freesewing/markdown/dev/howtos/design/slash-spread/en.md

title	for	about
Slash and spread	developers	Slash and spread is easy enough on paper, here's how to do it in code

See this example in our source code

• packages/jaeger/src/front.js

When we slash and spread a pattern, we cut out a triangle, and then rotate it around the tip of the triangle.

And that's exactly what we do in code. We just need to know:

• What point we want to rotate around
• Which points we want to rotate
• By how much we want to rotate

let rotate = [
  'splitEdge',
  'neckEdge',
  'cfNeck',
  'cfNeckCp1',
  'neckCp2Front',
  'neck',
  'shoulder',
  'shoulderCp1',
  'armholePitchCp2',
  'armholePitch',
  'armholePitchCp1',
  'armholeHollowCp2',
  'armholeHollow',
  'armholeHollowCp1',
  'splitCp2',
  'frontNeckCpEdge'
]
for (let p of rotate) {
  points[p] = points[p].rotate(options.chestShapingMax * options.chestShaping * -1, points.split)
}