issue #4150: Correct body position with the node has a parent. Add set/getPosition/Rotation method.

cocos/2d/CCNode.cpp

@@ -419,7 +419,9 @@ void Node::setPosition(const Point& position)
 #if CC_USE_PHYSICS
     if (_physicsBody)
     {
-        _physicsBody->setPosition(position);
+        Node* parent = getParent();
+        Point pos = parent != nullptr ? parent->convertToWorldSpace(getPosition()) : getPosition();
+        _physicsBody->setPosition(pos);
     }
 #endif
 }
@@ -534,6 +536,14 @@ const Point& Node::getAnchorPoint() const
 
 void Node::setAnchorPoint(const Point& point)
 {
+#if CC_USE_PHYSICS
+    if (_physicsBody != nullptr && point.equals(Point::ANCHOR_MIDDLE))
+    {
+        CCLOG("Node warning: This node has a physics body, the anchor must be in the middle, you cann't change this to other value.");
+        return;
+    }
+#endif
+    
     if( ! point.equals(_anchorPoint))
     {
         _anchorPoint = point;
@@ -719,6 +729,11 @@ void Node::addChild(Node *child, int zOrder, int tag)
     this->insertChild(child, zOrder);
     
 #if CC_USE_PHYSICS
+    if (child->getPhysicsBody() != nullptr)
+    {
+        child->getPhysicsBody()->setPosition(this->convertToWorldSpace(child->getPosition()));
+    }
+    
     for (Node* node = this->getParent(); node != nullptr; node = node->getParent())
     {
         if (dynamic_cast<Scene*>(node) != nullptr)
@@ -1511,6 +1526,14 @@ void Node::setPhysicsBody(PhysicsBody* body)
     {
         body->_node = this;
         body->retain();
+        
+        // physics rotation based on body position, but node rotation based on node anthor point
+        // it cann't support both of them, so I clear the anthor point to default.
+        if (!getAnchorPoint().equals(Point::ANCHOR_MIDDLE))
+        {
+            CCLOG("Node warning: setPhysicsBody sets anchor point to Point::ANCHOR_MIDDLE.");
+            setAnchorPoint(Point::ANCHOR_MIDDLE);
+        }
     }
     
     if (_physicsBody != nullptr)
@@ -1529,7 +1552,9 @@ void Node::setPhysicsBody(PhysicsBody* body)
     _physicsBody = body;
     if (body != nullptr)
     {
-        _physicsBody->setPosition(getPosition());
+        Node* parent = getParent();
+        Point pos = parent != nullptr ? parent->convertToWorldSpace(getPosition()) : getPosition();
+        _physicsBody->setPosition(pos);
         _physicsBody->setRotation(getRotation());
     }
 }

cocos/2d/CCNode.h

@@ -449,6 +449,7 @@ public:
      * The anchorPoint is normalized, like a percentage. (0,0) means the bottom-left corner and (1,1) means the top-right corner.
      * But you can use values higher than (1,1) and lower than (0,0) too.
      * The default anchorPoint is (0.5,0.5), so it starts in the center of the node.
+     * @note If node has a physics body, the anchor must be in the middle, you cann't change this to other value.
      *
      * @param anchorPoint   The anchor point of node.
      */
@@ -1432,6 +1433,7 @@ public:
 #if CC_USE_PHYSICS
     /**
      *   set the PhysicsBody that let the sprite effect with physics
+     * @note This method will set anchor point to Point::ANCHOR_MIDDLE if body not null, and you cann't change anchor point if node has a physics body.
      */
     void setPhysicsBody(PhysicsBody* body);
 

cocos/physics/CCPhysicsBody.cpp

@@ -75,6 +75,7 @@ PhysicsBody::PhysicsBody()
 , _group(0)
 , _positionResetTag(false)
 , _rotationResetTag(false)
+, _rotationOffset(0)
 {
 }
 
@@ -347,7 +348,7 @@ void PhysicsBody::setPosition(Point position)
 {
     if (!_positionResetTag)
     {
-        cpBodySetPos(_info->getBody(), PhysicsHelper::point2cpv(position));
+        cpBodySetPos(_info->getBody(), PhysicsHelper::point2cpv(position + _positionOffset));
     }
     _positionResetTag = false;
 }
@@ -356,7 +357,7 @@ void PhysicsBody::setRotation(float rotation)
 {
     if (!_rotationResetTag)
     {
-        cpBodySetAngle(_info->getBody(), -PhysicsHelper::float2cpfloat(rotation * M_PI / 180.0f));
+        cpBodySetAngle(_info->getBody(), -PhysicsHelper::float2cpfloat((rotation + _rotationOffset) * (M_PI / 180.0f)));
     }
     
     _rotationResetTag = false;
@@ -365,12 +366,12 @@ void PhysicsBody::setRotation(float rotation)
 Point PhysicsBody::getPosition() const
 {
     cpVect vec = cpBodyGetPos(_info->getBody());
-    return PhysicsHelper::cpv2point(vec);
+    return PhysicsHelper::cpv2point(vec) - _positionOffset;
 }
 
 float PhysicsBody::getRotation() const
 {
-    return -PhysicsHelper::cpfloat2float(cpBodyGetAngle(_info->getBody()) / M_PI * 180.0f);
+    return -PhysicsHelper::cpfloat2float(cpBodyGetAngle(_info->getBody()) * (180.0f / M_PI)) - _rotationOffset;
 }
 
 PhysicsShape* PhysicsBody::addShape(PhysicsShape* shape, bool addMassAndMoment/* = true*/)
@@ -767,27 +768,18 @@ void PhysicsBody::setResting(bool rest) const
 
 void PhysicsBody::update(float delta)
 {
-    if (_node != nullptr && _dynamic && !isResting())
+    if (_node != nullptr)
     {
-        cpVect pos = cpBodyGetPos(_info->getBody());
+        Node* parent = _node->getParent();
-        cpVect prePos = _info->getPosition();
-        cpVect rot = cpBodyGetRot(_info->getBody());
-        cpVect preRot = _info->getRotation();
         
-        // only reset the node position when body position/rotation changed.
+        Point position = parent != nullptr ? parent->convertToNodeSpace(getPosition()) : getPosition();
-        if (std::abs(pos.x - prePos.x) >= 0.3f || std::abs(pos.y - prePos.y) >= 0.3f
+        _positionResetTag = true;
-            || std::abs(rot.x - preRot.x) >= 0.01f || std::abs(rot.y - preRot.y) >= 0.01f)
+        _rotationResetTag = true;
-        {
+        _node->setPosition(position);
-            _positionResetTag = true;
+        _node->setRotation(getRotation());
-            _rotationResetTag = true;
-            _node->setPosition(getPosition());
-            _info->setPosition(pos);
-            _node->setRotation(getRotation());
-            _info->setRotation(rot);
-        }
         
         // damping compute
-        if (_isDamping)
+        if (_isDamping && _dynamic && !isResting())
         {
             _info->getBody()->v.x *= cpfclamp(1.0f - delta * _linearDamping, 0.0f, 1.0f);
             _info->getBody()->v.y *= cpfclamp(1.0f - delta * _linearDamping, 0.0f, 1.0f);
@@ -834,6 +826,46 @@ void PhysicsBody::setGroup(int group)
     }
 }
 
+void PhysicsBody::setPositionOffset(const Point& position)
+{
+    if (!_positionOffset.equals(position))
+    {
+        Point pos = getPosition();
+        
+        _positionOffset = position;
+        
+        if (_node!= nullptr)
+        {
+            setPosition(pos);
+        }
+    }
+}
+
+Point PhysicsBody::getPositionOffset()
+{
+    return _positionOffset;
+}
+
+void PhysicsBody::setRotationOffset(float rotation)
+{
+    if (std::abs(_rotationOffset - rotation) > 0.5f)
+    {
+        float rot = getRotation();
+        
+        _rotationOffset = rotation;
+        
+        if (_node != nullptr)
+        {
+            setRotation(rot);
+        }
+    }
+}
+
+float PhysicsBody::getRotationOffset()
+{
+    return _rotationOffset;
+}
+
 Point PhysicsBody::world2Local(const Point& point)
 {
     return PhysicsHelper::cpv2point(cpBodyWorld2Local(_info->getBody(), PhysicsHelper::point2cpv(point)));

cocos/physics/CCPhysicsBody.h

@@ -192,6 +192,15 @@ public:
     /** get the body rotation. */
     float getRotation() const;
     
+    /** set body position offset, it's the position witch relative to node */
+    void setPositionOffset(const Point& position);
+    /** get body position offset. */
+    Point getPositionOffset();
+    /** set body rotation offset, it's the rotation witch relative to node */
+    void setRotationOffset(float rotation);
+    /** set the body rotation offset */
+    float getRotationOffset();
+    
     /**
      * @brief test the body is dynamic or not.
      * a dynamic body will effect with gravity.
@@ -332,6 +341,8 @@ protected:
     
     bool _positionResetTag;     /// To avoid reset the body position when body invoke Node::setPosition().
     bool _rotationResetTag;     /// To avoid reset the body rotation when body invoke Node::setRotation().
+    Point _positionOffset;
+    float _rotationOffset;
     
     friend class PhysicsWorld;
     friend class PhysicsShape;