cairo_set_line_width(gc->cr, 2);
cairo_set_line_cap(gc->cr, CAIRO_LINE_CAP_ROUND);
cairo_set_line_join(gc->cr, CAIRO_LINE_JOIN_ROUND);
cairo_set_line_width(gc->cr, 2);
cairo_set_line_cap(gc->cr, CAIRO_LINE_CAP_ROUND);
cairo_set_line_join(gc->cr, CAIRO_LINE_JOIN_ROUND);