Reading layers

layer name = expr binds a name. input reads from the current design (after source), optionally from a second GDS once that binding is available.

← Language overview

`input(n)`

Available · yields polygons

layer m1 = input(68)

All shapes on GDS layer n, datatype 0, after flatten into source. Overlapping polygons are merged on read (union plus a vertex stitch).

Notes

An empty layer is an empty list, not a null shape.
Texts on the layer are invisible without texts(...).
Paths and boxes in the layout become polygons.
Hierarchy: instance transform (shift, mirror, angle) is already applied to the points.

`input(n, d)`

Available · yields polygons

layer via = input(70, 20)

Layer n, datatype d. Other datatypes on the same number are a different layer.

Notes

input(70) is not the union of all datatypes 70/* — only datatype 0.
A negative n or d is just another index and is usually empty.

`input.raw`

Available · yields polygons

layer raw = input(68, 20).raw

Like input, but without merge. Overlapping and kissing shapes stay separate polygons. Important for inside on raw shapes and for count.

Notes

Two identical stacked boxes: raw counts two, merged counts one.
Only a shared corner: merged stitches one polygon; raw keeps two.
Checks on raw measure the edges of each shape — self-space between copies is possible.

`input from=`

Available · yields polygons

layer b_m1 = input(1, 0, from=other)

Reads from the layout bound with gds other = …. Flatten and cells of the host apply; the main clip window does not.

Notes

An unknown from= is a runtime error.
The file is resolved relative to the deck baseDir.