8.OsgEarth 鼠标位置及LabelControl中文显示

news2025/10/31 17:38:36

愿你出走半生,归来仍是少年！

在人机交互中，最常用的就是鼠标。获取鼠标在三维场景中的空间位置是保证交互结果正确的保障。

1.LabelControl

文本标签控件，可方便的添加在场景顶层。

设置编码及字体可正确的显示出中文。

setFont(osgText::readFontFile("Fonts/simhei.ttf"));

setEncoding(osgText::String::ENCODING_UTF8);


	bottomStateLabel = new osgEarth::Util::Controls::LabelControl("底部状态栏", osg::Vec4f(1, 1, 1, 1), 14);
	 
	bottomStateLabel->setHorizAlign(osgEarth::Util::Controls::Control::ALIGN_CENTER);

	bottomStateLabel->setVertAlign(osgEarth::Util::Controls::Control::ALIGN_BOTTOM);

	bottomStateLabel->setBackColor(0, 0, 0, 0.8);

	 

	bottomStateLabel->setFont(osgText::readFontFile("Fonts/simhei.ttf"));

 

	bottomStateLabel->setEncoding(osgText::String::ENCODING_UTF8);

	bottomStateLabel->setPadding(5);

	 
	   
	ref_ptr<osgEarth::Util::Controls::ControlCanvas> canvas = osgEarth::Util::Controls::ControlCanvas::get(this);
	 

	canvas->addControl(bottomStateLabel);

2.MousePositionEvenHandler

通过继承osgGA::GUIEventHandler进行实现，仅用于鼠标移动时进行鼠标的空间位置解算。分别解算了鼠标所在的地形位置以及空间位置。

#include "MousePositionEvenHandler.h"

Cv::EventHandlers::MousePositionEvenHandler::MousePositionEvenHandler(MapNode* node, osgEarth::Util::Controls::LabelControl* control)
{

	this->mapNode = node;

	this->label = control;
}

bool Cv::EventHandlers::MousePositionEvenHandler::handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa)
{
	osgViewer::Viewer* viewer = dynamic_cast<osgViewer::Viewer*>(&aa);

	if (viewer)
	{
		std::string positionStr;

		//鼠标移动
		if (ea.getEventType()==ea.MOVE)
		{
  
			osg::Vec3d world;
			 
			if (mapNode->getTerrain()->getWorldCoordsUnderMouse(aa.asView(), ea.getX(), ea.getY(), world))
			{
				GeoPoint pt;

				pt.fromWorld(mapNode->getMapSRS(), world);
				  

				positionStr.append("  经度:"); 
				positionStr.append(boost::lexical_cast<std::string>(pt.x()));
				positionStr.append("  纬度:"); 
				positionStr.append(boost::lexical_cast<std::string>(pt.y()));
				positionStr.append("  地形高程:");
				positionStr.append(boost::lexical_cast<std::string>(pt.z())); 
			}
			  


			osgUtil::LineSegmentIntersector::Intersections hits;

			if (viewer->computeIntersections(ea.getX(),ea.getY(),hits))
			{
				auto first = hits.begin()->getWorldIntersectPoint();

				GeoPoint pt;

				pt.fromWorld(mapNode->getMapSRS(), first);

				positionStr.append("  交点经度:");
				positionStr.append(boost::lexical_cast<std::string>(pt.x()));
				positionStr.append("  交点纬度:");
				positionStr.append(boost::lexical_cast<std::string>(pt.y()));
				positionStr.append("  交点高程:");
				positionStr.append(boost::lexical_cast<std::string>(pt.z()));
			}

			this->label->setText(positionStr);
		}
		 
		 

	}

	return false;   
}