Cocos2dx之精灵坐标系

一、有哪些坐标系

1.屏幕坐标系

标准屏幕坐标系使用和OpenGL不同的坐标系，而Cocos2d则使用和OpenGL相同的坐标系。iOS, Android, Windows Phone等在开发应用时使用的是标准屏幕坐标系，原点为屏幕左上角，x向右，y向下。Cocos2d坐标系和OpenGL坐标系一样，原点为屏幕左下角，x向右，y向上。

setPosition(ccp(winSize.width / 2, winSize.height / 2)); bg->setTag(TAG_BG); CCSprite* sprite = CCSprite::create("CloseNormal.png"); addChild(sprite); sprite->setPosition(ccp(winSize.width / 2, winSize.height / 2)); sprite->setZOrder(1); sprite->setTag(TAG_SPRITE); setTouchEnabled(true); setTouchMode(kCCTouchesOneByOne); return true; } bool T05ODERandTag::ccTouchBegin(CCTouch *pTouch, CCEvent *pEvent) { CCNode* node = getChildByTag(TAG_SPRITE); node->setZOrder(0 - node->getZOrder()); return false; }

四、拖动节点设计和实现

#ifndef __T04DrawNode_H__
#define __T04DrawNode_H__
#include "f:\cocos2dx\cocos2d-x-2.2.6\cocos2dx\layers_scenes_transitions_nodes\cclayer.h"
#include "cocos2d.h"
USING_NS_CC;

class T04DrawNode :	public CCLayer
{
public:
	T04DrawNode(void);
	~T04DrawNode(void);

	static CCScene* scene();
	CREATE_FUNC(T04DrawNode);
	bool init();
	virtual bool ccTouchBegan(CCTouch *pTouch, CCEvent *pEvent);
	virtual void ccTouchMoved(CCTouch *pTouch, CCEvent *pEvent);
	CCSprite* _sprite;
};

#endif

#include "T04DrawNode.h"


T04DrawNode::T04DrawNode(void)
{
}


T04DrawNode::~T04DrawNode(void)
{
}

CCScene* T04DrawNode::scene()
{
	CCScene* scene = CCScene::create();
	T04DrawNode* layer = T04DrawNode::create();
	scene->addChild(layer);
	return scene;
}

bool T04DrawNode::init()
{
	CCLayer::init();

	CCSprite* sprite = CCSprite::create("CloseNormal.png");
	addChild(sprite);
	sprite->setPosition(ccp(100, 100));

	setTouchEnabled(true);
	setTouchMode(kCCTouchesOneByOne);

	_sprite = sprite;
	return true;
}

bool T04DrawNode::ccTouchBegan(CCTouch *pTouch, CCEvent *pEvent)
{
	// rc描述了精灵所占用的矩形，包括位置和大小
	CCRect rc=_sprite->boundingBox();

	// 鼠标按下的位置
	CCPoint pt = pTouch->getLocation();

	// 只有当鼠标点中精灵的时候，ccTouchMoved才要被调用
	return rc.containsPoint(pt);
}
void T04DrawNode::ccTouchMoved(CCTouch *pTouch, CCEvent *pEvent)
{
	CCPoint ptDelta = pTouch->getDelta();
	CCPoint oldPos = _sprite->getPosition();
	CCPoint newPos = oldPos  + ptDelta;
	_sprite->setPosition(newPos);
}