html直线动画 HTML5 Canvas流动线条动画特效

先看下演示：

HTML5 Canvas流动线条动画特效

或者看看的顶部背景，可以借鉴一下。

怎么样?很好看把？可以用他在做背景等特效。

首先看下html结构代码：

HTML5 Canvas流动线条动画特效

其次是css样式css/style.css，仅供参考：

* {

margin: 0;

padding: 0;

box-sizing: border-box;

}

body {

background-color: #000;

overflow: hidden;

}

#holder {

position: absolute;

top: 0;

left: 0;

width: 100%;

height: 100%;

overflow: hidden;

}

最后是重点，是js代码js/index.js：

(function () {

var pi = Math.PI;

var pi2 = 2 * Math.PI;

this.Waves = function (holder, options) {

var Waves = this;

Waves.options = extend(options || {}, {

resize: false,

rotation: 45,

waves: 5,

width: 100,

hue: [11, 14],

amplitude: 0.5,

background: true,

preload: true,

speed: [0.004, 0.008],

debug: false,

fps: false,

});

Waves.waves = [];

Waves.holder = document.querySelector(holder);

Waves.canvas = document.createElement('canvas');

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

Waves.holder.appendChild(Waves.canvas);

Waves.hue = Waves.options.hue[0];

Waves.hueFw = true;

Waves.stats = new Stats();

Waves.resize();

Waves.init(Waves.options.preload);

if (Waves.options.resize)

window.addEventListener('resize', function () {

Waves.resize();

}, false);

};

Waves.prototype.init = function (preload) {

var Waves = this;

var options = Waves.options;

for (var i = 0; i < options.waves; i++)

Waves.waves[i] = new Wave(Waves);

if (preload) Waves.preload();

};

Waves.prototype.preload = function () {

var Waves = this;

var options = Waves.options;

for (var i = 0; i < options.waves; i++) {

Waves.updateColor();

for (var j = 0; j < options.width; j++) {

Waves.waves[i].update();

}

}

};

Waves.prototype.render = function () {

var Waves = this;

var ctx = Waves.ctx;

var options = Waves.options;

Waves.updateColor();

Waves.clear();

if (Waves.options.debug) {

ctx.beginPath();

ctx.strokeStyle = '#f00';

ctx.arc(Waves.centerX, Waves.centerY, Waves.radius, 0, pi2);

ctx.stroke();

}

if (Waves.options.background) {

Waves.background();

}

each(Waves.waves, function (wave, i) {

wave.update();

wave.draw();

});

};

Waves.prototype.animate = function () {

var Waves = this;

Waves.render();

if (Waves.options.fps) {

Waves.stats.log();

Waves.ctx.font = '12px Arial';

Waves.ctx.fillStyle = '#fff';

//Waves.ctx.fillText(Waves.stats.fps() + ' FPS', 10, 22);

}

window.requestAnimationFrame(Waves.animate.bind(Waves));

};

Waves.prototype.clear = function () {

var Waves = this;

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

};

Waves.prototype.background = function () {

var Waves = this;

var ctx = Waves.ctx;

var gradient = Waves.ctx.createLinearGradient(0, 0, 0, Waves.height);

gradient.addColorStop(0, '#000');

gradient.addColorStop(1, Waves.color);

ctx.fillStyle = gradient;

ctx.fillRect(0, 0, Waves.width, Waves.height);

};

Waves.prototype.resize = function () {

var Waves = this;

var width = Waves.holder.offsetWidth;

var height = Waves.holder.offsetHeight;

Waves.scale = window.devicePixelRatio || 1;

Waves.width = width * Waves.scale;

Waves.height = height * Waves.scale;

Waves.canvas.width = Waves.width;

Waves.canvas.height = Waves.height;

Waves.canvas.style.width = width + 'px';

Waves.canvas.style.height = height + 'px';

Waves.radius = Math.sqrt(Math.pow(Waves.width, 2) + Math.pow(Waves.height, 2)) / 2;

Waves.centerX = Waves.width / 2;

Waves.centerY = Waves.height / 2;

//Waves.radius /= 2; // REMOVE FOR FULLSREEN

};

Waves.prototype.updateColor = function () {

var Waves = this;

Waves.hue += (Waves.hueFw) ? 0.01 : -0.01;

if (Waves.hue > Waves.options.hue[1] && Waves.hueFw) {

Waves.hue = Waves.options.hue[1];

Waves.Waves = false;

} else if (Waves.hue < Waves.options.hue[0] && !Waves.hueFw) {

Waves.hue = Waves.options.hue[0];

Waves.Waves = true;

}

var a = Math.floor(127 * Math.sin(0.3 * Waves.hue + 0) + 128);

var b = Math.floor(127 * Math.sin(0.3 * Waves.hue + 2) + 128);

var c = Math.floor(127 * Math.sin(0.3 * Waves.hue + 4) + 128);

Waves.color = 'rgba(' + a + ',' + b + ',' + c + ', 0.1)';

};

function Wave(Waves) {

var Wave = this;

var speed = Waves.options.speed;

Wave.Waves = Waves;

Wave.Lines = [];

Wave.angle = [

rnd(pi2),

rnd(pi2),

rnd(pi2),

rnd(pi2)

];

Wave.speed = [

rnd(speed[0], speed[1]) * rnd_sign(),

rnd(speed[0], speed[1]) * rnd_sign(),

rnd(speed[0], speed[1]) * rnd_sign(),

rnd(speed[0], speed[1]) * rnd_sign(),

];

return Wave;

}

Wave.prototype.update = function () {

var Wave = this;

var Lines = Wave.Lines;

var color = Wave.Waves.color;

Lines.push(new Line(Wave, color));

if (Lines.length > Wave.Waves.options.width) {

Lines.shift();

}

};

Wave.prototype.draw = function () {

var Wave = this;

var Waves = Wave.Waves;

var ctx = Waves.ctx;

var radius = Waves.radius;

var radius3 = radius / 3;

var x = Waves.centerX;

var y = Waves.centerY;

var rotation = dtr(Waves.options.rotation);

var amplitude = Waves.options.amplitude;

var debug = Waves.options.debug;

var Lines = Wave.Lines;

each(Lines, function (line, i) {

if (debug && i > 0) return;

var angle = line.angle;

var x1 = x - radius * Math.cos(angle[0] * amplitude + rotation);

var y1 = y - radius * Math.sin(angle[0] * amplitude + rotation);

var x2 = x + radius * Math.cos(angle[3] * amplitude + rotation);

var y2 = y + radius * Math.sin(angle[3] * amplitude + rotation);

var cpx1 = x - radius3 * Math.cos(angle[1] * amplitude * 2);

var cpy1 = y - radius3 * Math.sin(angle[1] * amplitude * 2);

var cpx2 = x + radius3 * Math.cos(angle[2] * amplitude * 2);

var cpy2 = y + radius3 * Math.sin(angle[2] * amplitude * 2);

ctx.strokeStyle = (debug) ? '#fff' : line.color;

ctx.beginPath();

ctx.moveTo(x1, y1);

ctx.bezierCurveTo(cpx1, cpy1, cpx2, cpy2, x2, y2);

ctx.stroke();

if (debug) {

ctx.strokeStyle = '#fff';

ctx.globalAlpha = 0.3;

ctx.beginPath();

ctx.moveTo(x1, y1);

ctx.lineTo(cpx1, cpy1);

ctx.stroke();

ctx.beginPath();

ctx.moveTo(x2, y2);

ctx.lineTo(cpx2, cpy2);

ctx.stroke();

ctx.globalAlpha = 1;

}

});

};

function Line(Wave, color) {

var Line = this;

var angle = Wave.angle;

var speed = Wave.speed;

Line.angle = [

Math.sin(angle[0] += speed[0]),

Math.sin(angle[1] += speed[1]),

Math.sin(angle[2] += speed[2]),

Math.sin(angle[3] += speed[3])

];

Line.color = color;

}

function Stats() {

this.data = [];

}

Stats.prototype.time = function () {

return (performance || Date)

.now();

};

Stats.prototype.log = function () {

if (!this.last) {

this.last = this.time();

return 0;

}

this.new = this.time();

this.delta = this.new - this.last;

this.last = this.new;

this.data.push(this.delta);

if (this.data.length > 10)

this.data.shift();

};

Stats.prototype.fps = function () {

var fps = 0;

each(this.data, function (data, i) {

fps += data;

});

return Math.round(1000 / (fps / this.data.length));

};

function each(items, callback) {

for (var i = 0; i < items.length; i++) {

callback(items[i], i);

}

}

function extend(options, defaults) {

for (var key in options)

if (defaults.hasOwnProperty(key))

defaults[key] = options[key];

return defaults;

}

function dtr(deg) {

return deg * pi / 180;

}

function rtd(rad) {

return rad * 180 / pi;

}

function diagonal_angle(w, h) {

var a = Math.atan2(h, w) * 1.27325;

return a;

}

function rnd(a, b) {

if (arguments.length == 1)

return Math.random() * a;

return a + Math.random() * (b - a);

}

function rnd_sign() {

return (Math.random() > 0.5) ? 1 : -1;

}

})();

var waves = new Waves('#holder', {

fps: true,

waves: 3,

width: 200,

});

waves.animate();

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