用HTML5实现祝贺用3D动态烟花

一时失言乱红尘 2023-01-04 10:25 69阅读 0赞

### 用HTML5实现祝贺用3D动态烟花 ###

将下列代码保存为html文件名，如：新年快乐3D动态烟花.HTML，用浏览器代开运行此文件，就可看到效果，当在浏览器（Microsoft Edge）打开时有礼花爆炸声响。演示图如下：

![20210219113847570.gif][]

源码如下：

<!doctype html>
    <html>
    <head>
    <meta charset="utf-8">
    <title>烟花动画特效</title>
     
    <style>
    :root {
      font-family: "Aleo", sans-serif;
      color:red
    }
    
    html,
    body {
      width: 100%;
      height: 100%;
      padding: 0;
      margin: 0;
      background: rgb(119, 13, 13);
      
    }
    
    canvas {
      width: 100%;
      height: 100%;
    }
    
    .middle {
      position: absolute;
      top: 50%;
      left: 50%;
      transform: translate(-50%, -50%);
      text-align: center;
      user-select: none;
    }
    
    
    </style>
    </head>
    <body>
    <div class="middle">
    	<h1 class="label">祝您快乐！万事如意 </h1>
                    <h2 class="label">某某 恭祝  </h2>
    	
    </div>
     
    <canvas id="canvas"></canvas><script>
    function initVars(){
     
    	pi=Math.PI;
    	ctx=canvas.getContext("2d");
    	canvas.width=canvas.clientWidth;
    	canvas.height=canvas.clientHeight;
    	cx=canvas.width/2;
    	cy=canvas.height/2;
    	playerZ=-25;
    	playerX=playerY=playerVX=playerVY=playerVZ=pitch=yaw=pitchV=yawV=0;
    	scale=600;
    	seedTimer=0;seedInterval=5,seedLife=100;gravity=.02;
    	seeds=new Array();
    	sparkPics=new Array();
    	s="https://cantelope.org/NYE/";
    	for(i=1;i<=10;++i){
    		sparkPic=new Image();
    		sparkPic.src=s+"spark"+i+".png";
    		sparkPics.push(sparkPic);
    	}
    	sparks=new Array();
    	pow1=new Audio(s+"pow1.ogg");
    	pow2=new Audio(s+"pow2.ogg");
    	pow3=new Audio(s+"pow3.ogg");
    	pow4=new Audio(s+"pow4.ogg");
    	frames = 0;
    }
     
    function rasterizePoint(x,y,z){
     
    	var p,d;
    	x-=playerX;
    	y-=playerY;
    	z-=playerZ;
    	p=Math.atan2(x,z);
    	d=Math.sqrt(x*x+z*z);
    	x=Math.sin(p-yaw)*d;
    	z=Math.cos(p-yaw)*d;
    	p=Math.atan2(y,z);
    	d=Math.sqrt(y*y+z*z);
    	y=Math.sin(p-pitch)*d;
    	z=Math.cos(p-pitch)*d;
    	var rx1=-1000,ry1=1,rx2=1000,ry2=1,rx3=0,ry3=0,rx4=x,ry4=z,uc=(ry4-ry3)*(rx2-rx1)-(rx4-rx3)*(ry2-ry1);
    	if(!uc) return {x:0,y:0,d:-1};
    	var ua=((rx4-rx3)*(ry1-ry3)-(ry4-ry3)*(rx1-rx3))/uc;
    	var ub=((rx2-rx1)*(ry1-ry3)-(ry2-ry1)*(rx1-rx3))/uc;
    	if(!z)z=.000000001;
    	if(ua>0&&ua<1&&ub>0&&ub<1){
    		return {
    			x:cx+(rx1+ua*(rx2-rx1))*scale,
    			y:cy+y/z*scale,
    			d:Math.sqrt(x*x+y*y+z*z)
    		};
    	}else{
    		return {
    			x:cx+(rx1+ua*(rx2-rx1))*scale,
    			y:cy+y/z*scale,
    			d:-1
    		};
    	}
    }
     
    function spawnSeed(){
    	
    	seed=new Object();
    	seed.x=-50+Math.random()*100;
    	seed.y=25;
    	seed.z=-50+Math.random()*100;
    	seed.vx=.1-Math.random()*.2;
    	seed.vy=-1.5;//*(1+Math.random()/2);
    	seed.vz=.1-Math.random()*.2;
    	seed.born=frames;
    	seeds.push(seed);
    }
     
    function splode(x,y,z){
    	
    	t=5+parseInt(Math.random()*150);
    	sparkV=1+Math.random()*2.5;
    	type=parseInt(Math.random()*3);
    	switch(type){
    		case 0:
    			pic1=parseInt(Math.random()*10);
    			break;
    		case 1:
    			pic1=parseInt(Math.random()*10);
    			do{ pic2=parseInt(Math.random()*10); }while(pic2==pic1);
    			break;
    		case 2:
    			pic1=parseInt(Math.random()*10);
    			do{ pic2=parseInt(Math.random()*10); }while(pic2==pic1);
    			do{ pic3=parseInt(Math.random()*10); }while(pic3==pic1 || pic3==pic2);
    			break;
    	}
    	for(m=1;m<t;++m){
    		spark=new Object();
    		spark.x=x; spark.y=y; spark.z=z;
    		p1=pi*2*Math.random();
    		p2=pi*Math.random();
    		v=sparkV*(1+Math.random()/6)
    		spark.vx=Math.sin(p1)*Math.sin(p2)*v;
    		spark.vz=Math.cos(p1)*Math.sin(p2)*v;
    		spark.vy=Math.cos(p2)*v;
    		switch(type){
    			case 0: spark.img=sparkPics[pic1]; break;
    			case 1:
    				spark.img=sparkPics[parseInt(Math.random()*2)?pic1:pic2];
    				break;
    			case 2:
    				switch(parseInt(Math.random()*3)){
    					case 0: spark.img=sparkPics[pic1]; break;
    					case 1: spark.img=sparkPics[pic2]; break;
    					case 2: spark.img=sparkPics[pic3]; break;
    				}
    				break;
    		}
    		spark.radius=25+Math.random()*50;
    		spark.alpha=1;
    		spark.trail=new Array();
    		sparks.push(spark);
    	}
    	switch(parseInt(Math.random()*4)){
    		case 0:	pow=new Audio(s+"pow1.ogg"); break;
    		case 1:	pow=new Audio(s+"pow2.ogg"); break;
    		case 2:	pow=new Audio(s+"pow3.ogg"); break;
    		case 3:	pow=new Audio(s+"pow4.ogg"); break;
    	}
    	d=Math.sqrt((x-playerX)*(x-playerX)+(y-playerY)*(y-playerY)+(z-playerZ)*(z-playerZ));
    	pow.volume=1.5/(1+d/10);
    	pow.play();
    }
     
    function doLogic(){
    	
    	if(seedTimer<frames){
    		seedTimer=frames+seedInterval*Math.random()*10;
    		spawnSeed();
    	}
    	for(i=0;i<seeds.length;++i){
    		seeds[i].vy+=gravity;
    		seeds[i].x+=seeds[i].vx;
    		seeds[i].y+=seeds[i].vy;
    		seeds[i].z+=seeds[i].vz;
    		if(frames-seeds[i].born>seedLife){
    			splode(seeds[i].x,seeds[i].y,seeds[i].z);
    			seeds.splice(i,1);
    		}
    	}
    	for(i=0;i<sparks.length;++i){
    		if(sparks[i].alpha>0 && sparks[i].radius>5){
    			sparks[i].alpha-=.01;
    			sparks[i].radius/=1.02;
    			sparks[i].vy+=gravity;
    			point=new Object();
    			point.x=sparks[i].x;
    			point.y=sparks[i].y;
    			point.z=sparks[i].z;
    			if(sparks[i].trail.length){
    				x=sparks[i].trail[sparks[i].trail.length-1].x;
    				y=sparks[i].trail[sparks[i].trail.length-1].y;
    				z=sparks[i].trail[sparks[i].trail.length-1].z;
    				d=((point.x-x)*(point.x-x)+(point.y-y)*(point.y-y)+(point.z-z)*(point.z-z));
    				if(d>9){
    					sparks[i].trail.push(point);
    				}
    			}else{
    				sparks[i].trail.push(point);
    			}
    			if(sparks[i].trail.length>5)sparks[i].trail.splice(0,1);				
    			sparks[i].x+=sparks[i].vx;
    			sparks[i].y+=sparks[i].vy;
    			sparks[i].z+=sparks[i].vz;
    			sparks[i].vx/=1.075;
    			sparks[i].vy/=1.075;
    			sparks[i].vz/=1.075;
    		}else{
    			sparks.splice(i,1);
    		}
    	}
    	p=Math.atan2(playerX,playerZ);
    	d=Math.sqrt(playerX*playerX+playerZ*playerZ);
    	d+=Math.sin(frames/80)/1.25;
    	t=Math.sin(frames/200)/40;
    	playerX=Math.sin(p+t)*d;
    	playerZ=Math.cos(p+t)*d;
    	yaw=pi+p+t;
    }
     
    function rgb(col){
    	
    	var r = parseInt((.5+Math.sin(col)*.5)*16);
    	var g = parseInt((.5+Math.cos(col)*.5)*16);
    	var b = parseInt((.5-Math.sin(col)*.5)*16);
    	return "#"+r.toString(16)+g.toString(16)+b.toString(16);
    }
     
    function draw(){
    	
    	ctx.clearRect(0,0,cx*2,cy*2);
    	
    	ctx.fillStyle="#ff8";
    	for(i=-100;i<100;i+=3){
    		for(j=-100;j<100;j+=4){
    			x=i;z=j;y=25;
    			point=rasterizePoint(x,y,z);
    			if(point.d!=-1){
    				size=250/(1+point.d);
    				d = Math.sqrt(x * x + z * z);
    				a = 0.75 - Math.pow(d / 100, 6) * 0.75;
    				if(a>0){
    					ctx.globalAlpha = a;
    					ctx.fillRect(point.x-size/2,point.y-size/2,size,size);				
    				}
    			}
    		}
    	}
    	ctx.globalAlpha=1;
    	for(i=0;i<seeds.length;++i){
    		point=rasterizePoint(seeds[i].x,seeds[i].y,seeds[i].z);
    		if(point.d!=-1){
    			size=200/(1+point.d);
    			ctx.fillRect(point.x-size/2,point.y-size/2,size,size);
    		}
    	}
    	point1=new Object();
    	for(i=0;i<sparks.length;++i){
    		point=rasterizePoint(sparks[i].x,sparks[i].y,sparks[i].z);
    		if(point.d!=-1){
    			size=sparks[i].radius*200/(1+point.d);
    			if(sparks[i].alpha<0)sparks[i].alpha=0;
    			if(sparks[i].trail.length){
    				point1.x=point.x;
    				point1.y=point.y;
    				switch(sparks[i].img){
    					case sparkPics[0]:ctx.strokeStyle="#f84";break;
    					case sparkPics[1]:ctx.strokeStyle="#84f";break;
    					case sparkPics[2]:ctx.strokeStyle="#8ff";break;
    					case sparkPics[3]:ctx.strokeStyle="#fff";break;
    					case sparkPics[4]:ctx.strokeStyle="#4f8";break;
    					case sparkPics[5]:ctx.strokeStyle="#f44";break;
    					case sparkPics[6]:ctx.strokeStyle="#f84";break;
    					case sparkPics[7]:ctx.strokeStyle="#84f";break;
    					case sparkPics[8]:ctx.strokeStyle="#fff";break;
    					case sparkPics[9]:ctx.strokeStyle="#44f";break;
    				}
    				for(j=sparks[i].trail.length-1;j>=0;--j){
    					point2=rasterizePoint(sparks[i].trail[j].x,sparks[i].trail[j].y,sparks[i].trail[j].z);
    					if(point2.d!=-1){
    						ctx.globalAlpha=j/sparks[i].trail.length*sparks[i].alpha/2;
    						ctx.beginPath();
    						ctx.moveTo(point1.x,point1.y);
    						ctx.lineWidth=1+sparks[i].radius*10/(sparks[i].trail.length-j)/(1+point2.d);
    						ctx.lineTo(point2.x,point2.y);
    						ctx.stroke();
    						point1.x=point2.x;
    						point1.y=point2.y;
    					}
    				}
    			}
    			ctx.globalAlpha=sparks[i].alpha;
    			ctx.drawImage(sparks[i].img,point.x-size/2,point.y-size/2,size,size);
    		}
    	}
    }
     
    function frame(){
     
    	if(frames>100000){
    		seedTimer=0;
    		frames=0;
    	}
    	frames++;
    	draw();
    	doLogic();
    	requestAnimationFrame(frame);
    }
     
    window.addEventListener("resize",()=>{
    	canvas.width=canvas.clientWidth;
    	canvas.height=canvas.clientHeight;
    	cx=canvas.width/2;
    	cy=canvas.height/2;
    });
     
    initVars();
    frame();
    </script>
     
    
    </body>
    </html>

[20210219113847570.gif]: /images/20221119/416eac5d97ec451c895acecb2e8bd95f.png