这是我18年写的一个烟花的特效,拿来骗骗小孩还是有点作用的,废话不多说直接上代码.
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>HTML5 Canvas 3D烟花动画</title>
<style>
html,body{margin:0px;width:100%;height:100%;overflow:hidden;background:#000;
}
#canvas{width:100%;height:100%;
}
</style>
</head>
<body>
<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>
