1 cocos2dx源码分析-程序启动与主循环

 

 

 

在iOS系统中，由main函数启动默认调用了AppController

main.m

NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

int retVal = UIApplicationMain(argc, argv, nil, @"AppController");

[pool release];

return retVal;

 

iOS的ViewController都熟悉吧，iOS程序的基础Controller 。 

 

 

    cocos2d::Application *app = cocos2d::Application::getInstance();
    app->initGLContextAttrs();

    cocos2d::GLViewImpl::convertAttrs();

 

 

如：

1>初始化EAGLContext

2> RenderBuffer 

3> FrameBuffer 

4> 关联RenderBuffer 与FrameBuffer 

5> 在这个View里有一个swapBuffer 其实就是  [context RenderBuffer:GL_RenderBuffer]，  这个函数在每个渲染循环都要调用， 主要是在Director::drawScene 里调用。 drawScene 是在下面要说到的run 里调用了iOS自更新函数displayLinker:mainLoop来实现的。 

 

// Override point for customization after application launch.

    // Add the view controller‘s view to the window and display.
    window = [[UIWindow alloc] initWithFrame: [[UIScreen mainScreen] bounds]];

    // Init the CCEAGLView
    CCEAGLView *eaglView = [CCEAGLView viewWithFrame: [window bounds]
                                         pixelFormat: (NSString*)cocos2d::GLViewImpl::_pixelFormat
                                         depthFormat: cocos2d::GLViewImpl::_depthFormat
                                  preserveBackbuffer: NO
                                          sharegroup: nil
                                       multiSampling: NO
                                     numberOfSamples: 0 ];

    // Use RootViewController manage CCEAGLView 
    _viewController = [[RootViewController alloc] initWithNibName:nil bundle:nil];
    _viewController.wantsFullScreenLayout = YES;

    _viewController.view = eaglView;

 

3. cocos:GLView 代理模式，代理了之前我们创建的CCEAGLView对象， 这样我们就可以转到使用统一的cocos的GLView了， 后面又把这个GLView给了director。 这样我们director及GLView就都算是初始化了。 

 

// IMPORTANT: Setting the GLView should be done after creating the RootViewController
    cocos2d::GLView *glview = cocos2d::GLViewImpl::createWithEAGLView(eaglView);

    cocos2d::Director::getInstance()->setOpenGLView(glview);

 

 

这里调用的是Application->run。 这个run最后用调用 到director的mainLoop， 从这里开始程序的控制权正式归入到director手中。 

 

    app->run();

 

int Application::run()
{
    if (applicationDidFinishLaunching())
    {
        [[CCDirectorCaller sharedDirectorCaller] startMainLoop];
    }
    return 0;

}

 

-(void) startMainLoop
{
        // Director::setAnimationInterval() is called, we should invalidate it first
    [self stopMainLoop];
   
    displayLink = [NSClassFromString(@"CADisplayLink") displayLinkWithTarget:selfselector:@selector(doCaller:)];
    [displayLink setFrameInterval: self.interval];
    [displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
}

 

                
-(void) doCaller: (id) sender
{
    cocos2d::Director* director = cocos2d::Director::getInstance();
    [EAGLContext setCurrentContext: [(CCEAGLView*)director->getOpenGLView()->getEAGLView()context]];
    director->mainLoop();
}