Rounding the corners

We already know how to round corners, we'll have the round macro take care of that for us.

With our corners rounded, we should also update our path. Fortunately, we merely have to update the start of it.

Code

function draftBib({
  Path,
  Point,
  paths,
  points,
  measurements,
  options,
  utils,
  macro,
  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()

  // 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)

  /*
   * Shape the straps
   */
  points.edgeLeft = new Point(points.topLeft.x, points.left.y)
  points.edgeRight = new Point(points.topRight.x, points.right.y)
  points.edgeTop = new Point(0, points.topLeft.y)

  points.edgeLeftCp = points.edgeLeft.shiftFractionTowards(points.topLeft, 0.5)
  points.edgeRightCp = points.edgeLeftCp.flipX()
  points.edgeTopLeftCp = points.edgeTop.shiftFractionTowards(
    points.topLeft,
    0.5
  )
  points.edgeTopRightCp = points.edgeTopLeftCp.flipX()

  // Round the straps
  const strap = points.edgeTop.dy(points.top)

  points.tipRight = points.edgeTop.translate(strap / 2, strap / 2)
  points.tipRightTop = new Point(points.tipRight.x, points.edgeTop.y)
  points.tipRightBottom = new Point(points.tipRight.x, points.top.y)

  /*
   * Macros will return the auto-generated IDs
   */
  const ids1 = {
    tipRightTop: macro("round", {
      id: "tipRightTop",
      from: points.edgeTop,
      to: points.tipRight,
      via: points.tipRightTop,
    }),
    tipRightBottom: macro("round", {
      id: "tipRightBottom",
      from: points.tipRight,
      to: points.top,
      via: points.tipRightBottom,
    })
  }

  /*
   * Create points from them with easy names
   */
  for (const side in ids1) {
    for (const id of ['start', 'cp1', 'cp2', 'end']) {
      points[`${side}${utils.capitalize(id)}`] = points[ids1[side].points[id]].copy()
    }
  }

    /*
   * This is the list of points we need to rotate
   * to move our strap out of the way
   */
  const rotateThese = [
    "edgeTopLeftCp",
    "edgeTop",
    "tipRight",
    "tipRightTop",
    "tipRightTopStart",
    "tipRightTopCp1",
    "tipRightTopCp2",
    "tipRightTopEnd",
    "tipRightBottomStart",
    "tipRightBottomCp1",
    "tipRightBottomCp2",
    "tipRightBottomEnd",
    "tipRightBottom",
    "top",
    "topCp2"
  ]
    /*
     * We're rotating all the points in
     * the `rotateThese` array around
     * the `edgeLeft` point.
     *
     * We're using increments of 1 degree
     * until the `tipRightBottomStart` point
     * is 1 mm beyond the center of our bib.
     */
  while (points.tipRightBottomStart.x > -1) {
    for (const p of rotateThese) points[p] = points[p].rotate(1, points.edgeLeft)
  }

  // Add points for second strap
  points.edgeTopRightCp = points.edgeTopLeftCp.flipX()
  points.topCp1 = points.topCp2.flipX()
  points.tipLeftTopStart = points.tipRightTopStart.flipX()
  points.tipLeftTopCp1 = points.tipRightTopCp1.flipX()
  points.tipLeftTopCp2 = points.tipRightTopCp2.flipX()
  points.tipLeftTopEnd = points.tipRightTopEnd.flipX()
  points.tipLeftBottomStart = points.tipRightBottomStart.flipX()
  points.tipLeftBottomCp1 = points.tipRightBottomCp1.flipX()
  points.tipLeftBottomCp2 = points.tipRightBottomCp2.flipX()
  points.tipLeftBottomEnd = points.tipRightBottomEnd.flipX()

  /*
   * Round the bottom corners
   * Macros will return the auto-generated IDs
   */
  const ids2 = {
    bottomLeft: macro("round", {
      id: "bottomLeft",
      from: points.topLeft,
      to: points.bottomRight,
      via: points.bottomLeft,
      radius: points.bottomRight.x / 4,
    }),
    bottomRight: macro("round", {
      id: "bottomRight",
      from: points.bottomLeft,
      to: points.topRight,
      via: points.bottomRight,
      radius: points.bottomRight.x / 4,
    })
  }

  /*
   * Create points from them with easy names
   */
  for (const side in ids2) {
    for (const id of ['start', 'cp1', 'cp2', 'end']) {
      points[`${side}${utils.capitalize(id)}`] = points[ids2[side].points[id]].copy()
    }
  }

  // Create one path for the bib outline
  paths.seam = new Path()
    .move(points.edgeLeft)
    // strikeout-start
    /* We only need to replace the start
     * with the new lines below
    .line(points.bottomLeft)
    .line(points.bottomRight)
    */
    // strikeout-end
    .line(points.bottomLeftStart)
    .curve(points.bottomLeftCp1, points.bottomLeftCp2, points.bottomLeftEnd)
    .line(points.bottomRightStart)
    .curve(points.bottomRightCp1, points.bottomRightCp2, points.bottomRightEnd)
    .line(points.edgeRight)
    .curve(
      points.edgeRightCp,
      points.edgeTopRightCp,
      points.tipLeftTopStart
    )
    .curve(
      points.tipLeftTopCp1,
      points.tipLeftTopCp2,
      points.tipLeftTopEnd
    )
    .curve(
      points.tipLeftBottomCp1,
      points.tipLeftBottomCp2,
      points.tipLeftBottomEnd
    )
    .curve(
      points.topCp1,
      points.rightCp2,
      points.right
    )
    .curve(
      points.rightCp1,
      points.bottomCp2,
      points.bottom
    )
    .curve(
      points.bottomCp1,
      points.leftCp2,
      points.left
    )
    .curve(
      points.leftCp1,
      points.topCp2,
      points.tipRightBottomEnd
    )
    .curve(
      points.tipRightBottomCp2,
      points.tipRightBottomCp1,
      points.tipRightBottomStart
    )
    .curve(
      points.tipRightTopCp2,
      points.tipRightTopCp1,
      points.tipRightTopStart
    )
    .curve(
      points.edgeTopLeftCp,
      points.edgeLeftCp,
      points.edgeLeft
    )
    .close()
    .addClass("fabric")

  return part
}

Preview

X-Ray

The shape of our bib is now completed