Cocos2d-X游戏【泰然网《跑酷》】JS到C++移植8： Jumping and Crouching

尊重开发者的劳动成果，转载的时候请务必注明出处：http://blog.csdn.net/haomengzhu/article/details/17383997

<捕鱼达人>回顾

【cocos2d-x IOS游戏开发-捕鱼达人1】内容介绍

<城市跑酷>回顾

【cocos2d-x IOS游戏开发-城市跑酷1】跑酷游戏介绍

上节回顾

Cocos2d-X游戏【泰然网《跑酷》】JS到C++移植7：Gesture Recognizer【手势识别】

这一节中将介绍如何添加一些跑酷游戏的常用的一些控制方式。

在修改runner类之前首先要在Utils.h中添加如下代码

// collision type for chipmunk
enum SpriteTag{
    SpriteTagRunner,
    SpriteTagCoin,
    SpriteTagRock,
};

需要定义一个标记chipmunk碰撞检测的枚举类型

打开Runner.cpp,通过添加如下代码来完成RunnerStat的定义:

// define enum for runner status
//1.定义一个runner状态的枚举，跑步者有许多状态
enum RunnerStat
{
    RunnerStatRunning,
    RunnerStatJumpUp,
    RunnerStatJumpDown,
    RunnerStatCrouch,
    RunnerStatIncredible,
};

为runner类定义几个新的成员变量

CCSize crouchSize;

	cpSpace *space;
	cpBody *body;// current chipmunk body

	cpShape  *shape;// current chipmunk shape

	static RunnerStat stat;// init with running status

	CCAction *runningAction;
	CCAction *jumpUpAction;
	CCAction *jumpDownAction;
	CCAction *crouchAction;

当游戏角色蹲下的时候它的形状将会发生改变,下面的代码会记录蹲下时候的大小。 在init()中添加如下代码:

// init crouchSize
	CCPhysicsSprite *tmpSprite = CCPhysicsSprite::createWithSpriteFrameName("runnerCrouch0.png");
	crouchSize = tmpSprite->getContentSize();

改变initShape

// start with running shape
    //7.在initShape里,创建与精灵大小相等的chipmunk形状
    initShape("running");

当然还要修改initShape()中的代码。用下面的代码替换它的内容:

void Runner::initShape(const char* type) {
	if (shape) {
		//space.removeShape(this.shape);
		cpSpaceRemoveShape(space, shape);
	}

	if (type == "running") {
		shape = cpBoxShapeNew(body,
			runningSize.width - 14, runningSize.height);
	} else {
		// crouch
		shape = cpBoxShapeNew(body,
			crouchSize.width, crouchSize.height);
	}

	//shape = cpBoxShapeNew(body,
		//runningSize.width, runningSize.height);
	//shape->setCollisionType(SpriteTag.runner);
	shape->collision_type = SpriteTagRunner;

	cpSpaceAddShape(space, shape);
}

还有initAction()中的三个动画初始化函数:jumpUpAction, jumpDownAction和crouchAction

// init jumpUpAction
	CCAnimation* animation1;
	animation1 = CCAnimation::create();
	CCSpriteFrame * frame1;

	// num equal to spriteSheet
	for (unsigned int i = 0; i < 4; i++) {
		char str[100] = {0};
		sprintf(str, "runnerJumpUp%i.png", i);
		frame1 = CCSpriteFrameCache::sharedSpriteFrameCache()->spriteFrameByName(str);
		animation1->addSpriteFrame(frame1);
	}
	animation1->setDelayPerUnit(0.2f);
	jumpUpAction = CCAnimate::create(animation1);
	jumpUpAction->retain();

	// init jumpDownAction
	CCAnimation* animation2;
	animation2 = CCAnimation::create();
	CCSpriteFrame * frame2;
	// num equal to spriteSheet
	for (unsigned int i = 0; i < 2; i++) {
		char str[100] = {0};
		sprintf(str, "runnerJumpDown%i.png", i);
		frame2 = CCSpriteFrameCache::sharedSpriteFrameCache()->spriteFrameByName(str);
		animation2->addSpriteFrame(frame);
	}
	animation2->setDelayPerUnit(0.2f);
	jumpDownAction = CCAnimate::create(animation2);
	jumpDownAction->retain();

	// init crouchAction
	CCAnimation* animation3;
	animation3 = CCAnimation::create();
	CCSpriteFrame * frame3;
	// num equal to spriteSheet
	for (unsigned int i = 0; i < 1; i++) {
		char str[100] = {0};
		sprintf(str, "runnerCrouch%i.png", i);
		frame3 = CCSpriteFrameCache::sharedSpriteFrameCache()->spriteFrameByName(str);
		animation3->addSpriteFrame(frame3);
	}
	animation3->setDelayPerUnit(0.3f);
	crouchAction = CCAnimate::create(animation3);
	crouchAction->retain();

已经完成了初始化,然后要做的是在Runner类中添加下面的函数:

void Runner::jump()
{
	if (stat == RunnerStatRunning) {

		//this.body.applyImpulse(cp.v(0, 250), cp.v(0, 0));
		cpVect arg1 = cpv(0, 250); 
		cpVect arg2 = cpv(0, 0); 

		cpBodyApplyImpulse((cpBody*)body , (cpVect)arg1 , (cpVect)arg2);

		stat = RunnerStatJumpUp;

		sprite->stopAllActions();
		sprite->runAction(jumpUpAction);

		//播放音效
		//audioEngine->playEffect(s_music_jump);
	}
}

只需要给runner的body一个向上的冲力，runner就会跳起来，在将动画换成跳跃动画之前，通过调用sprite->stopAllActions()来停止当前动画。

跳跃的动作可以分为两个部分－－上升和下降。可以通过观察body的重心的线速度来检测从上升到下降状态的转换。

如果在Y轴的线速度小于0.1,跳跃的动作正在从上升状态切换到下降状态,这时将精灵的动画切换到jumpDownAction.

如果Y轴的线速度等于0说明精灵的从下降的状态切换到了跑动的状态,这时将精灵动画改成runningAction.

void Runner::step(float dt)
{
	//线速度
	cpVect vel = body->v;
	
	if (stat == RunnerStatJumpUp) {
		if (vel.y < 0.1) {
			stat = RunnerStatJumpDown;
			sprite->stopAllActions();
			sprite->runAction(jumpDownAction);
		}
		return;
	}
	if (stat == RunnerStatJumpDown) {
		if (vel.y == 0) {
			stat = RunnerStatRunning;
			sprite->stopAllActions();
			sprite->runAction(runningAction);
		}
		return;
	}
}

在蹲下的时候,只需要修改body的shape.把下面的函数添加到Runner类中:

void Runner::crouch()
{
	if (stat == RunnerStatRunning) {
		initShape("crouch");
		sprite->stopAllActions();
		sprite->runAction(crouchAction);

		stat = RunnerStatCrouch;
		// after time turn to running stat
		scheduleOnce(schedule_selector(Runner::loadNormal), 1.5f);

		//audioEngine.playEffect(s_music_crouch);
	}
}

蹲下的状态不会持续太长的时间,可以通过调用

scheduleOnce(schedule_selector(Runner::loadNormal), 1.5f);

来返回到跑动状态.

loadNormal() 初始化跑动状态下body的shape.可以这样做:

void Runner::loadNormal(float dt)
{
	initShape("running");
	sprite->stopAllActions();
	sprite->runAction(runningAction);
	stat = RunnerStatRunning;
}

现在已经完成了Runner.cpp,用下面代码替换PlayScene.cpp中的onTouchEnded函数:

switch (rtn) {
	case SimpleGesturesUp:
		CCLOG("Runner::jump");
		runner->jump();
		break;

	case SimpleGesturesDown:
		CCLOG("Runner::crouch");
		runner->crouch();
		break;

	case SimpleGesturesNotSupport:
	case SimpleGesturesError:
		// try dollar Recognizer
		// 0:Use Golden Section Search (original) 
		// 1:Use Protractor (faster)
#if 0
		var result = dollar.Recognize(this.recognizer.getPoints(), 1);
		CCLOG(result.Name);
		if (result.Name == "circle") {
			runner->incredibleHulk();
		}
#endif
		CCLOG("not support or error touch,use geometricRecognizer!!");
		runner->incredibleHulk();
#if 0
		//通过GeometricRecognizer校准
		//可以选择屏蔽玩家单击操作
		if (p_2dPath.size() < 1){
			return ;
		}

		RecognitionResult r = geometricRecognizer->recognize(p_2dPath);
		if((r.name != "Unknown") && (r.score > 0.5))
		{
			runner->incredibleHulk();
			//return;
		}
#endif

添加下面代码来切换动画:

// runner step, to change animation
	runner->step(delta);

编译运行之,上下滑动来看看跳跃和蹲下的效果。