【cocos2d-x 3.7 飞机大战】 决战南海I (三) 敌机实现

如今来实现敌机类

敌机和我方飞机相似，具有生命值、能够发射子弹。而且有自己的运动轨迹。事实上能够为它们设计一个共同的基类，这样能够更方便扩展。

不同的敌机，应设置不同的标识、属性

// 敌机生命值

const int ENEMY1_MAXLIFE = 1;

const int ENEMY2_MAXLIFE = 2;

const int ENEMY3_MAXLIFE = 5;

const int ENEMY4_MAXLIFE = 10;

// 敌机分数

const int ENEMY1_SCORE = 1;

const int ENEMY2_SCORE = 6;

const int ENEMY3_SCORE = 20;

const int ENEMY4_SCORE = 50;

// 敌机类型

enum EnemyType

{

	Enemy1 = 1,

	Enemy2,

	Enemy3,

	Enemy4,

};

头文件里的主要函数

void setEnemyByType(EnemyType enType);

Sprite* getSprite();

int getLife();

void loseLife();

Rect getBoundingBox();

函数的实现

void Enemy::setEnemyByType(EnemyType enType)

{

	switch (enType)

	{

	case Enemy1:

		pEnemySprite = Sprite::createWithSpriteFrame(SpriteFrameCache::getInstance()->getSpriteFrameByName("enemy1.png"));

		nLife = ENEMY1_MAXLIFE;

		break;

	case Enemy2:

		pEnemySprite = Sprite::createWithSpriteFrame(SpriteFrameCache::getInstance()->getSpriteFrameByName("enemy2.png"));

		nLife = ENEMY2_MAXLIFE;

		break;

	case Enemy3:

		pEnemySprite = Sprite::createWithSpriteFrame(SpriteFrameCache::getInstance()->getSpriteFrameByName("enemy3.png"));

		nLife = ENEMY3_MAXLIFE;

		break;

	case Enemy4:

		pEnemySprite = Sprite::createWithSpriteFrame(SpriteFrameCache::getInstance()->getSpriteFrameByName("enemy4.png"));

		nLife = ENEMY4_MAXLIFE;

		break;

	default:

		return;

		break;

	}

	this->addChild(pEnemySprite);

	Size winSize = Director::getInstance()->getWinSize();

	Size enemySize = pEnemySprite->getContentSize();

	int minX = enemySize.width / 2;

	int maxX = winSize.width - enemySize.width / 2;

	int rangeX = maxX - minX;

	int actualX = (rand() % rangeX) + minX;

	// 设置敌机Node方位 Node包括Sprite

	this->setPosition(Point(actualX, winSize.height - enemySize.height / 2));

}

bool Enemy::init()

{

	bool pRet = true;

	if (!Node::init())

	{

		pRet = false;

	}

	return pRet;

}

Sprite* Enemy::getSprite()

{

	return pEnemySprite;

}

int Enemy::getLife()

{

	return nLife;

}

void Enemy::loseLife()

{

	--nLife;

}

Rect Enemy::getBoundingBox()

{

	Rect rect = pEnemySprite->boundingBox();

	Point pos = this->convertToWorldSpace(rect.origin);

	Rect enemyRect(pos.x, pos.y, rect.size.width, rect.size.height);

	return enemyRect;

}

依据敌机类型，绑定对应的图片和生命值，对于我方飞机。假设想依据生命值来设定不同的飞机样式，也能够通过此类方法。