dust/js/animation2b.js

import Rx, { Observable } from 'rxjs';
import Particle from './particle';
import Grid from './grid';
import Controls from './controls';
import Random from './random';
import { CONTROLS, ENTITIES } from './enums';

function Animation2b() {
    this.options = {
        count: 1,
        maxCount: 1000,
        speed: 4
    };

    this.container = document.getElementById('animation2b');
    this.particles = [];
    this.grid = this.createGlobalGrid(this.container, this.bounds);

    const controls = new Controls(
        document.getElementById('controls2b'),
        this.options
    );

    controls.mount().subscribe(this.subscriber.bind(this));

    this.updateAnimating(this.options.animating);
    this.updateCount(this.options.count);
};

Animation2b.prototype.subscriber = function({ key, value }) {
    switch(key) {
        case CONTROLS.ANIMATING: this.updateAnimating(value); break;
        case CONTROLS.COUNT: this.updateCount(value); break;
        case CONTROLS.SPEED: this.updateSpeed(value); break;
    }
}

Animation2b.prototype.nextFrame = function() {
    this.particles.forEach(p => p.nextFrame());
}

Animation2b.prototype.updateAnimating = function(isAnimating) {
    this.options.animating = isAnimating;

    if (isAnimating) {
        const fps$ = Rx.Observable.interval(1000 / 32)
            .takeWhile(_ => this.options.animating);

        fps$.subscribe(this.nextFrame.bind(this));
    }
}

Animation2b.prototype.updateCount = function(count) {
    const bounds = this.container.getBoundingClientRect();

    while (this.particles.length > count) {
        delete this.particles.pop().remove();
    }

    while (this.particles.length < count) {
        const p = new Particle(this.container, bounds, this.options, this.grid);
        this.particles.push(p);
    }
}

Animation2b.prototype.updateSpeed = function(value) {
    this.options.speed = value;
    this.particles.forEach(p => p.updateConfig({ speed: value }));
}

Animation2b.prototype.createGlobalGrid = function() {
    const bounds = this.container.getBoundingClientRect();
    const grid = new Grid();

    const n = Random.num(1, 3);
    for (let i = 0; i < n; i++) {
        const w = Random.num(50, 200);
        const h = Random.num(50, 200);

        grid.setArea({
            x: Random.num(0, bounds.width - w),
            y: Random.num(0, bounds.height - h),
            w,
            h,
            type: ENTITIES.HAZARD
        }, this.container);
    }

    return grid;
}

export default Animation2b;