simplify-flat-array

Lightweight 2D polyline simplification for flat coordinate arrays
Reduces the number of points in paths while preserving shape

Supports two popular algorithms:

• Douglas-Peucker (classic, fast, good for strict geometric fidelity)
• Visvalingam–Whyatt (usually smoother & more natural looking for hand-drawn/organic paths)

Features

• Works directly with flat arrays [x1,y1, x2,y2, ...] (no need for object arrays)
• 100% backward compatible with original v1.0.0 API
• Optional Visvalingam–Whyatt mode (added in v1.1.0) – often preferred for visual quality
• Target exact number of points (Visvalingam)
• Optional Float32Array output (great for PixiJS Line, Rope, Mesh, Graphics)
• Closed path support (polygons, zones, formations)
• Zero dependencies (~3 KB minified)

Installation

npm install simplify-flat-array
# or
yarn add simplify-flat-array

New in v1.1.0 – Visvalingam–Whyatt support

const simplify = require('simplify-flat-array');
// or
import simplify from 'simplify-flat-array';

// Classic Douglas-Peucker (same as old version)
simplify(points, 2.5, true);

// Visvalingam
simplify(points, null, false, { algorithm: 'visvalingam', tolerance: 1 });

// Target specific point count
simplify(points, null, false, { algorithm: 'visvalingam', targetPoints: 30 });

API

simplify(points, tolerance, highQuality, options)

Options

• algorithm (default: 'douglas-peucker')
• targetPoints (Visvalingam only)
• useTypedArray (default: false)
• closed (default: false)

Return value

Returns a flat array of coordinates [x1,y1, x2,y2, ...].

Performance Notes

Douglas-Peucker is significantly faster for large paths.
Visvalingam–Whyatt provides better visual quality but can be 3–10× slower in the current implementation when reducing to low point counts.

License

MIT © Steffen Bär