Voronoi Dreams

A Voronoi tessellation built from clustered seed points, with each cell recoloured using dm.oklch so that hue rotates with angular position and lightness modulates per cell. Boundary points keep the outer cells finite for clean polygon clipping.

Demonstrates how to mix scipy.spatial.Voronoi with dartwork-mpl’s OKLCH colour primitives for generative art.

import matplotlib.pyplot as plt
import numpy as np
from matplotlib.patches import Polygon
from scipy.spatial import Voronoi

import dartwork_mpl as dm

np.random.seed(42)
dm.style.use("scientific")

fig, ax = plt.subplots(figsize=dm.figsize("16cm", "square"))

n_clusters = 5
n_points_per_cluster = 8
points = []

for _ in range(n_clusters):
    center_x = np.random.uniform(-8, 8)
    center_y = np.random.uniform(-8, 8)
    cluster_points = np.random.randn(n_points_per_cluster, 2) * 1.5 + [
        center_x,
        center_y,
    ]
    points.extend(cluster_points)

points = np.array(points)

boundary_points = []
for x in np.linspace(-10, 10, 10):
    boundary_points.append([x, -10])
    boundary_points.append([x, 10])
for y in np.linspace(-10, 10, 10):
    boundary_points.append([-10, y])
    boundary_points.append([10, y])

all_points = np.vstack([points, boundary_points])
vor = Voronoi(all_points)

for i, region in enumerate(vor.regions):
    if not region or -1 in region:
        continue

    polygon = [vor.vertices[j] for j in region]
    if len(polygon) <= 2:
        continue

    polygon_array = np.array(polygon)
    if (
        polygon_array[:, 0].min() < -10
        or polygon_array[:, 0].max() > 10
        or polygon_array[:, 1].min() < -10
        or polygon_array[:, 1].max() > 10
    ):
        continue

    center = polygon_array.mean(axis=0)
    hue = (np.arctan2(center[1], center[0]) + np.pi) / (2 * np.pi) * 360
    color = dm.oklch(0.6 + 0.2 * np.sin(i), 0.2, hue)

    ax.add_patch(
        Polygon(
            polygon,
            facecolor=color.to_hex(),
            edgecolor="white",
            linewidth=0.5,
            alpha=0.8,
        )
    )

for point in points[: n_clusters * n_points_per_cluster]:
    ax.scatter(
        *point,
        s=20,
        c="white",
        edgecolors="dc.nordic3",
        linewidths=1,
        zorder=10,
    )

ax.set_xlim(-10, 10)
ax.set_ylim(-10, 10)
ax.set_aspect("equal")
for s in ax.spines.values():
    s.set_visible(False)
ax.set_facecolor("dc.nordic0")

ax.text(
    0,
    -11,
    "Voronoi Dreams",
    ha="center",
    fontsize=dm.fs(3),
    color="white",
    weight="bold",
    alpha=0.9,
)

dm.simple_layout(fig)
plt.show()