const unsigned x = x_(variables);
    const unsigned y = y_(variables);
    const unsigned w = w_(variables);
    const unsigned h = h_(variables);

    DBG_GUI_D << "Rectangle: draw from " << x << ',' << y << " width " << w
              << " height " << h << " canvas size " << canvas->w << ','
              << canvas->h << ".\n";

    VALIDATE(static_cast<int>(x) < canvas->w
             && static_cast<int>(x + w) <= canvas->w
             && static_cast<int>(y) < canvas->h
             && static_cast<int>(y + h) <= canvas->h,
             _("Rectangle doesn't fit on canvas."));


    surface_lock locker(canvas);

    // draw the border
    for(unsigned i = 0; i < border_thickness_; ++i) {
        SDL_Rect dimensions {
            x + i,
            y + i,
            w - (i * 2),
            h - (i * 2)
        };

        set_renderer_color(renderer, border_color_);

        SDL_RenderDrawRect(renderer, &dimensions);
    }