freesewing/markdown/dev/tutorials/pattern-design/avoiding-overlap/en.md

title	order
Avoiding overlap	220

While we've only drawn the end of one strap, it's pretty obvious they overlap. Which is a big no-no in sewing patterns, so we're going to have to address that.

Specifically, we're going to rotate our strap out of the way until it no longer overlaps. The rest of your bib should stay as it is, so let's start by making a list of points we need to rotate.

Once we have our list of points to rotate, we can rotate them. How far? Until the strap no longer overlaps.

```js function draftBib({ Path, Point, paths, points, measurements, options, 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() // Add this line

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')

// 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)

macro("round", { from: points.edgeTop, to: points.tipRight, via: points.tipRightTop, prefix: "tipRightTop", hide: false }) macro("round", { from: points.tipRight, to: points.top, via: points.tipRightBottom, prefix: "tipRightBottom", hide: false })

// highlight-start /*

• 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) } // highlight-end

// highlight-start /*

• This is not needed
• we are merely adding it to show
• what the rotated path looks like */ macro("round", { from: points.edgeTop, to: points.tipRight, via: points.tipRightTop, prefix: "tipRightTop", hide: false, class: 'contrast dotted', }) macro("round", { from: points.tipRight, to: points.top, via: points.tipRightBottom, prefix: "tipRightBottom", hide: false, class: 'contrast dotted', }) // highlight-end

// highlight-start /*

• Always draw your path at the end
• after you've manipulated your points */ paths.rect = new Path() .move(points.edgeTop) .curve(points.edgeTopLeftCp, points.edgeLeftCp, points.edgeLeft) .line(points.bottomLeft) .line(points.bottomRight) .line(points.edgeRight) .curve(points.edgeRightCp, points.edgeTopRightCp, points.edgeTop) .close() // highlight-end

return part }

</Example>