);
        }
    }
    synthesis_context.strokeStyle="#661100";
    synthesis_context.stroke();
    synthesis_context.closePath();

    // grid
    draw_grid_on(synthesis_context);

    // dots
    synthesis_context.beginPath();
    for(var i = 0; i < synthesis_n; ++i){
        synthesis_context.moveTo(x_to_client(synthesis_xs[i])-5.5, y_to_client(synthesis_ys[i])+5.5);
        synthesis_context.lineTo(x_to_client(synthesis_xs[i])+5.5, y_to_client(synthesis_ys[i])-5.5);
        synthesis_context.moveTo(x_to