模拟摇杆操作

现在很多手机APP都有模拟操控摇杆的功能，今天项目中接触到一个委托事件，我顺便试试实现这个摇杆功能。

代码如下

/*
 *  Joystick.h
 *  YaoGan
 *
 *  Created by Liu Yanghui on 11-10-27.
 *  Copyright 2011 ard8. All rights reserved.
 *
 */

#ifndef Joystick_H
#define Joystick_H
#include "cocos2d.h"
using namespace cocos2d;
class Joystick :public CCLayer {
	public :
	CCPoint centerPoint;//摇杆中心
	CCPoint currentPoint;//摇杆当前位置
	bool active;//是否激活摇杆
	float radius;//摇杆半径
	CCSprite *jsSprite;
	
	
	void Active();
	void Inactive();
	CCPoint getDirection();
	float getVelocity();
	void  updatePos(ccTime dt);
	
	//初始化 aPoint是摇杆中心 aRadius是摇杆半径 aJsSprite是摇杆控制点 aJsBg是摇杆背景
	static Joystick*  JoystickWithCenter(CCPoint aPoint ,float aRadius ,CCSprite* aJsSprite,CCSprite* aJsBg);
	Joystick * initWithCenter(CCPoint aPoint ,float aRadius ,CCSprite* aJsSprite,CCSprite* aJsBg);
	
	virtual bool ccTouchBegan(CCTouch *pTouch, CCEvent *pEvent);
	virtual void ccTouchMoved(CCTouch *pTouch, CCEvent *pEvent);
	virtual void ccTouchEnded(CCTouch *pTouch, CCEvent *pEvent);
	LAYER_NODE_FUNC(Joystick);
};
#endif

 

/*
 *  Joystick.cpp
 *  YaoGan
 *
 *  Created by Liu Yanghui on 11-10-27.
 *  Copyright 2011 ard8. All rights reserved.
 *
 */

#include "Joystick.h"

void Joystick::updatePos(ccTime dt){
	jsSprite->setPosition(ccpAdd(jsSprite->getPosition(),ccpMult(ccpSub(currentPoint, jsSprite->getPosition()),0.5)));
}

void Joystick::Active()
{
	if (!active) {
		active=true;
		schedule(schedule_selector(Joystick::updatePos));//添加刷新函数
		CCTouchDispatcher::sharedDispatcher()->addTargetedDelegate(this, 0,false);//添加触摸委托
	}else {
		
	}
}
//冻结摇杆
void   Joystick::Inactive()
{
	if (active) {
		active=false;
		this->unschedule(schedule_selector(Joystick::updatePos));//删除刷新
		CCTouchDispatcher::sharedDispatcher()->removeDelegate(this);//删除委托
	}else {
		
	}
}

bool Joystick::ccTouchBegan(CCTouch* touch, CCEvent* event)
{
	if (!active)
		return false;
	CCPoint touchPoint = touch->locationInView(touch->view());
	touchPoint = CCDirector:: sharedDirector()->convertToGL(touchPoint);
	if (ccpDistance(touchPoint, centerPoint) > radius)
		return false;
	currentPoint = touchPoint;
	return true;
}

void  Joystick::ccTouchMoved(CCTouch* touch, CCEvent* event)
{
	CCPoint touchPoint = touch->locationInView(touch->view());
	touchPoint = CCDirector:: sharedDirector()->convertToGL(touchPoint);
	if (ccpDistance(touchPoint, centerPoint) > radius)
	{
		currentPoint =ccpAdd(centerPoint,ccpMult(ccpNormalize(ccpSub(touchPoint, centerPoint)), radius));
	}else {
		currentPoint = touchPoint;
	}
}

void  Joystick::ccTouchEnded(CCTouch* touch, CCEvent* event)
{
	
	currentPoint = centerPoint;
}
//获取摇杆方位,注意是单位向量
CCPoint Joystick::getDirection()
{
	return ccpNormalize(ccpSub(centerPoint, currentPoint));
}
//获取摇杆力度
float Joystick::getVelocity()
{
	return ccpDistance(centerPoint, currentPoint);
}

Joystick* Joystick:: JoystickWithCenter(CCPoint aPoint ,float aRadius ,CCSprite* aJsSprite,CCSprite* aJsBg){
	Joystick *jstick=Joystick::node();
	jstick->initWithCenter(aPoint,aRadius,aJsSprite,aJsBg);
	return jstick;
}

Joystick* Joystick::initWithCenter(CCPoint aPoint ,float aRadius ,CCSprite* aJsSprite,CCSprite* aJsBg){
	
	
	active = false;
	radius = aRadius;
	centerPoint = aPoint;
	currentPoint = centerPoint;
	jsSprite = aJsSprite;
	jsSprite->setPosition(centerPoint);
	aJsBg->setPosition(centerPoint);
	this->addChild(jsSprite);
	this->addChild(aJsBg);
	return this;
}

好了，基本都实现了摇杆的功能，最后我来调用一下，看看结果如何。随便创建一个场景

初始化时加入我要得资源文件。

CCSize screenSize=CCDirector::sharedDirector()->getWinSize();
	CCSprite *mainBg=CCSprite::spriteWithFile("bg.png");
	mainBg->setPosition(ccp(screenSize.width*0.5,screenSize.height*0.5));
	this->addChild(mainBg);
	
	CCSprite *testPointL=CCSprite::spriteWithFile("point.png");//摇杆
	CCSprite *testBGL=CCSprite::spriteWithFile("joytickbg.png");//摇杆背景
	Joystick *testJSL=Joystick::JoystickWithCenter(ccp(80.0f,80.0f),60.0f ,testPointL ,testBGL);
	this->addChild(testJSL);
	testJSL->Active();
	
	return true;

运行，Ok，一切正常。

汗。突然发现了个很悲催的事，csdn不许我上传图片。注册不达一星期。我勒个去。以后加上效果图吧