程序员HTML新年,HTML之2021新年快乐牛年大吉＜除夕快乐噢＞

var canvas = document.getElementById("cas");

var ocas = document.createElement("canvas");

var octx = ocas.getContext("2d");

var ctx = canvas.getContext("2d");

ocas.width = canvas.width = window.innerWidth;

ocas.height = canvas.height = window.innerHeight;

var bigbooms = [];

window.onload = function() {

initAnimate()

}

function initAnimate() {

drawBg();

lastTime = new Date();

animate();

}

var lastTime;

function animate() {

ctx.save();

ctx.globalCompositeOperation = 'destination-out';

ctx.globalAlpha = 0.1;

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

ctx.restore();

var newTime = new Date();

if (newTime - lastTime > 200 + (window.innerHeight - 767) / 2) {

var random = Math.random() * 100 > 2 ? true : false;

var x = getRandom(canvas.width / 5, canvas.width * 4 / 5);

var y = getRandom(50, 200);

if (random) {

var bigboom = new Boom(getRandom(canvas.width / 3, canvas.width * 2 / 3), 2, "#FFF", {x: x, y: y});

bigbooms.push(bigboom)

}

else {

var bigboom = new Boom(getRandom(canvas.width / 3, canvas.width * 2 / 3), 2, "#FFF", {

x: canvas.width / 2,

y: 200

}, document.querySelectorAll(".shape")[parseInt(getRandom(0, document.querySelectorAll(".shape").length))]);

bigbooms.push(bigboom)

}

lastTime = newTime;

}

stars.foreach(function() {

this.paint();

})

drawMoon();

bigbooms.foreach(function(index) {

var that = this;

if (!this.dead) {

this._move();

this._drawLight();

}

else {

this.booms.foreach(function(index) {

if (!this.dead) {

this.moveTo(index);

}

else if (index === that.booms.length - 1) {

bigbooms.splice(bigbooms.indexOf(that), 1);

}

})

}

});

raf(animate);

}

function drawMoon() {

var moon = document.getElementById("moon");

var centerX = canvas.width - 200, centerY = 100, width = 80;

if (moon.complete) {

ctx.drawImage(moon, centerX, centerY, width, width)

}

else {

moon.onload = function() {

ctx.drawImage(moon, centerX, centerY, width, width)

}

}

var index = 0;

for (var i = 0; i < 10; i++) {

ctx.save();

ctx.beginPath();

ctx.arc(centerX + width / 2, centerY + width / 2, width / 2 + index, 0, 2 * Math.PI);

ctx.fillStyle = "rgba(240,219,120,0.005)";

index += 2;

ctx.fill();

ctx.restore();

}

}

Array.prototype.foreach = function(callback) {

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

if (this[i] !== null) callback.apply(this[i], [i])

}

}

var raf = window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame || function(callback) {

window.setTimeout(callback, 1000 / 10);

};

canvas.onclick = function() {

var x = event.clientX;

var y = event.clientY;

var bigboom = new Boom(getRandom(canvas.width / 3, canvas.width * 2 / 3), 2, "#FFF", {x: x, y: y});

bigbooms.push(bigboom)

}

var Boom = function(x, r, c, boomArea, shape) {

this.booms = [];

this.x = x;

this.y = (canvas.height + r);

this.r = r;

this.c = c;

this.shape = shape || false;

this.boomArea = boomArea;

this.theta = 0;

this.dead = false;

this.ba = parseInt(getRandom(80, 200));

var audio = document.getElementsByTagName("audio");

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

if (audio[i].src.indexOf("shotfire") >= 0 && (audio[i].paused || audio[i].ended)) {

audio[i].play();

break;

}

}

}

Boom.prototype = {

_paint: function() {

ctx.save();

ctx.beginPath();

ctx.arc(this.x, this.y, this.r, 0, 2 * Math.PI);

ctx.fillStyle = this.c;

ctx.fill();

ctx.restore();

},

_move: function() {

var dx = this.boomArea.x - this.x, dy = this.boomArea.y - this.y;

this.x = this.x + dx * 0.01;

this.y = this.y + dy * 0.01;

if (Math.abs(dx) <= this.ba && Math.abs(dy) <= this.ba) {

if (this.shape) {

this._shapBoom();

}

else this._boom();

this.dead = true;

}

else {

this._paint();

}

},

_drawLight: function() {

ctx.save();

ctx.fillStyle = "rgba(255,228,150,0.3)";

ctx.beginPath();

ctx.arc(this.x, this.y, this.r + 3 * Math.random() + 1, 0, 2 * Math.PI);

ctx.fill();

ctx.restore();

},

_boom: function() {

var fragNum = getRandom(100, 300);

var style = getRandom(0, 10) >= 5 ? 1 : 2;

var color;

if (style === 1) {

color = {

a: parseInt(getRandom(128, 255)),

b: parseInt(getRandom(128, 255)),

c: parseInt(getRandom(128, 255))

}

}

var fanwei = fragNum;

var audio = document.getElementsByTagName("audio");

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

if (audio[i].src.indexOf("boom") >= 0 && (audio[i].paused || audio[i].ended)) {

audio[i].play();

break;

}

}

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

if (style === 2) {

color = {

a: parseInt(getRandom(128, 255)),

b: parseInt(getRandom(128, 255)),

c: parseInt(getRandom(128, 255))

}

}

var a = getRandom(-Math.PI, Math.PI);

var x = getRandom(0, fanwei) * Math.cos(a) + this.x;

var y = getRandom(0, fanwei) * Math.sin(a) + this.y;

var radius = getRandom(0, 2)

var frag = new Frag(this.x, this.y, radius, color, x, y);

this.booms.push(frag);

}

},

_shapBoom: function() {

var that = this;

putValue(ocas, octx, this.shape, 5, function(dots) {

var dx = canvas.width / 2 - that.x;

var dy = canvas.height / 2 - that.y;

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

color = {a: dots[i].a, b: dots[i].b, c: dots[i].c}

var x = dots[i].x;

var y = dots[i].y;

var radius = 1;

var frag = new Frag(that.x, that.y, radius, color, x - dx, y - dy);

that.booms.push(frag);

}

})

}

}

function putValue(canvas, context, ele, dr, callback) {

context.clearRect(0, 0, canvas.width, canvas.height);

var img = new Image();

if (ele.innerHTML.indexOf("img") >= 0) {

img.src = ele.getElementsByTagName("img")[0].src;

imgload(img, function() {

context.drawImage(img, canvas.width / 2 - img.width / 2, canvas.height / 2 - img.width / 2);

dots = getimgData(canvas, context, dr);

callback(dots);

})

}

else {

var text = ele.innerHTML;

context.save();

var fontSize = 200;

context.font = fontSize + "px 宋体 bold";

context.textAlign = "center";

context.textBaseline = "middle";

context.fillStyle = "rgba(" + parseInt(getRandom(128, 255)) + "," + parseInt(getRandom(128, 255)) + "," + parseInt(getRandom(128, 255)) + " , 1)";

context.fillText(text, canvas.width / 2, canvas.height / 2);

context.restore();

dots = getimgData(canvas, context, dr);

callback(dots);

}

}

function imgload(img, callback) {

if (img.complete) {

callback.call(img);

}

else {

img.onload = function() {

callback.call(this);

}

}

}

function getimgData(canvas, context, dr) {

var imgData = context.getImageData(0, 0, canvas.width, canvas.height);

context.clearRect(0, 0, canvas.width, canvas.height);

var dots = [];

for (var x = 0; x < imgData.width; x += dr) {

for (var y = 0; y < imgData.height; y += dr) {

var i = (y * imgData.width + x) * 4;

if (imgData.data[i + 3] > 128) {

var dot = {x: x, y: y, a: imgData.data[i], b: imgData.data[i + 1], c: imgData.data[i + 2]};

dots.push(dot);

}

}

}

return dots;

}

function getRandom(a, b) {

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

}

var maxRadius = 1, stars = [];

function drawBg() {

for (var i = 0; i < 100; i++) {

var r = Math.random() * maxRadius;

var x = Math.random() * canvas.width;

var y = Math.random() * 2 * canvas.height - canvas.height;

var star = new Star(x, y, r);

stars.push(star);

star.paint()

}

}

var Star = function(x, y, r) {

this.x = x;

this.y = y;

this.r = r;

}

Star.prototype = {

paint: function() {

ctx.save();

ctx.beginPath();

ctx.arc(this.x, this.y, this.r, 0, 2 * Math.PI);

ctx.fillStyle = "rgba(255,255,255," + this.r + ")";

ctx.fill();

ctx.restore();

}

}

var focallength = 250;

var Frag = function(centerX, centerY, radius, color, tx, ty) {

this.tx = tx;

this.ty = ty;

this.x = centerX;

this.y = centerY;

this.dead = false;

this.centerX = centerX;

this.centerY = centerY;

this.radius = radius;

this.color = color;

}

Frag.prototype = {

paint: function() {

// ctx.beginPath();

// ctx.arc(this.x , this.y , this.radius , 0 , 2*Math.PI);

ctx.fillStyle = "rgba(" + this.color.a + "," + this.color.b + "," + this.color.c + ",1)";

ctx.fillRect(this.x - this.radius, this.y - this.radius, this.radius * 2, this.radius * 2)

},

moveTo: function(index) {

this.ty = this.ty + 0.3;

var dx = this.tx - this.x, dy = this.ty - this.y;

this.x = Math.abs(dx) < 0.1 ? this.tx : (this.x + dx * 0.1);

this.y = Math.abs(dy) < 0.1 ? this.ty : (this.y + dy * 0.1);

if (dx === 0 && Math.abs(dy) <= 80) {

this.dead = true;

}

this.paint();

}

}