coverage

Every region of the target layer (layers[0]) must lie inside the union of the remaining layers; any part sticking out is a violation. Used for “device must be covered by” rules such as a pin marker that must sit on real metal.

Semantics

Computed as the Difference residual target − (cover₁ ∪ cover₂ ∪ …) over the cached tiles — see Virtual layer operations. Unlike min_enclosure, this handles “covered by A or B” directly (a union of covers, not a single enclosing layer) and flags a target region that misses the cover entirely, not just one that’s short on margin at an edge.

Layers

layers[0]

The target layer that must be covered.

layers[1..]

One or more cover layers; the target only has to lie inside their union.

Parameters

None. value is unused (set it to 0.0 by convention).

Violation markers

One violation per residual region — the part of the target left over after subtracting all cover layers — owned by the tile containing its centroid.

KLayout equivalent

target.not(cover1.join(cover2, …)) — a plain NOT against the joined covers.

Example

- id: Pin.a
  check: coverage
  layers: [Activ.pin, Activ]
  value: 0.0