freesewing/designs/noble/src/backPoints.js

export default function (part) {
  const {
    points,
    Path,
    paths,
    options,
    snippets,
  } = part.shorthand()

  // Hide Bella paths
  for (let key of Object.keys(paths)) paths[key].render = false
  for (let i in snippets) delete snippets[i]

  delete points.__titleNr
  delete points.__titleName
  delete points.__titlePattern
  delete points.scaleboxAnchor
  delete points.__scaleboxImperialBottomLeft
  delete points.__scaleboxMetricBottomLeft
  delete points.__scaleboxImperialTopLeft
  delete points.__scaleboxMetricTopLeft
  delete points.__scaleboxImperialTopRight
  delete points.__scaleboxMetricTopRight
  delete points.__scaleboxImperialBottomRight
  delete points.__scaleboxMetricBottomRight
  delete points.__scaleboxLead
  delete points.__scaleboxTitle
  delete points.__scaleboxText
  delete points.__scaleboxLink
  delete points.__scaleboxImperial
  delete points.__scaleboxMetric
  delete points.bustDartLeft
  delete points.bustDartLeftCp

  points.shoulderDart = points.hps.shiftFractionTowards( points.shoulder, options.shoulderDartPosition )

  let aUp = points.dartTip.angle( points.shoulderDart )
  let aDown = points.dartBottomRight.angle( points.dartTip )
  let aDiff = Math.abs( aUp - aDown )

  // let dartCpAdjustment = Math.abs( options.shoulderDartPosition -.5) +.05
  let dartCpAdjustment = aDiff /50

  points.shoulderDartCpUp = points.shoulderDart.shiftFractionTowards( points.dartTip, 1 - dartCpAdjustment)
  points.shoulderDartCpDown = points.shoulderDart.shiftFractionTowards( points.dartTip, 1 +dartCpAdjustment )

  const length = {
    i: new Path()
      .move(points.dartBottomLeft)
      .curve(points.dartLeftCp, points.shoulderDartCpDown, points.dartTip)
      .curve(points.shoulderDartCpUp, points.shoulderDart, points.shoulderDart)
      .length()
  }

  let iteration = 0
  let diff = 0
  let angle = 0
  do {
    if (length?.o) angle = diff*( length.o > length.i ? -.1 : .1 )

    points.dartBottomRight = points.dartBottomRight.rotate( angle, points.waistSide )

    length.o = new Path()
      .move(points.shoulderDart)
      .curve(points.shoulderDart, points.shoulderDartCpUp, points.dartTip)
      .curve(points.shoulderDartCpDown, points.dartRightCp, points.dartBottomRight)
      .length()

    diff = length.o - length.i
    iteration ++

  } while( diff < -.5 || diff > .5 && iteration < 100 )
  if( iteration >= 100 ) {
    raise.error('Something is not quite right here!')
  }

  return part
}