pattapatta

Pen-plotter geometry library (inspired by PGS): hatching, image halftone (lines or circles), circle packing, triangulation / meshing, boolean path ops, Voronoi, tilings, and SVG I/O for Node and the browser.

Stroke marks only — solid area fills are not the goal.

Status: Built entirely with AI as an experiment. Not meant for public / production use yet. Feedback welcome via GitHub issues on the repository.

Install

pnpm add pattapatta

Requires Node ≥ 18 (ESM). Works in modern browsers via bundlers.

Quick example

import { createRect, union, hatchParallel, toSvg, group, segmentsToOpenPaths } from 'pattapatta'

const a = createRect(0, 0, 2, 1)
const b = createRect(1, 0, 2, 1)
const merged = union(a, b)
const strokes = hatchParallel(merged.paths[0]!, { spacing: 0.08, count: 40 })
console.log(toSvg(group(segmentsToOpenPaths(strokes))))

pnpm dlx pattapatta --help
pnpm dlx pattapatta svg:roundtrip in.svg -o out.svg

Docs site

Live: pattapatta.madorkestra.com (GitHub Pages; deploys on push to main).

For AI agents: llms.txt (index) and llms-full.txt (full API dump). Explainer: /llms-txt.

Local documentation PWA (SvelteKit + shadcn):

pnpm install
pnpm docs:dev
pnpm docs:build
pnpm docs:examples   # regenerate SVG figures (+ llms.txt)
pnpm docs:llms       # regenerate llms.txt / llms-full.txt only

Modules

Import	Role
pattapatta	Types, SVG, all facades
pattapatta/shapeBoolean	Union / intersect / subtract / occlusion
pattapatta/hatch	Parallel / cross hatch fills
pattapatta/halftone	Image tone → lines or circles
pattapatta/circlePacking	Lattices (overlap | contained), LEC, stochastic
pattapatta/triangulation	Earcut, Delaunay, Poisson Steiner, refine
pattapatta/morphology	Buffer, simplify, warps
pattapatta/meshing	Graph faces, quadrangulation, mesh process / repair
pattapatta/voronoi	Voronoi cells
…	See website/ API pages

License

MIT — clean-room implementation (not a GPL line-port of PGS). See docs/decisions/.

Source: github.com/MadOrkestra/pattapatta · Issues · Sponsor · Buy Me a Coffee