odin-js-fundamentals-part-4/node_modules/pure-rand/lib/generator/LinearCongruential.js

42 lines
1.3 KiB
JavaScript

"use strict";
exports.__esModule = true;
exports.congruential32 = void 0;
var MULTIPLIER = 0x000343fd;
var INCREMENT = 0x00269ec3;
var MASK = 0xffffffff;
var MASK_2 = (1 << 31) - 1;
var computeNextSeed = function (seed) {
return (seed * MULTIPLIER + INCREMENT) & MASK;
};
var computeValueFromNextSeed = function (nextseed) {
return (nextseed & MASK_2) >> 16;
};
var LinearCongruential32 = (function () {
function LinearCongruential32(seed) {
this.seed = seed;
}
LinearCongruential32.prototype.clone = function () {
return new LinearCongruential32(this.seed);
};
LinearCongruential32.prototype.next = function () {
var nextRng = new LinearCongruential32(this.seed);
var out = nextRng.unsafeNext();
return [out, nextRng];
};
LinearCongruential32.prototype.unsafeNext = function () {
var s1 = computeNextSeed(this.seed);
var v1 = computeValueFromNextSeed(s1);
var s2 = computeNextSeed(s1);
var v2 = computeValueFromNextSeed(s2);
this.seed = computeNextSeed(s2);
var v3 = computeValueFromNextSeed(this.seed);
var vnext = v3 + ((v2 + (v1 << 15)) << 15);
return vnext | 0;
};
return LinearCongruential32;
}());
var congruential32 = function (seed) {
return new LinearCongruential32(seed);
};
exports.congruential32 = congruential32;