十四、OSG学习笔记-事件响应

上一章节

十三、OSG学习笔记-osgDB文件读写-CSDN博客https://blog.csdn.net/weixin_36323170/article/details/146165712

本章节代码：

OsgStudy/EventHandle · CuiQingCheng/OsgStudy - 码云 - 开源中国https://gitee.com/cuiqingcheng/osg-study/tree/master/OsgStudy/EventHandle

一、事件的概念

事件：是计算机应用程序和人通过外设进行交互的途径。

核心模块 OSG::GA，通过事件回调，遍历响应各个事件处理的handle方法，所以在是现实时，可以通过自定义handle处理方法，从而实现事件操作器；

示例代码如下：

/**osg 事件处理器
**/#include <windows.h>
#include <iostream>#include <osgViewer/Viewer>
#include <osgDB/ReaderWriter>
#include <osgDB/ReadFile>
#include <osgGA/GUIEventHandler>
#include <osg/MatrixTransform>class TestInput:public osgGA::GUIEventHandler
{
public:// aa ,就是viewerbool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa) override{osgViewer::Viewer* vw = dynamic_cast<osgViewer::Viewer*>(&aa);switch (ea.getEventType()){case osgGA::GUIEventAdapter::KEYDOWN:std::cout << ea.getKey() << std::endl;_keyMap[ea.getKey()] = true;if (((_keyMap['w'] == true) || (_keyMap['W'] == true)) && ((_keyMap['a'] == true) || (_keyMap['A'] == true))){std::cout << "应该向左前方走" << std::endl;}if (ea.getKey() == osgGA::GUIEventAdapter::KEY_Alt_L){std::cout << "按下了左边的ALT键" << std::endl;}break;case osgGA::GUIEventAdapter::KEYUP:_keyMap[ea.getKey()] = false;break;case osgGA::GUIEventAdapter::PUSH:if (ea.getButton() == osgGA::GUIEventAdapter::LEFT_MOUSE_BUTTON){std::cout << "左键点击（" << ea.getX() << "," << ea.getY() << ")" << std::endl;}else if (ea.getButton() == osgGA::GUIEventAdapter::RIGHT_MOUSE_BUTTON){std::cout << "右键点击（" << ea.getX() << "," << ea.getY() << ")" << std::endl;}else if (ea.getButton() == osgGA::GUIEventAdapter::MIDDLE_MOUSE_BUTTON){std::cout << "中键点击（" << ea.getX() << "," << ea.getY() << ")" << std::endl;}else {}break;case osgGA::GUIEventAdapter::DRAG:// 拖拽std::cout << "你DRAG了" << std::endl;break;case osgGA::GUIEventAdapter::SCROLL: // 滚轮事件if (ea.getScrollingMotion() == osgGA::GUIEventAdapter::SCROLL_UP)// 滚轮向上{osg::ref_ptr<osg::MatrixTransform> mx = new osg::MatrixTransform;mx->addChild(vw->getSceneData());mx->setMatrix(osg::Matrix::rotate(0.1, osg::Vec3f(1.0, 0, 0)));vw->setSceneData(mx);}else if (ea.getScrollingMotion() == osgGA::GUIEventAdapter::SCROLL_DOWN) // 滚轮向下{osg::ref_ptr<osg::MatrixTransform> mx = new osg::MatrixTransform;mx->addChild(vw->getSceneData());mx->setMatrix(osg::Matrix::rotate(-0.1, osg::Vec3f(1.0, 0, 0)));vw->setSceneData(mx);}break;case osgGA::GUIEventAdapter::RESIZE:std::cout << "改变窗口大小" << std::endl;break;default:break;}//return true;// 如果为true,这这个事件不往后传递。return false;}private:std::map<int, bool>	_keyMap; // 按键状态记录map
};int main()
{osg::ref_ptr<osgViewer::Viewer> viewer = new osgViewer::Viewer;viewer->setUpViewInWindow(50, 50, 1500, 1000);viewer->setSceneData(osgDB::readNodeFile("glider.osg"));osg::ref_ptr<TestInput> Test = new TestInput;viewer->addEventHandler(Test);// 加入事件viewer->run();return 0;
}