for web

dist/fortuna.js

@@ -0,0 +1,75 @@
+// deno-fmt-ignore-file
+// deno-lint-ignore-file
+// This code was bundled using `deno bundle` and it's not recommended to edit it manually
+
+class GachaMachine {
+    #items;
+    #totalChance;
+    constructor(items){
+        this.#items = new Array(items.length);
+        this.#totalChance = 0;
+        this.#configItems(items);
+    }
+    set items(items) {
+        this.#items = new Array(items.length);
+        this.#totalChance = 0;
+        this.#configItems(items);
+    }
+    #configItems(items) {
+        let i = 0;
+        let cumulativeChance = 0;
+        while(i < items.length){
+            cumulativeChance += items[i].chance;
+            this.#items[i] = {
+                result: items[i].result,
+                cumulativeChance: cumulativeChance
+            };
+            i += 1;
+        }
+        this.#totalChance = cumulativeChance;
+    }
+    get(count, distinct = false) {
+        if (distinct && count > this.#items.length) {
+            throw new RangeError(`count must be less than number of items in pool.`);
+        }
+        const totalChance = this.#totalChance;
+        const result = new Array(count);
+        let i = 0;
+        if (distinct) {
+            const data = this.#items.slice(0);
+            while(i < count){
+                const res = rollWithBinarySearch(data, totalChance);
+                result[i] = data[res].result;
+                data.splice(res, 1);
+                i += 1;
+            }
+        } else {
+            const data1 = this.#items;
+            while(i < count){
+                result[i] = data1[rollWithBinarySearch(data1, totalChance)].result;
+                i += 1;
+            }
+        }
+        return result;
+    }
+}
+function rollWithBinarySearch(items, totalChance) {
+    if (!totalChance) totalChance = items[items.length - 1].cumulativeChance;
+    if (items.length === 1) return 0;
+    const rng = Math.random() * totalChance;
+    let lower = 0;
+    let max = items.length - 1;
+    let mid = Math.trunc((max + lower) / 2);
+    while(mid != 0 && lower <= max){
+        if (items[mid].cumulativeChance > rng && items[mid - 1].cumulativeChance < rng || items[mid].cumulativeChance == rng) return mid;
+        if (items[mid].cumulativeChance < rng) {
+            lower = mid + 1;
+            mid = Math.trunc((max + lower) / 2);
+        } else {
+            max = mid - 1;
+            mid = Math.trunc((max + lower) / 2);
+        }
+    }
+    return mid;
+}
+export { GachaMachine as GachaMachine };

dist/roll.js

@@ -0,0 +1,26 @@
+// deno-fmt-ignore-file
+// deno-lint-ignore-file
+// This code was bundled using `deno bundle` and it's not recommended to edit it manually
+
+function roll(choices, totalChance = 0) {
+    let total = totalChance;
+    let i = 0;
+    if (totalChance === 0) {
+        while(i < choices.length){
+            total += choices[i].chance;
+            i += 1;
+        }
+    }
+    const result = Math.random() * total;
+    let going = 0.0;
+    i = 0;
+    while(i < choices.length){
+        going += choices[i].chance;
+        if (result < going) {
+            return choices[i].result;
+        }
+        i += 1;
+    }
+    return choices[Math.floor(Math.random() * choices.length)].result;
+}
+export { roll as roll };