Jony/assets/backdrop/backdrop2.js
2021-01-25 12:59:40 +08:00

1 line
5.3 KiB
JavaScript

(function(t,i){"object"==typeof window&&(window[t]=i())})("Ribbons",function(){var t=window,i=document.body,n=document.documentElement,o=function(){if(1===arguments.length){if(Array.isArray(arguments[0])){var t=Math.round(o(0,arguments[0].length-1));return arguments[0][t]}return o(0,arguments[0])}return 2===arguments.length?Math.random()*(arguments[1]-arguments[0])+arguments[0]:0},s=function(o){var s=Math.max(0,t.innerWidth||n.clientWidth||i.clientWidth||0),h=Math.max(0,t.innerHeight||n.clientHeight||i.clientHeight||0),e=Math.max(0,t.pageXOffset||n.scrollLeft||i.scrollLeft||0)-(n.clientLeft||0),a=Math.max(0,t.pageYOffset||n.scrollTop||i.scrollTop||0)-(n.clientTop||0);return{width:s,height:h,ratio:s/h,centerx:s/2,centery:h/2,scrollx:e,scrolly:a}},h=function(t,i){this.x=0,this.y=0,this.set(t,i)};h.prototype={constructor:h,set:function(t,i){this.x=t||0,this.y=i||0},copy:function(t){return this.x=t.x||0,this.y=t.y||0,this},multiply:function(t,i){return this.x*=t||1,this.y*=i||1,this},divide:function(t,i){return this.x/=t||1,this.y/=i||1,this},add:function(t,i){return this.x+=t||0,this.y+=i||0,this},subtract:function(t,i){return this.x-=t||0,this.y-=i||0,this},clampX:function(t,i){return this.x=Math.max(t,Math.min(this.x,i)),this},clampY:function(t,i){return this.y=Math.max(t,Math.min(this.y,i)),this},flipX:function(){return this.x*=-1,this},flipY:function(){return this.y*=-1,this}};var e=function(t){this._canvas=null,this._context=null,this._sto=null,this._width=0,this._height=0,this._scroll=0,this._ribbons=[],this._options={colorSaturation:"80%",colorBrightness:"60%",colorAlpha:.65,colorCycleSpeed:6,verticalPosition:"center",horizontalSpeed:200,ribbonCount:3,strokeSize:0,parallaxAmount:-.5,animateSections:!0},this._onDraw=this._onDraw.bind(this),this._onResize=this._onResize.bind(this),this._onScroll=this._onScroll.bind(this),this.setOptions(t),this.init()};return e.prototype={constructor:e,setOptions:function(t){if("object"==typeof t)for(var i in t)t.hasOwnProperty(i)&&(this._options[i]=t[i])},init:function(){try{this._canvas=document.createElement("canvas"),this._canvas.style.position="fixed",this._canvas.style.left="0",this._canvas.style.top="0",this._canvas.style.right="0",this._canvas.style.bottom="0",this._canvas.style["z-index"]="-510",this._canvas.style["pointer-events"]="none",this._canvas.id="bgCanvas",this._onResize(),this._context=this._canvas.getContext("2d"),this._context.clearRect(0,0,this._width,this._height),this._context.globalAlpha=this._options.colorAlpha,window.addEventListener("resize",this._onResize),window.addEventListener("scroll",this._onScroll),document.body.appendChild(this._canvas)}catch(t){return void console.warn("Canvas Context Error: "+t.toString())}this._onDraw()},addRibbon:function(){var t=Math.round(o(1,9))>5?"right":"left",i=1e3,n=200,s=0-n,e=this._width+n,a=0,r=0,l="right"===t?s:e,c=Math.round(o(0,this._height));/^(top|min)$/i.test(this._options.verticalPosition)?c=0+n:/^(middle|center)$/i.test(this._options.verticalPosition)?c=this._height/2:/^(bottom|max)$/i.test(this._options.verticalPosition)&&(c=this._height-n);for(var _=[],p=new h(l,c),d=new h(l,c),u=null,f=Math.round(o(0,360)),b=0;!(i<=0);){if(i--,a=Math.round((1*Math.random()-.2)*this._options.horizontalSpeed),r=Math.round((1*Math.random()-.5)*(.25*this._height)),u=new h,u.copy(d),"right"===t){if(u.add(a,r),d.x>=e)break}else if("left"===t&&(u.subtract(a,r),d.x<=s))break;_.push({point1:new h(p.x,p.y),point2:new h(d.x,d.y),point3:u,color:f,delay:b,dir:t,alpha:0,phase:0}),p.copy(d),d.copy(u),b+=4,f+=this._options.colorCycleSpeed}this._ribbons.push(_)},_drawRibbonSection:function(t){if(t){if(t.phase>=1&&t.alpha<=0)return!0;if(t.delay<=0){if(t.phase+=.02,t.alpha=1*Math.sin(t.phase),t.alpha=t.alpha<=0?0:t.alpha,t.alpha=t.alpha>=1?1:t.alpha,this._options.animateSections){var i=.1*Math.sin(1+t.phase*Math.PI/2);"right"===t.dir?(t.point1.add(i,0),t.point2.add(i,0),t.point3.add(i,0)):(t.point1.subtract(i,0),t.point2.subtract(i,0),t.point3.subtract(i,0)),t.point1.add(0,i),t.point2.add(0,i),t.point3.add(0,i)}}else t.delay-=.5;var n=this._options.colorSaturation,o=this._options.colorBrightness,s="hsla("+t.color+", "+n+", "+o+", "+t.alpha+" )";this._context.save(),0!==this._options.parallaxAmount&&this._context.translate(0,this._scroll*this._options.parallaxAmount),this._context.beginPath(),this._context.moveTo(t.point1.x,t.point1.y),this._context.lineTo(t.point2.x,t.point2.y),this._context.lineTo(t.point3.x,t.point3.y),this._context.fillStyle=s,this._context.fill(),this._options.strokeSize>0&&(this._context.lineWidth=this._options.strokeSize,this._context.strokeStyle=s,this._context.lineCap="round",this._context.stroke()),this._context.restore()}return!1},_onDraw:function(){for(var t=0,i=this._ribbons.length;t<i;++t)this._ribbons[t]||this._ribbons.splice(t,1);this._context.clearRect(0,0,this._width,this._height);for(var n=0;n<this._ribbons.length;++n){for(var o=this._ribbons[n],s=o.length,h=0,e=0;e<s;++e)this._drawRibbonSection(o[e])&&h++;h>=s&&(this._ribbons[n]=null)}this._ribbons.length<this._options.ribbonCount&&this.addRibbon(),requestAnimationFrame(this._onDraw)},_onResize:function(t){var i=s(t);this._width=i.width,this._height=i.height,this._canvas&&(this._canvas.width=this._width,this._canvas.height=this._height,this._context&&(this._context.globalAlpha=this._options.colorAlpha))},_onScroll:function(t){var i=s(t);this._scroll=i.scrolly}},e}),new Ribbons;