重新写了地图双指缩放和单指拖动,适合所有机型屏幕配置

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前面已经写过一篇了,在这里就不具体解释细节了,大体原理都是一样的,双指缩放还是根据双指间占原距离的比例进行缩放。下面直接上代码了:

.h

#ifndef __MAPLAYER_H
#define __MAPLAYER_H
#include "cocos2d.h"
using namespace cocos2d;
class MapLayer:public Layer
{
public:
	Vec2 mpOrigin;
	virtual bool init();
	CREATE_FUNC(MapLayer);
private:

};
#endif // !__MAPLAYER_H

下面是 .cpp注释写的很详细不明白的话可以细看

auto dis = Director::getInstance()->getEventDispatcher();
	auto listen = EventListenerTouchAllAtOnce::create();

	listen->onTouchesMoved = [=](const std::vector<Touch*>& touches,Event  *event){

		if(touches.size() > 1)        // 多点进行缩放
		{
			// 得到当前两触摸点
			auto point1 = touches[0]->getLocation();
			auto point2 = touches[1]->getLocation();
			// 计算两点之间得距离
			auto currDistance = point1.distance(point2);
			// 计算两触摸点上一时刻之间得距离
			auto prevDistance = touches[0]->getPrevIoUsLocation().distance(touches[1]->getPrevIoUsLocation());
			// 两触摸点与原点的差向量,pointVec1和pointVec2是相对于maplayer的位置
			auto pointVec1 = point1  - mpOrigin;
			auto pointVec2 = point2  - mpOrigin;
			// 两触摸点的相对中点
			auto relMidx = (pointVec1.x + pointVec2.x) / 2 ;
			auto relMidy = (pointVec1.y + pointVec2.y) / 2 ;
			// 计算maplayer的锚点
			auto anchorX = relMidx / maplayer->getBoundingBox().size.width;
			auto anchorY = relMidy / maplayer->getBoundingBox().size.height;
			// 相对屏幕的中点
			auto absMidx = (point2.x + point1.x) / 2 ;
			auto absMidy = (point2.y + point1.y) / 2 ;

			// 缩放时,为了避免出现空白的区域,需要做以下的边界处理。        
			// 当bgSprite快要进入到屏幕时,修改maplayer的位置(既absMidx和absMidy)。
			if(  mpOrigin.x > 0)
			{
				absMidx -= mpOrigin.x;
			}
			if( mpOrigin.x < -maplayer->getBoundingBox().size.width + winSize.width )
			{
				absMidx +=  -maplayer->getBoundingBox().size.width + winSize.width - mpOrigin.x;
			}
			if( mpOrigin.y > 0 )
			{
				absMidy -= mpOrigin.y;
			}
			if( mpOrigin.y < -maplayer->getBoundingBox().size.height + winSize.height )
			{
				absMidy +=  -maplayer->getBoundingBox().size.height + winSize.height - mpOrigin.y;
			}
			// 重设bgSprite锚点和位置
			maplayer->setAnchorPoint(Vec2(anchorX,anchorY));
			maplayer->setPosition(Vec2(absMidx,absMidy));
			// 根据两触摸点前后的距离计算缩放倍率
			auto scalex = maplayer->getScaleX() * (currDistance / prevDistance);
			auto scaley = scalex * RATIO;
			// 控制缩放倍率在1~4倍之间,最小倍率不能太小,不让背景将不能填充满整个屏幕。

			scalex = MIN(1.8,MAX(preScalex,scalex));
			scaley = MIN(1.8,MAX(preScaley,scaley));

			maplayer->setScale(scalex,scaley);
			// 更新原点位置
			mpOrigin = Vec2(absMidx,absMidy) - Vec2(maplayer->getBoundingBox().size.width * anchorX,maplayer->getBoundingBox().size.height * anchorY) ;
		}
		else if(touches.size() == 1)        // 单点进行移动
		{
			// 单点时,touches中只有一个Touch对象,所以通过touches[0]就可以得到触摸对象
			auto touch = touches[0];
			// 计算滑动过程中的滑动增量
			auto diff = touch->getDelta();       
			// 得到当前maplayer的位置
			auto currentPos = maplayer->getPosition();
			// 得到滑动后maplayer应该所在的位置
			auto pos = currentPos + diff;
			// 得到此刻maplayer的尺寸
			auto maplayerCurrSize = maplayer->getBoundingBox().size;

			//边界控制,约束pos的位置
			pos.x = MIN(pos.x,maplayerCurrSize.width * maplayer->getAnchorPoint().x);
			pos.x = MAX(pos.x,-maplayerCurrSize.width + winSize.width + maplayerCurrSize.width * maplayer->getAnchorPoint().x);
			pos.y = MIN(pos.y,maplayerCurrSize.height * maplayer->getAnchorPoint().y);
			pos.y = MAX(pos.y,-maplayerCurrSize.height + winSize.height + maplayerCurrSize.height * maplayer->getAnchorPoint().y);
			// 重设bgSprite位置
			maplayer->setPosition(pos);

			// 更新原点位置
			if( pos.x >= maplayerCurrSize.width * maplayer->getAnchorPoint().x
				|| pos.x <= -maplayerCurrSize.width + winSize.width + maplayerCurrSize.width * maplayer->getAnchorPoint().x)
			{
				diff.x = 0;
			}
			if( pos.y >= maplayerCurrSize.height * maplayer->getAnchorPoint().y
				|| pos.y <= -maplayerCurrSize.height + winSize.height + maplayerCurrSize.height * maplayer->getAnchorPoint().y)
			{
				diff.y = 0;
			}
			mpOrigin += diff;
		}
	};
	dis->addEventListenerWithSceneGraPHPriority(listen,maplayer);

这样就能解决缩放与拖动了。

原文链接:https://www.f2er.com/cocos2dx/346371.html

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