cocos2d-x 3.0 游戏关卡滑动 弹动 不会出现黑边效果

#pragma once
#include "cocos2d.h"
#include "ShopScene.h"

using namespace cocos2d;

class ChooseScene : public Layer 
{
public:
	static Scene* createScene();
	virtual bool init(); 
	void menuCloseCallback(Ref* pSender);CREATE_FUNC(ChooseScene);
public: 
	bool onTouchBegan(Touch* touch, Event* event);
	void onTouchMoved(Touch* touch, Event* event);
	void onTouchEnded(Touch* touch, Event* event);
	Point diff_2; 
	Point diff_1;
	
	float bg_width_max;
	float bg_width_min;
	Sprite* cocosImage;
};


cpp
#include "ChooseScene.h"
USING_NS_CC;

Scene* ChooseScene::createScene()
{
	auto scene = Scene::create();
	auto layer = ChooseScene::create();
	scene->addChild(layer);return scene;
}

bool ChooseScene::init()
{
	if ( !Layer::init() )
	{return false;}
	
	Size visibleSize = Director::getInstance()->getVisibleSize();
	Point origin = Director::getInstance()->getVisibleOrigin();
	bg_width_max = 6500; // 背景全然出现 最大X 
	bg_width_min = 1024; // 最小X 
	
	background_init();
	return true;
}

void ChooseScene::background_init()
{
	cocosImage = Sprite::create("ChooseScene/map.png");
	cocosImage->setAnchorPoint(Point(1, 0)); ///锚点 1,0 图片的右下角
	cocosImage->setPosition(Point(1024, 0)); // 屏幕是 1024 768 锚点是1,0 所以所有显示在屏幕上 x 位置 是1024
	this->addChild(cocosImage, 1, 1);

	auto listener_1 = EventListenerTouchOneByOne::create(); //加入监听事件
	listener_1->setSwallowTouches(true);
	listener_1->onTouchBegan = CC_CALLBACK_2(ChooseScene::onTouchBegan, this);
	listener_1->onTouchMoved = CC_CALLBACK_2(ChooseScene::onTouchMoved,this);
	listener_1->onTouchEnded = CC_CALLBACK_2(ChooseScene::onTouchEnded,this);
	_eventDispatcher->addEventListenerWithSceneGraphPriority(listener_1, this);
}

bool ChooseScene::onTouchBegan(Touch* touch, Event* event) // 假设有触摸范围的话 能够再这里加入一个
{
	// auto beginPoint = touch->getLocation();
	// if (touch_bg.containsPoint(beginPoint)) /////touch_bg 是point 
	// {
	// return true;
	// }
	return true;
}

void ChooseScene::onTouchMoved(Touch* touch, Event* event)
{
	if (cocosImage->getPositionX() >= bg_width_min && cocosImage->getPositionX() <= bg_width_max) //推断 是不是在 规定的范围内
	{
		diff_2 = touch->getDelta();
		auto currentPos = cocosImage->getPosition();
		cocosImage->setPosition(currentPos.x + diff_2.x, currentPos.y);
	}
	if (cocosImage->getPositionX() > bg_width_max) // 最左边 //当移动到最左边的时候 返回最大范围
	{
		cocosImage->setPosition(bg_width_max, cocosImage->getPositionY());
	}
	if (cocosImage->getPositionX() < bg_width_min) /// 最右边 同上
	{
		cocosImage->setPosition(bg_width_min, cocosImage->getPositionY());
	}
}

void ChooseScene::onTouchEnded(Touch* touch, Event* event)
{
	if (diff_1.x == diff_2.x)      //推断 上次触摸点与这次触摸点 是否不同 假设同样 地图不进行移动
	{
		return;
	}

	diff_1 = diff_2;        //保留这次移动參数  
	
	float pm = 0;
	if (diff_1.y > 0)
	{
		pm = 1;
	}
	else
	{
		pm = -1;
	}

	if (cocosImage->getPositionX() >= bg_width_min - pm * 180 
		&& cocosImage->getPositionX() <= bg_width_max - pm * 180)    /// 滑动边界推断  最大范围
	{
		 if (abs(diff_1.x)>=30)
		 {
			 if (diff_1.x >0)
			 {
				 auto move_x = MoveTo::create(0.8f, Point(cocosImage->getPositionX() + 180, 
					 cocosImage->getPositionY()));   

				 cocosImage->runAction(move_x);
			 }
			 else
			 {
				 auto move_x = MoveTo::create(0.8f, Point(cocosImage->getPositionX() - 180, 
					 cocosImage->getPositionY())); 

				 cocosImage->runAction(move_x);
			 }

		 }

	}	
	if (cocosImage->getPositionX() >= bg_width_min - pm * 50 
		&& cocosImage->getPositionX() <= bg_width_max - pm * 50)     //边界推断  最小距离
	{
		if (abs(diff_1.x) < 30)
		{
			if (diff_1.x >0)
			{
				auto move_x = MoveTo::create(0.5, Point(cocosImage->getPositionX() + 50, 
					cocosImage->getPositionY()));

				cocosImage->runAction(move_x);
			}
			else
			{
				auto move_x = MoveTo::create(0.5, Point(cocosImage->getPositionX() - 50,
					cocosImage->getPositionY()));
				
				cocosImage->runAction(move_x);
			}

		}
	}
}

ScrollView 的滑动的时候 有两个效果 

1.移动到规定范围后 会弹回去。可是会看到范围外的图片。
2.不会有弹动效果，拖动到规定范围之后。将不能拖动。
所以 这段代码实现了 在没有出规定范围的时候 有滑动效果。

而且不会出现范围以外的图片地区。

移动的时候 使用setpostion 移动结束后 添加一个动作 
。起到了一个缓冲的惯性。这个横屏实例。竖屏 參照这个 改动參数就可以。