line-distance-calculator

A small collection of methods for calculating the distance from a point to a line.

An ES6 module containing a small collection of methods for calculating the distance between a point and a line (which is optionally either multi-segmented or infinite). Written for my project Nibriboard. Check out the demo!

It does the job as to distance-to-line-segment, but I ended up implemented this before I saw that package - and I wanted to have a go at implementing the algorithm successfully after I failed a few weeks ago.

Installation

You'll need support for ES6 Modules in your project / build tool / browser in order to use this package. Install this with npm: npm install --save line-distance-calculator.

Usage

There are 3 primary methods exported by this module:

point_line_distance_multi(point, line_points)

Calculates the minimum distance between a specified multi-segmented line and a specified point. Example:

import { point_line_distance_multi } from "line-distance-calculator";
 
let distance_data = point_line_distance_multi(
    { x: 45, y: 30 },
    [
        { x: 250, y: 337 },
        { x: 266, y: 326 },
        { x: 574, y: 177 },
        { x: 605, y: 254 },
        { x: 469, y: 120 },
        { x: 377, y: 315 },
        { x: 411, y: 328 },
        { x: 435, y: 335 },
        { x: 531, y: 344 }
    ]
);
console.log(`The minimum distance is ${distance_data[1]}`);
console.log(`The segment that's closest to the point starts at index ${distance_data[0]}`);

point_line_distance(point, line_start, line_end)

Calculates the minimum distance between a point and an infinite line specified by 2 more points. Example:

import { point_line_distance } from "line-distance-calculator";
 
let point = { x: 50, y: 82 };
let line_start = { x: 10, y: 52 };
let line_end = { x: 50, y: 18 };
 
let distance = point_line_distance(point, line_start, line_end);
 
console.log(`The distance to the line from the point is ${distance}`);

point_infinite_line_distance(point, line_a, line_b)

An implementation from this wikipedia article before I realised that the algorithm was for an infinite line and not a finite one. I've left this in because this implementation does work - it's just not what I wanted myself.

It works identically to point_line_distance demonstrated above. Example:

import { point_infinite_line_distance } from "line-distance-calculator";
 
let point = { x: 50, y: 82 };
let line_start = { x: 10, y: 52 };
let line_end = { x: 50, y: 18 };
 
let distance = point_infinite_line_distance(point, line_start, line_end);
 
console.log(`The distance to the infinite line from the point is ${distance}`);

Contribute

Contributions are welcome! If you find a bug, please open an issue - or even better open a pull request 😺

License

This package is licensed under the Mozilla Public License 2.0. The full license text is available here - along with a link to a summary summary on what you can and can't do with it.

If you'd like to do something that's prohibited by the license - please do get in touch! My email address is available on my website.

Sources

• Lines and Distance of a Point to a Line on Geometry Algorithms Home by Dan Sunday