The general idea is to implement something resembling the GDSII file-format, but with some vectorized element types (eg. circles, not just polygons) and the ability to output to multiple formats.

Installation

Requirements:

python >= 3.11
numpy
klamath (used for GDSII i/o)

Optional requirements:

ezdxf (DXF i/o): ezdxf
oasis (OASIS i/o): fatamorgana
svg (SVG output): svgwrite
visualization (shape plotting): matplotlib
text (Text shape): matplotlib, freetype

Install with pip:

pip install 'masque[oasis,dxf,svg,visualization,text]'

Overview

A layout consists of a hierarchy of Patterns stored in a single Library. Each Pattern can contain Refs pointing at other patterns, Shapes, and Labels.

masque departs from several "classic" GDSII paradigms:

Layer info for Shapess and Labels is not stored in the individual shape and label objects. Instead, the layer is determined by the key for the container dict (e.g. pattern.shapes[layer]).
- This simplifies many common tasks: filtering Shapes by layer, remapping layers, and checking if a layer is empty.
- Technically, this allows reusing the same shape or label object across multiple layers. This isn't part of the standard workflow since a mixture of single-use and multi-use shapes could be confusing.
- This is similar to the approach used in KLayout
Ref target names are also determined in the key of the container dict (e.g. pattern.refs[target_name]).
- This similarly simplifies filtering Refs by target name, updating to a new target, and checking if a given Pattern is referenced.
Pattern names are set by their containing Library and are not stored in the Pattern objects.
- This guarantees that there are no duplicate pattern names within any given Library.
- Likewise, enumerating all the names (and all the Patterns) in a Library is straightforward.
Each Ref, Shape, or Label can be repeated multiple times by attaching a repetition object to it.
- This is similar to how OASIS reptitions are handled, and provides extra flexibility over the GDSII approach of only allowing arrays through AREF (Ref + repetition).
Labels do not have an orientation or presentation
- This is in line with how they are used in practice, and how they are represented in OASIS.
Non-polygonal Shapes are allowed. For example, elliptical arcs are a basic shape type.
- This enables compatibility with OASIS (e.g. circles) and other formats.
- Shapes provide a .to_polygons() method for GDSII compatibility.
Most coordinate values are stored as 64-bit floats internally.
- 1 earth radii in nanometers (6e15) is still represented without approximation (53 bit mantissa -> 2^53 > 9e15)
- Operations that would otherwise clip/round on are still represented approximately.
- Memory usage is usually dominated by other Python overhead.
Pattern objects also contain Port information, which can be used to "snap" together multiple sub-components by matching up the requested port offsets and rotations.
- Port rotations are defined as counter-clockwise angles from the +x axis.
- Ports point into the interior of their associated device.
- Port rotations may be None in the case of non-oriented ports.
- Ports have a ptype string which is compared in order to catch mismatched connections at build time.
- Ports can be exported into/imported from Labels stored directly in the layout, editable from standard tools (e.g. KLayout). A default format is provided.

Glossary

Library: A collection of named cells. OASIS or GDS "library" or file.
Pattern: A collection of geometry, text labels, and reference to other patterns. OASIS or GDS "Cell", DXF "Block".
Ref: A reference to another pattern. GDS "AREF/SREF", OASIS "Placement".
Shape: Individual geometric entity. OASIS or GDS "Geometry element", DXF "LWPolyline" or "Polyline".
repetition: Repetition operation. OASIS "repetition". GDS "AREF" is a Ref combined with a Grid repetition.
Label: Text label. Not rendered into geometry. OASIS, GDS, DXF "Text".
annotation: Additional metadata. OASIS or GDS "property".

TODO

Better interface for polygon operations (e.g. with pyclipper)
- de-embedding
- boolean ops
Tests tests tests
check renderpather
pather and renderpather examples