def bezier(
name: None = None,
width: float = 0.5,
control_points: List[Tuple[float, float]] = [
(0.0, 0.0),
(5.0, 0.0),
(5.0, 2.0),
(10.0, 2.0),
],
t: ndarray = np.linspace(0, 1, 201),
layer: Tuple[int, int] = LAYER.WG,
**extrude_path_params
) -> Component:
""" bezier bend """
def _fmt_f(x):
return "{:.3f}".format(x).rstrip("0").rstrip(".")
def _fmt_cp(cps):
return "_".join(["({},{})".format(_fmt_f(p[0]), _fmt_f(p[1])) for p in cps])
if name is None:
points_hash = hashlib.md5(_fmt_cp(control_points).encode()).hexdigest()
name = "bezier_w{}_{}_{}".format(int(width * 1e3), points_hash, layer)
c = pp.Component(name=name)
path_points = bezier_curve(t, control_points)
polygon_points = extrude_path(path_points, width, **extrude_path_params)
angles = angles_deg(path_points)
c.info["start_angle"] = angles[0]
c.info["end_angle"] = angles[-2]
a0 = angles[0] + 180
a1 = angles[-2]
a0 = snap_angle(a0)
a1 = snap_angle(a1)
p0 = path_points[0]
p1 = path_points[-1]
c.add_polygon(polygon_points, layer=layer)
c.add_port(name="0", midpoint=p0, width=width, orientation=a0, layer=layer)
c.add_port(name="1", midpoint=p1, width=width, orientation=a1, layer=layer)
c.info["length"] = path_length(path_points)
curv = curvature(path_points, t)
c.info["min_bend_radius"] = 1 / max(np.abs(curv))
c.info["curvature"] = curv
c.info["t"] = t
return c
def path_length_matched_points_modify_segment(list_of_waypoints,
modify_segment_i, dL0):
if type(list_of_waypoints) != list:
raise ValueError("list_of_waypoints should be a list, got {}".format(
type(list_of_waypoints)))
list_of_waypoints = [
remove_flat_angles(waypoints) for waypoints in list_of_waypoints
]
lengths = [path_length(waypoints) for waypoints in list_of_waypoints]
L0 = max(lengths)
N = len(list_of_waypoints[0])
# Find how many turns there are per path
nb_turns = [len(waypoints) - 2 for waypoints in list_of_waypoints]
# The paths have to have the same number of turns, otherwise this algo
# cannot path length match
if min(nb_turns) != max(nb_turns):
raise ValueError("Number of turns in paths have to be identical got \
{}".format(nb_turns))
if modify_segment_i < 0:
modify_segment_i = modify_segment_i + N + 1
list_new_waypoints = []
# For each list of waypoints, modify one segment in-place
for i, waypoints in enumerate(list_of_waypoints):
p_s0, p_s1, p_next = waypoints[modify_segment_i - 1:modify_segment_i +
2]
p_s0 = np.array(p_s0)
p_s1 = np.array(p_s1)
L = lengths[i]
# Path length compensation length
dL = (L0 - L) / 2
# Additional fixed length
dL = dL + dL0
# Modify the segment to accomodate for path length matching
# Two cases: vertical or horizontal segment
if _is_vertical(p_s0, p_s1):
sx = np.sign(p_next[0] - p_s1[0])
dx = -sx * dL
dp = (dx, 0)
# Sequence of displacements to apply
elif _is_horizontal(p_s0, p_s1):
sy = np.sign(p_next[1] - p_s1[1])
dy = -sy * dL
dp = (0, dy)
waypoints[modify_segment_i - 1] = p_s0 + dp
waypoints[modify_segment_i] = p_s1 + dp
list_new_waypoints += [waypoints]
return list_new_waypoints
def f(y):
control_points = get_control_pts(x0, y)
t = np.linspace(0, 1, 51)
path_points = bezier_curve(t, control_points)
return path_length(path_points) - target_bend_length
def path_length_matched_points_add_waypoints(
list_of_waypoints,
modify_segment_i=-2,
bend_radius=10.0,
margin=0.5,
dL0=0.0,
nb_loops=1,
):
"""
Args:
list_of_waypoints: a list of list_of_points:
[[p1, p2, p3,...], [q1, q2, q3,...], ...]
- the number of turns have to be identical
(usually means same number of points. exception is if there are
some flat angles)
bend_radius: used to estimate the position of new waypoints to accommodate
bends with a given radius
margin: some extra space to budget for in addition to the bend radius
in most cases, the default is fine
dL0: distance added to all path length compensation.
Useful is we want to add space for extra taper on all branches
modify_segment_i: index of the segment which accomodates the new turns
default is next to last segment
nb_loops: number of extra loops added in the path
returns:
another list of waypoints where:
- the path_lenth of each waypoints list are identical
- the number of turns are identical
Several types of paths won't match correctly. We do not try to handle
all the corner cases here. If the paths are not well behaved enough,
the input list_of_waypoints needs to be modified.
"""
print(list_of_waypoints[0])
if type(list_of_waypoints) != list:
raise ValueError("list_of_waypoints should be a list, got {}".format(
type(list_of_waypoints)))
list_of_waypoints = [
remove_flat_angles(waypoints) for waypoints in list_of_waypoints
]
lengths = [path_length(waypoints) for waypoints in list_of_waypoints]
L0 = max(lengths)
N = len(list_of_waypoints[0])
# Find how many turns there are per path
nb_turns = [len(waypoints) - 2 for waypoints in list_of_waypoints]
# The paths have to have the same number of turns, otherwise cannot path-length
# match with this algorithm
if min(nb_turns) != max(nb_turns):
raise ValueError("Number of turns in paths have to be identical got \
{}".format(nb_turns))
# To have flexibility in the path length, we need to add 4 bends
"""
One path has to be converted in this way:
----
| |
| | This length is adjusted to make all path with the same length
| |
-------- ===> ---| |---
"""
# Get the points for the segment we need to modify
a = margin + bend_radius
if modify_segment_i < 0:
modify_segment_i = modify_segment_i + N + 1
list_new_waypoints = []
for i, waypoints in enumerate(list_of_waypoints):
p_s0, p_s1, p_next = waypoints[modify_segment_i - 2:modify_segment_i +
1]
p_s1 = np.array(p_s1)
L = lengths[i]
# Path length compensation length
dL = (L0 - L) / (2 * nb_loops)
# Additional fixed length
dL = dL + dL0
# Generate a new sequence of points which will replace this segment
# Two cases: vertical or horizontal segment
if _is_vertical(p_s0, p_s1):
sx = np.sign(p_next[0] - p_s1[0])
sy = np.sign(p_s1[1] - p_s0[1])
dx = sx * (2 * a + dL)
dy = sy * 2 * a
# First new point to insert
q0 = p_s1 + (0, -2 * nb_loops * dy)
# Sequence of displacements to apply
seq = [(dx, 0), (0, dy), (-dx, 0), (0, dy)] * nb_loops
seq.pop() # Remove last point to avoid flat angle with next point
elif _is_horizontal(p_s0, p_s1):
sy = np.sign(p_next[1] - p_s1[1])
sx = np.sign(p_s1[0] - p_s0[0])
dx = sx * 2 * a
dy = sy * (2 * a + dL)
q0 = p_s1 + (-2 * dx * nb_loops, 0)
# Sequence of displacements to apply
seq = [(0, dy), (dx, 0), (0, -dy), (dx, 0)] * nb_loops
seq.pop() # Remove last point to avoid flat angle with next point
# Generate points to insert
qs = [q0]
for dp in seq:
qs += [qs[-1] + dp]
# print()
# print(nb_loops)
# for q in qs:
# print(q)
# print()
inserted_points = np.stack(qs, axis=0)
waypoints = np.array(waypoints)
# Insert the points
new_points = np.vstack([
waypoints[:modify_segment_i - 1],
inserted_points,
waypoints[modify_segment_i - 1:],
])
list_new_waypoints += [new_points]
return list_new_waypoints
def bezier(
name: None = None,
width: float = 0.5,
control_points: List[Tuple[float, float]] = [
(0.0, 0.0),
(5.0, 0.0),
(5.0, 2.0),
(10.0, 2.0),
],
t: ndarray = np.linspace(0, 1, 201),
layer: Tuple[int, int] = LAYER.WG,
with_manhattan_facing_angles: bool = True,
spike_length: float = 0.0,
start_angle: Optional[int] = None,
end_angle: Optional[int] = None,
grid: float = 0.001,
) -> Component:
"""Bezier bend
We avoid autoname control_points and t spacing
Args:
width: waveguide width
control_points: list of points
t: 1D array of points varying between 0 and 1
layer: layer
"""
def format_float(x):
return "{:.3f}".format(x).rstrip("0").rstrip(".")
def _fmt_cp(cps):
return "_".join(
[f"({format_float(p[0])},{format_float(p[1])})" for p in cps])
if name is None:
points_hash = hashlib.md5(_fmt_cp(control_points).encode()).hexdigest()
name = f"bezier_w{int(width*1e3)}_{points_hash}_{layer[0]}_{layer[1]}"
c = pp.Component(name=name)
c.ignore.add("control_points")
c.ignore.add("t")
path_points = bezier_curve(t, control_points)
polygon_points = extrude_path(
path_points,
width=width,
with_manhattan_facing_angles=with_manhattan_facing_angles,
spike_length=spike_length,
start_angle=start_angle,
end_angle=end_angle,
grid=grid,
)
angles = angles_deg(path_points)
c.info["start_angle"] = pp.drc.snap_to_1nm_grid(angles[0])
c.info["end_angle"] = pp.drc.snap_to_1nm_grid(angles[-2])
a0 = angles[0] + 180
a1 = angles[-2]
a0 = snap_angle(a0)
a1 = snap_angle(a1)
p0 = path_points[0]
p1 = path_points[-1]
c.add_polygon(polygon_points, layer=layer)
c.add_port(name="0", midpoint=p0, width=width, orientation=a0, layer=layer)
c.add_port(name="1", midpoint=p1, width=width, orientation=a1, layer=layer)
curv = curvature(path_points, t)
c.info["length"] = pp.drc.snap_to_1nm_grid(path_length(path_points))
c.info["min_bend_radius"] = pp.drc.snap_to_1nm_grid(1 / max(np.abs(curv)))
# c.info["curvature"] = curv
# c.info["t"] = t
return c
