[SFML 3.0.2] sf::VertexArray - jak dodać punkty sf::Vertex ?

void Lasso::generateOutline( bool selectionComplete ) {
    //std::vector <sf::Vector2i> _points
    if( _points.size() < 3 ) return;
   
    if( _rect.size.x <= 0 || _rect.size.y <= 0 )
         return;
   
    if( _outlineRenderTexture.getSize() != sf::Vector2u( _rect.size ) )
         _outlineRenderTexture.resize( sf::Vector2u( _rect.size ) );
   
    _outlineRenderTexture.clear( sf::Color( 0, 0, 0, 0 ) );
   
    sf::Color lassoColor = sf::Color( 47, 127, 127, 255 );
   
    sf::VertexArray lines( sf::PrimitiveType::LineStrip );
    for( auto & point: _points )
         lines.append( sf::Vertex( sf::Vector2f( point ), lassoColor ) );
   
    // first and last point
    sf::VertexArray p( sf::PrimitiveType::Points );
   
    p.append( sf::Vertex( sf::Vector2f( _points.front() ), lassoColor ) );
    p.append( sf::Vertex( sf::Vector2f( _points.back() ), lassoColor ) );
   
    if( selectionComplete )
         lines.append( sf::Vertex( sf::Vector2f( _points.front() ), lassoColor ) );
   
    sf::RenderStates rs;
    rs.blendMode = sf::BlendAlpha;
    rs.transform.translate( { 0.5f, 0.5f } );
    _outlineRenderTexture.draw( lines, rs );
    _outlineRenderTexture.draw( p, rs );
    _outlineRenderTexture.display();
}

p.append( sf::Vertex { sf::Vector2f( _points.front() ), lassoColor } );