OSG学习：响应键盘鼠标示例

示例功能：示例里面有两个模型，一个是牛，另一个是飞机。鼠标右键时牛和飞机都隐藏，鼠标左键双击时牛和飞机都显示，按键盘上面的LEFT键，显示牛，按键盘上面的RIGHT键显示飞机。其中显示与隐藏节点使用的是setNodeMask(bool)。bool的值为0的时候是隐藏，1的时候是显示。

#include<osgDB\ReadFile>
#include<osgViewer\Viewer>
#include<osg\Node>

class UseEventHandler :public osgGA::GUIEventHandler
{
public:
virtual bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa)
{
osgViewer::Viewer* viewer = dynamic_cast<osgViewer::Viewer*>(&aa);
if (!viewer)return false;

switch (ea.getEventType())
{
case osgGA::GUIEventAdapter::KEYDOWN:
{
if (ea.getKey() == 0xFF51)
{
viewer->getSceneData()->asGroup()->getChild(1)->setNodeMask(0);
viewer->getSceneData()->asGroup()->getChild(0)->setNodeMask(1);
}
if (ea.getKey() == 0xFF53)
{
viewer->getSceneData()->asGroup()->getChild(0)->setNodeMask(0);
viewer->getSceneData()->asGroup()->getChild(1)->setNodeMask(1);
}
break;
}
case osgGA::GUIEventAdapter::PUSH:
if (ea.getButton() == 4)
{
viewer->getSceneData()->asGroup()->getChild(0)->setNodeMask(0);
viewer->getSceneData()->asGroup()->getChild(1)->setNodeMask(0);
}
break;
case osgGA::GUIEventAdapter::DOUBLECLICK:
if (ea.getButton() == 1)
{
viewer->getSceneData()->asGroup()->getChild(0)->setNodeMask(1);
viewer->getSceneData()->asGroup()->getChild(1)->setNodeMask(1);
}
break;
default:
break;
}
return false;
}
};

void main()
{
osgViewer::Viewer viewer;
osg::ref_ptr<osg::Group> root = new osg::Group();
root->addChild(osgDB::readNodeFile("cow.osg"));
root->addChild(osgDB::readNodeFile("glider.osg"));
viewer.setSceneData(root.get());
viewer.addEventHandler(new UseEventHandler);
viewer.realize();
viewer.run();
}

结果图：