cocos2dx封装一个具有Layout功能的Point类 (提供源码)

(原创文章，转载请注明原文出处：http://blog.csdn.net/while0/article/details/79032004）

基于cocos2dx开发游戏，免不了设置节点或精灵的位置，这些位置坐标常常不是一个绝对坐标值，而是相对于其它节点的相对坐标。例如：精灵A与精灵B左对齐，精灵A与精灵B中心对齐等等。

计算这些相对坐标值，每次都需要进行计算，计算时要考虑到精灵的anchorPoint,scale等，比较繁琐，一不留神就搞错了，调试来调试去浪费时间。本文封装了一个很方便的工具类，帮助你计算这些相对坐标。

直接上源码:

GmbsPoint.h (无cpp文件）

#ifndef __GMBSPOINT_H__
#define __GMBSPOINT_H__

#include "cocos2d.h"
#include "GmbsGrid.h"

NS_CC_BEGIN

class GmbsPoint : public Point
{
public:
    Node *m_targetNode;

    GmbsPoint(Node* targetNode = NULL)
    {
        m_targetNode = targetNode;
        if (targetNode)
        {
            Point pt = targetNode->getPosition();
            x = pt.x;
            y = pt.y;
        }
    }

    GmbsPoint(Node* targetNode,float xx,float yy)
    {
        m_targetNode = targetNode;
        x = xx;
        y = yy;
    }

    GmbsPoint& reset(Node* targetNode,float xx = 0,float yy = 0)
    {
        m_targetNode = targetNode;
        x = xx;
        y = yy;
        return *this;
    }

public:
    GmbsPoint& leftAlign(Node* baseNode,float leftPadding = 0)
    {
        Point baseAnchorPoint(0,0);
        Point basePoint = baseNode->getPosition();
        Node* baseParent = baseNode->getParent();
        if (baseParent != NULL)
            basePoint = baseParent->convertToWorldSpace(basePoint);
        if (!baseNode->isIgnoreAnchorPointForPosition())
            baseAnchorPoint = baseNode->getAnchorPoint();
        basePoint.x -= baseNode->getContentSize().width * baseAnchorPoint.x * getScaleX(baseNode);

        Point point(basePoint.x + leftPadding,basePoint.y);
        Point anchorPoint(0,0);
        if (!m_targetNode->isIgnoreAnchorPointForPosition())
            anchorPoint = m_targetNode->getAnchorPoint();
        point.x += m_targetNode->getContentSize().width * anchorPoint.x * getScaleX(m_targetNode);
        point = m_targetNode->getParent()->convertToNodeSpace(point);
        x = point.x;
        return *this;
    }

    GmbsPoint& leftAlign(GmbsGrid& baseGrid,float leftPadding = 0)
    {
        return leftAlign(baseGrid.m_ownerNode,leftPadding + baseGrid.origin.x);
    }

    GmbsPoint& rightAlign(Node* baseNode,float rightPadding = 0)
    {
        Point baseAnchorPoint(0,0);
        Point basePoint = baseNode->getPosition();
        Node* baseParent = baseNode->getParent();
        if (baseParent != NULL)
            basePoint = baseParent->convertToWorldSpace(basePoint);
        if (!baseNode->isIgnoreAnchorPointForPosition())
            baseAnchorPoint = baseNode->getAnchorPoint();
        basePoint.x += baseNode->getContentSize().width * (1 - baseAnchorPoint.x) * getScaleX(baseNode);

        Point point(basePoint.x - rightPadding,0);
        if (!m_targetNode->isIgnoreAnchorPointForPosition())
            anchorPoint = m_targetNode->getAnchorPoint();
        point.x -= m_targetNode->getContentSize().width * (1 - anchorPoint.x) * getScaleX(m_targetNode);
        point = m_targetNode->getParent()->convertToNodeSpace(point);
        x = point.x;
        return *this;
    }

    GmbsPoint& rightAlign(GmbsGrid& baseGrid,float rightPadding = 0)
    {
        Node* baseNode = baseGrid.m_ownerNode;
        Point baseAnchorPoint(0,0);
        Point basePoint = baseNode->getPosition();
        Node* baseParent = baseNode->getParent();
        if (baseParent != NULL)
            basePoint = baseParent->convertToWorldSpace(basePoint);
        if (!baseNode->isIgnoreAnchorPointForPosition())
            baseAnchorPoint = baseNode->getAnchorPoint();
        basePoint.x += baseGrid.origin.x + baseGrid.size.width - baseNode->getContentSize().width * baseAnchorPoint.x * getScaleX(baseNode);

        Point point(basePoint.x - rightPadding,0);
        if (!m_targetNode->isIgnoreAnchorPointForPosition())
            anchorPoint = m_targetNode->getAnchorPoint();
        point.x -= m_targetNode->getContentSize().width * (1 - anchorPoint.x) * getScaleX(m_targetNode);
        point = m_targetNode->getParent()->convertToNodeSpace(point);
        x = point.x;
        return *this;
    }

    GmbsPoint& topAlign(Node* baseNode,float topPadding = 0)
    {
        Point baseAnchorPoint(0,0);
        Point basePoint = baseNode->getPosition();
        Node* baseParent = baseNode->getParent();
        if (baseParent != NULL)
            basePoint = baseParent->convertToWorldSpace(basePoint);
        if (!baseNode->isIgnoreAnchorPointForPosition())
            baseAnchorPoint = baseNode->getAnchorPoint();
        basePoint.y += baseNode->getContentSize().height * (1 - baseAnchorPoint.y) * getScaleY(baseNode);

        Point point(basePoint.x,basePoint.y - topPadding);
        Point anchorPoint(0,0);
        if (!m_targetNode->isIgnoreAnchorPointForPosition())
            anchorPoint = m_targetNode->getAnchorPoint();
        point.y -= m_targetNode->getContentSize().height * (1 - anchorPoint.y) * getScaleY(m_targetNode);
        point = m_targetNode->getParent()->convertToNodeSpace(point);
        y = point.y;
        return *this;
    }

    GmbsPoint& topAlign(GmbsGrid& baseGrid,float topPadding = 0)
    {
        Node* baseNode = baseGrid.m_ownerNode;
        Point baseAnchorPoint(0,0);
        Point basePoint = baseNode->getPosition();
        Node* baseParent = baseNode->getParent();
        if (baseParent != NULL)
            basePoint = baseParent->convertToWorldSpace(basePoint);
        if (!baseNode->isIgnoreAnchorPointForPosition())
            baseAnchorPoint = baseNode->getAnchorPoint();
        basePoint.y += baseGrid.origin.y + baseGrid.size.height - baseNode->getContentSize().height * baseAnchorPoint.y * getScaleY(baseNode);

        Point point(basePoint.x,0);
        if (!m_targetNode->isIgnoreAnchorPointForPosition())
            anchorPoint = m_targetNode->getAnchorPoint();
        point.y -= m_targetNode->getContentSize().height * (1 - anchorPoint.y) * getScaleY(m_targetNode);
        point = m_targetNode->getParent()->convertToNodeSpace(point);
        y = point.y;
        return *this;
    }

    GmbsPoint& bottomAlign(Node* baseNode,float bottomPadding = 0)
    {
        Point baseAnchorPoint(0,0);
        Point basePoint = baseNode->getPosition();
        Node* baseParent = baseNode->getParent();
        if (baseParent != NULL)
            basePoint = baseParent->convertToWorldSpace(basePoint);
        if (!baseNode->isIgnoreAnchorPointForPosition())
            baseAnchorPoint = baseNode->getAnchorPoint();
        basePoint.y -= baseNode->getContentSize().height * baseAnchorPoint.y * getScaleY(baseNode);

        Point point(basePoint.x,basePoint.y + bottomPadding);
        Point anchorPoint(0,0);
        if (!m_targetNode->isIgnoreAnchorPointForPosition())
            anchorPoint = m_targetNode->getAnchorPoint();
        point.y += m_targetNode->getContentSize().height * anchorPoint.y * getScaleY(m_targetNode);
        point = m_targetNode->getParent()->convertToNodeSpace(point);
        y = point.y;
        return *this;
    }

    GmbsPoint& bottomAlign(GmbsGrid& baseGrid,float bottomPadding = 0)
    {
        return bottomAlign(baseGrid.m_ownerNode,bottomPadding + baseGrid.origin.y);
    }

    GmbsPoint& xMiddleAlign(Node* baseNode,float padding = 0)
    {
        Point baseAnchorPoint(0,0);
        Point basePoint = baseNode->getPosition();
        Node* baseParent = baseNode->getParent();
        if (baseParent != NULL)
            basePoint = baseParent->convertToWorldSpace(basePoint);
        if (!baseNode->isIgnoreAnchorPointForPosition())
            baseAnchorPoint = baseNode->getAnchorPoint();
        basePoint.x += baseNode->getContentSize().width * (0.5 - baseAnchorPoint.x) * getScaleX(baseNode);

        Point point(basePoint.x + padding,0);
        if (!m_targetNode->isIgnoreAnchorPointForPosition())
            anchorPoint = m_targetNode->getAnchorPoint();
        point.x -= m_targetNode->getContentSize().width * (0.5 - anchorPoint.x) * getScaleX(m_targetNode);
        point = m_targetNode->getParent()->convertToNodeSpace(point);
        x = point.x;
        return *this;
    }

    GmbsPoint& xMiddleAlign(GmbsGrid& baseGrid,float padding = 0)
    {
        Node* baseNode = baseGrid.m_ownerNode;
        Point baseAnchorPoint(0,0);
        Point basePoint = baseNode->getPosition();
        Node* baseParent = baseNode->getParent();
        if (baseParent != NULL)
            basePoint = baseParent->convertToWorldSpace(basePoint);
        if (!baseNode->isIgnoreAnchorPointForPosition())
            baseAnchorPoint = baseNode->getAnchorPoint();
        basePoint.x += baseGrid.origin.x + baseGrid.size.width/2 - baseNode->getContentSize().width * baseAnchorPoint.x * getScaleX(baseNode);
        
        Point point(basePoint.x + padding,0);
        if (!m_targetNode->isIgnoreAnchorPointForPosition())
            anchorPoint = m_targetNode->getAnchorPoint();
        point.x -= m_targetNode->getContentSize().width * (0.5 - anchorPoint.x) * getScaleX(m_targetNode);
        point = m_targetNode->getParent()->convertToNodeSpace(point);
        x = point.x;
        return *this;
    }

    GmbsPoint& yMiddleAlign(Node* baseNode,0);
        Point basePoint = baseNode->getPosition();
        Node* baseParent = baseNode->getParent();
        if (baseParent != NULL)
            basePoint = baseParent->convertToWorldSpace(basePoint);
        if (!baseNode->isIgnoreAnchorPointForPosition())
            baseAnchorPoint = baseNode->getAnchorPoint();
        basePoint.y += baseNode->getContentSize().height * (0.5 - baseAnchorPoint.y) * getScaleY(baseNode);

        Point point(basePoint.x,basePoint.y + padding);
        Point anchorPoint(0,0);
        if (!m_targetNode->isIgnoreAnchorPointForPosition())
            anchorPoint = m_targetNode->getAnchorPoint();
        point.y -= m_targetNode->getContentSize().height * (0.5 - anchorPoint.y) * getScaleY(m_targetNode);
        point = m_targetNode->getParent()->convertToNodeSpace(point);
        y = point.y;
        return *this;
    }

    GmbsPoint& yMiddleAlign(GmbsGrid& baseGrid,0);
        Point basePoint = baseNode->getPosition();
        Node* baseParent = baseNode->getParent();
        if (baseParent != NULL)
            basePoint = baseParent->convertToWorldSpace(basePoint);
        if (!baseNode->isIgnoreAnchorPointForPosition())
            baseAnchorPoint = baseNode->getAnchorPoint();
        basePoint.y += baseGrid.origin.y + baseGrid.size.height/2 - baseNode->getContentSize().height * baseAnchorPoint.y * getScaleY(baseNode);

        Point point(basePoint.x,0);
        if (!m_targetNode->isIgnoreAnchorPointForPosition())
            anchorPoint = m_targetNode->getAnchorPoint();
        point.y -= m_targetNode->getContentSize().height * (0.5 - anchorPoint.y) * getScaleY(m_targetNode);
        point = m_targetNode->getParent()->convertToNodeSpace(point);
        y = point.y;
        return *this;
    }

    GmbsPoint& rightTo(Node* baseNode,0);
        Point basePoint = baseNode->getPosition();
        Node* baseParent = baseNode->getParent();
        if (baseParent != NULL)
            basePoint = baseParent->convertToWorldSpace(basePoint);
        if (!baseNode->isIgnoreAnchorPointForPosition())
            baseAnchorPoint = baseNode->getAnchorPoint();
        basePoint.x -= baseNode->getContentSize().width * baseAnchorPoint.x * getScaleX(baseNode);

        Point point(basePoint.x - rightPadding,0);
        if (!m_targetNode->isIgnoreAnchorPointForPosition())
            anchorPoint = m_targetNode->getAnchorPoint();
        point.x -= m_targetNode->getContentSize().width * (1 - anchorPoint.x) * getScaleX(m_targetNode);;
        point = m_targetNode->getParent()->convertToNodeSpace(point);
        x = point.x;
        return *this;
    }

    GmbsPoint& leftTo(Node* baseNode,0);
        Point basePoint = baseNode->getPosition();
        Node* baseParent = baseNode->getParent();
        if (baseParent != NULL)
            basePoint = baseParent->convertToWorldSpace(basePoint);
        if (!baseNode->isIgnoreAnchorPointForPosition())
            baseAnchorPoint = baseNode->getAnchorPoint();
        basePoint.x += baseNode->getContentSize().width * (1 - baseAnchorPoint.x) * getScaleX(baseNode);

        Point point(basePoint.x + leftPadding,0);
        if (!m_targetNode->isIgnoreAnchorPointForPosition())
            anchorPoint = m_targetNode->getAnchorPoint();
        point.x += m_targetNode->getContentSize().width * anchorPoint.x * getScaleX(m_targetNode);;
        point = m_targetNode->getParent()->convertToNodeSpace(point);
        x = point.x;
        return *this;
    }

    GmbsPoint& bottomTo(Node* baseNode,0);
        if (!m_targetNode->isIgnoreAnchorPointForPosition())
            anchorPoint = m_targetNode->getAnchorPoint();
        point.y += m_targetNode->getContentSize().height * anchorPoint.y * getScaleY(m_targetNode);;
        point = m_targetNode->getParent()->convertToNodeSpace(point);
        y = point.y;
        return *this;
    }

    GmbsPoint& topTo(Node* baseNode,0);
        Point basePoint = baseNode->getPosition();
        Node* baseParent = baseNode->getParent();
        if (baseParent != NULL)
            basePoint = baseParent->convertToWorldSpace(basePoint);
        if (!baseNode->isIgnoreAnchorPointForPosition())
            baseAnchorPoint = baseNode->getAnchorPoint();
        basePoint.y -= baseNode->getContentSize().height * baseAnchorPoint.y * getScaleY(baseNode);;

        Point point(basePoint.x,0);
        if (!m_targetNode->isIgnoreAnchorPointForPosition())
            anchorPoint = m_targetNode->getAnchorPoint();
        point.y -= m_targetNode->getContentSize().height * (1 - anchorPoint.y) * getScaleY(m_targetNode);;;
        point = m_targetNode->getParent()->convertToNodeSpace(point);
        y = point.y;
        return *this;
    }

    static float getScaleX(Node* node)
    {
        float scale = node->getScaleX();
        Node* parent = node->getParent();
        while (parent != NULL)
        {
            scale *= parent->getScaleX();
            parent = parent->getParent();
        }
        return scale;
    }

    static float getScaleY(Node* node)
    {
        float scale = node->getScaleY();
        Node* parent = node->getParent();
        while (parent != NULL)
        {
            scale *= parent->getScaleY();
            parent = parent->getParent();
        }
        return scale;
    }
};

NS_CC_END

#endif

#ifndef __GMBSGRID_H__
#define __GMBSGRID_H__

#include "cocos2d.h"

NS_CC_BEGIN

class GmbsGrid : public Rect
{
protected:
    int m_xNum;
    int m_yNum;
    GmbsGrid** m_children;

public:
    Node *m_ownerNode;

    GmbsGrid(Node* ownerNode,int xNum,int yNum)
    {
        m_ownerNode = ownerNode;
    	origin = Point(0,0);
    	size = ownerNode->getContentSize();
    	m_xNum = xNum;
    	m_yNum = yNum;
    	m_children = (GmbsGrid**)malloc(xNum*yNum*sizeof(GmbsGrid*));
    	memset(m_children,xNum*yNum*sizeof(GmbsGrid*));
    }

    GmbsGrid(Node* ownerNode,Rect& rect,int yNum)
    {
    	m_ownerNode = ownerNode;
    	origin = rect.origin;
    	size = rect.size;
    	m_xNum = xNum;
    	m_yNum = yNum;
    	m_children = (GmbsGrid**)malloc(xNum*yNum*sizeof(GmbsGrid*));
    	memset(m_children,xNum*yNum*sizeof(GmbsGrid*));
    }

    GmbsGrid(Rect& rect,int yNum)
    {
    	m_ownerNode = NULL;
    	origin = rect.origin;
    	size = rect.size;
    	m_xNum = xNum;
    	m_yNum = yNum;
    	m_children = (GmbsGrid**)malloc(xNum*yNum*sizeof(GmbsGrid*));
    	memset(m_children,xNum*yNum*sizeof(GmbsGrid*));
    }

    virtual ~GmbsGrid()
    {
    	release();
    }

    void release()
    {
		for (int j = 0; j < m_yNum; j++)
		{
			for (int i = 0; i < m_xNum; i++)
			{
				if (m_children[j*m_xNum + i] != NULL)
				{
				    delete m_children[j*m_xNum + i];
				    m_children[j*m_xNum + i] = NULL;
				}
			}
		}
	}

    GmbsGrid& child(int x,int y)
    {
    	if (m_children[y*m_xNum + x] == NULL)
    	{
    		Rect rect;
    		rect.size.setSize(size.width/m_xNum,size.height/m_yNum);
    		rect.origin.setPoint(origin.x + rect.size.width*x,origin.y + rect.size.height*y);
    		m_children[y*m_xNum + x] = new GmbsGrid(m_ownerNode,rect,1,1);
    	}
    	return *m_children[y*m_xNum + x];
    }

    //counting from up to down
    GmbsGrid& childUtd(int x,int y)
    {
        int yNew = m_yNum - 1 - y;
    	if (m_children[yNew*m_xNum + x] == NULL)
    	{
    		Rect rect;
    		rect.size.setSize(size.width/m_xNum,origin.y + rect.size.height*yNew);
    		m_children[yNew*m_xNum + x] = new GmbsGrid(m_ownerNode,1);
    	}
    	return *m_children[yNew*m_xNum + x];
    }

    void setOwnerNode(Node* ownerNode)
    {
    	m_ownerNode = ownerNode;
    }
};

NS_CC_END

#endif

1) spriteA与spriteB中心对齐：

GmbsPoint pt(spriteA);
pt.xMiddleAlign(spriteB).yMiddleAlign(spriteB);
spriteA->setPosition(pt);

2) spriteA与spriteB左对齐且底对齐：

GmbsPoint pt(spriteA);  
pt.leftAlign(spriteB).bottomAlign(spriteB);  
spriteA->setPosition(pt);

3) spriteA在spriteB左侧，且相距间隔为10，它们底部对齐：

GmbsPoint pt(spriteA);  
pt.leftTo(spriteB,10).bottomAlign(spriteB);  
spriteA->setPosition(pt);