OptionalanchorFor resize chrome: which corner stays pinned. Mirrors the kit's
ResizeAnchor, spelled inline so affordances/ doesn't take a type
dependency on the gesture layer for one field.
Sequential anchor index in path walk order.
OptionalfixedWorld-space invariant point of the transform — the fixed corner for a resize, the pivot for a rotation.
Which of the anchor's three grabbable points this is.
Node id of the path the anchor belongs to.
The fields
buildAffordanceAtlifts out of a region'sinitialScratchwhen it turns a region hit into anAffordanceHit.Scratch is otherwise opaque — whatever the affordance wants to hand the action that picks up the drag. These few names are the exception: they mean the same thing to every affordance, and the actions that consume them (
resizeAction,rotateAction) read them offAffordanceHitrather than out of scratch. An affordance that doesn't set them simply produces a hit without those fields.