Class CachedInterpolator

packages/math/src/Animation/Interpolation.ts:22–69

 * 用于需要重复插值相同起始和目标值的情况
 */
export class CachedInterpolator<T> {
    private from?: T;
    private to?: T;
    private interpolator: InterpolatorFunction<T>;
    private cache: Map<number, T> = new Map();

    constructor(interpolator: InterpolatorFunction<T>) {
        this.interpolator = interpolator;
    }

    /**
   * 设置插值范围
   * @param from 起始值
   * @param to 目标值
   */
    setRange(from: T, to: T): void {
        if (this.from !== from || this.to !== to) {
            this.from = from;
            this.to = to;
            this.cache.clear();
        }
    }

    /**
   * 获取插值结果
   * @param t 插值参数
   * @returns 插值结果
   */
    get(t: number): T {
        if (!this.from || !this.to) {
            throw new Error('插值范围未设置');
        }

        if (!this.cache.has(t)) {
            const result = this.interpolator(this.from, this.to, t);
            this.cache.set(t, result);
        }

        return this.cache.get(t)!;
    }

    /**
   * 清空缓存
   */
    clearCache(): void {
        this.cache.clear();
    }
}

/**
 * 插值工具类