env is win10 osg3.6.4 GTX1660
osg::ref_ptr<osg::Program> createProgram()
{
osg::Program *program = new osg::Program();
program->addShader(new osg::Shader(osg::Shader::VERTEX,vertSource));
program->addShader(new osg::Shader(osg::Shader::GEOMETRY,geomSource));
program->addShader(new osg::Shader(osg::Shader::FRAGMENT,fragSource));
program->setParameter(GL_GEOMETRY_VERTICES_OUT_EXT, 3);
program->setParameter(GL_GEOMETRY_INPUT_TYPE_EXT, GL_TRIANGLES);
program->setParameter(GL_GEOMETRY_OUTPUT_TYPE_EXT,
GL_TRIANGLES );
return program;
}