Example of using fnpcell to build class

Example1: bend_bezier.py

Full script

from functools import cached_property
from typing import Sequence, Tuple

from fnpcell import all as fp
from gpdk.technology import get_technology


class BendBezier(fp.IWaveguideLike, fp.PCell):
    """
    Attributes:
        start: start point of bezier curve
        controls: control points of bezier, 1 for Quadratic Bezier, 2 for Cubic Bezier, ...
        end: end point of bezier curve
        waveguide_type: type of waveguide of the bend
        port_names: defaults to ["op_0", "op_1"]

    Examples:
    ```python
    TECH = get_technology()
        bend = BendBezier(name="q", start=(0, 0), controls=[(31, 30)], end=(60, 0), waveguide_type=TECH.WG.FWG.C.WIRE)
    fp.plot(bend)
    ```
    ![BendBezier](images/bend_bezier_q.png)
    """

    start: fp.Point2D = fp.PositionParam(default=(0, 0), doc="position where bend start, eg. (x, y)")
    controls: Sequence[fp.Point2D] = fp.PointsParam(default=[(10, 0)], min_count=1, doc="control points, count >= 1, eg. [(x1, y1), (x2, y2)]")
    end: fp.Point2D = fp.PositionParam(default=(10, 10), doc="position where bend end, eg. (x, y)")
    waveguide_type: fp.IWaveguideType = fp.WaveguideTypeParam(doc="Waveguide parameters")
    port_names: fp.IPortOptions = fp.PortOptionsParam(count=2, default=["op_0", "op_1"])

    def _default_waveguide_type(self):
        return get_technology().WG.FWG.C.WIRE

    @cached_property
    def raw_curve(self):
        return fp.g.Bezier(
            start=self.start,
            controls=self.controls,
            end=self.end,
        )

    def build(self) -> Tuple[fp.InstanceSet, fp.ElementSet, fp.PortSet]:
        insts, elems, ports = super().build()
        wg = self.waveguide_type(curve=self.raw_curve).with_ports(self.port_names)
        insts += wg
        ports += wg.ports
        return insts, elems, ports


if __name__ == "__main__":
    from pathlib import Path

    gds_file = Path(__file__).parent / "local" / Path(__file__).with_suffix(".gds").name
    library = fp.Library()

    TECH = get_technology()
    # =======================================================================
    # fmt: off

    library += BendBezier(name="bend1", start=(0, 0), controls=[(30, 30)], end=(60, 0), waveguide_type=TECH.WG.FWG.C.WIRE)
    library += BendBezier(name="bend2", start=(0, 0), controls=[(50, 20)], end=(60, 0), waveguide_type=TECH.WG.FWG.C.WIRE)
    library += BendBezier(name="bend3", start=(0, 0), controls=[(10, 20)], end=(60, 0), waveguide_type=TECH.WG.FWG.C.WIRE)

    # fmt: on
    # =============================================================
    fp.export_gds(library, file=gds_file)
    # fp.plot(library)

Section Script Definition

1. Use BendBezier() class in bend_bezier.py to create three layout units, named bend1, bend2, and bend3, and modify the controls parameter coordinates to different values, as follows:

   library += BendBezier(name="bend1", start=(0, 0), controls=[(30, 30)], end=(60, 0), waveguide_type=TECH.WG.FWG.C.WIRE)
   library += BendBezier(name="bend2", start=(0, 0), controls=[(50, 20)], end=(60, 0), waveguide_type=TECH.WG.FWG.C.WIRE)
   library += BendBezier(name="bend3", start=(0, 0), controls=[(10, 20)], end=(60, 0), waveguide_type=TECH.WG.FWG.C.WIRE)
   

   The units created by the three BendBezier() classes will generate three layout cells in the GDS file. The starting points of the three bends are in the same position, and the waypoints of the bezier curves will be different depending on the parameter settings.

2. Running the bend_bezier.py script will by default generate the GDS file under gpdk > components > bend > local. If the relevant file already exists in the original local folder, the newly generated bend_bezier.gds file will automatically overwrite the original file (no warning message), but you can confirm that the existing file is the newly generated GDS file by the file modification time.

3. Using the GDS file viewer to view the layout (e.g. KLayout), you will see three layout cells in the cell list, all prefixed with BendBezier_ and with the cell names defined when fetching the functions, i.e. bend1, bend2, bend3. To easily compare, create a new cell and import three bends to see the shape of the bend controlled by the parameter.

Example2: bend_circular.py

Full script

from functools import cached_property
from typing import Tuple

from fnpcell import all as fp
from gpdk.technology import get_technology


class BendCircular(fp.IWaveguideLike, fp.PCell):
    """
    Attributes:
        degrees: central angle of the bend, in degrees
        radius: raidus of the bend
        waveguide_type: type of waveguide of the bend
        port_names: defaults to ["op_0", "op_1"]

    Examples:
    ```python
    TECH = get_technology()
        bend = BendCircular(name="s", radius=5, waveguide_type=TECH.WG.FWG.C.WIRE)
    fp.plot(bend)
    ```
    ![BendCircular](images/bend_circular.png)
    """

    degrees: float = fp.DegreeParam(default=90, min=-180, max=180, doc="Bend angle in degrees")
    radius: float = fp.PositiveFloatParam(default=10, doc="Bend radius")
    waveguide_type: fp.IWaveguideType = fp.WaveguideTypeParam(doc="Waveguide parameters")
    port_names: fp.IPortOptions = fp.PortOptionsParam(count=2, default=["op_0", "op_1"])

    def _default_waveguide_type(self):
        return get_technology().WG.FWG.C.WIRE

    def __post_pcell_init__(self):
        assert fp.is_nonzero(self.degrees)

    @cached_property
    def raw_curve(self):
        return fp.g.EllipticalArc(
            radius=self.radius,
            final_degrees=self.degrees,
        )

    def build(self) -> Tuple[fp.InstanceSet, fp.ElementSet, fp.PortSet]:
        insts, elems, ports = super().build()
        wg = self.waveguide_type(curve=self.raw_curve).with_ports(self.port_names)
        insts += wg
        ports += wg.ports
        return insts, elems, ports


if __name__ == "__main__":
    from pathlib import Path

    gds_file = Path(__file__).parent / "local" / Path(__file__).with_suffix(".gds").name
    library = fp.Library()

    TECH = get_technology()
    # =======================================================================
    # fmt: off

    library += BendCircular(name="bend1", radius=5, waveguide_type=TECH.WG.FWG.C.WIRE)
    library += BendCircular(name="bend2", radius=10, degrees=30, waveguide_type=TECH.WG.FWG.C.WIRE, transform=fp.translate(0, 5))
    library += BendCircular(name="bend3", radius=10, degrees=-60, waveguide_type=TECH.WG.FWG.C.WIRE).translated(5, 5)
    library += BendCircular(name="bend4", radius=10, degrees=90, waveguide_type=TECH.WG.FWG.C.WIRE, transform=fp.translate(0, 5)).translated(5, 5)

    # fmt: on
    # =============================================================
    fp.export_gds(library, file=gds_file)
    fp.plot(library)

Section Script Definition

1. In bend_circular.py script, BendCircular() class is used to generate four layout cells, named bend1``~``bend4.

   Different radius parameters, degrees parameters and translate parameters are used to reflect their effects on the device, where the use of the transform parameter is mainly reflected in bend2 ~ bend4, please refer to the comments in the source code for details; examples are shown below:

   library += BendCircular(name="bend1", radius=5, waveguide_type=TECH.WG.FWG.C.WIRE)
   library += BendCircular(name="bend2", radius=10, degrees=30, waveguide_type=TECH.WG.FWG.C.WIRE, transform=fp.translate(0, 5))
   library += BendCircular(name="bend3", radius=10, degrees=-60, waveguide_type=TECH.WG.FWG.C.WIRE).translated(5, 5)
   library += BendCircular(name="bend4", radius=10, degrees=90, waveguide_type=TECH.WG.FWG.C.WIRE, transform=fp.translate(0, 5)).translated(5, 5)
   

2. Run the bend_circular.py script will, by default, generate the GDS file under gpdk > components > bend > local.

3. Open the GDS file to view the layout, there are four layout cells in the cell list, and they are all prefixed with BendCircular and suffixed with the cell names defined by the keyword name during creation, i.e., bend1 ~ bend4.

   Create a new cell and import the four bends, place the origin of the four bends at the same position, and you can see the effect on the device position due to the the effect of the fp.translate parameter on the device position.

   Note that in bend4, when creating the device using the BendCircular() class, we set translate both inside and outside of it, and its relative position is also the result of superimposing the two translate parameters, as shown below.