forked from OpenWF/SpaceNinjaServer
Sainan
f3f1bfc890
getRandomWeightedReward now takes any object with lowercase 'rarity', and the only alternative to it is the 'uc' variant which takes any object with uppercase 'Rarity' usage of IRngResult is now also optional Reviewed-on: OpenWF/SpaceNinjaServer#1073 Co-authored-by: Sainan <sainan@calamity.inc> Co-committed-by: Sainan <sainan@calamity.inc>
72 lines
2.3 KiB
TypeScript
72 lines
2.3 KiB
TypeScript
import { TRarity } from "warframe-public-export-plus";
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export interface IRngResult {
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type: string;
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itemCount: number;
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probability: number;
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}
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export const getRandomElement = <T>(arr: T[]): T => {
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return arr[Math.floor(Math.random() * arr.length)];
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};
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// Returns a random integer between min (inclusive) and max (inclusive).
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// https://stackoverflow.com/a/1527820
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export const getRandomInt = (min: number, max: number): number => {
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min = Math.ceil(min);
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max = Math.floor(max);
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return Math.floor(Math.random() * (max - min + 1)) + min;
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};
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export const getRandomReward = <T extends { probability: number }>(pool: T[]): T | undefined => {
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if (pool.length == 0) return;
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const totalChance = pool.reduce((accum, item) => accum + item.probability, 0);
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const randomValue = Math.random() * totalChance;
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let cumulativeChance = 0;
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for (const item of pool) {
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cumulativeChance += item.probability;
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if (randomValue <= cumulativeChance) {
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return item;
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}
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}
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throw new Error("What the fuck?");
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};
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export const getRandomWeightedReward = <T extends { rarity: TRarity }>(
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pool: T[],
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weights: Record<TRarity, number>
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): (T & { probability: number }) | undefined => {
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const resultPool: (T & { probability: number })[] = [];
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const rarityCounts: Record<TRarity, number> = { COMMON: 0, UNCOMMON: 0, RARE: 0, LEGENDARY: 0 };
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for (const entry of pool) {
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++rarityCounts[entry.rarity];
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}
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for (const entry of pool) {
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resultPool.push({
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...entry,
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probability: weights[entry.rarity] / rarityCounts[entry.rarity]
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});
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}
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return getRandomReward(resultPool);
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};
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export const getRandomWeightedRewardUc = <T extends { Rarity: TRarity }>(
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pool: T[],
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weights: Record<TRarity, number>
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): (T & { probability: number }) | undefined => {
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const resultPool: (T & { probability: number })[] = [];
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const rarityCounts: Record<TRarity, number> = { COMMON: 0, UNCOMMON: 0, RARE: 0, LEGENDARY: 0 };
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for (const entry of pool) {
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++rarityCounts[entry.Rarity];
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}
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for (const entry of pool) {
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resultPool.push({
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...entry,
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probability: weights[entry.Rarity] / rarityCounts[entry.Rarity]
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});
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}
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return getRandomReward(resultPool);
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};
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