Cocos2d-X3.0 刨根问底（五）----- Node类及显示对象列表源码分析

#include "ccMacros.h"
#include "CCAffineTransform.h"
#include "CCGL.h"
#include "ccGLStateCache.h"
#include "CCGLProgram.h"
#include "CCScriptSupport.h"
#include "CCProtocols.h"
#include "CCEventDispatcher.h"
#include "CCVector.h"
#include "kazmath/kazmath.h"

NS_CC_BEGIN

class GridBase;
class Point;
class Touch;
class Action;
class LabelProtocol;
class Scheduler;
class ActionManager;
class Component;
class ComponentContainer;
class EventDispatcher;
class Scene;
class Renderer;
#if CC_USE_PHYSICS
class PhysicsBody;
#endif

/**
 * @addtogroup base_nodes
 * @{
 */

enum {
    kNodeOnEnter,
    kNodeOnExit,
    kNodeOnEnterTransitionDidFinish,
    kNodeOnExitTransitionDidStart,
    kNodeOnCleanup
};

bool nodeComparisonLess(Node* n1, Node* n2);

class EventListener;

/**
     * Sets the rotation (X,Y,Z) in degrees.
     * Useful for 3d rotations
     */
    virtual void setRotation3D(const Vertex3F& rotation);
    /**
     * returns the rotation (X,Y,Z) in degrees.
     */
    virtual Vertex3F getRotation3D() const;

struct

.f) {}
    
    GLfloat x;
    GLfloat y;
    GLfloat z;
};

 /**
     * Sets the rotation (angle) of the node in degrees.
     *
     * 0 is the default rotation angle.
     * Positive values rotate node clockwise, and negative values for anti-clockwise.
     *
     * @param rotation     The rotation of the node in degrees.
     */
    virtual void setRotation(float rotation);
    /**
     * Returns the rotation of the node in degrees.
     *
     * @see `setRotation(float)`
     *
     * @return The rotation of the node in degrees.
     */
    virtual float getRotation() const;

/**
     * Sets the X rotation (angle) of the node in degrees which performs a horizontal rotational skew.
     *
     * The difference between `setRotationalSkew()` and `setSkew()` is that the first one simulate Flash‘s skew functionality
     * while the second one uses the real skew function.
     *
     * 0 is the default rotation angle.
     * Positive values rotate node clockwise, and negative values for anti-clockwise.
     *
     * @param rotationX    The X rotation in degrees which performs a horizontal rotational skew.
     */
    virtual void setRotationSkewX(float rotationX);
    CC_DEPRECATED_ATTRIBUTE virtual void setRotationX(float rotationX) { return setRotationSkewX(rotationX); }

    /**
     * Gets the X rotation (angle) of the node in degrees which performs a horizontal rotation skew.
     *
     * @see `setRotationSkewX(float)`
     *
     * @return The X rotation in degrees.
     */
    virtual float getRotationSkewX() const;
    CC_DEPRECATED_ATTRIBUTE virtual float getRotationX() const { return getRotationSkewX(); }

    /**
     * Sets the Y rotation (angle) of the node in degrees which performs a vertical rotational skew.
     *
     * The difference between `setRotationalSkew()` and `setSkew()` is that the first one simulate Flash‘s skew functionality
     * while the second one uses the real skew function.
     *
     * 0 is the default rotation angle.
     * Positive values rotate node clockwise, and negative values for anti-clockwise.
     *
     * @param rotationY    The Y rotation in degrees.
     */
    virtual void setRotationSkewY(float rotationY);
    CC_DEPRECATED_ATTRIBUTE virtual void setRotationY(float rotationY) { return setRotationSkewY(rotationY); }

    /**
     * Gets the Y rotation (angle) of the node in degrees which performs a vertical rotational skew.
     *
     * @see `setRotationSkewY(float)`
     *
     * @return The Y rotation in degrees.
     */
    virtual float getRotationSkewY() const;
    CC_DEPRECATED_ATTRIBUTE virtual float getRotationY() const { return getRotationSkewY(); }

void Node::setRotationSkewX(float rotationX)
{
    if (_rotationZ_X == rotationX)
        return;
    
    _rotationZ_X = rotationX;
    _transformUpdated = _transformDirty = _inverseDirty = true;
}

  // "cache" variables are allowed to be mutable
    mutable kmMat4 _transform;      ///< 变换矩阵
    mutable bool _transformDirty;   ///< 是否应该进行变换矩阵计算
    mutable kmMat4 _inverse;        ///< 倒转变换矩阵
    mutable bool _inverseDirty;     ///< 标记是否应该进行倒转计算
    mutable kmMat4 _additionalTransform; ///附加的变换矩阵
    bool _useAdditionalTransform;   ///< 使用附加变换
    bool _transformUpdated;         ///< 标记是否需要在场景更新的最后进行矩阵变换计算。

 /**
     * _scaleX的 get set 方法
     */
    virtual void setScaleX(float scaleX);
    virtual float getScaleX() const;


    /**
     * _scaleY的 get set 方法
     */
    virtual void setScaleY(float scaleY);
    virtual float getScaleY() const;

    /**
     * _scaleZ的get set 方法
     */
    virtual void setScaleZ(float scaleZ);
    virtual float getScaleZ() const;


    /**
     * 将_scaleX _scaleY  _scaleZ设置成相同值的 get set 方法
     */
    virtual void setScale(float scale);
    virtual float getScale() const;

class

const Point& Node::getAnchorPointInPoints() const
{
    return _anchorPointInPoints;
}

/// anchorPoint getter
const Point& Node::getAnchorPoint() const
{
    return _anchorPoint;
}

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;
        _anchorPointInPoints = Point(_contentSize.width * _anchorPoint.x, _contentSize.height * _anchorPoint.y );
        _transformUpdated = _transformDirty = _inverseDirty = true;
    }
}

class CC_DLL Size
{
public:
    float width;
    float height;

int _localZOrder;               ///< Local order (relative to its siblings) used to sort the node
    float _globalZOrder;            ///< Global order used to sort the node

    Vector<Node*> _children;        ///< array of children nodes
    Node *_parent;                  ///< weak reference to parent node

    int _tag;                         ///可以给当前的Node对象定义一个 int类型的标识
    
    std::string _name;               ///可以给当前Node对象起一个字符串类型的名称。

void Node::addChild(Node *child, int zOrder, int tag)
{    
    CCASSERT( child != nullptr, "Argument must be non-nil");
    CCASSERT( child->_parent == nullptr, "child already added. It can‘t be added again");

    if (_children.empty())
    {
        this->childrenAlloc();
    }

    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)
        {
            (dynamic_cast<Scene*>(node))->addChildToPhysicsWorld(child);
            break;
        }
    }
#endif

    child->_tag = tag;

    child->setParent(this);
    child->setOrderOfArrival(s_globalOrderOfArrival++);

    if( _running )
    {
        child->onEnter();
        // prevent onEnterTransitionDidFinish to be called twice when a node is added in onEnter
        if (_isTransitionFinished) {
            child->onEnterTransitionDidFinish();
        }
    }
    
    if (_cascadeColorEnabled)
    {
        updateCascadeColor();
    }
    
    if (_cascadeOpacityEnabled)
    {
        updateCascadeOpacity();
    }
}

void Node::insertChild(Node* child, int z)
{
    _reorderChildDirty = true;
    _children.pushBack(child);
    child->_setLocalZOrder(z);
}

void Node::sortAllChildren()
{
    if( _reorderChildDirty ) {
        std::sort( std::begin(_children), std::end(_children), nodeComparisonLess );
        _reorderChildDirty = false;
    }
}

void Node::setOrderOfArrival(int orderOfArrival)
{
    CCASSERT(orderOfArrival >=0, "Invalid orderOfArrival");
    _orderOfArrival = orderOfArrival;
}

int _orderOfArrival;            ///< used to preserve sequence while sorting children with the same localZOrder

// prevent onEnterTransitionDidFinish to be called twice when a node is added in onEnter
        if (_isTransitionFinished) {
            child->onEnterTransitionDidFinish();
        }

    if (_cascadeColorEnabled)
    {
        updateCascadeColor();
    }
    
    if (_cascadeOpacityEnabled)
    {
        updateCascadeOpacity();
    }

void Node::addChild(Node *child, int zOrder)
{
    CCASSERT( child != nullptr, "Argument must be non-nil");
    this->addChild(child, zOrder, child->_tag);
}

void Node::addChild(Node *child)
{
    CCASSERT( child != nullptr, "Argument must be non-nil");
    this->addChild(child, child->_localZOrder, child->_tag);
}

/**
     * 通过tag得到child指针     *
     * @param tag   An identifier to find the child node.
     *
     * @return a Node object whose tag equals to the input parameter
     */
    virtual Node * getChildByTag(int tag);
    /**
     * 返回_children的引用，与const引用     *
     * @return the array the node‘s children
     */
    virtual Vector<Node*>& getChildren() { return _children; }
    virtual const Vector<Node*>& getChildren() const { return _children; }
    
    /** 
     * 返回子结点的数量
     *
     * @return The amount of children.
     */
    virtual ssize_t getChildrenCount() const;

   /**
     * 将当前结点从它的父结点中清除，并且调用了clean方法做了清除，clean方法是什么后面我们有分析。.
     */
    virtual void removeFromParent();
    /** 同上面的removeFromParent方法，有一个参数可以指定是否调用 clean方法做清除
     */
    virtual void removeFromParentAndCleanup(bool cleanup);

    /**
     * 通过 child的指针来删除一个指定的结点
     */
    virtual void removeChild(Node* child, bool cleanup = true);

    /**
     * 通过tag值来删除一个子结点
     */
    virtual void removeChildByTag(int tag, bool cleanup = true);
    /**
     * 清除所有的子结点并且所有的子结点都会调用 cleanup 方法 
     */
    virtual void removeAllChildren();
    /**
     * 清除所有子结点，根据cleanup的参数设置来决定是否调用cleanup方法 (这里出现了多次cleanup这个函数后面我们重点分析一下源码）
     */
    virtual void removeAllChildrenWithCleanup(bool cleanup);

    /**

     * 这个函数干了几件事，

     * 1. 设置了_reorderChildDirty = true 设置当前结点的子结点进行排序

     * 2. 重新更新了child的 _orderOfArrival 值为最新的

     * 3. 设置 child的 _localZOrder值为 localZOrder 
     */
    virtual void reorderChild(Node * child, int localZOrder);

    /**
     * 根据 子结点的的 _localZOrder排列当前结点所有的child ,有了这个方法不用每加一个结点或者改变某个子结点的zOrder就排一次，这个排列方法要在结点显示到屏幕之前调用。

*/
    virtual void sortAllChildren();

    /**
     * tag的get set 方法 
     */
    virtual int getTag() const;
    virtual void setTag(int tag);

// XXX: Yes, nodes might have a sort problem once every 15 days if the game runs at 60 FPS and each frame sprites are reordered.
int Node::s_globalOrderOfArrival = 1;

void Node::cleanup()
{
    // actions
    this->stopAllActions();
    this->unscheduleAllSelectors();
    
#if CC_ENABLE_SCRIPT_BINDING
    if ( _scriptType != kScriptTypeNone)
    {
        int action = kNodeOnCleanup;
        BasicScriptData data(this,(void*)&action);
        ScriptEvent scriptEvent(kNodeEvent,(void*)&data);
        ScriptEngineManager::getInstance()->getScriptEngine()->sendEvent(&scriptEvent);
    }
#endif // #if CC_ENABLE_SCRIPT_BINDING
    
    // timers
    for( const auto &child: _children)
        child->cleanup();
}

    void *_userData;                ///< A user assingned void pointer, Can be point to any cpp object
    Ref *_userObject;               ///< A user assigned Object

    GLProgram *_shaderProgram;      ///< OpenGL shader 
    Scheduler *_scheduler;          ///< scheduler used to schedule timers and updates

    ActionManager *_actionManager;  ///< a pointer to ActionManager singleton, which is used to handle all the actions

    EventDispatcher* _eventDispatcher;  ///< event dispatcher used to dispatch all kinds of events

bool _visible;                  ///< is this node visible

// opacity controls
    GLubyte        _displayedOpacity;
    GLubyte     _realOpacity;
    Color3B        _displayedColor;
    Color3B     _realColor;

Node::Node(void)
: _rotationX(0.0f)
, _rotationY(0.0f)
, _rotationZ_X(0.0f)
, _rotationZ_Y(0.0f)
, _scaleX(1.0f)
, _scaleY(1.0f)
, _scaleZ(1.0f)
, _positionZ(0.0f)
, _position(Point::ZERO)
, _skewX(0.0f)
, _skewY(0.0f)
, _anchorPointInPoints(Point::ZERO)
, _anchorPoint(Point::ZERO)
, _contentSize(Size::ZERO)
, _useAdditionalTransform(false)
, _transformDirty(true)
, _inverseDirty(true)
, _transformUpdated(true)
// children (lazy allocs)
// lazy alloc
, _localZOrder(0)
, _globalZOrder(0)
, _parent(nullptr)
// "whole screen" objects. like Scenes and Layers, should set _ignoreAnchorPointForPosition to true
, _tag(Node::INVALID_TAG)
// userData is always inited as nil
, _userData(nullptr)
, _userObject(nullptr)
, _shaderProgram(nullptr)
, _orderOfArrival(0)
, _running(false)
, _visible(true)
, _ignoreAnchorPointForPosition(false)
, _reorderChildDirty(false)
, _isTransitionFinished(false)
#if CC_ENABLE_SCRIPT_BINDING
, _updateScriptHandler(0)
#endif
, _componentContainer(nullptr)
#if CC_USE_PHYSICS
, _physicsBody(nullptr)
#endif
, _displayedOpacity(255)
, _realOpacity(255)
, _displayedColor(Color3B::WHITE)
, _realColor(Color3B::WHITE)
, _cascadeColorEnabled(false)
, _cascadeOpacityEnabled(false)
{
    // set default scheduler and actionManager
    Director *director = Director::getInstance();
    _actionManager = director->getActionManager();
    _actionManager->retain();
    _scheduler = director->getScheduler();
    _scheduler->retain();
    _eventDispatcher = director->getEventDispatcher();
    _eventDispatcher->retain();
    
#if CC_ENABLE_SCRIPT_BINDING
    ScriptEngineProtocol* engine = ScriptEngineManager::getInstance()->getScriptEngine();
    _scriptType = engine != nullptr ? engine->getScriptType() : kScriptTypeNone;
#endif
    
    kmMat4Identity(&_transform);
    kmMat4Identity(&_inverse);
    kmMat4Identity(&_additionalTransform);
}

Node::~Node()
{
    CCLOGINFO( "deallocing Node: %p - tag: %i", this, _tag );
    
#if CC_ENABLE_SCRIPT_BINDING
    if (_updateScriptHandler)
    {
        ScriptEngineManager::getInstance()->getScriptEngine()->removeScriptHandler(_updateScriptHandler);
    }
#endif

    // User object has to be released before others, since userObject may have a weak reference of this node
    // It may invoke `node->stopAllAction();` while `_actionManager` is null if the next line is after `CC_SAFE_RELEASE_NULL(_actionManager)`.
    CC_SAFE_RELEASE_NULL(_userObject);
    
    // attributes
    CC_SAFE_RELEASE_NULL(_shaderProgram);

    for (auto& child : _children)
    {
        child->_parent = nullptr;
    }

    removeAllComponents();
    
    CC_SAFE_DELETE(_componentContainer);
    
#if CC_USE_PHYSICS
    setPhysicsBody(nullptr);

#endif
    
    CC_SAFE_RELEASE_NULL(_actionManager);
    CC_SAFE_RELEASE_NULL(_scheduler);
    
    _eventDispatcher->removeEventListenersForTarget(this);
    
#if CC_NODE_DEBUG_VERIFY_EVENT_LISTENERS && COCOS2D_DEBUG > 0
    _eventDispatcher->debugCheckNodeHasNoEventListenersOnDestruction(this);
#endif

    CCASSERT(!_running, "Node still marked as running on node destruction! Was base class onExit() called in derived class onExit() implementations?");
    CC_SAFE_RELEASE(_eventDispatcher);
}

private:
    CC_DISALLOW_COPY_AND_ASSIGN(Node);

Node * Node::create(void)
{
    Node * ret = new Node();
    if (ret && ret->init())
    {
        ret->autorelease();
    }
    else
    {
        CC_SAFE_DELETE(ret);
    }
    return ret;
}

virtual bool init();

bool Node::init()
{
    return true;
}

/**
     * Override this method to draw your own node.
     * The following GL states will be enabled by default:
     * - `glEnableClientState(GL_VERTEX_ARRAY);`
     * - `glEnableClientState(GL_COLOR_ARRAY);`
     * - `glEnableClientState(GL_TEXTURE_COORD_ARRAY);`
     * - `glEnable(GL_TEXTURE_2D);`
     * AND YOU SHOULD NOT DISABLE THEM AFTER DRAWING YOUR NODE
     * But if you enable any other GL state, you should disable it after drawing your node.
     */
    virtual void draw(Renderer *renderer, const kmMat4& transform, bool transformUpdated);
    virtual void draw() final;

/**
     * Visits this node‘s children and draw them recursively.
     */
    virtual void visit(Renderer *renderer, const kmMat4& parentTransform, bool parentTransformUpdated);
    virtual void visit() final;

void Node::visit(Renderer* renderer, const kmMat4 &parentTransform, bool parentTransformUpdated)
{
    // quick return if not visible. children won‘t be drawn.
    if (!_visible)
    {
        return;
    }

    bool dirty = _transformUpdated || parentTransformUpdated;
    if(dirty)
        _modelViewTransform = this->transform(parentTransform);
    _transformUpdated = false;


    // IMPORTANT:
    // To ease the migration to v3.0, we still support the kmGL stack,
    // but it is deprecated and your code should not rely on it
    kmGLPushMatrix();
    kmGLLoadMatrix(&_modelViewTransform);

    int i = 0;

    if(!_children.empty())
    {
        sortAllChildren();
        // draw children zOrder < 0
        for( ; i < _children.size(); i++ )
        {
            auto node = _children.at(i);

            if ( node && node->_localZOrder < 0 )
                node->visit(renderer, _modelViewTransform, dirty);
            else
                break;
        }
        // self draw
        this->draw(renderer, _modelViewTransform, dirty);

        for(auto it=_children.cbegin()+i; it != _children.cend(); ++it)
            (*it)->visit(renderer, _modelViewTransform, dirty);
    }
    else
    {
        this->draw(renderer, _modelViewTransform, dirty);
    }

    // reset for next frame
    _orderOfArrival = 0;
 
    kmGLPopMatrix();
}

void Node::resume()
{
    _scheduler->resumeTarget(this);
    _actionManager->resumeTarget(this);
    _eventDispatcher->resumeEventListenersForTarget(this);
}

void Node::pause()
{
    _scheduler->pauseTarget(this);
    _actionManager->pauseTarget(this);
    _eventDispatcher->pauseEventListenersForTarget(this);
}

class CC_DLL __NodeRGBA : public Node, public __RGBAProtocol
{
public:
    // overrides
    virtual GLubyte getOpacity() const override { return Node::getOpacity(); }
    virtual GLubyte getDisplayedOpacity() const  override { return Node::getDisplayedOpacity(); }
    virtual void setOpacity(GLubyte opacity) override { return Node::setOpacity(opacity); }
    virtual void updateDisplayedOpacity(GLubyte parentOpacity) override { return Node::updateDisplayedOpacity(parentOpacity); }
    virtual bool isCascadeOpacityEnabled() const  override { return Node::isCascadeOpacityEnabled(); }
    virtual void setCascadeOpacityEnabled(bool cascadeOpacityEnabled) override { return Node::setCascadeOpacityEnabled(cascadeOpacityEnabled); }

    virtual const Color3B& getColor(void) const override { return Node::getColor(); }
    virtual const Color3B& getDisplayedColor() const override { return Node::getDisplayedColor(); }
    virtual void setColor(const Color3B& color) override { return Node::setColor(color); }
    virtual void updateDisplayedColor(const Color3B& parentColor) override { return Node::updateDisplayedColor(parentColor); }
    virtual bool isCascadeColorEnabled() const override { return Node::isCascadeColorEnabled(); }
    virtual void setCascadeColorEnabled(bool cascadeColorEnabled) override { return Node::setCascadeColorEnabled(cascadeColorEnabled); }

    virtual void setOpacityModifyRGB(bool bValue) override { return Node::setOpacityModifyRGB(bValue); }
    virtual bool isOpacityModifyRGB() const override { return Node::isOpacityModifyRGB(); }

protected:
    __NodeRGBA();
    virtual ~__NodeRGBA() {}

private:
    CC_DISALLOW_COPY_AND_ASSIGN(__NodeRGBA);
};