Line Arrangements (Mohr)

Math essence

For each of n_columns grid cells we drop h_lines_per_col vertical segments inside the cell with a uniform random horizontal offset jitter·cell_width and random vertical trim; symmetrically for n_rows. A second pass draws d_lines_total segments at ±45° with uniformly random centers and uniformly random lengths in [0.04·dim, 0.42·dim].

Parameters

Reference

First 60 lines of reference.py. Full source: library_external/generative_pioneers/mohr_line_arrangement/reference.py

from __future__ import annotations

from typing import ClassVar

import imageio.v2 as imageio
import numpy as np


class MohrLineArrangement:
    family: ClassVar[str] = "generative_pioneers"
    sketch: ClassVar[str] = "mohr_line_arrangement"

    def __init__(
        self,
        dim: int = 512,
        n_columns: int = 12,
        n_rows: int = 12,
        h_lines_per_col: int = 3,
        v_lines_per_row: int = 3,
        d_lines_total: int = 24,
        jitter: float = 0.35,
        thickness: float = 1.2,
        bg_color: tuple[int, int, int] = (245, 240, 230),
        line_color: tuple[int, int, int] = (15, 15, 20),
        seed: int | None = None,
    ) -> None:
        self.dim = dim
        self.n_columns = n_columns
        self.n_rows = n_rows
        self.h_lines_per_col = h_lines_per_col
        self.v_lines_per_row = v_lines_per_row
        self.d_lines_total = d_lines_total
        self.jitter = jitter
        self.thickness = thickness
        self.bg_color = np.array(bg_color, dtype=np.uint8)
        self.line_color = np.array(line_color, dtype=np.uint8)
        self._seed = seed
        self.rng = np.random.default_rng(seed)
        self.canvas = np.full((dim, dim, 3), self.bg_color, dtype=np.uint8)
        self.time = 0
        self._dirty = True

    def reset(self, seed: int | None = None) -> None:
        if seed is not None:
            self._seed = seed
        self.rng = np.random.default_rng(self._seed)
        self.canvas = np.full((self.dim, self.dim, 3), self.bg_color, dtype=np.uint8)
        self.time = 0
        self._dirty = True

    def _draw_segment(
        self,
        x0: float,
        y0: float,
        x1: float,
        y1: float,
        color: np.ndarray,
        thickness: float,
    ) -> None:
        d = float(np.hypot(x1 - x0, y1 - y0))