飞机大战03之飞机发射子弹，添加敌人

飞机发射子弹：

弹幕，是雷电游戏的精华。这就需要对子弹的运动轨迹进行控制。

先做一个最简单的子弹发射，后面再添加各种弹幕（实际上主要是研究弹幕）

说是最简单，其实也是最普通的子弹发射，产生一个颗子弹移动就OK了。

方法：做一个子弹发射的计时器，产生子弹，子弹做MoveBy动作就OK了。

代码：

GameLayer.cpp

void GameLayer::fireSchedule(float dt)
{
	Size screenSize = Director::getInstance()->getWinSize() ;
	Vec2 crePos = m_pPlayerPlane->getPosition() ;//子弹的初始位置
	float flyTime = 1.0f ;
	Sprite * pBullet = Sprite::create("bullet1.png") ;
	pBullet->setPosition(crePos) ;
	addChild(pBullet,ZORDER_BULLET) ;

	flyTime = ((screenSize.height - crePos.y) / screenSize.height)*flyTime ;//移动的时间跟，发射的距离相关

	pBullet->runAction(
		Sequence::create(
		MoveBy::create(flyTime,Vec2(0,screenSize.height - crePos.y)),
		RemoveSelf::create(true),nullptr)
		) ;
}

敌人新建了一个类，因为，到后面敌人可能还需要有一些自己的属性。

EnermySprite.h

#ifndef _ENERMY_SPRITE_H_
#define _ENERMY_SPRITE_H_

#include "cocos2d.h"
USING_NS_CC ;
typedef enum
{
	kEnermyTypeNone = 0,
	kEnermyType1,
	kEnermyType2,
	kEnermyType3,
	kEnermyType4,
}EnermyType;
class EnermySprite : public Sprite
{
public:
	static EnermySprite * createByType(EnermyType type);
	static const char * getImageNameByType(EnermyType type);
public:
	EnermySprite();
	~EnermySprite();

private:

};
#endif

EnermySprite.cpp

#include "EnermySprite.h"

EnermySprite * EnermySprite::createByType(EnermyType type)
{
	const char * pImage = getImageNameByType(type) ;
	EnermySprite * pRet = new EnermySprite() ;
	pRet->initWithFile(pImage) ;
	pRet->autorelease() ;
	return pRet ;
}
const char * EnermySprite::getImageNameByType(EnermyType type)
{
	const char* pImageName = nullptr;
	switch (type)
	{
	case kEnermyType1:
		pImageName = "enemy1.png" ;
		break;
	case kEnermyType2:
		pImageName = "enemy2.png" ;
		break;
	case kEnermyType3:
		pImageName = "enemy3.png" ;
		break;
	case kEnermyType4:
		pImageName = "enemy4.png" ;
		break;
	default:
		break;
	}
	return pImageName ;
}
EnermySprite::EnermySprite()
{

}

EnermySprite::~EnermySprite()
{

}

添加到游戏中：

GameLayer.h

void GameLayer::createEneSchedule(float dt)
{
	int ran = CCRANDOM_0_1() * 4 + 1 ;
	EnermyType type ;
	switch (ran)
	{
	case 1:
		type = kEnermyType1;
		break;
	case 2:
		type = kEnermyType2;
		break;
	case 3:
		type = kEnermyType3;
		break;
	case 4:
		type = kEnermyType4;
		break;
	default:
		break;
	}

	auto pEne = EnermySprite::createByType(type) ;
	float x = CCRANDOM_0_1()*(Director::getInstance()->getWinSize().width - pEne->getBoundingBox().size.width / 2) +  pEne->getBoundingBox().size.width / 2;
	float y = Director::getInstance()->getWinSize().height + pEne->getBoundingBox().size.height / 2 ;
	float flyTime = 2.0f ;
	pEne->runAction(
			Sequence::create(
				MoveBy::create(flyTime,Vec2(0,-(Director::getInstance()->getWinSize().height + pEne->getBoundingBox().size.height))),
				CallFuncN::create(CC_CALLBACK_1(GameLayer::enermyMoveEndCallback,this)),
				RemoveSelf::create(true),nullptr
			)
		) ;
	addChild(pEne) ;
	pEne->setPosition(x,y) ;
	m_pEnermyVec.pushBack(pEne) ;
}
void GameLayer::enermyMoveEndCallback(Node * pNode)
{
	EnermySprite * pEnermy = dynamic_cast<EnermySprite*>(pNode) ;
	m_pEnermyVec.eraseObject(pEnermy);
}

又是一个计时器，记得要添加一个敌人的vector来存放敌人。