HTML之2021新年快乐牛年大吉＜除夕快乐噢＞

效果截图：

在这里插入图片描述
视频效果：

2021happy
源码：

  1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
  2 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
  3 <head>
  4   <meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
  5   <style>
  6     body {
  7       margin: 0;
  8       padding: 0;
  9       overflow: hidden;
 10     }
 11 
 12     .city {
 13       width: 100%;
 14       position: fixed;
 15       bottom: 0px;
 16       z-index: 100;
 17     }
 18 
 19     .city img {
 20       width: 100%;
 21     }
 22   </style>
 23   <title>2021牛年快乐</title>
 24 </head>
 25 <body onselectstart="return false">
 26 <canvas id='cas' style="background-color:rgba(0,5,24,1)">浏览器不支持canvas</canvas>
 27 <div class="city"><img src="city.png" alt=""/></div>
 28 <img src="moon.png" alt="" id="moon" style="visibility: hidden;"/>
 29 <div style="display:none">
 30   <div class="shape">2021新年快乐</div>
 31   <div class="shape">牛年大吉</div>
 32   <div class="shape">ヾ(^∀^)ﾉ</div>
 33 </div>
 34 <audio src="boom.mp3" preload="auto"></audio>
 35 <audio src="boom.mp3" preload="auto"></audio>
 36 <audio src="boom.mp3" preload="auto"></audio>
 37 <audio src="boom.mp3" preload="auto"></audio>
 38 <audio src="boom.mp3" preload="auto"></audio>
 39 <audio src="boom.mp3" preload="auto"></audio>
 40 <audio src="shotfire.mp3" preload="auto"></audio>
 41 <audio src="shotfire.mp3" preload="auto"></audio>
 42 <audio src="shotfire.mp3" preload="auto"></audio>
 43 <script>
 44   var canvas = document.getElementById("cas");
 45   var ocas = document.createElement("canvas");
 46   var octx = ocas.getContext("2d");
 47   var ctx = canvas.getContext("2d");
 48   ocas.width = canvas.width = window.innerWidth;
 49   ocas.height = canvas.height = window.innerHeight;
 50   var bigbooms = [];
 51 
 52   window.onload = function() {
 53     initAnimate()
 54   }
 55 
 56   function initAnimate() {
 57     drawBg();
 58 
 59     lastTime = new Date();
 60     animate();
 61   }
 62 
 63   var lastTime;
 64   function animate() {
 65     ctx.save();
 66     ctx.globalCompositeOperation = 'destination-out';
 67     ctx.globalAlpha = 0.1;
 68     ctx.fillRect(0, 0, canvas.width, canvas.height);
 69     ctx.restore();
 70 
 71     var newTime = new Date();
 72     if (newTime - lastTime > 200 + (window.innerHeight - 767) / 2) {
 73       var random = Math.random() * 100 > 2 ? true : false;
 74       var x = getRandom(canvas.width / 5, canvas.width * 4 / 5);
 75       var y = getRandom(50, 200);
 76       if (random) {
 77         var bigboom = new Boom(getRandom(canvas.width / 3, canvas.width * 2 / 3), 2, "#FFF", {x: x, y: y});
 78         bigbooms.push(bigboom)
 79       }
 80       else {
 81         var bigboom = new Boom(getRandom(canvas.width / 3, canvas.width * 2 / 3), 2, "#FFF", {
 82           x: canvas.width / 2,
 83           y: 200
 84         }, document.querySelectorAll(".shape")[parseInt(getRandom(0, document.querySelectorAll(".shape").length))]);
 85         bigbooms.push(bigboom)
 86       }
 87       lastTime = newTime;
 88     }
 89 
 90     stars.foreach(function() {
 91       this.paint();
 92     })
 93 
 94     drawMoon();
 95 
 96     bigbooms.foreach(function(index) {
 97       var that = this;
 98       if (!this.dead) {
 99         this._move();
100         this._drawLight();
101       }
102       else {
103         this.booms.foreach(function(index) {
104           if (!this.dead) {
105             this.moveTo(index);
106           }
107           else if (index === that.booms.length - 1) {
108             bigbooms.splice(bigbooms.indexOf(that), 1);
109           }
110         })
111       }
112     });
113 
114     raf(animate);
115   }
116 
117   function drawMoon() {
118     var moon = document.getElementById("moon");
119     var centerX = canvas.width - 200, centerY = 100, width = 80;
120     if (moon.complete) {
121       ctx.drawImage(moon, centerX, centerY, width, width)
122     }
123     else {
124       moon.onload = function() {
125         ctx.drawImage(moon, centerX, centerY, width, width)
126       }
127     }
128     var index = 0;
129     for (var i = 0; i < 10; i++) {
130       ctx.save();
131       ctx.beginPath();
132       ctx.arc(centerX + width / 2, centerY + width / 2, width / 2 + index, 0, 2 * Math.PI);
133       ctx.fillStyle = "rgba(240,219,120,0.005)";
134       index += 2;
135       ctx.fill();
136       ctx.restore();
137     }
138 
139   }
140 
141   Array.prototype.foreach = function(callback) {
142     for (var i = 0; i < this.length; i++) {
143       if (this[i] !== null) callback.apply(this[i], [i])
144     }
145   }
146 
147   var raf = window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame || function(callback) {
148         window.setTimeout(callback, 1000 / 10);
149       };
150 
151   canvas.onclick = function() {
152     var x = event.clientX;
153     var y = event.clientY;
154     var bigboom = new Boom(getRandom(canvas.width / 3, canvas.width * 2 / 3), 2, "#FFF", {x: x, y: y});
155     bigbooms.push(bigboom)
156   }
157 
158   var Boom = function(x, r, c, boomArea, shape) {
159     this.booms = [];
160     this.x = x;
161     this.y = (canvas.height + r);
162     this.r = r;
163     this.c = c;
164     this.shape = shape || false;
165     this.boomArea = boomArea;
166     this.theta = 0;
167     this.dead = false;
168     this.ba = parseInt(getRandom(80, 200));
169 
170     var audio = document.getElementsByTagName("audio");
171     for (var i = 0; i < audio.length; i++) {
172       if (audio[i].src.indexOf("shotfire") >= 0 && (audio[i].paused || audio[i].ended)) {
173         audio[i].play();
174         break;
175       }
176     }
177   }
178   Boom.prototype = {
179     _paint: function() {
180       ctx.save();
181       ctx.beginPath();
182       ctx.arc(this.x, this.y, this.r, 0, 2 * Math.PI);
183       ctx.fillStyle = this.c;
184       ctx.fill();
185       ctx.restore();
186     },
187     _move: function() {
188       var dx = this.boomArea.x - this.x, dy = this.boomArea.y - this.y;
189       this.x = this.x + dx * 0.01;
190       this.y = this.y + dy * 0.01;
191 
192       if (Math.abs(dx) <= this.ba && Math.abs(dy) <= this.ba) {
193         if (this.shape) {
194           this._shapBoom();
195         }
196         else this._boom();
197         this.dead = true;
198       }
199       else {
200         this._paint();
201       }
202     },
203     _drawLight: function() {
204       ctx.save();
205       ctx.fillStyle = "rgba(255,228,150,0.3)";
206       ctx.beginPath();
207       ctx.arc(this.x, this.y, this.r + 3 * Math.random() + 1, 0, 2 * Math.PI);
208       ctx.fill();
209       ctx.restore();
210     },
211     _boom: function() {
212       var fragNum = getRandom(100, 300);
213       var style = getRandom(0, 10) >= 5 ? 1 : 2;
214       var color;
215       if (style === 1) {
216         color = {
217           a: parseInt(getRandom(128, 255)),
218           b: parseInt(getRandom(128, 255)),
219           c: parseInt(getRandom(128, 255))
220         }
221       }
222 
223       var fanwei = fragNum;
224       var audio = document.getElementsByTagName("audio");
225       for (var i = 0; i < audio.length; i++) {
226         if (audio[i].src.indexOf("boom") >= 0 && (audio[i].paused || audio[i].ended)) {
227           audio[i].play();
228           break;
229         }
230       }
231       for (var i = 0; i < fragNum; i++) {
232         if (style === 2) {
233           color = {
234             a: parseInt(getRandom(128, 255)),
235             b: parseInt(getRandom(128, 255)),
236             c: parseInt(getRandom(128, 255))
237           }
238         }
239         var a = getRandom(-Math.PI, Math.PI);
240         var x = getRandom(0, fanwei) * Math.cos(a) + this.x;
241         var y = getRandom(0, fanwei) * Math.sin(a) + this.y;
242         var radius = getRandom(0, 2)
243         var frag = new Frag(this.x, this.y, radius, color, x, y);
244         this.booms.push(frag);
245       }
246     },
247     _shapBoom: function() {
248       var that = this;
249       putValue(ocas, octx, this.shape, 5, function(dots) {
250         var dx = canvas.width / 2 - that.x;
251         var dy = canvas.height / 2 - that.y;
252         for (var i = 0; i < dots.length; i++) {
253           color = {a: dots[i].a, b: dots[i].b, c: dots[i].c}
254           var x = dots[i].x;
255           var y = dots[i].y;
256           var radius = 1;
257           var frag = new Frag(that.x, that.y, radius, color, x - dx, y - dy);
258           that.booms.push(frag);
259         }
260       })
261     }
262   }
263 
264   function putValue(canvas, context, ele, dr, callback) {
265     context.clearRect(0, 0, canvas.width, canvas.height);
266     var img = new Image();
267     if (ele.innerHTML.indexOf("img") >= 0) {
268       img.src = ele.getElementsByTagName("img")[0].src;
269       imgload(img, function() {
270         context.drawImage(img, canvas.width / 2 - img.width / 2, canvas.height / 2 - img.width / 2);
271         dots = getimgData(canvas, context, dr);
272         callback(dots);
273       })
274     }
275     else {
276       var text = ele.innerHTML;
277       context.save();
278       var fontSize = 200;
279       context.font = fontSize + "px 宋体 bold";
280       context.textAlign = "center";
281       context.textBaseline = "middle";
282       context.fillStyle = "rgba(" + parseInt(getRandom(128, 255)) + "," + parseInt(getRandom(128, 255)) + "," + parseInt(getRandom(128, 255)) + " , 1)";
283       context.fillText(text, canvas.width / 2, canvas.height / 2);
284       context.restore();
285       dots = getimgData(canvas, context, dr);
286       callback(dots);
287     }
288   }
289 
290   function imgload(img, callback) {
291     if (img.complete) {
292       callback.call(img);
293     }
294     else {
295       img.onload = function() {
296         callback.call(this);
297       }
298     }
299   }
300 
301   function getimgData(canvas, context, dr) {
302     var imgData = context.getImageData(0, 0, canvas.width, canvas.height);
303     context.clearRect(0, 0, canvas.width, canvas.height);
304     var dots = [];
305     for (var x = 0; x < imgData.width; x += dr) {
306       for (var y = 0; y < imgData.height; y += dr) {
307         var i = (y * imgData.width + x) * 4;
308         if (imgData.data[i + 3] > 128) {
309           var dot = {x: x, y: y, a: imgData.data[i], b: imgData.data[i + 1], c: imgData.data[i + 2]};
310           dots.push(dot);
311         }
312       }
313     }
314     return dots;
315   }
316 
317   function getRandom(a, b) {
318     return Math.random() * (b - a) + a;
319   }
320 
321 
322   var maxRadius = 1, stars = [];
323   function drawBg() {
324     for (var i = 0; i < 100; i++) {
325       var r = Math.random() * maxRadius;
326       var x = Math.random() * canvas.width;
327       var y = Math.random() * 2 * canvas.height - canvas.height;
328       var star = new Star(x, y, r);
329       stars.push(star);
330       star.paint()
331     }
332 
333   }
334 
335   var Star = function(x, y, r) {
336     this.x = x;
337     this.y = y;
338     this.r = r;
339   }
340   Star.prototype = {
341     paint: function() {
342       ctx.save();
343       ctx.beginPath();
344       ctx.arc(this.x, this.y, this.r, 0, 2 * Math.PI);
345       ctx.fillStyle = "rgba(255,255,255," + this.r + ")";
346       ctx.fill();
347       ctx.restore();
348     }
349   }
350 
351   var focallength = 250;
352   var Frag = function(centerX, centerY, radius, color, tx, ty) {
353     this.tx = tx;
354     this.ty = ty;
355     this.x = centerX;
356     this.y = centerY;
357     this.dead = false;
358     this.centerX = centerX;
359     this.centerY = centerY;
360     this.radius = radius;
361     this.color = color;
362   }
363 
364   Frag.prototype = {
365     paint: function() {
366       // ctx.beginPath();
367       // ctx.arc(this.x , this.y , this.radius , 0 , 2*Math.PI);
368       ctx.fillStyle = "rgba(" + this.color.a + "," + this.color.b + "," + this.color.c + ",1)";
369       ctx.fillRect(this.x - this.radius, this.y - this.radius, this.radius * 2, this.radius * 2)
370     },
371     moveTo: function(index) {
372       this.ty = this.ty + 0.3;
373       var dx = this.tx - this.x, dy = this.ty - this.y;
374       this.x = Math.abs(dx) < 0.1 ? this.tx : (this.x + dx * 0.1);
375       this.y = Math.abs(dy) < 0.1 ? this.ty : (this.y + dy * 0.1);
376       if (dx === 0 && Math.abs(dy) <= 80) {
377         this.dead = true;
378       }
379       this.paint();
380     }
381   }
382   
383 </script>
384 </body>
385 </html>