Director of cocos2dx study notes (director class)

In Cocos2d-x, the class that coordinates the overall situation of the game is abstracted into the Director class (Director). Director is the core of the entire cocos2d-x engine and the navigator of the entire game. Some common operations in the game are controlled by Director, such as OpenGL ES initialization, scene conversion, control of game pause and continuation, switching between world coordinates and GL coordinates, control of nodes, etc., as well as some game data The save call, the acquisition of screen size, etc. are all managed and controlled by the Director class.

Because Director is the general director of the game project and will often call for some control, the Director uses the single-piece design pattern, that is, there is only one director class in the entire game. Use the getInstance() method to obtain an instance of Director.

 

Tips: In the cocos2d-x2.x version, use the sharedDirector() method to get the director class object, and in the 3.x version use getInstance() to get it, but sharedDirector() can also be used.

The inheritance relationship of the Director class is as follows:

DisplayLinkDirector inherits CCDirector and is a director class that can be automatically refreshed. It supports three animation intervals (frame intervals) of 60/1, 1/30 and 1/15.

The main public functions of the Director class are as follows:

Function name	return type	describe
getRunningScene	scene class	Get the currently running scene
getAnimationInterval	floating point	Get the time of each frame
setAnimationInterval	floating point	Set the time of each frame
isDisplayStats	boolean	Returns whether to display the time of each frame in the lower left corner of the screen
setDisplayStats	without	Set whether to display the time of each frame in the lower left corner of the screen
getSecondsPerFrame	floating point	Get the time of each frame (in seconds)
getOpenGLView	GL view	Get an OpenGL view that draws all objects
setOpenGLView	without	Sets the OpenGL view where all objects are drawn
isPaused	boolean	Whether the director class object is paused
getTotalFrames	Integer	Get the number of frames running from the director class
getProjection	Projection class	Get OpenGL projection
setProjection	without	Set up OpenGL projection
setViewport	without	Set up the OpenGL interface
isSendCleanupToScene	boolean	Whether the switched scene receives clear information
getNotificationNode	Node class	Get a node object traversed after the main scene traversal
setNotificationNode	without	Sets a node object to traverse after the main scene is traversed
getWinSize	size	Get screen size (in points)
getWinSizeInPixels	size	Get the screen size in pixels (in pixels)
getVisibleSize	size	Get the visible screen size
getVisibleOrigin	vector	Get the orientation of the visible screen
convertToGL	vector	Convert to OpenGL coordinate system
convertToUI	vector	Convert to UI coordinate system
runWithScene	without	run the current scene
pushScene	without	Suspend the current scene and push it onto the stack
popScene	without	Pop the scene from the stack
popToRootScene	without	Pop all scenes from the stack up to the root scene
popToSceneStackLevel	without	Pop all scenes from the stack up to a certain level (level 0 is director, level 1 is root scene)
replaceScene	without	replace the current scene
end	without	End Game
pause	without	Pause the game
resume	without	resume game
stopAnimation	without	stop animation
startAnimation	without	start animation
drawScene	without	draw the scene
purgeCachedData	without	remove all cached data
setDefaultValues	without	Set default values ​​based on configuration information
setGLDefaultValues	without	Set OpenGL defaults
setAlphaBlending	without	Set whether OpenGL uses the alpha channel
setDepthTest	without	Set whether to test OpenGL depth
setContentScaleFactor	without	Set the surface pixel size (different from the screen size)
getContentScaleFactor	floating point	Get surface pixel size
getScheduler	scheduling class	Get the time schedule object
setScheduler	without	Set the time schedule object
getActionManager	Action management class	Get the action management object
setActionManager	without	Set the action management object
getEventDispatcher	事件调度类	获取事件调度对象
setEventDispatcher	无	设置事件调度对象
getRenderer	渲染器	返回渲染器
getDeltaTime	浮点型	返回控制台
getFrameRate	浮点型	获取帧率

在新建的HelloWorld项目中，打开AppDelegate.cpp，我们可以看到如下代码：

 

[cpp] view plain copy

1. //初始化函数  
2. boolAppDelegate::applicationDidFinishLaunching() {  
3. //获取导演对象  
4. auto director =Director::getInstance();  
5. //获取OpenGL视图  
6.     auto glview = director->getOpenGLView();  
7.     if(!glview) {  
8.         glview = GLView::create("MyGame");  
9.             //设置OpenGL视图  
10.         director->setOpenGLView(glview);  
11.     }  
12.     // 设置显示每帧显示时间  
13.     director->setDisplayStats(true);  
14. // 设置每帧时间  
15. director->setAnimationInterval(1.0/ 60);  
16.     autoscene = HelloWorld::createScene();  
17.     // 运行场景  
18.     director->runWithScene(scene);  
19.     return true;  
20. }  
21. // 游戏进入后台  
22. voidAppDelegate::applicationDidEnterBackground() {  
23.      //停止动画  
24.     Director::getInstance()->stopAnimation();  
25. }  
26. // 从后台返回游戏  
27. voidAppDelegate::applicationWillEnterForeground() {  
28.      //开始动画  
29.     Director::getInstance()->startAnimation();  
30. }  

在HelloWorldScene.cpp中有：

 

[cpp] view plain copy

1. //初始化  
2. boolHelloWorld::init()  
3. {  
4.     if ( !Layer::init() )  
5.     {  
6.         return false;  
7.     }  
8.     //获取OpenGL视图可见大小  
9. Size visibleSize= Director::getInstance()->getVisibleSize();  
10. //获取OpenGL视图可见方向  
11. Vec2 origin =Director::getInstance()->getVisibleOrigin();  
12. …………………………….  
13. }  
14. //导演类结束  
15. voidHelloWorld::menuCloseCallback(Ref* pSender)  
16. {  
17. #if(CC_TARGET_PLATFORM == CC_PLATFORM_WP8) || (CC_TARGET_PLATFORM ==CC_PLATFORM_WINRT)  
18.      MessageBox("You pressed the close button.Windows Store Apps do not implement a close button.","Alert");  
19.     return;  
20. #endif  
21.      //导演类结束  
22.     Director::getInstance()->end();  
23. #if(CC_TARGET_PLATFORM == CC_PLATFORM_IOS)  
24.     exit(0);  
25. #endif  
26. }  

由此看来，Director不愧是整个游戏的“导演”。它在游戏中无所不在，大到整个游戏的控制，小到获取屏幕的尺寸，起着至关重要的作用。