43 lines
1.2 KiB
TypeScript
43 lines
1.2 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 getRandomReward = (pool: IRngResult[]): IRngResult | 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 = (
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pool: { Item: string; Rarity: TRarity }[],
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weights: Record<TRarity, number>
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): IRngResult | undefined => {
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const resultPool: IRngResult[] = [];
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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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type: entry.Item,
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itemCount: 1,
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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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