192 lines
5.8 KiB
JavaScript
192 lines
5.8 KiB
JavaScript
(function() {
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var width, height, largeHeader, canvas, ctx, points, target, animateHeader = true;
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// Main
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initHeader();
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initAnimation();
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addListeners();
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function initHeader() {
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width = window.innerWidth;
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height = 300;
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target = {x: width/2, y: height/2};
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largeHeader = document.getElementById('large-header');
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largeHeader.style.height = height+'px';
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canvas = document.getElementById('demo-canvas');
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canvas.width = width;
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canvas.height = height;
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ctx = canvas.getContext('2d');
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// create points
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points = [];
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for(var x = 0; x < width; x = x + width/20) {
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for(var y = 0; y < height; y = y + height/20) {
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var px = x + Math.random()*width/20;
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var py = y + Math.random()*height/20;
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var p = {x: px, originX: px, y: py, originY: py };
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points.push(p);
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}
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}
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// for each point find the 5 closest points
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for(var i = 0; i < points.length; i++) {
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var closest = [];
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var p1 = points[i];
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for(var j = 0; j < points.length; j++) {
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var p2 = points[j]
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if(!(p1 == p2)) {
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var placed = false;
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for(var k = 0; k < 5; k++) {
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if(!placed) {
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if(closest[k] == undefined) {
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closest[k] = p2;
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placed = true;
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}
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}
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}
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for(var k = 0; k < 5; k++) {
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if(!placed) {
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if(getDistance(p1, p2) < getDistance(p1, closest[k])) {
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closest[k] = p2;
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placed = true;
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}
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}
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}
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}
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}
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p1.closest = closest;
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}
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// assign a circle to each point
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for(var i in points) {
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var c = new Circle(points[i], 2+Math.random()*2, 'rgba(255,255,255,0.3)');
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points[i].circle = c;
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}
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}
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// Event handling
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function addListeners() {
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if(!('ontouchstart' in window)) {
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window.addEventListener('mousemove', mouseMove);
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}
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window.addEventListener('scroll', scrollCheck);
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window.addEventListener('resize', resize);
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}
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function mouseMove(e) {
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var posx = posy = 0;
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if (e.pageX || e.pageY) {
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posx = e.pageX;
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posy = e.pageY;
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}
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else if (e.clientX || e.clientY) {
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posx = e.clientX + document.body.scrollLeft + document.documentElement.scrollLeft;
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posy = e.clientY + document.body.scrollTop + document.documentElement.scrollTop;
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}
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target.x = posx;
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target.y = posy;
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}
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function scrollCheck() {
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if(document.body.scrollTop > height) animateHeader = false;
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else animateHeader = true;
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}
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function resize() {
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var element = document.getElementById('demo-canvas');
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if(element.style.display == 'none') {
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animateHeader = false;
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} else {
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animateHeader = true;
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}
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width = window.innerWidth;
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height = 300;
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largeHeader.style.height = height+'px';
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canvas.width = width;
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canvas.height = height;
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}
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// animation
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function initAnimation() {
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animate();
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for(var i in points) {
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shiftPoint(points[i]);
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}
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}
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function animate() {
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if(animateHeader) {
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ctx.clearRect(0,0,width,height);
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for(var i in points) {
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// detect points in range
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if(Math.abs(getDistance(target, points[i])) < 4000) {
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points[i].active = 0.3;
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points[i].circle.active = 0.6;
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} else if(Math.abs(getDistance(target, points[i])) < 20000) {
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points[i].active = 0.1;
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points[i].circle.active = 0.3;
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} else if(Math.abs(getDistance(target, points[i])) < 40000) {
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points[i].active = 0.02;
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points[i].circle.active = 0.1;
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} else {
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points[i].active = 0;
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points[i].circle.active = 0;
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}
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drawLines(points[i]);
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points[i].circle.draw();
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}
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}
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requestAnimationFrame(animate);
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}
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function shiftPoint(p) {
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TweenLite.to(p, 1+1*Math.random(), {x:p.originX-50+Math.random()*100,
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y: p.originY-50+Math.random()*100, ease:Circ.easeInOut,
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onComplete: function() {
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shiftPoint(p);
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}});
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}
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// Canvas manipulation
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function drawLines(p) {
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if(!p.active) return;
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for(var i in p.closest) {
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ctx.beginPath();
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ctx.moveTo(p.x, p.y);
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ctx.lineTo(p.closest[i].x, p.closest[i].y);
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ctx.strokeStyle = 'rgba(210,212,188,'+ p.active+')';
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ctx.stroke();
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}
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}
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function Circle(pos,rad,color) {
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var _this = this;
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// constructor
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(function() {
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_this.pos = pos || null;
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_this.radius = rad || null;
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_this.color = color || null;
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})();
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this.draw = function() {
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if(!_this.active) return;
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ctx.beginPath();
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ctx.arc(_this.pos.x, _this.pos.y, _this.radius, 0, 2 * Math.PI, false);
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ctx.fillStyle = 'rgba(210,212,188,'+ _this.active+')';
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ctx.fill();
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};
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}
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// Util
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function getDistance(p1, p2) {
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return Math.pow(p1.x - p2.x, 2) + Math.pow(p1.y - p2.y, 2);
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}
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})();
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