JavaScript

语言：

JaveScriptBabelCoffeeScript

确定

var canvas,

ctx,

width,

height,

xCenter,

yCenter,

squares;

function square(opt) {

this.x = opt.x;

this.y = opt.y;

this.size = opt.size;

this.rotation = opt.rotation;

this.hue = opt.hue;

this.speed = opt.speed;

this.angle = this.rotation;

this.scale = 1;

this.xBase = this.x;

this.yBase = this.y;

this.xTarget = this.x + Math.cos(this.angle) * this.speed;

this.yTarget = this.y + Math.sin(this.angle) * this.speed;

}

square.prototype.step = function(i) {

this.rotation -= 0.05;

this.x = this.xBase + (this.xTarget - this.xBase) * (1 + Math.sin(tick / 25));

this.y = this.yBase + (this.yTarget - this.yBase) * (1 + Math.sin(tick / 25));

};

square.prototype.draw = function(i) {

ctx.save();

ctx.translate(this.x, this.y);

ctx.scale(this.scale, this.scale);

ctx.rotate(this.rotation);

ctx.fillStyle = 'hsla( ' + this.hue + ' , 80%, 60%, 1)';

ctx.fillRect(-this.size / 2, -this.size / 2, this.size, this.size);

ctx.restore();

ctx.save();

ctx.translate(xCenter, yCenter);

ctx.rotate(Math.PI);

ctx.scale(this.scale, this.scale * 1);

ctx.translate(-xCenter + this.x, -yCenter + this.y);

ctx.scale(this.scale, this.scale);

ctx.rotate(this.rotation);

ctx.fillStyle = 'hsla( ' + this.hue + ' , 80%, 60%, 1)';

ctx.fillRect(-this.size / 2, -this.size / 2, this.size, this.size);

ctx.restore();

};

function squareRow(count, size, radius, speed, hue) {

if (count <= 1) return;

for (var i = 0; i < count; i++) {

var angle = (Math.PI + (i / (count - 1)) * Math.PI) || 0,

x = xCenter + Math.cos(angle) * radius,

y = yCenter + Math.sin(angle) * radius;

squares.push(new square({

x: x,

y: y,

size: size,

rotation: angle,

hue: hue,

speed: speed

}));

}

}

function init() {

canvas = document.getElementById('canvas');

ctx = canvas.getContext('2d');

squares = [];

reset();

loop();

}

function reset() {

width = window.innerWidth;

height = window.innerHeight;

xCenter = width / 2;

yCenter = height / 2;

squares.length = 0;

canvas.width = width;

canvas.height = height;

tick = 0;

}

function create() {

if (tick == 0) {

for (var i = 0, length = 7; i < length; i++) {

var count = 7 + i * 2,

size = 5 + i,

radius = 20 + i * 20,

speed = 30,

hue = 360 - ((i + 1) / length) * 360;

squareRow(count, size, radius, speed, hue);

}

}

}

function step() {

var i = squares.length;

while (i--) {

squares[i].step(i);

}

}

function clear() {

ctx.clearRect(0, 0, width, height);

}

function draw() {

ctx.fillStyle = '#fff';

ctx.fillRect(0, 0, width, height / 2);

ctx.fillStyle = '#000';

ctx.fillRect(0, yCenter, width, height / 2);

var i = squares.length;

while (i--) {

ctx.save();

ctx.translate(xCenter, yCenter);

ctx.rotate(tick / 100);

ctx.translate(-xCenter, -yCenter);

squares[i].draw(i);

ctx.restore();

}

}

function loop() {

requestAnimationFrame(loop);

create();

step();

clear();

draw();

tick++;

}

function onresize() {

reset();

}

window.addEventListener('resize', onresize);

init();