2 lines
3.5 KiB
JavaScript
2 lines
3.5 KiB
JavaScript
snow={count:60,delay:20,flutter:0.2,wobble:0.5,spin:1,wind:1,w1:1,minSpeed:0.3,maxSpeed:4,cv:null,flakes:[],toggle:function(){if(window.snowtimer){snow.stop()}else{snow.start()}},resize:function(){snow.cv.width=innerWidth;snow.cv.height=innerHeight;snow.gt=snow.ct.createLinearGradient(0,0,0,snow.cv.height);snow.gt.addColorStop(0,"#6666ff");snow.gt.addColorStop(1,"#ffffff");snow.ct.fillStyle=snow.gt},start:function(){snow.cv=document.createElement("canvas");snow.cv.width=snow.cv.height=10;snow.cv.id="backgroundSnowCanvas";document.body.appendChild(snow.cv);snow.createFlake();snow.ct=snow.cv.getContext("2d"),snow.cv.style.position="fixed";snow.cv.style.top=0;snow.cv.style.left=0;snow.cv.style.zIndex=-1;snow.resize();var a=snow.count;snow.flakes=[];do{snow.flakes.push(new snow.flake())}while(--a);snow.ct.clearRect(0,0,snow.cv.width,snow.cv.height);window.snowtimer=window.setInterval(snow.draw,snow.delay);window.addEventListener("resize",snow.resize)},stop:function(){window.clearInterval(window.snowtimer);var a=document.getElementById("backgroundSnowCanvas");a.parentNode.removeChild(a);window.snowtimer=snow=null},draw:function(){var a=snow.ct,b=snow.flakes,d=snow.count;a.clearRect(0,0,snow.cv.width,snow.cv.height);do{if(b[--d].draw(a)&&++fdone){}}while(d);snow.wind+=Math.cos(snow.w1++/180)},flake:function(){this.draw=function(c){var b=this.x+snow.wind,e=this.y,a=b+this.sz/2,d=e+this.sz/2;c.translate(a,d);c.rotate(this.a);c.translate(-a,-d);c.drawImage(snow.flakeImages[this.flake],b,e,this.sz,this.sz);if(this.flakebits>=0){c.drawImage(snow.flakeBits[this.flakebits],b,e,this.sz,this.sz)}c.setTransform(1,0,0,1,0,0);this.animate()};this.animate=function(){this.y+=this.speed;this.x+=this.flutter*Math.cos(snow.flutter*snow.flutter*this.y);this.a=(this.spin*this.y)+(this.wobble*Math.sin(this.y/this.sz));if(this.y>innerHeight){this.init(1)}};this.init=function(a){this.speed=snow.minSpeed+(Math.random()*(snow.maxSpeed-snow.minSpeed));this.sz=~~(Math.random()*40)+20;this.flutter=~~(Math.random()*snow.flutter*(60-this.sz));this.wobble=Math.random()*snow.wobble;this.spin=snow.spin*0.1*(Math.random()-0.5);this.a=0;this.x=(Math.random()*(innerWidth+this.sz))-this.sz;this.y=a?-this.sz:Math.random()*innerHeight;this.flake=~~(Math.random()*snow.flakeImages.length);this.flakebits=~~(Math.random()*(snow.flakeBits.length+1))-1};this.init()},createFlake:function(){var A,z,B,s,r,j=document.createElement("canvas"),m,d;j.width=j.height=40;snow.flakeImages=[];snow.flakeBits=[];for(A=0;A<6;++A){snow.flakeImages[A]=s=j.cloneNode();B=s.getContext("2d");B.fillStyle="#fff";B.translate(20,20);B.beginPath();r=1+(A/2);B.rect(-r,-20,r*2,40);B.rotate(Math.PI/3);B.rect(-r,-20,r*2,40);B.rotate(Math.PI/3);B.rect(-r,-20,r*2,40);B.closePath();B.fill()}function x(f){f.arc(0,-16,4,0,7,0)}function b(I,F,f,H,G,g){I.moveTo(0,-f);I.lineTo(F,-H);I.lineTo(F,-G);I.lineTo(0,-H-g);I.lineTo(-F,-G);I.lineTo(-F,-H);I.lineTo(0,-f)}function i(f){b(f,5,6,8,10,0)}function v(f){b(f,5,10,12,14,0)}function u(f){b(f,4,6,8,12,2)}function k(f){b(f,9,6,8,11,0)}function y(f){b(f,4,16,16,18,2)}function E(f){b(f,5,12,12,14,2)}function e(f){x(f);u(f)}function t(f){v(f);u(f)}function l(f){i(f);v(f)}function o(f){x(f);i(f)}function a(f){y(f);E(f)}function D(f){y(f);k(f)}function n(f){y(f);u(f)}function C(f){y(f);i(f)}function q(f){E(f);i(f)}function p(f){y(f);v(f)}function h(f){x(f);k(f)}d=[h,q,p,C,n,D,y,E,a,k,x,i,v,u,e,t,l,o];for(A=0;A<d.length;++A){snow.flakeBits[A]=s=j.cloneNode();m=d[A];B=s.getContext("2d");B.translate(20,20);B.fillStyle="#fff";for(z=0;z<6;++z){B.beginPath();m(B);B.closePath();B.fill();B.rotate(Math.PI/3)}}}};
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