Skip to main content

TWKBWriter 🆕 🚧

From-v4.0

Writer for the Tiny Well-known binary format for representation of geometry.

LoaderCharacteristic
File Extension.wkb,
File TypeBinary
File FormatTiny Well Known Binary
Data FormatGeometry
Supported APIsencode, encodeSync
Encoder TypeSynchronous
Worker Thread SupportYes

Installation

npm install @loaders.gl/wkt
npm install @loaders.gl/core

Usage

import {TWKBWriter} from '@loaders.gl/wkt';
import {encodeSync} from '@loaders.gl/core';

const geometry = {
type: "Polygon",
coordinates: [[[1, 2], [3, 4], [5, 6], [1, 2]]]
}
const arrayBuffer = encodeSync(geometry, TWKBWriter, {wkt: {hasZ: false, hasM: false}})

Options

  • hasZ: Should be true if the GeoJSON input has Z values. These values are expected to be the third coordinate position.
  • hasM: Should be true if the GeoJSON input has M values. Thes are expected to be the third coordinate position if Z values do not exist, or fourth if Z values do exist.

Format Summary

Well-known binary (TWKB) is a binary geometry encoding to store geometries (it doesn't store attributes). It's used in databases such as PostGIS and as the internal storage format of Shapefiles. It's also being discussed as the internal storage format for a "GeoArrow" specification. TWKB is defined starting on page 62 of the OGC Simple Features specification.

  • Coordinates can be 2-4 dimensions and are interleaved.
  • Positions stored as double precision

image