From 2ca592de8b63080ac9d329db1ba3d57f472d7428 Mon Sep 17 00:00:00 2001
From: Seth Alves <seth.alves@gmail.com>
Date: Thu, 23 Apr 2015 10:02:29 -0700
Subject: [PATCH] fix logic with infectious simulation ownership

---
 libraries/physics/src/EntityMotionState.h |  7 ++--
 libraries/physics/src/ObjectMotionState.h |  6 ++++
 libraries/physics/src/PhysicsEngine.cpp   | 42 ++++++++++++-----------
 3 files changed, 31 insertions(+), 24 deletions(-)

diff --git a/libraries/physics/src/EntityMotionState.h b/libraries/physics/src/EntityMotionState.h
index d3678a81fe..07f82aaa42 100644
--- a/libraries/physics/src/EntityMotionState.h
+++ b/libraries/physics/src/EntityMotionState.h
@@ -62,14 +62,13 @@ public:
     virtual uint32_t getIncomingDirtyFlags() const;
     virtual void clearIncomingDirtyFlags(uint32_t flags) { _entity->clearDirtyFlags(flags); }
 
-    EntityItem* getEntity() const { return _entity; }
-
     void incrementAccelerationNearlyGravityCount() { _accelerationNearlyGravityCount++; }
     void resetAccelerationNearlyGravityCount() { _accelerationNearlyGravityCount = 0; }
     quint8 getAccelerationNearlyGravityCount() { return _accelerationNearlyGravityCount; }
 
-    void setShouldClaimSimulationOwnership(bool value) { _shouldClaimSimulationOwnership = value; }
-    bool getShouldClaimSimulationOwnership() { return _shouldClaimSimulationOwnership; }
+    virtual EntityItem* getEntity() const { return _entity; }
+    virtual void setShouldClaimSimulationOwnership(bool value) { _shouldClaimSimulationOwnership = value; }
+    virtual bool getShouldClaimSimulationOwnership() { return _shouldClaimSimulationOwnership; }
 
 protected:
     EntityItem* _entity;
diff --git a/libraries/physics/src/ObjectMotionState.h b/libraries/physics/src/ObjectMotionState.h
index ad9ef861b9..9e0917a3ab 100644
--- a/libraries/physics/src/ObjectMotionState.h
+++ b/libraries/physics/src/ObjectMotionState.h
@@ -111,6 +111,12 @@ public:
     virtual bool isMoving() const = 0;
 
     friend class PhysicsEngine;
+
+    // these are here so we can call into EntityMotionObject with a base-class pointer
+    virtual EntityItem* getEntity() const { return NULL; }
+    virtual void setShouldClaimSimulationOwnership(bool value) { }
+    virtual bool getShouldClaimSimulationOwnership() { return false; }
+
 protected:
     void setRigidBody(btRigidBody* body);
 
diff --git a/libraries/physics/src/PhysicsEngine.cpp b/libraries/physics/src/PhysicsEngine.cpp
index f187f5727d..45f3c97e30 100644
--- a/libraries/physics/src/PhysicsEngine.cpp
+++ b/libraries/physics/src/PhysicsEngine.cpp
@@ -391,29 +391,31 @@ void PhysicsEngine::computeCollisionEvents() {
                 continue;
             }
 
-            void* a = objectA->getUserPointer();
-            EntityMotionState* entityMotionStateA = static_cast<EntityMotionState*>(a);
-            EntityItem* entityA = entityMotionStateA ? entityMotionStateA->getEntity() : NULL;
-            void* b = objectB->getUserPointer();
-            EntityMotionState* entityMotionStateB = static_cast<EntityMotionState*>(b);
-            EntityItem* entityB = entityMotionStateB ? entityMotionStateB->getEntity() : NULL;
+            ObjectMotionState* a = static_cast<ObjectMotionState*>(objectA->getUserPointer());
+            ObjectMotionState* b = static_cast<ObjectMotionState*>(objectB->getUserPointer());
+            EntityItem* entityA = a ? a->getEntity() : NULL;
+            EntityItem* entityB = b ? b->getEntity() : NULL;
+            bool aIsDynamic = entityA && !objectA->isStaticOrKinematicObject();
+            bool bIsDynamic = entityB && !objectB->isStaticOrKinematicObject();
+
             if (a || b) {
                 // the manifold has up to 4 distinct points, but only extract info from the first
                 _contactMap[ContactKey(a, b)].update(_numContactFrames, contactManifold->getContactPoint(0), _originOffset);
-
-                // collisions cause infectious spread of simulation-ownership.  we also attempt to take
-                // ownership of anything that collides with our avatar.
-                if (entityA && entityB && !objectA->isStaticOrKinematicObject() && !objectB->isStaticOrKinematicObject()) {
-                    if (entityA->getSimulatorID() == myNodeID || 
-                        entityMotionStateA->getShouldClaimSimulationOwnership() ||
-                        objectA == characterCollisionObject) {
-                        entityMotionStateB->setShouldClaimSimulationOwnership(true);
-                    }
-                    if (entityB->getSimulatorID() == myNodeID ||
-                        entityMotionStateB->getShouldClaimSimulationOwnership() ||
-                        objectB == characterCollisionObject) {
-                        entityMotionStateA->setShouldClaimSimulationOwnership(true);
-                    }
+            }
+            // collisions cause infectious spread of simulation-ownership.  we also attempt to take
+            // ownership of anything that collides with our avatar.
+            if ((aIsDynamic && entityA->getSimulatorID() == myNodeID) ||
+                (a && a->getShouldClaimSimulationOwnership()) ||
+                (objectA == characterCollisionObject)) {
+                if (bIsDynamic) {
+                    b->setShouldClaimSimulationOwnership(true);
+                }
+            }
+            if ((bIsDynamic && entityB->getSimulatorID() == myNodeID) ||
+                (b && b->getShouldClaimSimulationOwnership()) ||
+                (objectB == characterCollisionObject)) {
+                if (aIsDynamic) {
+                    a->setShouldClaimSimulationOwnership(true);
                 }
             }
         }