irrlicht引擎消息系统

说说irrlicht的消息系统，除了irrlicht绘制主窗体，默认的消息处理过程，外部的消息监听是通过IrrlichtDevice设备类中一个接口

virtual void setEventReceiver(IEventReceiver* receiver) = 0;

这个接口是把receiver监听类作物除默认窗体过程外，消息传递对象，

先看看看IEventReceiver接口里面有什么东东，

class IEventReceiver

{

public:

//! Destructor

virtual ~IEventReceiver() {}

//! Called if an event happened.

/** Please take care that you should only return 'true' when you want to _prevent_ Irrlicht

* from processing the event any further. So 'true' does mean that an event is completely done.

* Therefore your return value for all unprocessed events should be 'false'.

\return True if the event was processed.

*/

virtual bool OnEvent(const SEvent& event) = 0;

};

这是一个抽象类，用户可以写一个事件监听类来实现这个接口，处理用户关心的事件

例如

class MyEventReceiver : public IEventReceiver

{

public:

MyEventReceiver() { }

virtual bool OnEvent(const SEvent& event)

{

if (event.EventType == EET_GUI_EVENT)

{

}

return false

}

};

具体消息流程如下图


要注意的是在MyEventReceiver类中，没有处理过的消息一定要返回，不然下面的GUI和场景系统会收不到消息.到时候你会感到很奇怪，为什么我GUI收不到点击的消息.