《Cocos2d-x for iPhone游戏开发实例详解---1.~ 运动条纹》

《Cocos2d-x for iPhone游戏开发实例详解》系列博文，基于 人民邮电出版社 《Cocos2d for iPhone游戏开发实例详解》一书，使用Cocosd-x技术重写。示例代码中所引用的相关资料归于原书作者 Nathan Burba 以及出版社所有，本系列博文提供的C++版代码仅供学习使用。

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开发环境：

  Cocos2d-x  cocos2d-2.1rc0-x-2.1.2-hotfix.zip @ Apr.08, 2013

  MacBook Pro 13'  Mountain Lion 10.8.3

  Xcode 4.6

  iPhone5   IOS 6.1.4

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本章 代码相对于中文翻译版以及英文原版有很大出入，以英文原版Cocos2d.for.iPhone.1.Game.Development.Cookbook Coder Source 为基准修改。

本示例展示了绘制运动条纹的方法。

//****************************************************************************************************
//            Author:          Last Ranker
//            DateTime:        2013年08月24日
//            SearchMe:        http://blog.youkuaiyun.com/lastranker
//            Email:           tubufeng@foxmail.com
//
//****************************************************************************************************

//  DrawingSprites.h
//  Chapter_1
//
//  Created by Last Ranker on 13-8-15.
//
//
//
//  MotionStreak.h
//  Chapter_1
//
//  Created by Last Ranker on 13-8-24.
//
//

#ifndef __Chapter_1__MotionStreak__
#define __Chapter_1__MotionStreak__

#include <iostream>
#include "cocos2d.h"
using namespace cocos2d;
class MotionStreak: public cocos2d::CCLayer
{
public:
    CCPoint rocketDirection;
    CCSprite *rocket;
    CCMotionStreak *streak;
    virtual bool init();
    static cocos2d::CCScene * scene();
    CREATE_FUNC(MotionStreak);
    CCLayer * runRecipe();
    void step(CCTime delta);

    static float VectorToRadians(CCPoint vector);

    float RadiansToDegrees(float radians);
    
};
#endif /* defined(__Chapter_1__MotionStreak__) */

//****************************************************************************************************
//            Author:          Last Ranker
//            DateTime:        2013年08月24日
//            SearchMe:        http://blog.youkuaiyun.com/lastranker
//            Email:           tubufeng@foxmail.com
//
//****************************************************************************************************
//
//  MotionStreak.cpp
//  Chapter_1
//
//  Created by Last Ranker on 13-8-24.
//
//

#include "MotionStreak.h"
#include <math.h>
CCScene * MotionStreak::scene()
{
    CCScene *scene=CCScene::create();
    MotionStreak *layer=MotionStreak::create();
    scene->addChild(layer);
    return scene;
    
}

bool MotionStreak::init()
{
    //
    // 1. super init first
    if ( !CCLayer::init() )
    {
        return false;
    }
    runRecipe();
    return true;
}
CCLayer * MotionStreak::runRecipe()
{
    CCSize s=CCDirector::sharedDirector()->getWinSize();
    //Set the rocket initially in a random direction.
    rocketDirection=ccp(arc4random()%4+1, arc4random()%4+1);
    //Add the rocket sprite.
    rocket=CCSprite::create("rocket.png");
    rocket->setPosition(ccp(s.width/2, s.height/2));
    rocket->setScale(0.5f);
    this->addChild(rocket);
    //Create the streak object and add it to the scene.
    streak=CCMotionStreak::create(1, 1, 32, ccc3(255, 255, 255), "streak.png");
    
    this->addChild(streak);
    
    streak->setPosition(ccp(s.width/2, s.height/2));
    
    //this->schedule(schedule_selector(MotionStreak::step),0.0000001);
    this->schedule(schedule_selector(MotionStreak::step));
    
    
    
    return this;
}
void MotionStreak::step(CCTime delta)
{
    
    CCSize s=CCDirector::sharedDirector()->getWinSize();
	//Make rocket bounce off walls
    if (rocket->getPosition().x>s.width||rocket->getPosition().x<0) {
        rocketDirection=ccp(-rocketDirection.x, rocketDirection.y);
    }
    else if(rocket->getPosition().y>s.width||rocket->getPosition().y<0)
    {
        rocketDirection=ccp(rocketDirection.x, -rocketDirection.y);
    }
    
	//Slowly turn the rocket
	rocketDirection = ccp(rocketDirection.x, rocketDirection.y+0.05f);
    
	//Update rocket position based on direction
    rocket->setPosition(ccp(rocket->getPosition().x+rocketDirection.x,rocket->getPosition().y+rocketDirection.y));
    streak->setPosition(rocket->getPosition());
    
	//Set the rocket's rotation
    rocket->setRotation(RadiansToDegrees(VectorToRadians(rocketDirection)));


}
float MotionStreak::VectorToRadians(CCPoint vector)
{
   return (float)atan2(vector.x,-vector.y);
}
float MotionStreak::RadiansToDegrees(float radians)
{
    return radians*180/M_PI;
}

源代码：http://pan.baidu.com/share/link?shareid=287519970&uk=1962963338