e);

    spline.addEventListener('mousedown', function(e){
        var canvas_rect = spline.getBoundingClientRect();
        spline_xs[spline_i] = client_to_x(e.clientX - canvas_rect.left);
        spline_ys[spline_i] = client_to_y(e.clientY - canvas_rect.top);
        spline_draw(e.clientX - canvas_rect.left, e.clientY - canvas_rect.top, false);
    }, false);

    spline.addEventListener('mouseleave', function(e){
        spline_draw(0, 0, false);
    }, false);
}

function spline_draw(client_x, client_y,