10.cocos2d坐标系

一、笛卡儿坐标系

　　OpenGl坐标系为笛卡儿右手系。x向右，y向上，z向外。在cocos2d-lua中坐标系原点在屏幕的左下角，x向右，y向上，z则是指的zorder（层级）。

二、世界坐标系，本地坐标系

　　世界坐标系的原点固定在屏幕的左下角。
　　本地坐标是和节点相关的坐标系，每个节点都有独立的坐标系，是以节点左下角为原点。当节点移动或改变方向时，和该节点关联的坐标系将随之移动或者改变方向。

三、锚点

　　锚点Anchor Point的两个参数范围在0-1 之间，他们是乘数因子。比如（0.5，0.5）表示锚点位于节点长乘于0.5，宽*0.5的位置。可以设置锚点,如果没设置,默认在(0.5,0.5);

　　下面给个代码看看效果:

        //创建大的精灵
     CCSprite *big = CCSprite::create();
     //设置背景颜色
     big->setColor(Color3B(,,));
     //设置锚点为左下角
     big->setAnchorPoint(ccp(, ));
     //设置大小
     big->setTextureRect(CCRectMake(, , , ));
     //设置位置
     big->setPosition(ccp(, ));
     //加载
     addChild(big);

　　如果不忽略锚点

         //创建大的精灵
     CCSprite *big = CCSprite::create();
     //设置背景颜色
     big->setColor(Color3B(,,));
     //设置锚点为左下角
     //big->setAnchorPoint(ccp(0, 0));
     big->ignoreAnchorPointForPosition(false);
     //设置大小
     big->setTextureRect(CCRectMake(, , , ));
     //设置位置
     big->setPosition(ccp(, ));
     //加载
     addChild(big);

　　忽略锚点

 //创建大的精灵
     CCSprite *big = CCSprite::create();
     //设置背景颜色
     big->setColor(Color3B(,,));
     //设置锚点为左下角
     //big->setAnchorPoint(ccp(0, 0));
     big->ignoreAnchorPointForPosition(true);
     //设置大小
     big->setTextureRect(CCRectMake(, , , ));
     //设置位置
     big->setPosition(ccp(, ));
     //加载
     addChild(big);

4、世界坐标和本地坐标的转化

convertToNodeSpace//将世界坐标转换为本地坐标系
convertToWorldSpaceAR//将本地坐标系转换为世界坐标系

总的来说世界坐标就是相对于窗口的坐标,本地坐标就是相对于某个节点的坐标

整体代码:

T5Coordinate.h

 #pragma once
 #include "cocos2d.h"
 USING_NS_CC;

 class T5Coordinate :public CCLayer
 {
 public:
     static CCScene *scene();
     CREATE_FUNC(T5Coordinate);
     bool init();

     bool onTouchBegan(CCTouch *pTouch, CCEvent *pEvent);//创建点击事件
 };

T5Coordinate.cpp

 #include "T5Coordinate.h"

 CCScene *T5Coordinate::scene()
 {
     CCScene *scene = CCScene::create();
     T5Coordinate *layer = T5Coordinate::create();
     scene->addChild(layer);
     return scene;
 }

 bool T5Coordinate::init()
 {
     CCLayer::init();
     setTouchEnabled(true);//打开触摸开关
     setTouchMode(kCCTouchesOneByOne);//单点

     //创建大的精灵
     CCSprite *big = CCSprite::create();
     //设置背景颜色
     big->setColor(Color3B(,,));
     //设置锚点为左下角
     //big->setAnchorPoint(ccp(0, 0));
     big->ignoreAnchorPointForPosition(true);
     //设置大小
     big->setTextureRect(CCRectMake(, , , ));
     //设置位置
     big->setPosition(ccp(, ));
     //加载
     addChild(big);

     //创建小的精灵
     CCSprite *little = CCSprite::create();
     //设置背景颜色
     little->setColor(Color3B(, , ));
     //设置锚点为左下角
     little->setAnchorPoint(ccp(, ));
     //设置大小
     little->setTextureRect(CCRectMake(, , , ));
     //设置位置
     little->setPosition(ccp(, ));
     //加载到大的精灵里面,以大的精灵的锚点为坐标原点
     big->addChild(little);

     //世界坐标转化为本地坐标
     CCPoint toWorld = big->convertToWorldSpace(little->getPosition());

     CCSprite *little2 = CCSprite::create();
     little2->setColor(Color3B(, , ));
     little2->setAnchorPoint(ccp(, ));
     little2->setTextureRect(CCRectMake(, , , ));
     little2->setPosition(ccp(, ));
     big->addChild(little2);

     //将本地坐标转化为世界坐标     //CCPoint toNode = big->convertToNodeSpace(little2->getPosition());

     //创建动作
     //移动到的位置
     CCMoveBy *by = CCMoveBy::create(, ccp(, ));
     //从移动到的位置回来
     CCMoveBy *by2 = (CCMoveBy *)by->reverse();
     //创建动作
     CCSequence *seq = CCSequence::create(by, by2, NULL);
     //把动作给大的精灵
     big->runAction(CCRepeatForever::create(seq));

     CCMoveBy *l1by = CCMoveBy::create(, ccp(, -));
     CCMoveBy *l1by2 = (CCMoveBy *)l1by->reverse();
     CCSequence *l1seq = CCSequence::create(l1by, l1by2, NULL);
     little->runAction(CCRepeatForever::create(l1seq));

     CCMoveBy *lby = CCMoveBy::create(, ccp(, ));
     CCMoveBy *lby2 = (CCMoveBy *)lby->reverse();
     CCSequence *lseq = CCSequence::create(lby, lby2, NULL);
     little2->runAction(CCRepeatForever::create(lseq));

     return true;
 }

 bool T5Coordinate::onTouchBegan(CCTouch *pTouch, CCEvent *pEvent)
 {
     //获取GL坐标
     CCPoint pGl = pTouch->getLocation();
     //获取UI坐标
     CCPoint pUi = pTouch->getLocationInView();
     //世界坐标转化为相对坐标
     CCPoint pnode = this->convertToNodeSpace(pGl);
     //UI->GL坐标转换
     CCPoint ptoGl = CCDirector::sharedDirector()->convertToGL(pUi);
     //GL->UI坐标的转换
     CCPoint ptoUi = CCDirector::sharedDirector()->convertToUI(pGl);

     //存储结果并且显示
     char Gl[];
     char Ui[];
     char toGl[];
     char toUi[];
     char node[];
     char res[];
     sprintf(Gl, "GL坐标:x = %f   y = %f", pGl.x, pGl.y);
     sprintf(Ui, "UI坐标: x = %f  y = %f", pUi.x, pUi.y);
     sprintf(toGl, "toGL坐标:x = %f   y = %f", ptoGl.x, ptoGl.y);
     sprintf(toUi, "toUi坐标:x = %f   y = %f", ptoUi.x, ptoUi.y);
     sprintf(node , "相对坐标:x = %f   y = %f", pnode.x, pnode.y);
     sprintf(res, "%s\n%s\n%s\n%s\n%s", Gl, Ui,toGl,toUi,node);
     MessageBoxA(, res, "当前点击坐标", );
     return true;
 }