Random functions

random.ts

// Random integer from <low, high> interval
export function randInt(low: number, high: number) {
  return low + Math.floor(Math.random() * (high - low + 1));
}

// Random float from <low, high> interval
export function randFloat(low: number, high: number) {
  return low + Math.random() * (high - low);
}

// Random float from <-range/2, range/2> interval
export function randFloatSpread(range: number) {
  return range * (0.5 - Math.random());
}

let _seed = 1234567;

// Deterministic pseudo-random float in the interval [ 0, 1 ]
export function seededRandom(s: number) {
  if (s !== undefined) _seed = s;

  // Mulberry32 generator

  let t = (_seed += 0x6d2b79f5);

  t = Math.imul(t ^ (t >>> 15), t | 1);

  t ^= t + Math.imul(t ^ (t >>> 7), t | 61);

  return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
}