@smoud/tiny/examples/js/particles/Firework.js

Fast and tiny JavaScript library for HTML5 game and playable ads creation.

Tiny.FireworkParticle = function (emitter) {
    Tiny.Particle.call(this, emitter);
};

Tiny.FireworkParticle.prototype = Object.create(Tiny.Particle.prototype);
Tiny.FireworkParticle.prototype.constructor = Tiny.FireworkParticle;

var normTime, speed;

Tiny.FireworkParticle.prototype.update = function (time, delta) {
    normTime = time / this.maxlifespan;

    this.scale.set(Math.tan(normTime * normTime));

    this.alpha = Math.min(Math.tan(normTime), 1);

    speed = normTime * normTime * normTime * 10;

    this.x += this.xspeed * speed * delta * normTime;
    this.y += this.yspeed * speed * delta + normTime * 0.8 * delta;
};

Tiny.FireworkParticle.prototype.onEmit = function () {
    var randAgle = Math.random() * Math.PI * 2;

    var rand_speed = Math.random() * 3;

    this.maxlifespan = this.lifespan;

    this.xspeed = Math.sin(randAgle) * rand_speed * 0.05;
    this.yspeed = Math.cos(randAgle) * rand_speed * 0.05;
};

Tiny.FireworkParticle.prototype.draw = function (context, resolution) {
    context.beginPath();
    context.arc(0, 0, 20 * resolution, 0, 2 * Math.PI, false);
    context.fill();
};