Application gets a ThreadSafePhysicsWorld

interface/src/Application.cpp

@@ -2011,7 +2011,7 @@ void Application::init() {
     connect(_myAvatar, &MyAvatar::transformChanged, this, &Application::updateMyAvatarTransform);
 
 #ifdef USE_BULLET_PHYSICS
-    _physicsWorld.init();
+    _physicsWorld.initSafe(_entities.getTree());
 #endif // USE_BULLET_PHYSICS
 }
 

interface/src/Application.h

@@ -35,7 +35,7 @@
 #include <NetworkPacket.h>
 #include <NodeList.h>
 #include <PacketHeaders.h>
-#include <PhysicsWorld.h>
+//#include <PhysicsWorld.h>
 #include <ScriptEngine.h>
 #include <OctreeQuery.h>
 #include <ViewFrustum.h>
@@ -53,6 +53,7 @@
 #include "Menu.h"
 #include "MetavoxelSystem.h"
 #include "PacketHeaders.h"
+#include "Physics.h"
 #include "Stars.h"
 #include "avatar/Avatar.h"
 #include "avatar/AvatarManager.h"
@@ -504,7 +505,7 @@ private:
     MetavoxelSystem _metavoxels;
 
 #ifdef USE_BULLET_PHYSICS
-    PhysicsWorld _physicsWorld;
+    ThreadSafePhysicsWorld _physicsWorld;
 #endif // USE_BULLET_PHYSICS
 
     ViewFrustum _viewFrustum; // current state of view frustum, perspective, orientation, etc.

interface/src/Physics.cpp

@@ -9,12 +9,55 @@
 //
 
 #include <glm/glm.hpp>
+
+#include <EntityTree.h>
 #include <SharedUtil.h>
+#include <ThreadSafeDynamicsWorld.h>
 
 #include "Util.h"
 #include "world.h"
 #include "Physics.h"
 
+// DynamicsImpl is an implementation of ThreadSafeDynamicsWorld that knows how to lock an EntityTree
+class DynamicsImpl : public ThreadSafeDynamicsWorld {
+public:
+    DynamicsImpl(
+        btDispatcher* dispatcher,
+        btBroadphaseInterface* pairCache,
+        btConstraintSolver* constraintSolver,
+        btCollisionConfiguration* collisionConfiguration,
+        EntityTree* entities)
+        :   ThreadSafeDynamicsWorld(dispatcher, pairCache, constraintSolver, collisionConfiguration), _entities(entities) {
+        assert(entities);
+    }
+
+    bool tryLock() {
+        // wait for lock
+        _entities->lockForRead();
+        return true;
+    }
+
+    void unlock() {
+        _entities->unlock();
+    }
+private:
+    EntityTree* _entities;
+};
+
+ThreadSafePhysicsWorld::ThreadSafePhysicsWorld(const glm::vec3& offset) : PhysicsWorld(offset) {
+}
+
+void ThreadSafePhysicsWorld::initSafe(EntityTree* entities) {
+    assert(!_dynamicsWorld); // only call this once
+    assert(entities);
+    _collisionConfig = new btDefaultCollisionConfiguration();                             
+    _collisionDispatcher = new btCollisionDispatcher(_collisionConfig);                   
+    _broadphaseFilter = new btDbvtBroadphase();                                           
+    _constraintSolver = new btSequentialImpulseConstraintSolver;                          
+    // ThreadSafePhysicsWorld gets a DynamicsImpl, which derives from ThreadSafeDynamicsWorld
+    _dynamicsWorld = new DynamicsImpl(_collisionDispatcher, _broadphaseFilter, _constraintSolver, _collisionConfig, entities);
+}
+
 //
 //  Applies static friction:  maxVelocity is the largest velocity for which there
 //  there is friction, and strength is the amount of friction force applied to reduce
@@ -41,4 +84,4 @@ void applyDamping(float deltaTime, glm::vec3& velocity, float linearStrength, fl
 
 void applyDampedSpring(float deltaTime, glm::vec3& velocity, glm::vec3& position, glm::vec3& targetPosition, float k, float damping) {
     
-}
+}

interface/src/Physics.h

@@ -12,6 +12,20 @@
 #ifndef hifi_Physics_h
 #define hifi_Physics_h
 
+#include <PhysicsWorld.h>
+
+class EntityTree;
+
+class ThreadSafePhysicsWorld : public PhysicsWorld {
+public:
+    ThreadSafePhysicsWorld(const glm::vec3& offset);
+
+    // virtual override from PhysicsWorld
+    void init() { assert(false); } // call initSafe() instead
+
+    void initSafe(EntityTree* entities);
+};
+
 void applyStaticFriction(float deltaTime, glm::vec3& velocity, float maxVelocity, float strength);
 void applyDamping(float deltaTime, glm::vec3& velocity, float linearStrength, float squaredStrength);
 

libraries/physics/src/PhysicsWorld.cpp

@@ -15,12 +15,15 @@
 PhysicsWorld::~PhysicsWorld() {
 }
 
+// virtual
 void PhysicsWorld::init() {
-    _collisionConfig = new btDefaultCollisionConfiguration();
-    _collisionDispatcher = new btCollisionDispatcher(_collisionConfig);
-    _broadphaseFilter = new btDbvtBroadphase();
-    _constraintSolver = new btSequentialImpulseConstraintSolver;
-    _dynamicsWorld = new btDiscreteDynamicsWorld(_collisionDispatcher, _broadphaseFilter, _constraintSolver, _collisionConfig);
+    if (!_dynamicsWorld) {
+        _collisionConfig = new btDefaultCollisionConfiguration();
+        _collisionDispatcher = new btCollisionDispatcher(_collisionConfig);
+        _broadphaseFilter = new btDbvtBroadphase();
+        _constraintSolver = new btSequentialImpulseConstraintSolver;
+        _dynamicsWorld = new btDiscreteDynamicsWorld(_collisionDispatcher, _broadphaseFilter, _constraintSolver, _collisionConfig);
+    }
 }
 
 void PhysicsWorld::stepSimulation() {

libraries/physics/src/PhysicsWorld.h

@@ -39,7 +39,7 @@ public:
 
     ~PhysicsWorld();
 
-    void init();
+    virtual void init();
 
     void stepSimulation();