fix: rng impl

src/utils/rng.ts

@@ -1,6 +1,8 @@
 export interface RNG {
     /** 设置随机数种子 */
-    (seed: number): void;
+    setSeed(seed: number): void;
+
+    getSeed(): number;
 
     /** 获取一个 [0,1) 随机数 */
     next(max?: number):  number;
@@ -14,33 +16,7 @@
  * 这是一个快速、高质量的 32 位 PRNG
  */
 export function createRNG(seed?: number): RNG {
-    let currentSeed: number = seed ?? 1;
-
-    function rng(seed: number): void {
-        currentSeed = seed;
-    }
-
-    rng.next = function(max?: number): number {
-        let t = (currentSeed += 0x6d2b79f5);
-        t = Math.imul(t ^ (t >>> 15), t | 1);
-        t ^= t + Math.imul(t ^ (t >>> 7), t | 61);
-        const result = ((t ^ (t >>> 14)) >>> 0) / 4294967296;
-        return max !== undefined ? result * max : result;
-    };
-
-    rng.nextInt = function(max: number): number {
-        return Math.floor(rng.next(max));
-    };
-
-    (rng as any).setSeed = function(seed: number): void {
-        currentSeed = seed;
-    };
-
-    (rng as any).getSeed = function(): number {
-        return currentSeed;
-    };
-
-    return rng;
+  return new Mulberry32RNG(seed);
 }
 
 /** Mulberry32RNG 类实现（用于类型兼容） */

tests/utils/rng.test.ts

@@ -70,12 +70,6 @@ describe('createRNG', () => {
         expect(firstSequence).toEqual(secondSequence);
     });
 
-    it('should work as callable function', () => {
-        const rng = createRNG(42);
-        rng(123);
-        expect(rng.getSeed()).toBe(123);
-    });
-
     it('should generate uniformly distributed integers', () => {
         const rng = createRNG(42);
         const buckets = new Array(10).fill(0);