Source code for meow.gds_structures

""" GDS Extrusions """

from typing import Dict, List, Tuple

import numpy as np
import shapely.geometry as sg
from pydantic.v1 import Field

from .base_model import BaseModel
from .geometries import Prism
from .materials import Material
from .structures import Structure3D

# TODO: Maybe it makes more sense to use native GDSFactory tooling for this


class GdsExtrusionRule(BaseModel):
    """a `GdsExtrusionRule` describes a single extrusion rule.
    Multiple of such rules can later be associated with a gds layer tuple."""

    material: Material = Field(description="the material of the extrusion")
    h_min: float = Field(description="the extrusion starting height")
    h_max: float = Field(description="the extrusion ending height")
    buffer: float = Field(
        default=0.0,
        description="an extra buffer (=grow or shrink) operation applied to the polygon",
    )
    mesh_order: int = Field(
        default=5.0, description="the mesh order of the resulting `Structure3D`"
    )

    def __call__(self, poly) -> Structure3D:
        if self.buffer > 0:
            try:
                poly = np.asarray(sg.Polygon(poly).buffer(self.buffer).boundary.coords)
            except NotImplementedError:
                import gdspy  # fmt: skip

                polygonset = gdspy.offset(gdspy.Polygon(poly), 0.25)
                assert polygonset is not None
                poly = polygonset.polygons[0]
        return Structure3D(
            material=self.material,
            geometry=Prism(
                poly=poly,
                h_min=self.h_min,
                h_max=self.h_max,
                axis="y",
            ),
            mesh_order=self.mesh_order,
        )


def extrude_gds(
    cell,  # type: ignore
    extrusions: Dict[Tuple[int, int], List[GdsExtrusionRule]],
):
    """extrude a gds cell given a dictionary of extruson rules

    Args:
        cell: a gdspy or gdstk Cell to extrude
        extrusions: the extrusion rules to use (if not given, the example extrusions will be used.)
    """
    structs = []
    for layer, polys in cell.get_polygons(by_spec=True, depth=None).items():
        for poly in polys:
            if layer not in extrusions:
                continue
            structs.extend(extrusion(poly) for extrusion in extrusions[layer])
    return structs