Retrospring/vendor/assets/javascripts/jquery.particleground.js

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2015-05-12 14:53:42 -07:00
/*!
* Particleground
*
* @author Jonathan Nicol - @mrjnicol
* @version 1.1.0
* @description Creates a canvas based particle system background
*
* Inspired by http://requestlab.fr/ and http://disruptivebydesign.com/
*/
;(function(window, document) {
"use strict";
var pluginName = 'particleground';
// http://youmightnotneedjquery.com/#deep_extend
function extend(out) {
out = out || {};
for (var i = 1; i < arguments.length; i++) {
var obj = arguments[i];
if (!obj) continue;
for (var key in obj) {
if (obj.hasOwnProperty(key)) {
if (typeof obj[key] === 'object')
deepExtend(out[key], obj[key]);
else
out[key] = obj[key];
}
}
}
return out;
};
var $ = window.jQuery;
function Plugin(element, options) {
var canvasSupport = !!document.createElement('canvas').getContext;
var canvas;
var ctx;
var particles = [];
var raf;
var mouseX = 0;
var mouseY = 0;
var winW;
var winH;
var desktop = !navigator.userAgent.match(/(iPhone|iPod|iPad|Android|BlackBerry|BB10|mobi|tablet|opera mini|nexus 7)/i);
var orientationSupport = !!window.DeviceOrientationEvent;
var tiltX = 0;
var pointerX;
var pointerY;
var tiltY = 0;
var paused = false;
options = extend({}, window[pluginName].defaults, options);
/**
* Init
*/
function init() {
if (!canvasSupport) { return; }
//Create canvas
canvas = document.createElement('canvas');
canvas.className = 'pg-canvas';
canvas.style.display = 'block';
element.insertBefore(canvas, element.firstChild);
ctx = canvas.getContext('2d');
styleCanvas();
// Create particles
var numParticles = Math.round((canvas.width * canvas.height) / options.density);
for (var i = 0; i < numParticles; i++) {
var p = new Particle();
p.setStackPos(i);
particles.push(p);
};
window.addEventListener('resize', function() {
resizeHandler();
}, false);
document.addEventListener('mousemove', function(e) {
mouseX = e.pageX;
mouseY = e.pageY;
}, false);
if (orientationSupport && !desktop) {
window.addEventListener('deviceorientation', function () {
// Contrain tilt range to [-30,30]
tiltY = Math.min(Math.max(-event.beta, -30), 30);
tiltX = Math.min(Math.max(-event.gamma, -30), 30);
}, true);
}
draw();
hook('onInit');
}
/**
* Style the canvas
*/
function styleCanvas() {
canvas.width = element.offsetWidth;
canvas.height = element.offsetHeight;
ctx.fillStyle = options.dotColor;
ctx.strokeStyle = options.lineColor;
ctx.lineWidth = options.lineWidth;
}
/**
* Draw particles
*/
function draw() {
if (!canvasSupport) { return; }
winW = window.innerWidth;
winH = window.innerHeight;
// Wipe canvas
ctx.clearRect(0, 0, canvas.width, canvas.height);
// Update particle positions
for (var i = 0; i < particles.length; i++) {
particles[i].updatePosition();
};
// Draw particles
for (var i = 0; i < particles.length; i++) {
particles[i].draw();
};
// Call this function next time screen is redrawn
if (!paused) {
raf = requestAnimationFrame(draw);
}
}
/**
* Add/remove particles.
*/
function resizeHandler() {
// Resize the canvas
styleCanvas();
var elWidth = element.offsetWidth;
var elHeight = element.offsetHeight;
// Remove particles that are outside the canvas
for (var i = particles.length - 1; i >= 0; i--) {
if (particles[i].position.x > elWidth || particles[i].position.y > elHeight) {
particles.splice(i, 1);
}
};
// Adjust particle density
var numParticles = Math.round((canvas.width * canvas.height) / options.density);
if (numParticles > particles.length) {
while (numParticles > particles.length) {
var p = new Particle();
particles.push(p);
}
} else if (numParticles < particles.length) {
particles.splice(numParticles);
}
// Re-index particles
for (i = particles.length - 1; i >= 0; i--) {
particles[i].setStackPos(i);
};
}
/**
* Pause particle system
*/
function pause() {
paused = true;
}
/**
* Start particle system
*/
function start() {
paused = false;
draw();
}
/**
* Particle
*/
function Particle() {
this.stackPos;
this.active = true;
this.layer = Math.ceil(Math.random() * 3);
this.parallaxOffsetX = 0;
this.parallaxOffsetY = 0;
// Initial particle position
this.position = {
x: Math.ceil(Math.random() * canvas.width),
y: Math.ceil(Math.random() * canvas.height)
}
// Random particle speed, within min and max values
this.speed = {}
switch (options.directionX) {
case 'left':
this.speed.x = +(-options.maxSpeedX + (Math.random() * options.maxSpeedX) - options.minSpeedX).toFixed(2);
break;
case 'right':
this.speed.x = +((Math.random() * options.maxSpeedX) + options.minSpeedX).toFixed(2);
break;
default:
this.speed.x = +((-options.maxSpeedX / 2) + (Math.random() * options.maxSpeedX)).toFixed(2);
this.speed.x += this.speed.x > 0 ? options.minSpeedX : -options.minSpeedX;
break;
}
switch (options.directionY) {
case 'up':
this.speed.y = +(-options.maxSpeedY + (Math.random() * options.maxSpeedY) - options.minSpeedY).toFixed(2);
break;
case 'down':
this.speed.y = +((Math.random() * options.maxSpeedY) + options.minSpeedY).toFixed(2);
break;
default:
this.speed.y = +((-options.maxSpeedY / 2) + (Math.random() * options.maxSpeedY)).toFixed(2);
this.speed.x += this.speed.y > 0 ? options.minSpeedY : -options.minSpeedY;
break;
}
}
/**
* Draw particle
*/
Particle.prototype.draw = function() {
// Draw circle
ctx.beginPath();
ctx.arc(this.position.x + this.parallaxOffsetX, this.position.y + this.parallaxOffsetY, options.particleRadius / 2, 0, Math.PI * 2, true);
ctx.closePath();
ctx.fill();
// Draw lines
ctx.beginPath();
// Iterate over all particles which are higher in the stack than this one
for (var i = particles.length - 1; i > this.stackPos; i--) {
var p2 = particles[i];
// Pythagorus theorum to get distance between two points
var a = this.position.x - p2.position.x
var b = this.position.y - p2.position.y
var dist = Math.sqrt((a * a) + (b * b)).toFixed(2);
// If the two particles are in proximity, join them
if (dist < options.proximity) {
ctx.moveTo(this.position.x + this.parallaxOffsetX, this.position.y + this.parallaxOffsetY);
if (options.curvedLines) {
ctx.quadraticCurveTo(Math.max(p2.position.x, p2.position.x), Math.min(p2.position.y, p2.position.y), p2.position.x + p2.parallaxOffsetX, p2.position.y + p2.parallaxOffsetY);
} else {
ctx.lineTo(p2.position.x + p2.parallaxOffsetX, p2.position.y + p2.parallaxOffsetY);
}
}
}
ctx.stroke();
ctx.closePath();
}
/**
* update particle position
*/
Particle.prototype.updatePosition = function() {
if (options.parallax) {
if (orientationSupport && !desktop) {
// Map tiltX range [-30,30] to range [0,winW]
var ratioX = (winW - 0) / (30 - -30);
pointerX = (tiltX - -30) * ratioX + 0;
// Map tiltY range [-30,30] to range [0,winH]
var ratioY = (winH - 0) / (30 - -30);
pointerY = (tiltY - -30) * ratioY + 0;
} else {
pointerX = mouseX;
pointerY = mouseY;
}
// Calculate parallax offsets
this.parallaxTargX = (pointerX - (winW / 2)) / (options.parallaxMultiplier * this.layer);
this.parallaxOffsetX += (this.parallaxTargX - this.parallaxOffsetX) / 10; // Easing equation
this.parallaxTargY = (pointerY - (winH / 2)) / (options.parallaxMultiplier * this.layer);
this.parallaxOffsetY += (this.parallaxTargY - this.parallaxOffsetY) / 10; // Easing equation
}
var elWidth = element.offsetWidth;
var elHeight = element.offsetHeight;
switch (options.directionX) {
case 'left':
if (this.position.x + this.speed.x + this.parallaxOffsetX < 0) {
this.position.x = elWidth - this.parallaxOffsetX;
}
break;
case 'right':
if (this.position.x + this.speed.x + this.parallaxOffsetX > elWidth) {
this.position.x = 0 - this.parallaxOffsetX;
}
break;
default:
// If particle has reached edge of canvas, reverse its direction
if (this.position.x + this.speed.x + this.parallaxOffsetX > elWidth || this.position.x + this.speed.x + this.parallaxOffsetX < 0) {
this.speed.x = -this.speed.x;
}
break;
}
switch (options.directionY) {
case 'up':
if (this.position.y + this.speed.y + this.parallaxOffsetY < 0) {
this.position.y = elHeight - this.parallaxOffsetY;
}
break;
case 'down':
if (this.position.y + this.speed.y + this.parallaxOffsetY > elHeight) {
this.position.y = 0 - this.parallaxOffsetY;
}
break;
default:
// If particle has reached edge of canvas, reverse its direction
if (this.position.y + this.speed.y + this.parallaxOffsetY > elHeight || this.position.y + this.speed.y + this.parallaxOffsetY < 0) {
this.speed.y = -this.speed.y;
}
break;
}
// Move particle
this.position.x += this.speed.x;
this.position.y += this.speed.y;
}
/**
* Setter: particle stacking position
*/
Particle.prototype.setStackPos = function(i) {
this.stackPos = i;
}
function option (key, val) {
if (val) {
options[key] = val;
} else {
return options[key];
}
}
function destroy() {
console.log('destroy');
canvas.parentNode.removeChild(canvas);
hook('onDestroy');
if ($) {
$(element).removeData('plugin_' + pluginName);
}
}
function hook(hookName) {
if (options[hookName] !== undefined) {
options[hookName].call(element);
}
}
init();
return {
option: option,
destroy: destroy,
start: start,
pause: pause
};
}
window[pluginName] = function(elem, options) {
return new Plugin(elem, options);
};
window[pluginName].defaults = {
minSpeedX: 0.1,
maxSpeedX: 0.7,
minSpeedY: 0.1,
maxSpeedY: 0.7,
directionX: 'center', // 'center', 'left' or 'right'. 'center' = dots bounce off edges
directionY: 'center', // 'center', 'up' or 'down'. 'center' = dots bounce off edges
density: 10000, // How many particles will be generated: one particle every n pixels
dotColor: '#666666',
lineColor: '#666666',
particleRadius: 7, // Dot size
lineWidth: 1,
curvedLines: false,
proximity: 100, // How close two dots need to be before they join
parallax: true,
parallaxMultiplier: 5, // The lower the number, the more extreme the parallax effect
onInit: function() {},
onDestroy: function() {}
};
// nothing wrong with hooking into jQuery if it's there...
if ($) {
$.fn[pluginName] = function(options) {
if (typeof arguments[0] === 'string') {
var methodName = arguments[0];
var args = Array.prototype.slice.call(arguments, 1);
var returnVal;
this.each(function() {
if ($.data(this, 'plugin_' + pluginName) && typeof $.data(this, 'plugin_' + pluginName)[methodName] === 'function') {
returnVal = $.data(this, 'plugin_' + pluginName)[methodName].apply(this, args);
}
});
if (returnVal !== undefined){
return returnVal;
} else {
return this;
}
} else if (typeof options === "object" || !options) {
return this.each(function() {
if (!$.data(this, 'plugin_' + pluginName)) {
$.data(this, 'plugin_' + pluginName, new Plugin(this, options));
}
});
}
};
}
})(window, document);
/**
* requestAnimationFrame polyfill by Erik Möller. fixes from Paul Irish and Tino Zijdel
* @see: http://paulirish.com/2011/requestanimationframe-for-smart-animating/
* @see: http://my.opera.com/emoller/blog/2011/12/20/requestanimationframe-for-smart-er-animating
* @license: MIT license
*/
(function() {
var lastTime = 0;
var vendors = ['ms', 'moz', 'webkit', 'o'];
for(var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) {
window.requestAnimationFrame = window[vendors[x]+'RequestAnimationFrame'];
window.cancelAnimationFrame = window[vendors[x]+'CancelAnimationFrame']
|| window[vendors[x]+'CancelRequestAnimationFrame'];
}
if (!window.requestAnimationFrame)
window.requestAnimationFrame = function(callback, element) {
var currTime = new Date().getTime();
var timeToCall = Math.max(0, 16 - (currTime - lastTime));
var id = window.setTimeout(function() { callback(currTime + timeToCall); },
timeToCall);
lastTime = currTime + timeToCall;
return id;
};
if (!window.cancelAnimationFrame)
window.cancelAnimationFrame = function(id) {
clearTimeout(id);
};
}());