console
(function (window) {
var ctx,
hue,
logo,
form,
buffer,
target = {},
tendrils = [],
settings = {};
settings.debug = true;
settings.friction = 0.5;
settings.trails = 20;
settings.size = 50;
settings.dampening = 0.25;
settings.tension = 0.98;
Math.TWO_PI = Math.PI * 2;
// ========================================================================================
// Oscillator 何问起
// ----------------------------------------------------------------------------------------
function Oscillator(options) {
this.init(options || {});
}
Oscillator.prototype = (function () {
var value = 0;
return {
init: function (options) {
this.phase = options.phase || 0;
this.offset = options.offset || 0;
this.frequency = options.frequency || 0.001;
this.amplitude = options.amplitude || 1;
},
update: function () {
this.phase += this.frequency;
value = this.offset + Math.sin(this.phase) * this.amplitude;
return value;
},
value: function () {
return value;
}
};
})();
// ========================================================================================
// Tendril hovertree.com
// ----------------------------------------------------------------------------------------
function Tendril(options) {
this.init(options || {});
}
Tendril.prototype = (function () {
function Node() {
this.x = 0;
this.y = 0;
this.vy = 0;
this.vx = 0;
}
return {
init: function (options) {
this.spring = options.spring + (Math.random() * 0.1) - 0.05;
this.friction = settings.friction + (Math.random() * 0.01) - 0.005;
this.nodes = [];
for (var i = 0, node; i < settings.size; i++) {
node = new Node();
node.x = target.x;
node.y = target.y;
this.nodes.push(node);
}
},
update: function () {
var spring = this.spring,
node = this.nodes[0];
node.vx += (target.x - node.x) * spring;
node.vy += (target.y - node.y) * spring;
for (var prev, i = 0, n = this.nodes.length; i < n; i++) {
node = this.nodes[i];
if (i > 0) {
prev = this.nodes[i - 1];
node.vx += (prev.x - node.x) * spring;
node.vy += (prev.y - node.y) * spring;
node.vx += prev.vx * settings.dampening;
node.vy += prev.vy * settings.dampening;
}
node.vx *= this.friction;
node.vy *= this.friction;
node.x += node.vx;
node.y += node.vy;
spring *= settings.tension;
}
},
draw: function () {
var x = this.nodes[0].x,
y = this.nodes[0].y,
a, b;
ctx.beginPath();
ctx.moveTo(x, y);
for (var i = 1, n = this.nodes.length - 2; i < n; i++) {
a = this.nodes[i];
b = this.nodes[i + 1];
x = (a.x + b.x) * 0.5;
y = (a.y + b.y) * 0.5;
ctx.quadraticCurveTo(a.x, a.y, x, y);
}
a = this.nodes[i];
b = this.nodes[i + 1];
ctx.quadraticCurveTo(a.x, a.y, b.x, b.y);
ctx.stroke();
ctx.closePath();
}
};
})();
// ----------------------------------------------------------------------------------------
function init(event) {
document.removeEventListener('mousemove', init);
document.removeEventListener('touchstart', init);
document.addEventListener('mousemove', mousemove);
document.addEventListener('touchmove', mousemove);
document.addEventListener('touchstart', touchstart);
mousemove(event);
reset();
loop();
}
function reset() {
tendrils = [];
for (var i = 0; i < settings.trails; i++) {
tendrils.push(new Tendril({
spring: 0.45 + 0.025 * (i / settings.trails)
}));
}
}
function loop() {
if (!ctx.running) return;
ctx.globalCompositeOperation = 'source-over';
ctx.fillStyle = 'rgba(8,5,16,0.4)';
ctx.fillRect(0, 0, ctx.canvas.width, ctx.canvas.height);
ctx.globalCompositeOperation = 'lighter';
ctx.strokeStyle = 'hsla(' + Math.round(hue.update()) + ',90%,50%,0.25)';
ctx.lineWidth = 1;
if (ctx.frame % 60 == 0) {
console.log(hue.update(), Math.round(hue.update()), hue.phase, hue.offset, hue.frequency, hue.amplitude);
}
for (var i = 0, tendril; i < settings.trails; i++) {
tendril = tendrils[i];
tendril.update();
tendril.draw();
}
ctx.frame++;
ctx.stats.update();
requestAnimFrame(loop);
}
function resize() {
ctx.canvas.width = window.innerWidth;
ctx.canvas.height = window.innerHeight;
}
function start() {
if (!ctx.running) {
ctx.running = true;
loop();
}
}
function stop() {
ctx.running = false;
}
function mousemove(event) {
if (event.touches) {
target.x = event.touches[0].pageX;
target.y = event.touches[0].pageY;
} else {
target.x = event.clientX
target.y = event.clientY;
}
event.preventDefault();
}
function touchstart(event) {
if (event.touches.length == 1) {
target.x = event.touches[0].pageX;
target.y = event.touches[0].pageY;
}
}
function keyup(event) {
switch (event.keyCode) {
case 32:
save();
break;
default:
// console.log(event.keyCode); hovertree.com
}
}
function letters(id) {
var el = document.getElementById(id),
letters = el.innerHTML.replace('&', '&').split(''),
heading = '';
for (var i = 0, n = letters.length, letter; i < n; i++) {
letter = letters[i].replace('&', '&');
heading += letter.trim() ? '<span class="letter-' + i + '">' + letter + '</span>' : ' ';
}
el.innerHTML = heading;
setTimeout(function () {
el.className = 'transition-in';
}, (Math.random() * 500) + 500);
}
function save() {
if (!buffer) {
buffer = document.createElement('canvas');
buffer.width = screen.availWidth;
buffer.height = screen.availHeight;
buffer.ctx = buffer.getContext('2d');
form = document.createElement('form');
form.method = 'post';
form.input = document.createElement('input');
form.input.type = 'hidden';
form.input.name = 'data';
form.appendChild(form.input);
document.body.appendChild(form);
}
buffer.ctx.fillStyle = 'rgba(8,5,16)';
buffer.ctx.fillRect(0, 0, buffer.width, buffer.height);
buffer.ctx.drawImage(canvas,
Math.round(buffer.width / 2 - canvas.width / 2),
Math.round(buffer.height / 2 - canvas.height / 2)
);
buffer.ctx.drawImage(logo,
Math.round(buffer.width / 2 - logo.width / 4),
Math.round(buffer.height / 2 - logo.height / 4),
logo.width / 2,
logo.height / 2
);
window.open(buffer.toDataURL(), 'wallpaper', 'top=0,left=0,width=' + buffer.width + ',height=' + buffer.height);
// form.input.value = buffer.toDataURL().substr(22);
// form.submit(); hovertree.com
}
window.requestAnimFrame = (function () {
return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || function (fn) { window.setTimeout(fn, 1000 / 60) };
})();
window.onload = function () {
ctx = document.getElementById('canvas').getContext('2d');
ctx.stats = new Stats();
ctx.running = true;
ctx.frame = 1;
hue = new Oscillator({
phase: Math.random() * Math.TWO_PI,
amplitude: 85,
frequency: 0.0015,
offset: 285
});
document.addEventListener('mousemove', init);
document.addEventListener('touchstart', init);
document.body.addEventListener('orientationchange', resize);
window.addEventListener('resize', resize);
window.addEventListener('keyup', keyup);
window.addEventListener('focus', start);
window.addEventListener('blur', stop);
resize();
if (window.DEBUG) {
var gui = new dat.GUI();
// gui.add(settings, 'debug');
settings.gui.add(settings, 'trails', 1, 30).onChange(reset);
settings.gui.add(settings, 'size', 25, 75).onFinishChange(reset);
settings.gui.add(settings, 'friction', 0.45, 0.55).onFinishChange(reset);
settings.gui.add(settings, 'dampening', 0.01, 0.4).onFinishChange(reset);
settings.gui.add(settings, 'tension', 0.95, 0.999).onFinishChange(reset);
document.body.appendChild(ctx.stats.domElement);
}
};
})(window);
<canvas id="canvas" width="100%" height="100%"></canvas>