Merge pull request #10696 from AndrewMeadows/avoid-ownership-bid-race

ignore remote update younger than recent ownership bid

libraries/entities/src/EntityItem.cpp

@@ -386,7 +386,13 @@ int EntityItem::readEntityDataFromBuffer(const unsigned char* data, int bytesLef
         return 0;
     }
 
-    qint64 clockSkew = args.sourceNode ? args.sourceNode->getClockSkewUsec() : 0;
+    int64_t clockSkew = 0;
+    uint64_t maxPingRoundTrip = 33333; // two frames periods at 60 fps
+    if (args.sourceNode) {
+        clockSkew = args.sourceNode->getClockSkewUsec();
+        const float MSECS_PER_USEC = 1000;
+        maxPingRoundTrip += args.sourceNode->getPingMs() * MSECS_PER_USEC;
+    }
 
     BufferParser parser(data, bytesLeftToRead);
 
@@ -653,7 +659,6 @@ int EntityItem::readEntityDataFromBuffer(const unsigned char* data, int bytesLef
     const QUuid& myNodeID = nodeList->getSessionUUID();
     bool weOwnSimulation = _simulationOwner.matchesValidID(myNodeID);
 
-
     // pack SimulationOwner and terse update properties near each other
     // NOTE: the server is authoritative for changes to simOwnerID so we always unpack ownership data
     // even when we would otherwise ignore the rest of the packet.
@@ -678,7 +683,7 @@ int EntityItem::readEntityDataFromBuffer(const unsigned char* data, int bytesLef
             if (newSimOwner.getID().isNull() && !_simulationOwner.pendingRelease(lastEditedFromBufferAdjusted)) {
                 // entity-server is trying to clear our ownership (probably at our own request)
                 // but we actually want to own it, therefore we ignore this clear event
-                // and pretend that we own it (we assume we'll recover it soon)
+                // and pretend that we own it (e.g. we assume we'll receive ownership soon)
 
                 // However, for now, when the server uses a newer time than what we sent, listen to what we're told.
                 if (overwriteLocalData) {
@@ -690,16 +695,19 @@ int EntityItem::readEntityDataFromBuffer(const unsigned char* data, int bytesLef
                 // recompute weOwnSimulation for later
                 weOwnSimulation = _simulationOwner.matchesValidID(myNodeID);
             }
-        } else if (newSimOwner.getID().isNull() && _simulationOwner.pendingTake(lastEditedFromBufferAdjusted)) {
-            // entity-server is trying to clear someone  else's ownership
-            // but we want to own it, therefore we ignore this clear event
-            // and pretend that we own it (we assume we'll get it soon)
+        } else if (_simulationOwner.pendingTake(now - maxPingRoundTrip)) {
+            // we sent a bid before this packet could have been sent from the server
+            // so we ignore it and pretend we own the object's simulation
             weOwnSimulation = true;
-            if (!_simulationOwner.isNull()) {
-                // someone else really did own it
-                markDirtyFlags(Simulation::DIRTY_SIMULATOR_ID);
-                somethingChanged = true;
-                _simulationOwner.clearCurrentOwner();
+            if (newSimOwner.getID().isNull()) {
+                // entity-server is trying to clear someone  else's ownership
+                // but we want to own it, therefore we ignore this clear event
+                if (!_simulationOwner.isNull()) {
+                    // someone else really did own it
+                    markDirtyFlags(Simulation::DIRTY_SIMULATOR_ID);
+                    somethingChanged = true;
+                    _simulationOwner.clearCurrentOwner();
+                }
             }
         } else if (newSimOwner.matchesValidID(myNodeID) && !_hasBidOnSimulation) {
             // entity-server tells us that we have simulation ownership while we never requested this for this EntityItem,

libraries/physics/src/ObjectActionTractor.cpp

@@ -23,14 +23,16 @@ const uint16_t ObjectActionTractor::tractorVersion = 1;
 
 ObjectActionTractor::ObjectActionTractor(const QUuid& id, EntityItemPointer ownerEntity) :
     ObjectAction(DYNAMIC_TYPE_TRACTOR, id, ownerEntity),
-    _positionalTarget(glm::vec3(0.0f)),
-    _desiredPositionalTarget(glm::vec3(0.0f)),
+    _positionalTarget(0.0f),
+    _desiredPositionalTarget(0.0f),
     _linearTimeScale(FLT_MAX),
-    _positionalTargetSet(true),
-    _rotationalTarget(glm::quat()),
-    _desiredRotationalTarget(glm::quat()),
+    _positionalTargetSet(false),
+    _rotationalTarget(),
+    _desiredRotationalTarget(),
     _angularTimeScale(FLT_MAX),
-    _rotationalTargetSet(true) {
+    _rotationalTargetSet(true),
+    _linearVelocityTarget(0.0f)
+{
     #if WANT_DEBUG
     qCDebug(physics) << "ObjectActionTractor::ObjectActionTractor";
     #endif
@@ -77,7 +79,6 @@ bool ObjectActionTractor::prepareForTractorUpdate(btScalar deltaTimeStep) {
 
     glm::quat rotation;
     glm::vec3 position;
-    glm::vec3 linearVelocity;
     glm::vec3 angularVelocity;
 
     bool linearValid = false;
@@ -117,7 +118,6 @@ bool ObjectActionTractor::prepareForTractorUpdate(btScalar deltaTimeStep) {
                 linearValid = true;
                 linearTractorCount++;
                 position += positionForAction;
-                linearVelocity += linearVelocityForAction;
             }
         }
     }
@@ -126,9 +126,18 @@ bool ObjectActionTractor::prepareForTractorUpdate(btScalar deltaTimeStep) {
         withWriteLock([&]{
             if (linearValid && linearTractorCount > 0) {
                 position /= linearTractorCount;
-                linearVelocity /= linearTractorCount;
+                if (_positionalTargetSet) {
+                    _lastPositionTarget = _positionalTarget;
+                } else {
+                    _lastPositionTarget = position;
+                }
                 _positionalTarget = position;
-                _linearVelocityTarget = linearVelocity;
+                if (deltaTimeStep > EPSILON) {
+                    // blend the new velocity with the old (low-pass filter)
+                    glm::vec3 newVelocity = (1.0f / deltaTimeStep) * (position - _lastPositionTarget);
+                    const float blend = 0.25f;
+                    _linearVelocityTarget = (1.0f - blend) * _linearVelocityTarget + blend * newVelocity;
+                }
                 _positionalTargetSet = true;
                 _active = true;
             }
@@ -169,19 +178,19 @@ void ObjectActionTractor::updateActionWorker(btScalar deltaTimeStep) {
         }
 
         if (_linearTimeScale < MAX_TRACTOR_TIMESCALE) {
-            btVector3 targetVelocity(0.0f, 0.0f, 0.0f);
+            btVector3 offsetVelocity(0.0f, 0.0f, 0.0f);
             btVector3 offset = rigidBody->getCenterOfMassPosition() - glmToBullet(_positionalTarget);
             float offsetLength = offset.length();
             if (offsetLength > FLT_EPSILON) {
                 float speed = glm::min(offsetLength / _linearTimeScale, TRACTOR_MAX_SPEED);
-                targetVelocity = (-speed / offsetLength) * offset;
+                offsetVelocity = (-speed / offsetLength) * offset;
                 if (speed > rigidBody->getLinearSleepingThreshold()) {
                     forceBodyNonStatic();
                     rigidBody->activate();
                 }
             }
             // this action is aggresively critically damped and defeats the current velocity
-            rigidBody->setLinearVelocity(targetVelocity);
+            rigidBody->setLinearVelocity(glmToBullet(_linearVelocityTarget) + offsetVelocity);
         }
 
         if (_angularTimeScale < MAX_TRACTOR_TIMESCALE) {

libraries/physics/src/ObjectActionTractor.h

@@ -36,6 +36,7 @@ protected:
 
     glm::vec3 _positionalTarget;
     glm::vec3 _desiredPositionalTarget;
+    glm::vec3 _lastPositionTarget;
     float _linearTimeScale;
     bool _positionalTargetSet;