPacket() {
-    _voxelPacket[0] = getWantColor() ? PACKET_HEADER_VOXEL_DATA : PACKET_HEADER_VOXEL_DATA_MONOCHROME;
+    bool wantColor = getWantColor();
+    _voxelPacket[0] = wantColor ? PACKET_HEADER_VOXEL_DATA : PACKET_HEADER_VOXEL_DATA_MONOCHROME;
     _voxelPacketAt = &_voxelPacket[1];
     _voxelPacketAvailableBytes = MAX_VOXEL_PACKET_SIZE - 1;
     _voxelPacketWaiting = false;
@@ -63,6 +65,7 @@ bool VoxelNodeData::updateCurrentViewFrustum() {
         _currentViewFrustum.calculate();
         currentViewFrustumChanged = true;
     }
+    _viewFrustumChanging = currentViewFrustumChanged;
     return currentViewFrustumChanged;
 }
 
diff --git a/voxel-server/src/VoxelNodeData.h b/voxel-server/src/VoxelNodeData.h
index bb30372f35..66fa096a3a 100644
--- a/voxel-server/src/VoxelNodeData.h
+++ b/voxel-server/src/VoxelNodeData.h
@@ -67,6 +67,7 @@ private:
     ViewFrustum _currentViewFrustum;
     ViewFrustum _lastKnownViewFrustum;
     long long _lastTimeBagEmpty;
+    bool _viewFrustumChanging;
 
 };
 
diff --git a/voxel-server/src/main.cpp b/voxel-server/src/main.cpp
index e71e456359..b6a3833275 100644
--- a/voxel-server/src/main.cpp
+++ b/voxel-server/src/main.cpp
@@ -128,6 +128,8 @@ void deepestLevelVoxelDistributor(NodeList* nodeList,
 
     // FOR NOW... node tells us if it wants to receive only view frustum deltas
     bool wantDelta = viewFrustumChanged && nodeData->getWantDelta();
+    bool wantColor = nodeData->getWantColor();
+    
     const ViewFrustum* lastViewFrustum =  wantDelta ? &nodeData->getLastKnownViewFrustum() : NULL;
 
     if (::debugVoxelSending) {
@@ -227,7 +229,7 @@ void deepestLevelVoxelDistributor(NodeList* nodeList,
                 bool wantOcclusionCulling = nodeData->getWantOcclusionCulling();
                 CoverageMap* coverageMap = wantOcclusionCulling ? &nodeData->map : IGNORE_COVERAGE_MAP;
                 
-                EncodeBitstreamParams params(INT_MAX, &nodeData->getCurrentViewFrustum(), nodeData->getWantColor(), 
+                EncodeBitstreamParams params(INT_MAX, &nodeData->getCurrentViewFrustum(), wantColor, 
                                              WANT_EXISTS_BITS, DONT_CHOP, wantDelta, lastViewFrustum,
                                              wantOcclusionCulling, coverageMap);