《Cocos2d学习之路》七、场景切换效果TransitionScene

转载请说明出处：http://blog.youkuaiyun.com/lsmfeixiang/article/details/43411919

github地址：https://github.com/teffy/cocos2dx

这几天接着看了一下场景切换的效果TransitionScene，而cocos也在系统中提供了很多种不同的切换效果，那么我们先看一下TransitionScene的类继承关系图：

每一个类在cocos2d的官网文档中有说明

而且在官方demo的cpp-test中也有demo，我也跟着写了一遍

首先是要理解一下一些宏定义

#define STRINGIFY(x) #x
#define TRANS(__classname__){\//根据传入的类名构造一个结构体，结构体内有一个function和一个name，类似于java中XXX.class经过反射可以拿到很多东西
[](float t, Scene* s){ return __classname__::create(t,s);},\
STRINGIFY(__classname__),\
}

struct  transitions{//结构体
	std::function<TransitionScene*(float t, Scene* s)> function;
	const char* name;
}transitions[] = {//结构体数组，用来保存定义的类的create方法和name
	TRANS(MTransitionCrossFade),
	TRANS(MTransitionFade),
	TRANS(MTransitionFadeTR),
	TRANS(MTransitionFadeBL),
	TRANS(MTransitionFadeDown),
	TRANS(MTransitionFadeUp),
	TRANS(MTransitionJumpZoom),
	TRANS(MTransitionFlipAngular_DOWN),
	TRANS(MTransitionFlipAngular_LEFT),
	TRANS(MTransitionFlipAngular_RIGHT),
	TRANS(MTransitionFlipAngular_UP),
	TRANS(MTransitionFlipX_DOWN),
	TRANS(MTransitionFlipX_LEFT),
	TRANS(MTransitionFlipX_RIGHT),
	TRANS(MTransitionFlipX_UP),
	TRANS(MTransitionFlipY_DOWN),
	TRANS(MTransitionFlipY_LEFT),
	TRANS(MTransitionFlipY_RIGHT),
	TRANS(MTransitionFlipY_UP),
	TRANS(MTransitionZoomFlipAngular),
	TRANS(MTransitionZoomFlipX_DOWN),
	TRANS(MTransitionZoomFlipX_LEFT),
	TRANS(MTransitionZoomFlipX_RIGHT),
	TRANS(MTransitionZoomFlipX_UP),
	TRANS(MTransitionZoomFlipY_DOWN),
	TRANS(MTransitionZoomFlipY_LEFT),
	TRANS(MTransitionZoomFlipY_RIGHT),
	TRANS(MTransitionZoomFlipY_UP),
	TRANS(MTransitionShrinkGrow),
	TRANS(MTransitionSlideInL),
	TRANS(MTransitionSlideInB),
	TRANS(MTransitionSlideInR),
	TRANS(MTransitionSplitCols),
	TRANS(MTransitionSplitRows),
	TRANS(MTransitionTurnOffTiles),
};

#define MAX_TRANSITION_COUNT (sizeof(transitions)/sizeof(transitions[0]))

TransitionScene* createTranstion(int _index,float t,Scene* s){
	//Director::getInstance()->setDepthTest(false);
	return transitions[_index].function(t, s);
}

然后就是每一个切换效果的类，例举一个

class MTransitionTurnOffTiles : TransitionTurnOffTiles{
public:
	static TransitionScene* create(float duration, Scene* scene){
		return TransitionTurnOffTiles::create(duration, scene);
	}
};

为了可以来回切换着看这些效果，通过向MainScene中添加不同的layer，每一个layer中有三个按钮，点击按钮的时候，然后构造一个切换效果Scene，进行切换场景，具体看code

LayerOne::LayerOne(){
	init();
}
LayerOne::~LayerOne(){}
bool LayerOne::init(){
	if (!Layer::init()) {
		return false;
	}

	Size visibleSize = Director::getInstance()->getVisibleSize();
	Vec2 origin = Director::getInstance()->getVisibleOrigin();

	MenuItemImage* restart = MenuItemImage::create("res/r1.png", "res/r2.png", CC_CALLBACK_1(LayerOne::menuRestartCallback, this));
	restart->setPosition(Vec2(visibleSize.width / 2, restart->getContentSize().height));
	MenuItemImage* back = MenuItemImage::create("res/b1.png", "res/b2.png", CC_CALLBACK_1(LayerOne::menuBackCallback, this));
	back->setPosition(Vec2(visibleSize.width / 2 - restart->getContentSize().width*1.5, back->getContentSize().height));
	MenuItemImage* forward = MenuItemImage::create("res/f1.png", "res/f2.png", CC_CALLBACK_1(LayerOne::menuForwardCallback, this));
	forward->setPosition(Vec2(visibleSize.width / 2 + restart->getContentSize().width*1.5, forward->getContentSize().height));
	auto menu = Menu::create(restart, back, forward, NULL);
	menu->setPosition(Vec2::ZERO);
	this->addChild(menu, 1);

	auto label = Label::createWithTTF("LayerOne", "fonts/Marker Felt.ttf", 24);
	label->setPosition(Vec2(origin.x + visibleSize.width / 2,
		origin.y + visibleSize.height - label->getContentSize().height));
	this->addChild(label, 1);
	auto transitionName = Label::createWithTTF(transitions[transition_index].name, "fonts/Marker Felt.ttf", 24);
	transitionName->setPosition(Vec2(origin.x + visibleSize.width / 2,
		origin.y + visibleSize.height - transitionName->getContentSize().height * 2));
	this->addChild(transitionName, 1);
	auto sprite = Sprite::create("res/background1.png");
	sprite->setPosition(Vec2(visibleSize.width / 2 + origin.x, visibleSize.height / 2 + origin.y));
	this->addChild(sprite, 0);
	return true;
}

void LayerOne::menuRestartCallback(Ref* pSender){
	auto go = MainScene::createScene();
	Director::getInstance()->replaceScene(go);
}

void LayerOne::menuBackCallback(Ref* pSender){
	transition_index--;
	if (transition_index < 0){
		transition_index += MAX_TRANSITION_COUNT;
	}

	Scene* s = MainScene::createScene();
	Layer* layer2 = new LayerTwo();
	s->addChild(layer2);

	auto scene = createTranstion(transition_index, DURATION, s);
	if (scene){
		Director::getInstance()->replaceScene(scene);
	}
}

void LayerOne::menuForwardCallback(Ref* pSender){
	transition_index++;
	transition_index = transition_index % MAX_TRANSITION_COUNT;
	
	Scene* s = MainScene::createScene();
	Layer* layer2 = new LayerTwo();
	s->addChild(layer2);

	auto scene = createTranstion(transition_index, DURATION, s);
	if (scene){
		Director::getInstance()->replaceScene(scene);
	}
}

另外一个LayerTwo也是类似，只不过背景图片不同

win上可以运行，Android下，我刚开始不能run as，会报一些宏定义的错误，但是用命令编译过之后就好了

android下效果图：