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masque/masque/shapes/arc.py

274 lines
8.5 KiB
Python

from typing import List
import math
import numpy
from numpy import pi
from . import Shape, Polygon, normalized_shape_tuple, DEFAULT_POLY_NUM_POINTS
from .. import PatternError
from ..utils import is_scalar, vector2
__author__ = 'Jan Petykiewicz'
class Arc(Shape):
"""
An elliptical arc, formed by cutting off an elliptical ring with two rays which exit from its
center. It has a position, two radii, a start and stop angle, a rotation, and a width.
The radii define an ellipse; the ring is formed with radii +/- width/2.
The rotation gives the angle from x-axis, counterclockwise, to the first (x) radius.
The start and stop angle are measure counterclockwise from the first (x) radius.
"""
_radii = None # type: numpy.ndarray
_angles = None # type: numpy.ndarray
_width = 1.0 # type: float
_rotation = 0.0 # type: float
# Defaults for to_polygons
poly_num_points = DEFAULT_POLY_NUM_POINTS # type: int
poly_max_arclen = None # type: float
# radius properties
@property
def radii(self) -> numpy.ndarray:
"""
Return the radii [rx, ry]
:return: [rx, ry]
"""
return self.radii
@radii.setter
def radii(self, val: vector2):
val = numpy.array(val, dtype=float).flatten()
if not val.size == 2:
raise PatternError('Radii must have length 2')
if not val.min() >= 0:
raise PatternError('Radii must be non-negative')
self.radii = val
@property
def radius_x(self) -> float:
return self.radii[0]
@radius_x.setter
def radius_x(self, val: float):
if not val >= 0:
raise PatternError('Radius must be non-negative')
self.radii[0] = val
@property
def radius_y(self) -> float:
return self.radii[1]
@radius_y.setter
def radius_y(self, val: float):
if not val >= 0:
raise PatternError('Radius must be non-negative')
self.radii[1] = val
# arc start/stop angle properties
@property
def angles(self) -> vector2:
"""
Return the start and stop angles [a_start, a_stop].
Angles are measured from x-axis after rotation, and are stored mod 2*pi
:return: [a_start, a_stop]
"""
return self._angles
@angles.setter
def angles(self, val: vector2):
val = numpy.array(val, dtype=float).flatten()
if not val.size == 2:
raise PatternError('Angles must have length 2')
angles = val % (2 * pi)
if angles[0] > pi:
self.rotation += pi
angles -= pi
self._angles = angles
@property
def start_angle(self) -> float:
return self.angles[0]
@start_angle.setter
def start_angle(self, val: float):
self.angles[0] = val % (2 * pi)
@property
def stop_angle(self) -> float:
return self.angles[1]
@stop_angle.setter
def stop_angle(self, val: float):
self.angles[1] = val % (2 * pi)
# Rotation property
@property
def rotation(self) -> float:
"""
Rotation of radius_x from x_axis, counterclockwise, in radians. Stored mod 2*pi
:return: rotation counterclockwise in radians
"""
return self._rotation
@rotation.setter
def rotation(self, val: float):
if not is_scalar(val):
raise PatternError('Rotation must be a scalar')
self._rotation = val % (2 * pi)
# Width
@property
def width(self) -> float:
"""
Width of the arc (difference between inner and outer radii)
:return: width
"""
return self._width
@width.setter
def width(self, val: float):
if not is_scalar(val):
raise PatternError('Width must be a scalar')
if not val > 0:
raise PatternError('Width must be positive')
self._width = val
def __init__(self,
radii: vector2,
angles: vector2,
rotation: float=0,
poly_num_points: int=DEFAULT_POLY_NUM_POINTS,
poly_max_arclen: float=None,
offset: vector2=(0.0, 0.0),
layer: int=0,
dose: float=1.0):
self.offset = offset
self.layer = layer
self.dose = dose
self.radii = radii
self.angles = angles
self.rotation = rotation
self.poly_num_points = poly_num_points
self.poly_max_arclen = poly_max_arclen
def to_polygons(self, poly_num_points: int=None, poly_max_arclen: float=None) -> List[Polygon]:
if poly_num_points is None:
poly_num_points = self.poly_num_points
if poly_max_arclen is None:
poly_max_arclen = self.poly_max_arclen
if (poly_num_points is None) and (poly_max_arclen is None):
raise PatternError('Max number of points and arclength left unspecified' +
' (default was also overridden)')
rxy = self.radii
ang = self.angles
# Approximate perimeter
# Ramanujan, S., "Modular Equations and Approximations to ,"
# Quart. J. Pure. Appl. Math., vol. 45 (1913-1914), pp. 350-372
h = ((rxy[1] - rxy[0]) / rxy.sum()) ** 2
ellipse_perimeter = pi * rxy.sum() * (1 + 3 * h / (10 + math.sqrt(4 - 3 * h)))
perimeter = abs(ang[0] - ang[1]) / (2 * pi) * ellipse_perimeter
n = []
if poly_num_points is not None:
n += [poly_num_points]
if poly_max_arclen is not None:
n += [perimeter / poly_max_arclen]
thetas = numpy.linspace(2 * pi, 0, max(n), endpoint=False)
sin_th, cos_th = (numpy.sin(thetas), numpy.cos(thetas))
wh = self.width / 2.0
xs1 = (rxy[0] + wh) * cos_th - (rxy[1] + wh) * sin_th
ys1 = (rxy[0] + wh) * cos_th - (rxy[1] + wh) * sin_th
xs2 = (rxy[0] - wh) * cos_th - (rxy[1] - wh) * sin_th
ys2 = (rxy[0] - wh) * cos_th - (rxy[1] - wh) * sin_th
xs = numpy.hstack((xs1, xs2[::-1]))
ys = numpy.hstack((ys1, ys2[::-1]))
xys = numpy.vstack((xs, ys)).T
poly = Polygon(xys, dose=self.dose, layer=self.layer, offset=self.offset)
poly.rotate(self.rotation)
return [poly]
def get_bounds(self) -> numpy.ndarray:
a = self.angles - 0.5 * pi
mins = []
maxs = []
for sgn in (+1, -1):
wh = sgn * self.width/2
rx = self.radius_x + wh
ry = self.radius_y + wh
sin_r = numpy.sin(self.rotation)
cos_r = numpy.cos(self.rotation)
tan_r = numpy.tan(self.rotation)
sin_a = numpy.sin(a)
cos_a = numpy.cos(a)
xpt = numpy.arctan(-ry / rx * tan_r)
ypt = numpy.arctan(+ry / rx / tan_r)
xnt = numpy.arcsin(numpy.sin(xpt - pi))
ynt = numpy.arcsin(numpy.sin(ypt - pi))
xr = numpy.sqrt((rx * cos_r) ** 2 + (ry * sin_r) ** 2)
yr = numpy.sqrt((rx * sin_r) ** 2 + (ry * cos_r) ** 2)
xn, xp = sorted(rx * cos_r * cos_a - ry * sin_r * sin_a)
yn, yp = sorted(rx * sin_r * cos_a - ry * cos_r * sin_a)
if min(a) < xpt < max(a):
xp = xr
if min(a) < xnt < max(a):
xn = -xr
if min(a) < ypt < max(a):
yp = yr
if min(a) < ynt < max(a):
yn = -yr
mins.append([xn, yn])
maxs.append([xp, yp])
return numpy.vstack((numpy.min(mins, axis=0) + self.offset,
numpy.max(maxs, axis=0) + self.offset))
def rotate(self, theta: float) -> 'Arc':
self.rotation += theta
return self
def scale_by(self, c: float) -> 'Arc':
self.radii *= c
self.width *= c
return self
def normalized_form(self, norm_value: float) -> normalized_shape_tuple:
if self.radius_x < self.radius_y:
radii = self.radii / self.radius_x
scale = self.radius_x
rotation = self.rotation
angles = self.angles
else: # rotate by 90 degrees and swap radii
radii = self.radii[::-1] / self.radius_y
scale = self.radius_y
rotation = self.rotation + pi / 2
angles = self.angles - pi / 2
return (type(self), radii, angles, self.layer), \
(self.offset, scale/norm_value, rotation, self.dose), \
lambda: Arc(radii=radii*norm_value, angles=angles, layer=self.layer)