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仿《雷霆战机》飞行射击手游开发--子弹、跟踪导弹和激光

转载请注明:http://www.cnblogs.com/thorqq/p/6563904.html
试玩版下载:https://pan.baidu.com/s/1mhLBNVa (Windows版)

飞机的武器类型众多,大致可分为子弹、跟踪导弹和激光。子弹是直线飞行的;导弹会自动跟踪目标,可曲线飞行;而激光是一道光束,可持续地对照射到的敌机产生伤害。子弹根据一次性发射的数量,可分为单发和多发,根据子弹发射的方向可分为:自动瞄准、平行、散射。本文将结合代码讲述有关飞机武器的程序设计。

程序设计

先看一下本游戏中有关武器的类的设计
类结构
其中,BulletGroup可理解为弹匣,Bullet就是其中一颗一颗的子弹,每颗子弹都有相同的属性,包括外观、伤害值以及飞行属性。而继承自Bullet的五个子类分别为:

  • ScatterBullet 散弹。含单发和多发,平行和散射。
  • AimScatterBullet 自动瞄准子弹。继承自ScatterBullet,但是初始发射角度指向距离最近的敌机(飞行轨迹是直线,发射后不会改变方向)。
  • CustomBullet 可自定义每颗子弹初始的方向、速度。
  • Missile 跟踪导弹。顾名思义,在飞行过程中会自动改变方向,始终对准敌机,但受限于飞行速度、角速度等参数,也可能无法射中目标。
  • Laser 激光。一道光束,伤害值依赖于接触的时间。

参数

下面是Bullet的所有参数,包含在结构体TBulletData中:

std::string name; //名称
std::string type; //类型:散弹、导弹、激光

std::vector<std::string> styleArray; //帧动画图片资源
float aniDura;//帧动画时间间隔

std::string armatureName; //骨骼动画名称

int topOfAircraft;//出现在飞机的上层还是下层
int musicId;//音效

int attack; //攻击值
int speed;  //飞行速度。单位:像素/秒

int count;//每次发射的子弹的颗数

int max_count;//最多发射多少颗子弹。当达到最大值时,停止发射或自动降档
float timeLimit; //时间限制。当达到这个时间时,停止发射或自动降档

float angle_of_center;//中心法线的角度。
float angle_interval;//多颗子弹同时发射时,这个角度就是相邻子弹间的夹角

float x_interval;//多颗子弹同时发射时,两两间的横向间距

float delay;//发射第一颗子弹时的延迟时间

//假设发射的顺序为:1.1.1...1.1.1...1.1.1... 其中“1”表示发射子弹,“.”表示间隔时间
//我们称“1.1.1...”是一个大周期,“1.1.1”是三个小周期
float interval;//大周期之间的时间间隔,这里是“...”代表的时间
float interval_2;//小周期之间的时间间隔,这里是“.”代表的时间
int interval_2_cnt;//小周期里子弹数量,这里是3

float rotate_angle; //连续发射时,每次发射偏转的角度
float rotate_max_angle;//最大累计偏转角度
int rotate_flag;//累计偏转角度达到最大值时的处理方法,0:逐渐减小偏转角度;1:立刻还原到零

float bodyCenterX;//碰撞体相对子弹中心点的坐标偏移
float bodyCenterY;
float bodySizeW;//碰撞体的大小
float bodySizeH;

//发射原点相对飞机中心点的坐标偏移
float origin_offset_x;
float origin_offset_y;

std::vector<std::string> fireFameNameArray; //尾部火焰动画,图片列表
float fireAniDura; //动画帧时长
int   fireOnTop; //尾部火焰显示在子弹的上层还是下层
float fireOffsetX;//火焰中心点相对于飞机底部中心点的偏移。如果等于0,则只有一个火焰;否则是两个火焰
float fireOffsetY;
	
std::vector<std::string> blastStyleArray;//子弹打到目标后产生的爆炸的帧动画资源列表

基类设计

Bullet

Bullet类很简单,仅仅用于维护子弹的外观,所以重要的只有bool Bullet::init(BulletGroup* pBulletGroup)这一个方法。详见如下代码:

class Bullet : public GameObject
{
public:
	friend class BulletGroup;

	static Bullet* create(BulletGroup* pBulletGroup);

	//根据pBulletGroup中的子弹相关属性创建子弹
	virtual bool init(BulletGroup* pBulletGroup);
	virtual void reset();

protected:
	Bullet();
	virtual ~Bullet();

	//添加尾部的左右两个火焰动画
	bool addFire(float offsetX, float offsetY, bool isFlipped);

protected:
	cocostudio::Armature* m_pArmature;
	BulletGroup* m_pBulletGroup;
	bool m_bBlast;
};

Bullet::Bullet()
{
	reset();
}

Bullet::~Bullet()
{
}

void Bullet::reset()
{
	GameObject::reset();

	m_pArmature = nullptr;
	m_pBulletGroup = NULL;
	m_bBlast = false;
}

Bullet* Bullet::create(BulletGroup* pBulletGroup)
{
	Bullet *pRet = new(std::nothrow) Bullet();
	if (pRet && pRet->init(pBulletGroup))
	{
		pRet->autorelease();
		return pRet;
	}
	else
	{
		delete pRet;
		pRet = NULL;
		return NULL;
	}
}

//根据pBulletGroup中的子弹相关属性创建子弹
bool Bullet::init(BulletGroup* pBulletGroup)
{
	m_pBulletGroup = pBulletGroup;
	bool bRet = false;
	do
	{
		CC_BREAK_IF(!GameObject::init());

		if (m_pBulletGroup->m_data.topOfAircraft)
		{
			m_pBulletGroup->getParent()->addChild(this, CONSTANT::ZORDER_BULLET_ONTOP);
		}
		else
		{
			if (m_pBulletGroup->getPlane()->getAircraftType() == EAircraftType::Type_Enemy)
			{
				m_pBulletGroup->getParent()->addChild(this, CONSTANT::ZORDER_BULLET_ENEMY);
			}
			else
			{
				m_pBulletGroup->getParent()->addChild(this, CONSTANT::ZORDER_BULLET_PLAYER);
			}
		}


		setBodyCenter(m_pBulletGroup->getBodyCenter());
		setBodySize(m_pBulletGroup->getBodySize());

		GameObject::initSpriteWithFileList(m_pBulletGroup->m_data.styleArray, m_pBulletGroup->m_data.aniDura);

		if (m_pBulletGroup->m_data.armatureName.length() > 0)
		{
			m_pArmature = cocostudio::Armature::create(m_pBulletGroup->m_data.armatureName);
			m_pArmature->setPosition(getContentSize() / 2);
			m_pArmature->getAnimation()->play(GlobalData::getInstance()->getArmatureData(m_pBulletGroup->m_data.armatureName)->defaultAction);

			addChild(m_pArmature);
		}
		else
		{
			if (m_pBulletGroup->m_data.fireFameNameArray.size() > 0)
			{
				m_pBulletGroup->m_data.fireOffsetX = abs(m_pBulletGroup->m_data.fireOffsetX);

				if (m_pBulletGroup->m_data.fireOffsetX > 0.01)
				{
					addFire(+m_pBulletGroup->m_data.fireOffsetX, m_pBulletGroup->m_data.fireOffsetY, false);
					addFire(-m_pBulletGroup->m_data.fireOffsetX, m_pBulletGroup->m_data.fireOffsetY, true);
				}
				else
				{
					addFire(0, m_pBulletGroup->m_data.fireOffsetY, false);
				}
			}
		}

		bRet = true;
	} while (0);

	return bRet;
}

bool Bullet::addFire(float offsetX, float offsetY, bool isFlipped)
{
	Sprite* fire = GameObject::createSpriteWithFileList(
		m_pBulletGroup->m_data.fireFameNameArray, m_pBulletGroup->m_data.fireAniDura);

	//子弹的飞行速度比较快,所以火焰不需要动画
	//if (m_pBulletGroup->m_data.fireFameNameArray.size() == 1)
	//{
	//	ScaleTo* pScale1 = ScaleTo::create(m_pBulletGroup->m_data.fireAniDura, 1.0f, 0.9f);
	//	ScaleTo* pScale2 = ScaleTo::create(m_pBulletGroup->m_data.fireAniDura, 1.0f, 1.0f);
	//	Sequence* sequence = Sequence::create(pScale1, pScale2, NULL);
	//	Repeat* repeat = Repeat::create(sequence, CC_REPEAT_FOREVER);
	//	fire->runAction(repeat);
	//}

	//添加
	if (m_pBulletGroup->m_data.fireOnTop)
	{
		addChild(fire);
	}
	else
	{
		addChild(fire, CONSTANT::ZORDER_PLAYERPLANE_FIRE);
	}

	//镜像翻转
	if (isFlipped)
	{
		fire->setFlippedX(true);
	}
	//位置
	fire->setPosition(Vec2(getContentSize().width / 2 + offsetX, offsetY));

	return true;
}

BulletGroup

BulletGroup是比较重要的类,包含了子弹的基本参数(结构体TBulletData,用于”复制“出一颗一颗的子弹)、发射动作、与飞机以及敌机间的关系。详细代码如下:

//子弹的基类。内部维护了一个子弹池
class BulletGroup : public GameObjectContainer
{
public:
	friend class Bullet;
	friend class Missile;
	friend class Laser;

	BulletGroup();
	virtual ~BulletGroup();

	virtual bool init(Node* pParent, Aircraft* pPlane, const TBulletData* pData);
	virtual void reset();
	virtual void destory();

	//开始射击
	virtual void startShoot();
	//发射指定数量的子弹
	virtual void startShoot(int cnt);
	//停止射击
	virtual void stopShoot();
	//是否正在射击
	virtual bool isShooting();

	//从子弹池中删除一颗子弹。超出屏幕范围,或者击中目标
	virtual void RemoveBullet(Bullet* pBullet);
	//爆炸
	virtual void blast(Bullet* pBullet);

	//当对方飞机增加或者减少时,通知导弹
	virtual void nodifyTargetRemove(Aircraft* pAircraft) {}

	//注册子弹用完监听器
	void regBulletUseUpListener(IBulletUseUpListener* l);
	void notifyBulletUseUp();
	inline bool isUseUp() { return m_bIsUseUp; }

public:
	//子弹飞出屏幕后的完成动作(内部函数)
	virtual void bulletMoveFinished(Node* pSender);

	inline int getAttack()
	{
		return m_data.attack;
	}

	inline void setAttack(int a)
	{
		m_data.attack = a;
	}

	inline void setPlane(Aircraft* plane)
	{
		m_plane = plane;
	}

	inline Aircraft* getPlane()
	{
		return m_plane;
	}

	inline void setOtherSidePlane(Vector<Aircraft*>* const planes)
	{
		m_otherSideArray = planes;
	}

	virtual void update(float dt) override;

protected:

	//发射一次子弹(可能会包含多颗子弹)
	virtual void AddBullet(float dt) {};

	//从子弹池中获取一颗子弹
	virtual Bullet* getOneBullet();

	float getPara(const char* const param);

	bool isSameGroup() { return m_bSameGroup; }
protected:

	TBulletData m_data;

	int m_iCount;
	int m_iAvailableBullet;
	bool m_bIsShooting;
	Aircraft* m_plane;
	Vector<Aircraft*> * m_otherSideArray;

	int m_iIntervalCnt; //小间隔子弹发射次数
	float m_iTimeCum;   //时间累计
	float m_iTimeCumThisGrade;   //本等级下的时间累计
	bool m_bFirstShoot; //

	bool m_bSameGroup;  //是否在同一个大间隔内

	IBulletUseUpListener* m_pBulletUseUpListener;
	bool m_bIsUseUp;
	float m_timeLimitAdd;
};


BulletGroup::BulletGroup()
{
	this->reset();
}

BulletGroup::~BulletGroup()
{
}

void BulletGroup::reset()
{
	m_data.reset();

	m_iCount = 0;
	m_bIsShooting = false;
	m_plane = NULL;
	m_otherSideArray = NULL;
	m_iAvailableBullet = 0;

	m_iIntervalCnt = 0;
	m_iTimeCum = 0;
	m_iTimeCumThisGrade = 0;
	m_bFirstShoot = false;

	m_pBulletUseUpListener = NULL;
	m_bIsUseUp = false;
	m_timeLimitAdd = 0;
}

bool BulletGroup::init(Node* pParent, Aircraft* pPlane, const TBulletData* pData)
{
	bool bRet = false;
	do
	{
		CC_BREAK_IF(!GameObjectContainer::init());

		setPlane(pPlane);
		m_data.clone(*pData);

		Node::setName(m_data.type);

		if (m_data.topOfAircraft)
		{
			pParent->addChild(this, CONSTANT::ZORDER_BULLET_ONTOP);
		}
		else
		{
			if (pPlane->getAircraftType() == EAircraftType::Type_Enemy)
			{
				pParent->addChild(this, CONSTANT::ZORDER_BULLET_ENEMY);
			}
			else
			{
				pParent->addChild(this, CONSTANT::ZORDER_BULLET_PLAYER);
			}
		}

		//body
		Vec2 center(m_data.bodyCenterX, m_data.bodyCenterY);
		setBodyCenter(center);

		//如果没有设置刚体大小,则默认是图片尺寸的60%
		Size size(m_data.bodySizeW, m_data.bodySizeH);
		if (fabs(size.width) < 0.01 || fabs(size.height) < 0.01)
		{
			size.width = this->getContentSize().width * 0.6f;
			size.height = this->getContentSize().height * 0.6f;
		}
		setBodySize(size);

		//获取对方飞机列表
		m_otherSideArray = pPlane->getOtherSidePlane();

		if (pPlane->getAircraftType() == EAircraftType::Type_Enemy)
		{
			m_timeLimitAdd = GameData::getInstance()->getValueToFloat(GAMEDATA::REINFORCE_VALUE_RAMPAGE_DURA);
		}

		bRet = true;
	} while (0);

	return bRet;
}

void BulletGroup::destory()
{
	if (this->m_plane == NULL)
	{
		int i = 0;

		for (i = 0; i < getAllObject()->count(); i++)
		{
			Bullet* p = dynamic_cast<Bullet*>(getAllObject()->getObjectAtIndex(i));

			if (p != NULL && p->isVisible())
			{
				//无需释放
				return;
			}
		}

		if (getAllObject()->count() == i)
		{
			for (i = 0; i < getAllObject()->count(); i++)
			{
				Bullet* p = dynamic_cast<Bullet*>(getAllObject()->getObjectAtIndex(i));

				if (p != NULL)
				{
					p->destory();
				}
			}

			getAllObject()->removeAllObjects();
			
			removeFromParent();
		}
	}
}

void BulletGroup::startShoot()
{
	m_bIsShooting = true;

	this->scheduleUpdate();
}

void BulletGroup::startShoot(int cnt)
{
	m_bIsShooting = false;
	m_iCount = 0;
	m_iIntervalCnt = 0;
	m_iTimeCum = 0;
	m_iTimeCumThisGrade = 0;
	m_bFirstShoot = 0;
	m_bSameGroup = false;
	m_bIsUseUp = false;

	m_data.max_count = cnt;
	m_bIsShooting = true;

	this->scheduleUpdate();
}

void BulletGroup::stopShoot()
{
	unscheduleUpdate();
	unscheduleAllCallbacks();

	m_bIsShooting = false;
}

bool BulletGroup::isShooting()
{
	return m_bIsShooting;
}

void BulletGroup::update(float dt)
{
	m_iTimeCum += dt;
	m_iTimeCumThisGrade += dt;

	if (m_data.timeLimit > 0 && m_iTimeCumThisGrade > m_data.timeLimit + m_timeLimitAdd)
	{
		m_bIsUseUp = true;
		m_iTimeCumThisGrade = 0;
		this->notifyBulletUseUp();
		this->stopShoot();
		return;
	}

	if (!m_bFirstShoot && m_iTimeCum < m_data.delay && m_data.delay >= 0.00001) //还没进行第一次发射,等待延迟
	{
		return;
	}
	else if (!m_bFirstShoot && m_iTimeCum >= m_data.delay && m_data.delay >= 0.00001) //第一次发射,超时了
	{
		m_iTimeCum -= m_data.delay;
		m_bFirstShoot = true;

		m_iIntervalCnt++;
		if (Sound::isBulletSound())
		{
			Sound::playSound(m_data.musicId);
		}
		m_bSameGroup = true;
		AddBullet(dt);
		return;
	}

	//小间隔内
	if (m_iIntervalCnt < m_data.interval_2_cnt)
	{
		if (m_iTimeCum >= m_iIntervalCnt * m_data.interval_2)
		{
			m_iIntervalCnt++;
			if (Sound::isBulletSound())
			{
				Sound::playSound(m_data.musicId);
			}

			m_bSameGroup = true;
			AddBullet(dt);
			return;
		}

	}
	else //大间隔
	{
		if (m_iTimeCum >= m_data.interval_2_cnt * m_data.interval_2 + m_data.interval)
		{
			m_iIntervalCnt = 1;
			m_iTimeCum = 0;
			if (Sound::isBulletSound())
			{
				Sound::playSound(m_data.musicId);
			}

			m_bSameGroup = false;
			AddBullet(dt);
			return;
		}
	}
}

Bullet* BulletGroup::getOneBullet()
{
	if (!m_bIsShooting)
	{
		return NULL;
	}

	if (m_data.max_count > 0 && m_iCount >= m_data.max_count)
	{
		m_bIsUseUp = true;
		this->notifyBulletUseUp();

		return NULL;
	}

	int i = 0;
	int size = getAllObject()->count();
	for (; i < size; i++)
	{
		Bullet* p = dynamic_cast<Bullet*>(m_pAllObject->getObjectAtIndex(i));

		if (p != NULL && p->isVisible() == false)
		{
			p->setVisible(true);
			p->startAnimate();
			m_iAvailableBullet++;
			m_iCount++;
			return p;
		}
	}

	if (m_pAllObject->count() == i)
	{
		Bullet* pBullet = Bullet::create(this);
		m_pAllObject->addObject(pBullet);
		m_iAvailableBullet++;
		m_iCount++;
		//CCLOG("Add bullet[%s], size = %d", Node::getName().c_str(), m_pAllObject->count());
		return pBullet;
	}

	return NULL;
}

//击中目标后爆炸并删掉
void BulletGroup::blast(Bullet* pBullet)
{
	//在父层中生成爆炸动画
	PlaneLayer* pLayer = dynamic_cast<PlaneLayer*>(getParent());
	if (NULL != pLayer)
	{
		Rect rect = pBullet->getBodyBox();
		Vec2 pos(rect.getMidX(), rect.getMidY());

		//击中的爆炸动画
		pLayer->addBlast(this->getLocalZOrder(), pos, m_data.blastStyleArray, m_data.blastAniDura);

		//粒子效果。TODO 后续要使用particle表里读取粒子配置
		ParticleSystemQuad *emitter1 = ParticleSystemQuad::create("img/blast/hitEnemy.plist");
		emitter1->setPosition(pos);    // 设置发射粒子的位置  
		emitter1->setAutoRemoveOnFinish(true);                          // 完成后制动移除  
		emitter1->setDuration(0.3f);                                      // 设置粒子系统的持续时间秒  

		pLayer->addChild(emitter1, getLocalZOrder() + 1);
	}
	
	RemoveBullet(pBullet);
}

//子弹飞出屏幕后删掉
void BulletGroup::bulletMoveFinished(Node* pSender)
{
	RemoveBullet((Bullet*)pSender);
}

void BulletGroup::RemoveBullet(Bullet* pBullet)
{
	if (pBullet != NULL)
	{
		pBullet->stopAllActions();
		pBullet->setVisible(false);
		Node* parent = getParent();

		m_iAvailableBullet--;

		int size = getAllObject()->count();
		int i = 0;
		for (; i < size; i++)
		{
			Bullet* p = dynamic_cast<Bullet*>(m_pAllObject->getObjectAtIndex(i));
			
			if (p != NULL && p->isVisible() == true && m_iAvailableBullet <= 0)
			{
				return;
			}
		}

	}

	//清除本对象
	if (m_plane == NULL && m_iAvailableBullet <= 0 && getParent() != NULL && !this->isShooting())
	{
		int size = getAllObject()->count();
		int i = 0;
		for (; i < size; i++)
		{
			Bullet* p = dynamic_cast<Bullet*>(m_pAllObject->getObjectAtIndex(i));
			p->m_pBulletGroup = NULL;
			p->getParent()->removeChild(p);
		}

		PlaneLayer* layer = dynamic_cast<PlaneLayer*>(getParent());
		getParent()->removeChild(this);
		if (layer)
		{
			layer->removeBullet(this);
		}
	}

}

void BulletGroup::regBulletUseUpListener(IBulletUseUpListener* l)
{
	m_pBulletUseUpListener = l;
}

void BulletGroup::notifyBulletUseUp()
{
	if (m_pBulletUseUpListener != NULL)
	{
		m_pBulletUseUpListener->bulletUseUp();
	}
}

float BulletGroup::getPara(const char* const param)
{
	auto it = m_data.paramMap.find(param);
	if (it != m_data.paramMap.end())
	{
		return it->second;
	}
	else
	{
		return 0;
	}
}

子弹的每次发射的时间点控制在update方法中,其中使用到了延时delay、大小周期intervalinterval_2interval_2_cnt等相关参数。当确定好每次发射的时间点后,会通过AddBullet来添加一颗子弹,放在某个位置上,并让其发射出去,具体的放置位置和发射的角度速度等参数留给子类来实现,这里仅仅定义一个空方法:virtual void AddBullet(float dt) {};。从方法RemoveBullet可以看到,当子弹飞出屏幕或者击中目标时,我们销毁子弹的方法仅仅是停止其动画效果,并设置为不可见,这样可以减少频繁创建/销毁子弹带来的性能损失。当子弹用完时,会通过方法notifyBulletUseUp来通知飞机,这样,飞机就会对子弹进行降档,例如从暴走状态恢复到普通状态。

下面我们看看散弹、跟踪导弹、激光等各个子类的具体实现。

散弹

最简单的散弹就是每次只发射一颗子弹,并且所有子弹都朝着一个不变的方向飞行,看起来就像一条直线。当每次发射两颗或多颗子弹时,看起来就是两条或多条直线,这多条直线或平行,或相邻之间存在一个固定的夹角。在代码中是通过angle_interval参数来控制的。

还有一种偏转角度随时间变化的散弹,即每发射一颗子弹,其飞行角度都会向某个方向偏转一个固定的角度,当达到一个最大角度值时,又会逐渐减小偏转角度,看起来就像个“之”字形。如果最大偏转角度不存在时,子弹轨迹看起来就是个螺旋形状了。在代码中是通过rotate_anglerotate_max_angle来控制的。 下面我们看下具体代码。

//可自定义子弹的个数、夹角、偏移
class ScatterBullet : public BulletGroup
{
public:
	ScatterBullet();

	virtual bool init(Node* pParent, Aircraft* pPlane, const TBulletData* pData);
	virtual void reset();

protected:
	//发射一次子弹
	virtual void AddBullet(float dt) override;
	//计算发射中心线的角度
	virtual float calculateCenterLineDegree(Bullet* pBullet, Vec2& src);
	//发射一颗子弹
	virtual bool AddBulletOne(Vec2& srcOffset, float degree);

protected:
	float m_flyDistance;
	long m_shootCnt;
	int m_shootAddFlag;
};


ScatterBullet::ScatterBullet()
	: m_flyDistance(0)
	, m_shootCnt(0)
	, m_shootAddFlag(0)
{

}

void ScatterBullet::reset()
{
	BulletGroup::reset();

	m_flyDistance = 0;
	m_shootCnt = 0;
	m_shootAddFlag = 0;
}

bool ScatterBullet::init(Node* pParent, Aircraft* pPlane, const TBulletData* pData)
{
	bool bRet = false;
	do
	{
		CC_BREAK_IF(!BulletGroup::init(pParent, pPlane, pData));

		m_flyDistance = CONSTANT::DESIGN_RES_DIAGONAL;
		m_shootAddFlag = 1;

		if (m_data.count < 0)
		{
			m_data.count = 1;
		}

		bRet = true;
	} while (0);

	return bRet;
}

void ScatterBullet::AddBullet(float dt)
{
	m_shootCnt += m_shootAddFlag;

	float angleLeft = 0;
	float offsetXLeft = 0;
	if (m_data.count % 2 == 0)//偶数
	{
		//计算最左边的子弹的夹角、偏移
		angleLeft = m_data.angle_interval / 2 + (m_data.count / 2 - 1) * m_data.angle_interval;
		offsetXLeft = -1 * (m_data.x_interval / 2 + (m_data.count / 2 - 1)*m_data.x_interval);
	}
	else //奇数
	{
		angleLeft = (m_data.count - 1) / 2 * m_data.angle_interval;
		offsetXLeft = -1 * (m_data.count - 1) / 2 * m_data.x_interval;
	}

	float offsetAngle = 0;
	if (m_data.angle_of_center > 0 && m_data.angle_of_center < 180)
	{
		offsetAngle = m_data.angle_of_center - 90;
	}
	else
	{
		offsetAngle = m_data.angle_of_center - 270;
	}

	for (int i = 0; i < m_data.count; i++)
	{
		float a = angleLeft - m_data.angle_interval * i;

		float l = offsetXLeft + m_data.x_interval * i;
		float x = l * cos(CC_DEGREES_TO_RADIANS(offsetAngle));
		float y = -l * sin(CC_DEGREES_TO_RADIANS(offsetAngle));
		Vec2 v(m_data.origin_offset_x + x, m_data.origin_offset_y + y);		
		if (!AddBulletOne(v, a))
		{
			break;
		}
	}
}

float ScatterBullet::calculateCenterLineDegree(Bullet* pBullet, Vec2& src)
{
	float angle = (m_shootCnt - 1) * m_data.rotate_angle;
	if (fabs(angle) > m_data.rotate_max_angle && m_data.rotate_max_angle >= 1)
	{
		if (m_data.rotate_flag == 0)
		{
			//m_shootAddFlag = -m_shootAddFlag;
			if (angle * m_data.rotate_angle > 0)
			{
				m_shootAddFlag = -1;
			}
			else
			{
				m_shootAddFlag = 1;
			}
		}
		else
		{
			m_shootCnt = 0;
			m_shootAddFlag = 1;
		}
	}

	return m_data.angle_of_center + angle;
}

//degree 角度偏移。正数表示逆时针,负数表示顺时针
bool ScatterBullet::AddBulletOne(Vec2& srcOffset, float degree)
{
	//添加一个子弹精灵
	Bullet* pBullet = BulletGroup::getOneBullet();
	if (!pBullet || !getPlane())
	{
		return false;
	}

	//子弹的位置
	Vec2 src;
	if (getPlane()->getAircraftType() == EAircraftType::Type_Wingman) //僚机
	{
		Aircraft* pMainPlane = dynamic_cast<Aircraft*>(getPlane()->getParent());

		src = pMainPlane->getPosition() + getPlane()->getPosition() - pMainPlane->getContentSize() / 2;
	}
	else //非僚机
	{
		src = getPlane()->getPosition();
	}

	src.y += srcOffset.y;

	if (m_data.count == 1)
	{
		if (m_data.angle_of_center > 0 && m_data.angle_of_center < 180)
		{
			src.x += srcOffset.x;
		}
		else
		{
			src.x += -srcOffset.x;
		}
	}

	//这一句必须要放在src.x += srcOffset.x之前
	float centerLineDegree = calculateCenterLineDegree(pBullet, src)/* + offsetDegree*/;

	if (m_data.count > 1)
	{
		if (m_data.angle_of_center > 0 && m_data.angle_of_center < 180)
		{
			src.x += srcOffset.x;
			src.y += pBullet->getContentSize().height / 2;
		}
		else
		{
			src.x += -srcOffset.x;
			src.y -= pBullet->getContentSize().height / 2;
		}
	}
	pBullet->setPosition(src);


	if (sinf(CC_DEGREES_TO_RADIANS(m_data.angle_of_center)) > 0)
	{
		pBullet->setRotation(90 - (centerLineDegree + degree));
	}
	else
	{
		pBullet->setRotation(90 - (centerLineDegree + degree) + 180);
	}

	if (degree > 0)
	{
		pBullet->setFlippedX(true);
	}

	//body
	Vec2& pos = m_bodyCenter;
	Vec2 pos2;
	pos2.x = sqrt(pow(pos.x, 2) + pow(pos.y, 2)) * cos(CC_DEGREES_TO_RADIANS(centerLineDegree + degree));
	pos2.y = sqrt(pow(pos.x, 2) + pow(pos.y, 2)) * sin(CC_DEGREES_TO_RADIANS(centerLineDegree + degree));
	pBullet->setBodyCenter(pos2);
	pBullet->setBodySize(getBodySize());

	//子弹飞出屏幕所需的距离、飞行速度、飞行时间
	float realMoveDuration = m_flyDistance / m_data.speed;

	//在realMoveDuration时间内,飞到指定位置
	float deltaX = m_flyDistance * cos(CC_DEGREES_TO_RADIANS(centerLineDegree + degree));
	float deltaY = m_flyDistance * sin(CC_DEGREES_TO_RADIANS(centerLineDegree + degree));

	Vec2 dest = Vec2(src.x + deltaX, src.y + deltaY);
	FiniteTimeAction* actionMove = CCMoveTo::create(realMoveDuration, dest);
	FiniteTimeAction* actionDone = CallFuncN::create(CC_CALLBACK_0(BulletGroup::bulletMoveFinished, this, pBullet));

	//开始执行动作
	Sequence* sequenceL = Sequence::create(actionMove, actionDone, NULL);
	pBullet->runAction(sequenceL);

	return true;
}

跟踪导弹

跟踪导弹是一种特殊的子弹,当发射出导弹时,它首先会自动寻找并锁定距离最近敌机,然后从一个初速度开始,加速飞向目标(普通子弹是匀速飞行)。由于目标是运动的,所以导弹还具备自动调整飞行角度的能力。但是,导弹还存在转弯半径这个限制,即导弹并不能任意转弯,它存在角速度参数,每个单位时间内最大只能偏转一个固定的角度。上述所有的逻辑都在Missile类的update方法中,详见下面的代码:

void Missile::update(float dt)
{
	if (!this->isVisible() || m_pBulletGroup == NULL)
	{
		return;
	}

	//飞出屏幕
	const Rect& rect = this->getBoundingBox();
	const Size& windowSize = Director::getInstance()->getWinSize();
	if (rect.getMinX() > windowSize.width || rect.getMaxX() < 0
		|| rect.getMinY() > windowSize.height || rect.getMaxY() < 0)
	{
		m_pBulletGroup->bulletMoveFinished(this);
		return;
	}

	//寻找距离最近,且夹角小于70度的敌机
	if ((!m_pEnemy || !m_pEnemy->isAlive()) && m_pBulletGroup && m_pBulletGroup->m_otherSideArray)
	{
		((MissileGroup*)m_pBulletGroup)->searchEnemy(this);
	}

	float f = 0;
	if (m_pEnemy && m_pEnemy->isAlive())
	{
		//转向目标
		float curRot = getRotation();
		float angle = -CC_RADIANS_TO_DEGREES((getPosition() - m_pEnemy->getPosition()).getAngle());
		float tmpAngle = angle;
		if (angle - 90 - curRot < -90 && angle - 90 - curRot + 360 < 90)
		{
			angle += 360;
		}
		else if (angle - 90 - curRot > 90 && angle - 90 - curRot - 360 > -90)
		{
			angle -= 360;
		}
		else
		{
			if (fabsf(m_fLastAngle - angle) > 180)
			{
				if (m_fLastAngle > 0)
				{
					angle += 360;
				}
				else if (m_fLastAngle < 0)
				{
					angle -= 360;
				}
			}
		}

		m_fLastAngle = angle;

		//最大偏转角度
		float angleDif = std::min(std::max((angle - 90) - curRot, -m_fTurnRate*dt), m_fTurnRate*dt);
		f = curRot + angleDif;
		//DEBUG_LOG("Missile[%p,%.0f,%.0f] aimed emeny[%p,%.0f,%.0f], "
		//	"angle[%.2f, %.2f],max[%.2f], curRot[%.2f],angleDif[%.2f],f[%.2f]",
		//	this, getPosition().x, getPosition().y,
		//	m_pEnemy, m_pEnemy->getPosition().x, m_pEnemy->getPosition().y,
		//	tmpAngle, angle, m_fTurnRate*dt, curRot, angleDif, f);

	}
	
	if (!m_pEnemy || !m_pEnemy->isAlive())
	{
		f = getRotation();
		//DEBUG_LOG("Missile[%p,%.0f,%.0f] aimed emeny[NULL], angle[%f]", 
		//	this, getPosition().x, getPosition().y, f);
	}

	setRotation(f);
	setPosition(getPosition() + 
		Vec2(sinf(CC_DEGREES_TO_RADIANS(f))*m_fVelocity, cosf(CC_DEGREES_TO_RADIANS(f))*m_fVelocity)
		* Director::getInstance()->getScheduler()->getTimeScale());

	Vec2 pos2;
	float dd = sqrt(pow(m_bodyCenter.x, 2) + pow(m_bodyCenter.y, 2));
	pos2.x = dd * cos(CC_DEGREES_TO_RADIANS(90 - f));
	pos2.y = dd * sin(CC_DEGREES_TO_RADIANS(90 - f));
	this->setBodyCenter(pos2);

	//当子弹旋转超过45°时,宽高值交换
	if (fabsf(f) > 45 && fabsf(f) < 135)
	{
		Size size = getOrignBodySize();
		float tmp = size.width;
		size.width = size.height;
		size.height = tmp;
		this->setBodySize(size);
	}

	m_fVelocity += m_fAccel*dt;
}

激光

激光看似与普通子弹或者导弹完全不同,但是仔细分析下来,也可以看成是一颗特殊的子弹:

  1. 激光始终都只是一颗子弹(并没有多颗子弹)
  2. 激光外形是一个长度可变的矩形。最大长度是屏幕的高度,当遇到敌机时,激光的长度是从飞机到敌机之间的距离
  3. 激光对目标产生的伤害依赖于其接触目标的时间,并具有线性关系。
    通过以上分析,可以得到激光最与众不同的地方在于其外观的可变性,下面是具体的代码:
bool Laser::init(BulletGroup* pBulletGroup)
{
	if (!GameObject::init())
	{
		return false;
	}

	m_pBulletGroup = pBulletGroup;
	//int planeZOrder = m_pBulletGroup->m_plane->getLocalZOrder();
	if (m_pBulletGroup->getPlane()->getAircraftType() == EAircraftType::Type_Killer)
	{
		m_pBulletGroup->getParent()->addChild(this, CONSTANT::ZORDER_BULLET_KILLER);
	}
	else if (m_pBulletGroup->getPlane()->getAircraftType() == EAircraftType::Type_Player)
	{
		m_pBulletGroup->getParent()->addChild(this, CONSTANT::ZORDER_BULLET_PLAYER);
	}
	else
	{
		int planeZOrder = CONSTANT::ZORDER_BULLET_PLAYER;
		m_pBulletGroup->getParent()->addChild(this, planeZOrder - 1);
	}

	//这里不能用createWithSpriteFrameName,否则激光会变成一段一段的(中间有黑色间隙)
	Sprite* pLaserNode = Sprite::create(m_pBulletGroup->m_data.styleArray.at(0));

	m_fWidth = pLaserNode->getContentSize().width;//宽度
	m_fHeight = CONSTANT::DESIGN_RES_HEIGHT + 50;//初始长度,理论上是无限高,这里只需要大于屏幕的高度即可

	//设置刚体的大小
	setBodySize(Size(pBulletGroup->getBodySize().width, m_fHeight)); 
	setBodyCenter(pBulletGroup->getBodyCenter());

	setContentSize(Size(pBulletGroup->getBodySize().width, m_fHeight));

	//计算纹理的个数
	int cnt = (int)(m_fHeight / pLaserNode->getContentSize().height + 0.9999);
	//实际高度
	float h = cnt * pLaserNode->getContentSize().height;

	//高度调整为2的n次方
	h = toPOT(h);
	cnt = (int)(h / pLaserNode->getContentSize().height + 0.9999);

	// 1: Create new CCRenderTexture
	int potW = toPOT(m_fWidth);
	RenderTexture *rt = RenderTexture::create(potW, h);

	// 2: Call CCRenderTexture:begin
	rt->begin();

	//开始贴图
	pLaserNode->setFlippedY(true);
	pLaserNode->setPosition(Vec2(m_fWidth / 2, pLaserNode->getContentSize().height / 2));
	pLaserNode->visit();

	for (int i = 1; i < cnt; i++)
	{
		//这里不能用createWithSpriteFrameName,否则激光会变成一段一段的(中间有黑色间隙)
		Sprite* pLaserNode2 = Sprite::create(m_pBulletGroup->m_data.styleArray.at(0));
		pLaserNode2->setFlippedY(true);
		pLaserNode2->setPosition(Vec2(m_fWidth / 2, 
			pLaserNode->getContentSize().height / 2 + pLaserNode->getContentSize().height * i));
		pLaserNode2->visit();
	}

	// 4: Call CCRenderTexture:end
	rt->end();

	// 5: Create a new Sprite from the texture
	m_pLaser = Sprite::createWithTexture(rt->getSprite()->getTexture());

	m_pLaser->setTextureRect(Rect(0, 0, m_fWidth, m_fHeight));

	Texture2D::TexParams tp = { GL_LINEAR, GL_LINEAR, GL_REPEAT, GL_REPEAT };
	m_pLaser->getTexture()->setTexParameters(tp);

	m_pLaser->setAnchorPoint(Vec2(0.5, 0));
	m_pLaser->setPosition(Vec2(getContentSize().width / 2, 0));
	addChild(m_pLaser);

	//添加爆炸点
	m_pBlast = GameObject::createSpriteWithFileList(m_pBulletGroup->m_data.blastStyleArray, m_pBulletGroup->m_data.blastAniDura);
	if (m_pBlast)
	{
		m_pBlast->setPosition(Vec2(getBodySize().width / 2, getBodySize().height));
		addChild(m_pBlast);
	}

	scheduleUpdate();

	return true;
}

void Laser::rejustHeight(float fMinY)
{
	if (m_pBulletGroup && m_pBulletGroup->m_plane)
	{
		//根据敌机的位置计算激光的高度
		m_fHeight = fMinY - m_pBulletGroup->m_plane->getPosition().y;
		if (m_fHeight < 0)
		{
			m_fHeight = CONSTANT::DESIGN_RES_HEIGHT + 200;
		}
		setBodySize(Size(m_pBulletGroup->getBodySize().width, m_fHeight));
		if (m_pBlast)
		{
			m_pBlast->setPosition(Vec2(getBodySize().width / 2, getBodySize().height));
		}
	}
}

void Laser::update(float dt)
{
	if (!this->isVisible() || m_pBulletGroup == NULL)
	{
		return;
	}

	//计算当前位置
	setBodySize(Size(getBodySize().width, CONSTANT::DESIGN_RES_HEIGHT));

	m_fTmpOffset += m_pBulletGroup->m_data.speed * dt;

	const Size& textureSize = m_pLaser->getTextureRect().size;
	m_pLaser->setTextureRect(Rect(0, m_fTmpOffset, textureSize.width, m_fHeight));
	
}

其中,init用于创建激光外观,这里通过{ GL_LINEAR, GL_LINEAR, GL_REPEAT, GL_REPEAT }来创建一个重复的纹理,然后在update中让纹理不停的向上滚动。在rejustHeight中,我们根据目标的Y轴坐标来计算激光的高度,并在激光接触目标的位置增加一个击中效果的贴图。

转载请注明:http://www.cnblogs.com/thorqq/p/6563904.html
本文相关源码:http://files.cnblogs.com/files/thorqq/Bullet.rar

posted on 2017-03-20 22:36  雁惊寒  阅读(693)  评论(0编辑  收藏