smartgame/js/Shaker.js

import Vec2 from "./Vec2.js";

export default class Shaker {
	constructor(decay = 7) {
		this.vec = new Vec2();
		this.decay = decay;
		this.shakeX = 0;
		this.shakeY = 0;
	}

	shake(x, y = x) {
		this.shakeX = x;
		this.shakeY = y;
	}

	update(dt) {
		if (this.shakeX > 0.1)
			this.vec.x = (Math.random() - 0.5) * this.shakeX * dt;
		else
			this.vec.x = 0;

		if (this.shakeY > 0.1)
			this.vec.y = (Math.random() - 0.5) * this.shakeY * dt;
		else
			this.vec.y = 0;

		var xRatio = 1 / (1 + (dt * this.decay));
		this.shakeX *= xRatio;
		this.shakeY *= xRatio;
	}
}