From ab8e2916d32aca4bcc8ed84e60e990e73fff15c1 Mon Sep 17 00:00:00 2001
From: ZappoMan <bradh@konamoxt.com>
Date: Wed, 10 Jul 2013 19:49:50 -0700
Subject: [PATCH] improvements to delta sending

---
 libraries/voxels/src/VoxelTree.cpp | 31 ++++++++++++++++++++++--------
 libraries/voxels/src/VoxelTree.h   |  3 +++
 voxel-server/src/main.cpp          |  6 +++++-
 3 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/libraries/voxels/src/VoxelTree.cpp b/libraries/voxels/src/VoxelTree.cpp
index 2f0ec4727c..70bca504cb 100644
--- a/libraries/voxels/src/VoxelTree.cpp
+++ b/libraries/voxels/src/VoxelTree.cpp
@@ -1331,10 +1331,6 @@ int VoxelTree::encodeTreeBitstreamRecursion(VoxelNode* node, unsigned char* outp
                 } // wants occlusion culling & isLeaf()
 
 
-                bool childWasInView = (childNode && params.deltaViewFrustum &&
-
-                                      (params.lastViewFrustum && ViewFrustum::INSIDE == childNode->inFrustum(*params.lastViewFrustum)));
-
                 // There are two types of nodes for which we want to send colors:
                 // 1) Leaves - obviously
                 // 2) Non-leaves who's children would be visible and beyond our LOD.
@@ -1360,15 +1356,34 @@ int VoxelTree::encodeTreeBitstreamRecursion(VoxelNode* node, unsigned char* outp
                     }
                     // if any of our grandchildren ARE in view, then we don't want to include our color. If none are, then
                     // we do want to include our color
-                    if (grandChildrenInView > 0 && grandChildrenInLOD==0) {
+                    if (grandChildrenInView > 0 && grandChildrenInLOD == 0) {
                         isLeafOrLOD = true;
                     }
                 }
                 
                 // track children with actual color, only if the child wasn't previously in view!
-                if (childNode && isLeafOrLOD && childNode->isColored() && !childWasInView && !childIsOccluded) {
-                    childrenColoredBits += (1 << (7 - originalIndex));
-                    inViewWithColorCount++;
+                if (childNode && isLeafOrLOD && childNode->isColored() && !childIsOccluded) {
+                    bool childWasInView = false;
+                    
+                    if (childNode && params.deltaViewFrustum && params.lastViewFrustum) {
+                        ViewFrustum::location location = childNode->inFrustum(*params.lastViewFrustum);
+                        
+                        // If we're a leaf, then either intersect or inside is considered "formerly in view"
+                        if (childNode->isLeaf()) {
+                            childWasInView = location != ViewFrustum::OUTSIDE;
+                        } else {
+                            childWasInView = location == ViewFrustum::INSIDE;
+                        }
+                    }                    
+
+                    // If our child wasn't in view (or we're ignoring wasInView) then we add it to our sending items
+                    if (!childWasInView) {
+                        childrenColoredBits += (1 << (7 - originalIndex));
+                        inViewWithColorCount++;
+                    } else {
+                        // otherwise just track stats of the items we discarded
+                        params.childWasInViewDiscarded++;
+                    }
                 }
             }
         }
diff --git a/libraries/voxels/src/VoxelTree.h b/libraries/voxels/src/VoxelTree.h
index 4c0e7d33c4..a94afe0d79 100644
--- a/libraries/voxels/src/VoxelTree.h
+++ b/libraries/voxels/src/VoxelTree.h
@@ -45,6 +45,8 @@ public:
     bool                deltaViewFrustum;
     const ViewFrustum*  lastViewFrustum;
     bool                wantOcclusionCulling;
+    long                childWasInViewDiscarded;
+
     CoverageMap*        map;
     
     EncodeBitstreamParams(
@@ -66,6 +68,7 @@ public:
             deltaViewFrustum    (deltaViewFrustum),
             lastViewFrustum     (lastViewFrustum),
             wantOcclusionCulling(wantOcclusionCulling),
+            childWasInViewDiscarded(0),
             map                 (map)
     {}
 };
diff --git a/voxel-server/src/main.cpp b/voxel-server/src/main.cpp
index 74780ed52a..e71e456359 100644
--- a/voxel-server/src/main.cpp
+++ b/voxel-server/src/main.cpp
@@ -127,7 +127,7 @@ void deepestLevelVoxelDistributor(NodeList* nodeList,
     long long start = usecTimestampNow();
 
     // FOR NOW... node tells us if it wants to receive only view frustum deltas
-    bool wantDelta = nodeData->getWantDelta();
+    bool wantDelta = viewFrustumChanged && nodeData->getWantDelta();
     const ViewFrustum* lastViewFrustum =  wantDelta ? &nodeData->getLastKnownViewFrustum() : NULL;
 
     if (::debugVoxelSending) {
@@ -233,6 +233,10 @@ void deepestLevelVoxelDistributor(NodeList* nodeList,
 
                 bytesWritten = serverTree.encodeTreeBitstream(subTree, &tempOutputBuffer[0], MAX_VOXEL_PACKET_SIZE - 1,
                                                               nodeData->nodeBag, params);
+
+                if (::debugVoxelSending && wantDelta) {
+                    printf("encodeTreeBitstream() childWasInViewDiscarded=%ld\n", params.childWasInViewDiscarded);
+                }
                 
                 if (nodeData->getAvailable() >= bytesWritten) {
                     nodeData->writeToPacket(&tempOutputBuffer[0], bytesWritten);