offset

The offset macro will offset and join paths.

Unlike the core path.join(...) and path.offset(...) functions, the offset macro can extend line ends to meet in a sharp corner and will automatically trim useless path ends when adjacent paths in the array are intersecting.

The offset macro accepts an array of Path objects with their offset, like {p: 'somePath', offset: 30} or {p: ['path1', 'path2'], offset: sa * 3, hidden: true}. For the paths in the p attribute, you can reference either names in the paths array or insert direct references to Path objects. The array can contain null values to create gaps (e.g., for cuts on the fold or for other sections that don't need seam allowance).

By default, the offset macro will offset the paths in a circular fashion, joining the end of the last path in the array to the start of the first path, creating a full outline. If this is not desired, insert null elements where you want to create gaps.

You can use offset: 0 to include paths which don't need an additional offset.

You can use hidden: true to omit path segments from the output, but still build corner joins as if they were there. This can be used for cut-on-fold lines, where no seam allowance is needed.

note

To create a seam allowance, prefer the sa macro instead of the offset macro. It does pretty much the same, but the sa macro defaults to offsetting paths by the user defined seam allowance.

Signature

Path macro('offset', {
  Array paths,
  number limit,
  string mode,
  string class
})

Example

Preview

fixme: Errors logged. Please implement log view

Code

;({ Point, points, Path, paths, macro, part }) => {
  paths.outline = new Path()
    .move(new Point(10, 30))
    .line(new Point(30, 30))
    .line(new Point(30, 50))
    .line(new Point(50, 50))
    .line(new Point(50, 70))
    .line(new Point(70, 70))
    .curve(new Point(55, 15), new Point(55, 15), new Point(30, 0))

  paths.outline2 = new Path().move(new Point(30, 0)).line(new Point(10, 30))

  paths.offset = macro('offset', {
    paths: [
      { p: 'outline', offset: 10 },
      { p: 'outline2', offset: 30 },
    ],
  }).setClass('stroke-sm mark dotted')

  paths.halfCircle = new Path().move(new Point(100, 0)).circleSegment(37, new Point(200, 0)).hide()

  paths.halfCircleClosed = paths.halfCircle.clone().line(new Point(200, 0)).unhide().close()

  paths.halfCircleSa = macro('offset', {
    paths: [{ p: 'halfCircle', offset: 10 }, null],
  }).setClass('stroke-sm mark dotted')

  return part
}

X-Ray

fixme: Errors logged. Please implement log view

An example of the offset macro

Configuration

Property	Default	Type	Description
paths		array	An array of paths with their offset and visibility. You can use path names in the paths array or reference Path objects directly, or insert null elements to create gaps.
mode	'corner'	string	Mode for joining paths. Either 'corner' or 'cut'. 'cut' will join the paths directly (like path.join(...)) without extending the corners.
limit	null	number	Allows limiting the length of extended path corners in 'corner' mode. Prevents overly long joins on very sharp angles. Ignored if null or false.
class	'offset'	string	CSS class that is automatically applied to the resulting path.