实例介绍Cocos2d-x物理引擎：HelloPhysicsWorld

我们通过一个实例介绍一下，在Cocos2d-x 3.x中使用物理引擎的开发过程，熟悉这些API的使用。这个实例的运行后的场景，当场景启动后，玩家可以触摸点击屏幕，每次触摸时候，就会在触摸点生成一个新的精灵，精灵的运行是自由落体运动。

#ifndef __HELLOWORLD_SCENE_H__
#define __HELLOWORLD_SCENE_H__


#include "cocos2d.h"
USING_NS_CC;


class HelloWorld : public cocos2d::Layer
{
public:
    static cocos2d::Scene* createScene();


 
    virtual bool init();  
	virtual bool onTouchBegan(cocos2d::Touch* touch, cocos2d::Event* event);			①


    CREATE_FUNC(HelloWorld);


	void addNewSpriteAtPosition(Vec2 p);									②
};


#endif // __HELLOWORLD_SCENE_H__

Scene* HelloWorld::createScene()
{
    auto scene = Scene::createWithPhysics();									①
	scene->getPhysicsWorld()->setDebugDrawMask(PhysicsWorld::DEBUGDRAW_ALL);		②
    
    auto layer = HelloWorld::create();


    scene->addChild(layer);


    return scene;


}

bool HelloWorld::init()
{
    if ( !Layer::init() )
    {
        return false;
    }
    
    Size visibleSize = Director::getInstance()->getVisibleSize();
    Vec2 origin = Director::getInstance()->getVisibleOrigin();


	//定义世界的边界
		auto body = PhysicsBody::createEdgeBox(visibleSize,
						PHYSICSBODY_MATERIAL_DEFAULT,5.0f);						①
	auto edgeNode = Node::create();											②
	edgeNode->setPosition(Vec2(visibleSize.width/2,visibleSize.height/2)); 				③
	edgeNode->setPhysicsBody(body); 										④
	this->addChild(edgeNode); 											⑤


	setTouchEnabled(true);												⑥
	//设置为单点触摸
	setTouchMode(Touch::DispatchMode::ONE_BY_ONE);							⑦


    return true;
}

bool HelloWorld::onTouchBegan(Touch* touch, Event* event)						①
{
	Vec2 location = touch->getLocation();
	addNewSpriteAtPosition(location);
	return false;
}	


void HelloWorld::addNewSpriteAtPosition(Vec2 p) 								②
{    
    auto sp = Sprite::create("Ball.png");										③
	sp->setTag(1);														④
	
	auto body = PhysicsBody::createCircle(sp->getContentSize().width / 2);				⑤
	//auto body = PhysicsBody::createBox(sp->getContentSize());						⑥
    sp->setPhysicsBody(body);											⑦
    sp->setPosition(p);													
	this->addChild(sp);
}

第⑥行代码PhysicsBody::createBox(sp->getContentSize())是创建一个没有边的矩形盒子。第⑦行代码sp->setPhysicsBody(body)是设置与精灵相关的物体对象。

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实例介绍Cocos2d-x物理引擎：HelloPhysicsWorld

原文：http://blog.csdn.net/tonny_guan/article/details/39482331