closestPoint = (line, point) => {
  const orig = origin(line)
  const dir = direction(line)

  const v = vec2.subtract(vec2.create(), point, orig)
  const dist = vec2.dot(v, dir)
  vec2.scale(v, dir, dist)
  vec2.add(v, v, orig)
  return v
}
Determine the closest point on the given line to the given point.

@param {line2} line - line of reference
@param {vec2} point - point of reference
@returns {vec2} closest point
@alias module:modeling/maths/line2.closestPoint