Completing the neck opening

We've constructed the perfectly sized quarter neck, and we're going to use this to create our complete neck path by flipping and mirroring it.

Hiding our quarter neck opening

To make our code easier to understand, we're going to leave the quarterNeck path as it is, and simply chose to not show it.

To accomplish this, we'll call the hide() method on our path:

Code

function draftBib({
  Path,
  Point,
  paths,
  points,
  measurements,
  options,
  part,
}) {

  /*
   * Construct the quarter neck opening
   */
  let tweak = 1
  let target = (measurements.head * options.neckRatio) /4
  let delta
  do {
    points.right = new Point(
      tweak * measurements.head / 10, 
      0
    )
    points.bottom = new Point(
      0, 
      tweak * measurements.head / 12
    )

    points.rightCp1 = points.right.shift(
      90, 
      points.bottom.dy(points.right) / 2
    )
    points.bottomCp2 = points.bottom.shift(
      0, 
      points.bottom.dx(points.right) / 2
    )

    paths.quarterNeck = new Path()
      .move(points.right)
      .curve(
        points.rightCp1, 
        points.bottomCp2, 
        points.bottom
      )
      .hide()

    delta = paths.quarterNeck.length() - target
    if (delta > 0) tweak = tweak * 0.99
    else tweak = tweak * 1.02
  } while (Math.abs(delta) > 1)

  return part
}

Preview

X-Ray

A hidden path is not shown

We're saying: hide this path. In other words, don't show it. The path is still known, and we can still use it to calculate the length of the neck opening. But it won't show up on screen or on the page.

Create the complete neck opening

Now that we've hidden our homework, let's create the complete neck path. As the neck opening is symmetrical, there's no need to re-calculate the points on the other side. We can just flip them over, so to speak. And that's exactly what we'll do.

Let's add some more points, and then construct the complete path for the neck opening.

Code

function draftBib({
  Path,
  Point,
  paths,
  points,
  measurements,
  options,
  part,
}) {

  /*
   * Construct the quarter neck opening
   */
  let tweak = 1
  let target = (measurements.head * options.neckRatio) /4
  let delta
  do {
    points.right = new Point(
      tweak * measurements.head / 10, 
      0
    )
    points.bottom = new Point(
      0, 
      tweak * measurements.head / 12
    )

    points.rightCp1 = points.right.shift(
      90, 
      points.bottom.dy(points.right) / 2
    )
    points.bottomCp2 = points.bottom.shift(
      0, 
      points.bottom.dx(points.right) / 2
    )
    
    paths.quarterNeck = new Path()
      .move(points.right)
      .curve(
        points.rightCp1, 
        points.bottomCp2, 
        points.bottom
      )
      .hide()

    delta = paths.quarterNeck.length() - target
    if (delta > 0) tweak = tweak * 0.99
    else tweak = tweak * 1.02
  } while (Math.abs(delta) > 1)

  /*
   * Construct the complete neck opening
   */
  points.rightCp2 = points.rightCp1.flipY()
  points.bottomCp1 = points.bottomCp2.flipX()
  points.left = points.right.flipX()
  points.leftCp1 = points.rightCp2.flipX()
  points.leftCp2 = points.rightCp1.flipX()
  points.top = points.bottom.flipY()
  points.topCp1 = points.bottomCp2.flipY()
  points.topCp2 = points.bottomCp1.flipY()

  paths.neck = new Path()
    .move(points.top)
    .curve(points.topCp2, points.leftCp1, points.left)
    .curve(points.leftCp2, points.bottomCp1, points.bottom)
    .curve(points.bottomCp2, points.rightCp1, points.right)
    .curve(points.rightCp2, points.topCp1, points.top)
    .close()
    .addClass('fabric')
  return part
}

Preview

X-Ray

Our completed neck opening

To add the points, we're using the Point.flipX() and Point.flipY() methods here. There's a few new Path methods too, like close() and addClass().

Perhaps you can figure out what they do? If not, both the Point documentation and the Path documentation have detailed info on all the methods available, including these.