geometry.py

import numpy as np
from gdspy import Cell, Round, fast_boolean
from functools import partial

MAX_POINTS = 4094#8191 # same as LayoutEditor
ROUND_POINTS = 100

Cell = partial(Cell, exclude_from_current=True)
Round = partial(Round, number_of_points=ROUND_POINTS, max_points=MAX_POINTS)
fast_boolean = partial(fast_boolean, max_points=MAX_POINTS)

def polygon_orientation(polygon):
    # SEE: https://en.wikipedia.org/wiki/Curve_orientation
    polygon = np.array(polygon)
    x_min = polygon[:,0].min()
    y_min = polygon[polygon[:,0] == x_min,1].min()
    idx_b = np.where((polygon[:,0] == x_min) & (polygon[:,1] == y_min))[0][0]
    idx_a = (idx_b - 1) % len(polygon)
    idx_c = (idx_b + 1) % len(polygon)
    x_a, y_a = polygon[idx_a]
    x_b, y_b = polygon[idx_b]
    x_c, y_c = polygon[idx_c]
    det = (x_b - x_a) * (y_c - y_a) - (x_c - x_a) * (y_b - y_c)
    return det

def get_bounding_box(polygons):
    all_points = np.concatenate(polygons).transpose()
    bbox = np.array(((all_points[0].min(), all_points[1].min()),
                      (all_points[0].max(), all_points[1].max())))
    return bbox

def mirror(polygons, axis='y'):
    x = y = False
    if axis == 'both':
        x = y = True
    elif axis == 'x':
        x = True
    elif axis == 'y':
        y = True
    else:
        raise ValueError('bad axis specification')
    factor = np.ones(2)
    if x:
        factor[0] = -1
    if y:
        factor[1] = -1
    polygons[:] = [factor*poly for poly in polygons]
    return polygons

def mirror_refs(refs, axis='x'):
    x = y = False
    if axis == 'both':
        x = y = True
    elif axis == 'x':
        x = True
    elif axis == 'y':
        y = True
    else:
        raise ValueError('bad axis specification')
    factor = np.ones(2)
    if x:
        factor[0] = -1
    if y:
        factor[1] = -1
    for ref in refs:
        if x:
            ref.rotation += 180
            ref.x_reflection = not ref.x_reflection
        if y:
            raise NotImplementedError
        ref.origin *= factor
    return refs

# TODO: right/left switched
def align(polygons, position=(0, 0), alignment='left'):
    bbox = get_bounding_box(polygons)
    if alignment == 'left':
        offset = np.array([bbox[1,0],0])
    elif alignment == 'centered':
        offset = np.array([(bbox[0,0] + bbox[1,0])/2,0])
    elif alignment == 'right':
        offset = np.array([bbox[0,0],0])
    else:
        raise NotImplementedError
    factor = np.array([-1,1])
    position = np.array(position) + offset
    polygons[:] = [position + factor*poly for poly in polygons]
    return polygons

def align_refs(refs, position=(0, 0), alignment='left'):
    position = np.array(position)
    polygons = sum([ref.get_polygons() for ref in refs], [])
    bbox = get_bounding_box(polygons)
    if alignment == 'right':
        offset = -np.array([bbox[1,0],0])
    elif alignment == 'centered':
        offset = -np.array([(bbox[0,0] + bbox[1,0])/2,0])
    elif alignment == 'left':
        offset = -np.array([bbox[0,0],0])
    else:
        raise NotImplementedError
    # position = np.array(position) + offset
    # polygons[:] = [position + factor*poly for poly in polygons]
    # return polygons
    for ref in refs:
        ref.origin += position + offset
    return refs