la-visitor/assets/factor.js

import * as three from "three-js";

class factor {
    #mesh;

    constructor(mesh) {
        if (!(mesh instanceof three.Mesh)) {
            throw new TypeError("Must initialize with Mesh.");
        }

        this.#mesh = mesh;
    }

    get mesh() {
        if (!(this.#mesh instanceof three.Mesh)) {
            throw new TypeError("Mesh is not initialized.");
        }

        return this.#mesh;
    }

    loop() {
        return null;
    }
}

class functional_factor extends factor {
    #animation
    
    constructor (init, animation = null) {
        if (typeof(init) !== "function") {
            throw new TypeError("Init must be an function.");
        }   

        if (animation !== null && typeof(animation) !== "function") {
            throw new TypeError("Animation could only be null or function.");
        }

        const mesh = init(this);
        
        if (!(mesh instanceof three.Mesh)) {
            throw new TypeError("Factor initializer must return mesh.");  
        }

        super(mesh);
        this.#animation = animation;
    }   

    loop() {
        if (this.#animation !== null) {
            this.#animation(this);   
        }
    }
} 

export { factor, functional_factor }