Drawing the bib outline

With our neck opening in place, let us draw the basic outline of our bib.

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')

  /*
   * Drawing the bib outline
   */
  const width = measurements.head * options.widthRatio
  const length = measurements.head * options.lengthRatio

  points.topLeft = new Point(
    width / -2,
    points.top.y - (width / 2 - points.right.x)
  )
  points.topRight = points.topLeft.shift(0, width)
  points.bottomLeft = points.topLeft.shift(-90, length)
  points.bottomRight = points.topRight.shift(-90, length)

  paths.rect = new Path()
    .move(points.topLeft)
    .line(points.bottomLeft)
    .line(points.bottomRight)
    .line(points.topRight)
    .line(points.topLeft)
    .close()
    .addClass('fabric')

  return part
}

Preview

X-Ray

Note how the neck opening is the same distance from the left, right, and top edge

First thing we did was create the width and length variables to save ourselves some typing:

const width = measurements.head * options.widthRatio
const length = measurements.head * options.lengthRatio

Both the length and width of our bib are a factor of the head circumference. This way, our bib size will adapt to the size of the baby, and the user can tweak the length and width by playing with the options we added to the pattern.

Once we have our variables, we're adding some new points, and a second path called rect.

points.topLeft = new Point(
  width / -2,
  points.top.y - (width / 2 - points.right.x)
)
points.topRight = points.topLeft.shift(0, width)
points.bottomLeft = points.topLeft.shift(-90, length)
points.bottomRight = points.topRight.shift(-90, length)

paths.rect = new Path()
  .move(points.topLeft)
  .line(points.bottomLeft)
  .line(points.bottomRight)
  .line(points.topRight)
  .line(points.topLeft)
  .close()
  .addClass('fabric')

We're calculating the topLeft point so that the top edge of our bib and the sides are equidistant from the neck opening.

We didn't have to do that. But it looks nicely balanced this way.