text: /****************************************************************************
   Copyright (c) 2015-2016 Chukong Technologies Inc.
   Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.
   
   http://www.cocos2d-x.org
   
   Permission is hereby granted, free of charge, to any person obtaining a copy
   of this software and associated documentation files (the "Software"), to deal
   in the Software without restriction, including without limitation the rights
   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   copies of the Software, and to permit persons to whom the Software is
   furnished to do so, subject to the following conditions:
   
   The above copyright notice and this permission notice shall be included in
   all copies or substantial portions of the Software.
   
   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   THE SOFTWARE.
   ****************************************************************************/
  
  #include "physics3d/CCPhysics3D.h"
  #include "renderer/CCRenderer.h"
  
  #if CC_USE_3D_PHYSICS
  
  #if (CC_ENABLE_BULLET_INTEGRATION)
  
  NS_CC_BEGIN
  
  Physics3DWorld::Physics3DWorld()
  : _needCollisionChecking(false)
  , _collisionCheckingFlag(false)
  , _needGhostPairCallbackChecking(false)
  , _btPhyiscsWorld(nullptr)
  , _collisionConfiguration(nullptr)
  , _dispatcher(nullptr)
  , _broadphase(nullptr)
  , _solver(nullptr)
  , _ghostCallback(nullptr)
  , _debugDrawer(nullptr)
  {
      
  }
  Physics3DWorld::~Physics3DWorld()
  {
      removeAllPhysics3DConstraints();
      removeAllPhysics3DObjects();
  
      CC_SAFE_DELETE(_collisionConfiguration);
      CC_SAFE_DELETE(_dispatcher);
      CC_SAFE_DELETE(_broadphase);
      CC_SAFE_DELETE(_ghostCallback);
      CC_SAFE_DELETE(_solver);
      CC_SAFE_DELETE(_btPhyiscsWorld);
      CC_SAFE_DELETE(_debugDrawer);
      for (auto it : _physicsComponents)
          it->setPhysics3DObject(nullptr);
      _physicsComponents.clear();
  }
  
  Physics3DWorld* Physics3DWorld::create(Physics3DWorldDes* info)
  {
      auto world = new (std::nothrow) Physics3DWorld();
      world->init(info);
      world->autorelease();
      return world;
  }
  
  void Physics3DWorld::setGravity(const Vec3& gravity)
  {
      _btPhyiscsWorld->setGravity(convertVec3TobtVector3(gravity));
  }
  
  Vec3 Physics3DWorld::getGravity() const
  {
      return convertbtVector3ToVec3(_btPhyiscsWorld->getGravity());
  }
  
  bool Physics3DWorld::init(Physics3DWorldDes* info)
  {
      ///collision configuration contains default setup for memory, collision setup
      _collisionConfiguration = new (std::nothrow) btDefaultCollisionConfiguration();
      //_collisionConfiguration->setConvexConvexMultipointIterations();
      
      ///use the default collision dispatcher. For parallel processing you can use a different dispatcher (see Extras/BulletMultiThreaded)
      _dispatcher = new (std::nothrow) btCollisionDispatcher(_collisionConfiguration);
      
      _broadphase = new (std::nothrow) btDbvtBroadphase();
      
      ///the default constraint solver. For parallel processing you can use a different solver (see Extras/BulletMultiThreaded)
      btSequentialImpulseConstraintSolver* sol = new btSequentialImpulseConstraintSolver();
      _solver = sol;
  
      btGhostPairCallback *ghostCallback = new btGhostPairCallback();
      _ghostCallback = ghostCallback;
      
      _btPhyiscsWorld = new btDiscreteDynamicsWorld(_dispatcher,_broadphase,_solver,_collisionConfiguration);
      _btPhyiscsWorld->setGravity(convertVec3TobtVector3(info->gravity));
      if (info->isDebugDrawEnabled)
      {
          _debugDrawer = new (std::nothrow) Physics3DDebugDrawer();
          _btPhyiscsWorld->setDebugDrawer(_debugDrawer);
      }
      
      return true;
  }
  
  void Physics3DWorld::setDebugDrawEnable(bool enableDebugDraw)
  {
      if (enableDebugDraw && _btPhyiscsWorld->getDebugDrawer() == nullptr)
      {
          _debugDrawer = new (std::nothrow) Physics3DDebugDrawer();
      }
      enableDebugDraw ? _btPhyiscsWorld->setDebugDrawer(_debugDrawer) : _btPhyiscsWorld->setDebugDrawer(nullptr);
  }
  
  bool Physics3DWorld::isDebugDrawEnabled() const
  {
      return _btPhyiscsWorld->getDebugDrawer() != nullptr;
  }
  
  void Physics3DWorld::addPhysics3DObject(Physics3DObject* physicsObj)
  {
      auto it = std::find(_objects.begin(), _objects.end(), physicsObj);
      if (it == _objects.end())
      {
          _objects.push_back(physicsObj);
          physicsObj->retain();
          if (physicsObj->getObjType() == Physics3DObject::PhysicsObjType::RIGID_BODY)
          {
              _btPhyiscsWorld->addRigidBody(static_cast<Physics3DRigidBody*>(physicsObj)->getRigidBody());
          }
          else if (physicsObj->getObjType() == Physics3DObject::PhysicsObjType::COLLIDER)
          {
              _btPhyiscsWorld->addCollisionObject(static_cast<Physics3DCollider*>(physicsObj)->getGhostObject());
          }
          _collisionCheckingFlag = true;
          _needGhostPairCallbackChecking = true;
      }
  }
  
  void Physics3DWorld::removePhysics3DObject(Physics3DObject* physicsObj)
  {
      auto it = std::find(_objects.begin(), _objects.end(), physicsObj);
      if (it != _objects.end())
      {
          if (physicsObj->getObjType() == Physics3DObject::PhysicsObjType::RIGID_BODY)
          {
              _btPhyiscsWorld->removeRigidBody(static_cast<Physics3DRigidBody*>(physicsObj)->getRigidBody());
          }
          else if (physicsObj->getObjType() == Physics3DObject::PhysicsObjType::COLLIDER)
          {
              _btPhyiscsWorld->removeCollisionObject(static_cast<Physics3DCollider*>(physicsObj)->getGhostObject());
          }
          physicsObj->release();
          _objects.erase(it);
          _collisionCheckingFlag = true;
          _needGhostPairCallbackChecking = true;
      }
  }
  
  void Physics3DWorld::removeAllPhysics3DObjects()
  {
      for (auto it : _objects) {
          if (it->getObjType() == Physics3DObject::PhysicsObjType::RIGID_BODY)
          {
              _btPhyiscsWorld->removeRigidBody(static_cast<Physics3DRigidBody*>(it)->getRigidBody());
          }
          else if (it->getObjType() == Physics3DObject::PhysicsObjType::COLLIDER)
          {
              _btPhyiscsWorld->removeCollisionObject(static_cast<Physics3DCollider*>(it)->getGhostObject());
          }
          it->release();
      }
      _objects.clear();
      _collisionCheckingFlag = true;
      _needGhostPairCallbackChecking = true;
  }
  
  void Physics3DWorld::addPhysics3DConstraint(Physics3DConstraint* constraint, bool disableCollisionsBetweenLinkedObjs)
  {
      auto body = constraint->getBodyA();
      if (body)
          body->addConstraint(constraint);
      
      body = constraint->getBodyB();
      if (body)
      {
          body->addConstraint(constraint);
      }
      _btPhyiscsWorld->addConstraint(constraint->getbtContraint(), disableCollisionsBetweenLinkedObjs);
  }
  
  void Physics3DWorld::removePhysics3DConstraint(Physics3DConstraint* constraint)
  {
      _btPhyiscsWorld->removeConstraint(constraint->getbtContraint());
      
      auto bodyA = constraint->getBodyA();
      auto bodyB = constraint->getBodyB();
      if (bodyA)
          bodyA->removeConstraint(constraint);
      if (bodyB)
          bodyB->removeConstraint(constraint);
  }
  
  void Physics3DWorld::removeAllPhysics3DConstraints()
  {
      for(auto it : _objects)
      {
          auto type = it->getObjType();
          if (type == Physics3DObject::PhysicsObjType::RIGID_BODY)
          {
              auto& constraints = static_cast<Physics3DRigidBody*>(it)->_constraintList;
              for (auto constraint : constraints) {
                  _btPhyiscsWorld->removeConstraint(constraint->getbtContraint());
                  constraint->release();
              }
              constraints.clear();
          }
      }
      
  }
  
  void Physics3DWorld::stepSimulate(float dt)
  {
      if (_btPhyiscsWorld)
      {
          setGhostPairCallback();
          //should sync kinematic node before simulation
          for (auto it : _physicsComponents)
          {
              it->preSimulate();
          }
          _btPhyiscsWorld->stepSimulation(dt, 3);
          //sync dynamic node after simulation
          for (auto it : _physicsComponents)
          {
              it->postSimulate();
          }
          if (needCollisionChecking())
              collisionChecking();
      }
  }
  
  void Physics3DWorld::debugDraw(Renderer* renderer)
  {
      if (_debugDrawer)
      {
          _debugDrawer->clear();
          _btPhyiscsWorld->debugDrawWorld();
          _debugDrawer->draw(renderer);
      }
  }
  
  bool Physics3DWorld::rayCast(const cocos2d::Vec3& startPos, const cocos2d::Vec3& endPos, Physics3DWorld::HitResult* result)
  {
      auto btStart = convertVec3TobtVector3(startPos);
      auto btEnd = convertVec3TobtVector3(endPos);
      btCollisionWorld::ClosestRayResultCallback btResult(btStart, btEnd);
      _btPhyiscsWorld->rayTest(btStart, btEnd, btResult);
      if (btResult.hasHit())
      {
          result->hitObj = getPhysicsObject(btResult.m_collisionObject);
          result->hitPosition = convertbtVector3ToVec3(btResult.m_hitPointWorld);
          result->hitNormal = convertbtVector3ToVec3(btResult.m_hitNormalWorld);
          return true;
      }
      result->hitObj = nullptr;
      return false;
  }
  
  bool Physics3DWorld::sweepShape(Physics3DShape* shape, const cocos2d::Mat4& startTransform, const cocos2d::Mat4& endTransform, Physics3DWorld::HitResult* result)
  {
      CC_ASSERT(shape->getShapeType() != Physics3DShape::ShapeType::HEIGHT_FIELD && shape->getShapeType() != Physics3DShape::ShapeType::MESH);
      auto btStart = convertMat4TobtTransform(startTransform);
      auto btEnd = convertMat4TobtTransform(endTransform);
      btCollisionWorld::ClosestConvexResultCallback btResult(btStart.getOrigin(), btEnd.getOrigin());
      _btPhyiscsWorld->convexSweepTest((btConvexShape*)shape->getbtShape(), btStart, btEnd, btResult);
      if (btResult.hasHit())
      {
          result->hitObj = getPhysicsObject(btResult.m_hitCollisionObject);
          result->hitPosition = convertbtVector3ToVec3(btResult.m_hitPointWorld);
          result->hitNormal = convertbtVector3ToVec3(btResult.m_hitNormalWorld);
          return true;
      }
      result->hitObj = nullptr;
      return false;
  }
  
  Physics3DObject* Physics3DWorld::getPhysicsObject(const btCollisionObject* btObj)
  {
      for(auto it : _objects)
      {
          if (it->getObjType() == Physics3DObject::PhysicsObjType::RIGID_BODY)
          {
              if (static_cast<Physics3DRigidBody*>(it)->getRigidBody() == btObj)
                  return it;
          }
          else if (it->getObjType() == Physics3DObject::PhysicsObjType::COLLIDER)
          {
              if (static_cast<Physics3DCollider*>(it)->getGhostObject() == btObj)
                  return it;
          }
      }
      return nullptr;
  }
  
  void Physics3DWorld::collisionChecking()
  {
      int numManifolds = _dispatcher->getNumManifolds();
      for (int i = 0; i < numManifolds; ++i){
          btPersistentManifold * contactManifold = _dispatcher->getManifoldByIndexInternal(i);
          int numContacts = contactManifold->getNumContacts();
          if (0 < numContacts){
              const btCollisionObject* obA = static_cast<const btCollisionObject*>(contactManifold->getBody0());
              const btCollisionObject* obB = static_cast<const btCollisionObject*>(contactManifold->getBody1());
              Physics3DObject *poA = getPhysicsObject(obA);
              Physics3DObject *poB = getPhysicsObject(obB);
              if (poA->needCollisionCallback() || poB->needCollisionCallback()){
                  Physics3DCollisionInfo ci;
                  ci.objA = poA;
                  ci.objB = poB;
                  for (int c = 0; c < numContacts; ++c){
                      btManifoldPoint& pt = contactManifold->getContactPoint(c);
                      Physics3DCollisionInfo::CollisionPoint cp = {
                            convertbtVector3ToVec3(pt.m_localPointA), convertbtVector3ToVec3(pt.m_positionWorldOnA)
                          , convertbtVector3ToVec3(pt.m_localPointB), convertbtVector3ToVec3(pt.m_positionWorldOnB)
                          , convertbtVector3ToVec3(pt.m_normalWorldOnB)
                      };
                      ci.collisionPointList.push_back(cp);
                  }
  
                  if (poA->needCollisionCallback()){
                      poA->getCollisionCallback()(ci);
                  }
                  if (poB->needCollisionCallback()){
                      poB->getCollisionCallback()(ci);
                  }
              }
          }
      }
  }
  
  bool Physics3DWorld::needCollisionChecking()
  {
      if (_collisionCheckingFlag){
          _needCollisionChecking = false;
          for(auto it : _objects)
          {
              if (it->getCollisionCallback() != nullptr){
                  _needCollisionChecking = true;
                  break;
              }
          }
          _collisionCheckingFlag = false;
      }
      return _needCollisionChecking;
  }
  
  void Physics3DWorld::setGhostPairCallback()
  {
      if (_needGhostPairCallbackChecking){
          bool needCallback = false;
          for (auto it : _objects)
          {
              if (it->getObjType() == Physics3DObject::PhysicsObjType::COLLIDER){
                  needCallback = true;
                  break;
              }
          }
          _btPhyiscsWorld->getPairCache()->setInternalGhostPairCallback(needCallback == true? _ghostCallback: nullptr);
          _needGhostPairCallbackChecking = false;
      }
  }
  
  NS_CC_END
  
  #endif // CC_ENABLE_BULLET_INTEGRATION
  
  #endif //CC_USE_3D_PHYSICS
  