static bool writeInternalFormat( osgDB::OutputStream& os, const osg::Texture& tex ) { if ( os.isBinary() && tex.getInternalFormatMode()!=osg::Texture::USE_USER_DEFINED_FORMAT ) os << GLENUM(GL_NONE) << std::endl; // Avoid use of OpenGL extensions else os << GLENUM(tex.getInternalFormat()) << std::endl; return true; }