osg读取自定义格式插件

#include <sstream>
#include <osg/Image>
#include <osg/Group>
#include <osg/Notify>
#include <osg/Geode>
#include <osg/Shape>
#include <osg/ShapeDrawable>

#include <osgDB/FileNameUtils>
#include <osgDB/FileUtils>
#include <osgDB/fstream>
#include <osgDB/Registry>
#include <osgDB/Input>
#include <osgDB/Output>
#include <iostream>

using namespace osg;
using namespace osgDB;


class FSReaderWriter :public ReaderWriter
{
public:
	FSReaderWriter()
	{
		supportsExtension("fs", "FreeSouth's format");
	}
	virtual const char* className() const
	{
		return "FSReaderWriter";
	}
	virtual ReadResult readNode(const std::string& file, const Options* opt) const
	{
		std::string ext = osgDB::getLowerCaseFileExtension(file);
		if (!acceptsExtension(ext))
			return ReadResult::FILE_NOT_HANDLED;
		std::string fileName = osgDB::findDataFile(file, opt);
		if (fileName.empty())
			return ReadResult::FILE_NOT_FOUND;
		osgDB::ifstream fin(fileName.c_str());
		if (fin)
			return readNode(fin, opt);
		return 0L;
	}
	
	
	virtual ReadResult readNode(std::istream& fin, const Options* opt) const
	{
		Input fr;
		fr.attach(&fin);

		osg::ref_ptr<osg::Geode> gnode = new osg::Geode;
		osg::Vec3 center;
		float radius;

		while (!fr.eof())
		{
			std::cout << "out" << std::endl;
			if (fr.matchSequence("%f %f %f %f"))
			{
				std::cout << "in" << std::endl;
				fr.readSequence(center);
				fr.readSequence(radius);
				std::cout << "Center is :" << center.x() << "" << center.y() << " " << center.z() << " " << std::endl;
				std::cout << "Radius is " << radius << std::endl;
				gnode->addDrawable(new osg::ShapeDrawable(new osg::Sphere(center, radius)));
			}
			else
			{
				std::cout << "fr is NULL" << std::endl;
				++fr;
			}
		}
		return gnode;
	}
};

REGISTER_OSGPLUGIN(fs, FSReaderWriter)//注册

命名为osgdb_fs.dll，复制到OSG3.4\bin\osgPlugins-3.4目录下。

#include <osgViewer/Viewer>
#include <osgDB/ReadFile>

int main()
{
	osgDB::Registry::instance()->addFileExtensionAlias("fs", "fs");//将文件扩展名与dll名关联起来

	osg::ref_ptr<osg::Group> group = new osg::Group;
	group->addChild(osgDB::readNodeFile("D://data//osg_study//test.fs"));

	osg::ref_ptr<osgViewer::Viewer> viewer = new osgViewer::Viewer;
	viewer->setSceneData(group.get());
	viewer->run();
	return 0;
}