Method constructor

docs/app/js/sanddance-app.js:74678–74682

(x = 0, y = 0, z = 0, w = 1)

];
class Quaternion extends (0, _mathArrayDefault.default) {
    constructor(x = 0, y = 0, z = 0, w = 1){
        super(-0, -0, -0, -0);
        if (Array.isArray(x) && arguments.length === 1) this.copy(x);
        else this.set(x, y, z, w);
    }
    copy(array) {
        this[0] = array[0];
        this[1] = array[1];