code: function savePoint(x, y) {
    let svg = findSVGAtPoint(x, y);
    if (!svg) {
      return;
    }
  
    let rect = svg.getBoundingClientRect();
    let point = scaleDown(svg, {
      x: x - rect.left,
      y: y - rect.top
    });
  
    lines.push([point.x, point.y]);
  
    if (lines.length <= 1) {
      return;
    }
  
    if (path) {
      svg.removeChild(path);
    }
  
    path = appendChild(svg, {
      type: 'drawing',
      color: _penColor,
      width: _penSize,
      lines
    });
  }
docs: Save a point to the line being drawn.
  
  @param {Number} x The x coordinate of the point
  @param {Number} y The y coordinate of the point