polyline-in-polygon

code:

video:

# based on https://raw.githubusercontent.com/marcomusy/vedo/master/examples/basic/spline_tool.py
# recorded video:
#   -   youtube: https://www.youtube.com/watch?v=1dPJ3P84FxE
#   -   bilibil: https://www.bilibili.com/video/BV1D24y1u7uB

import math
import random
from typing import List, Tuple

import numpy as np
from vedo import Circle, show  # noqa
from vedo.plotter import Event  # noqa
from vedo.pointcloud import Points  # noqa
from vedo.shapes import Line, Polygon  # noqa

from fast_crossing import PolylineRuler, polyline_in_polygon  # noqa


# https://stackoverflow.com/questions/8997099/algorithm-to-generate-random-2d-polygon
def generate_polygon(
    *,
    center: Tuple[float, float] = (0.0, 0.0),
    avg_radius: float = 100.0,
    irregularity: float = 2.0,
    spikiness: float = 0.3,
    num_vertices: int = 100,
    close: bool = True,
) -> List[Tuple[float, float]]:
    if irregularity < 0 or irregularity > 1:
        raise ValueError("Irregularity must be between 0 and 1.")
    if spikiness < 0 or spikiness > 1:
        raise ValueError("Spikiness must be between 0 and 1.")
    if close:
        num_vertices -= 1
    irregularity *= 2 * math.pi / num_vertices
    spikiness *= avg_radius

    def random_angle_steps(steps: int, irregularity: float) -> List[float]:
        angles = []
        lower = (2 * math.pi / steps) - irregularity
        upper = (2 * math.pi / steps) + irregularity
        cumsum = 0
        for _ in range(steps):
            angle = random.uniform(lower, upper)
            angles.append(angle)
            cumsum += angle
        cumsum /= 2 * math.pi
        for i in range(steps):
            angles[i] /= cumsum
        return angles

    angle_steps = random_angle_steps(num_vertices, irregularity)
    points = []
    angle = random.uniform(0, 2 * math.pi)

    def clip(value, lower, upper):
        return min(upper, max(value, lower))

    for i in range(num_vertices):
        radius = clip(random.gauss(avg_radius, spikiness), 0, 2 * avg_radius)
        point = (
            center[0] + radius * math.cos(angle),
            center[1] + radius * math.sin(angle),
        )
        points.append(point)
        angle += angle_steps[i]
    if close:
        points.append(points[0])
    return np.array(points)


def on_key_press(evt):
    if evt.keypress == "c":
        print("==== Cleared all points ====", c="r", invert=True)


# def update(self):
#     self.remove([self.spline, self.points])  # remove old points and spline
#     self.points = Points(self.cpoints).ps(10).c("purple5")
#     self.points.pickable(False)  # avoid picking the same point
#     if len(self.cpoints) > 2:
#         self.spline = Spline(self.cpoints, closed=False).c("yellow5").lw(3)
#         self.add(self.points, self.spline)
#     else:
#         self.add(self.points)


radius = 100

polygon = generate_polygon(avg_radius=radius, irregularity=1.0, spikiness=0.2)
polygon = Line(polygon)
# print(polygon.points().shape)

xs = np.linspace(-radius, radius, 30)
ys = np.sin(xs * 2) * radius / 6
rs = np.linspace(0, np.pi, len(xs))[::-1]  # upper half circle
xs += np.cos(rs) * radius
ys += np.sin(rs) * radius
ys -= radius / 3
polyline = Line(np.c_[xs, ys, np.ones(len(xs))])
# print(polyline.points().shape)

sptool = None


def update_polyline_segments():
    if sptool is None:
        coords = polyline.points()
    else:
        coords = sptool.spline().points()
    chunks = polyline_in_polygon(coords, polygon.points()[:, :2])
    layer = []
    np.random.seed(0)
    for label, coords in chunks.items():
        l1, l2 = label[:3], label[3:]  # noqa
        coords[:, 2] += radius / 50
        seg = Line(coords).linewidth(10)
        seg.color((np.random.random(3) * 200 + 55).astype(np.uint8).tolist())
        # length = l2[-1] - l1[-1]
        # ruler = PolylineRuler(coords)
        # ranges = (np.copy(ruler.ranges()) + l1[-1]).round(3).tolist()
        # seg.labels(ranges, ratio=100)
        layer.append(seg)
    return layer


plt = show([polygon], __doc__, interactive=False, axes=1)
sptool = plt.add_spline_tool(polyline, closed=False)
layer = update_polyline_segments()
plt.add(layer)


def on_sptool(obj, evt):
    global layer
    plt.remove(layer)
    layer = update_polyline_segments()
    plt.add(layer)


sptool.AddObserver("InteractionEvent", on_sptool)

plt.interactive()