segseg

Intersection detection between two line segments in 2d space.

Usage

import segseg from 'segseg'


/*
                (0, 5)
                   |
  (-10, 0) --------+-------  (10, 0)
                   |
                (0, -5)
*/

const isect = [ NaN, NaN ] // the output vector where collision point is stored

//                       seg 1                   seg 2
//                ┌-------------------┐   ┌-----------------┐
if (segseg(isect, [ -10, 0 ], [ 10, 0 ],  [ 0, 5 ], [ 0, -5 ]))
    console.log('intersected!', isect.join(','))  // output:   intersected! 0,0

Node compatibility

This is a pure es module, and requires node v12+ to run. However if you're using a popular bundler such as rollup, webpack, etc. This should be compatible with most frontend setups too.

Credits

This code was ported from Mukesh Prasad's example implementation which was included in graphics gems 2.

Internally the code uses a point-segment check for some edge cases, from https://gist.github.com/mattdesl/47412d930dcd8cd765c871a65532ffac