@seroh/roll/dist/randomizer/KarmicRandomizer.js

An RPG dice-rolling library with a variety of built-in roll mechanics.

import { Randomizer } from "./Randomizer";
var HistoryEntry;
(function (HistoryEntry) {
    HistoryEntry[HistoryEntry["HIGH"] = 0] = "HIGH";
    HistoryEntry[HistoryEntry["LOW"] = 1] = "LOW";
    HistoryEntry[HistoryEntry["NEUTRAL"] = 2] = "NEUTRAL";
})(HistoryEntry || (HistoryEntry = {}));
export class KarmicRandomizer extends Randomizer {
    static HistoryEntry = HistoryEntry;
    historyQueue = [];
    historyLimit;
    highRollThreshold;
    lowRollThreshold;
    biasFactor;
    constructor({ highRollThreshold, lowRollThreshold, biasFactor, historyLimit } = {}) {
        //validate high roll / low roll
        super();
        this.historyLimit = historyLimit || 10;
        this.highRollThreshold = highRollThreshold || 0.8;
        this.lowRollThreshold = lowRollThreshold || 0.2;
        this.biasFactor = biasFactor || 0.2;
        this.historyLimit = historyLimit || 10;
    }
    generator() {
        const rawRoll = this.generateRawRoll();
        const biasedRoll = this.applyBias(this.biasFactor, rawRoll);
        const rollType = this.evaluateRoll(biasedRoll);
        // Update history and maintain the limit
        this.historyQueue.push(rollType);
        if (this.historyQueue.length > this.historyLimit) {
            this.historyQueue.shift();
        }
        return biasedRoll;
    }
    applyBias(biasFactor, rawRoll) {
        if (this.recentLowRolls > this.recentHighRolls) {
            return Math.min(1, rawRoll + biasFactor); // Skew slightly toward high
        }
        else if (this.recentHighRolls > this.recentLowRolls) {
            return Math.max(0, rawRoll - biasFactor); // Skew slightly toward low
        }
        return rawRoll;
    }
    get recentHighRolls() {
        return this.historyQueue.filter((entry) => entry === HistoryEntry.HIGH).length;
    }
    get recentLowRolls() {
        return this.historyQueue.filter((entry) => entry === HistoryEntry.LOW).length;
    }
    evaluateRoll(rawRoll) {
        if (rawRoll >= this.highRollThreshold)
            return HistoryEntry.HIGH;
        if (rawRoll <= this.lowRollThreshold)
            return HistoryEntry.LOW;
        return HistoryEntry.NEUTRAL;
    }
    generateRawRoll() {
        return Math.random();
    }
}
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