)
}
}
)
(
}
{
)
)
(
)
(
(
{
}
)
(
)
}
)
)
{
(
(
)
)
}
)
(
}

Super Simple Seeded Random

  1. let _seed = 1234567;
  2.  
  3. // Deterministic pseudo-random float in the interval [ 0, 1 ]
  4. function seededRandom( s ) {
  5.   if ( s !== undefined ) _seed = s % 2147483647;
  6.  
  7.   // Park-Miller algorithm
  8.   _seed = _seed * 16807 % 2147483647;
  9.   return ( _seed - 1 ) / 2147483646;
  10. }

Straight from the THREE.js source code – a fun and simple seeded random. The best libraries are always filled with gems like this…

If I were going to use this I would do a couple things out of pure preference:

  1. let seed = 1234567;
  2.  
  3. const setSeed = newSeed => seed = newSeed
  4. function seededRand() {
  5.   // Park-Miller algorithm
  6.   seed *= 16807 % 0x7fffffff;
  7.   return (seed - 1) / 0x7fffffff;
  8. }
  9.  
  10. // try it out:
  11.  
  12. console.log('one', seededRand());
  13. console.log('two', seededRand());
  14. console.log('three', seededRand());
  15.  
  16. seed = 9999
  17. console.log('one new seed', seededRand());
  18. console.log('one new seed', seededRand());
  19.  
  20. seed = 1234567;
  21. console.log('one old seed', seededRand());

If you’re wondering about what this is doing… read more about it here.

snippet.zone ~ 2021-22 /// {s/z}