mr5z/screensaver.js

## screensaver.js
!function(t,e){var i=document.createElement("canvas");i.id="world",i.style.backgroundColor="transparent",i.style.zIndex="10000",i.style.width=window.innerWidth+"px",i.style.height=window.innerHeight+"px",i.style.position="fixed",i.style.left="0",i.style.top="0",i.style.pointerEvents="none",document.body.appendChild(i);var h=30,s=300,o=3,r=10,n=4e3,a=.5,c=function(t,e){var i,h,s,o,r=null;return function(){if(null!==r)return o=r,r=null,h*o+t;do{i=2*Math.random()-1,h=2*Math.random()-1,s=i*i+h*h}while(s>=1);return r=e*Math.sqrt(-2*Math.log(s)/s),i*r+t}};pointCopy=function(t,e){return e.x=t.x,e.y=t.y,e.z=t.z,e},Trail=function(t,e,i){this.pos={x:0,y:0,z:0},this.start={x:0,y:0,z:0},this.goal={x:0,y:0,z:0},this.anchor_1={x:0,y:0,z:0},this.anchor_2={x:0,y:0,z:0},this.start_time=0,this.take_time=1,this.vertexes=[],this.anchors_1=[],this.anchors_2=[],this.color_f=i,pointCopy(t,this.pos),pointCopy(t,this.start),pointCopy(t,this.goal),this.setNextGoal(e)},Trail.prototype.setNextGoal=function(t,e){pointCopy(this.goal,this.start),this.anchor_1.x=this.start.x+(this.start.x-this.anchor_2.x)*a,this.anchor_1.y=this.start.y+(this.start.y-this.anchor_2.y)*a,this.anchor_1.z=this.start.z+(this.start.z-this.anchor_2.z)*a,e?(this.anchor_2.x=(this.anchor_1.x+e.x)/2+y(),this.anchor_2.y=(this.anchor_1.y+e.y)/2+y(),this.anchor_2.z=(this.anchor_1.z+e.z)/2+y(),this.goal.x=e.x,this.goal.y=e.y,this.goal.z=e.z):(this.anchor_2.x=this.anchor_1.x+y(),this.anchor_2.y=this.anchor_1.y+y(),this.anchor_2.z=this.anchor_1.z+y(),this.goal.x=this.anchor_2.x+y(),this.goal.y=this.anchor_2.y+y(),this.goal.z=this.anchor_2.z+y()),this.start_time=t,this.take_time=200+200*Math.random(),this.vertexes.push(pointCopy(this.start,{x:0,y:0,z:0})),this.anchors_1.push(pointCopy(this.anchor_1,{x:0,y:0,z:0})),this.anchors_2.push(pointCopy(this.anchor_2,{x:0,y:0,z:0})),this.vertexes.length>r&&(this.vertexes.splice(0,this.vertexes.length-r),this.anchors_1.splice(0,this.anchors_1.length-r),this.anchors_2.splice(0,this.anchors_2.length-r))},Trail.prototype.update=function(t,e){bezier3(t-this.start_time,this.start,this.anchor_1,this.anchor_2,this.goal,this.take_time,this.pos),t-this.start_time>this.take_time&&(this.setNextGoal(this.start_time+this.take_time,e),this.update(t,e))},Trail.prototype.draw=function(t,e,i){var h,s,o,a,c,l,y={x:0,y:0,z:0},p={x:0,y:0};t.beginPath(),perspective(this.vertexes[0],e,p)&&t.moveTo(p.x,p.y);p.x;for(c=(i-this.start_time)/this.take_time,h=1;h<this.vertexes.length;h++)for(a=.01,o=0;o<1;o+=a)bezier3(o,this.vertexes[h-1],this.anchors_1[h-1],this.anchors_2[h-1],this.vertexes[h],1,y),perspective(y,e,p)&&(s=y.z-e.z,l=1-(this.vertexes.length-h+1-o+c)/r,this.color_f(t,l,s),t.lineTo(p.x,p.y),t.stroke(),t.beginPath(),t.moveTo(p.x,p.y),a=s/n+.01);for(a=.01,o=0;o<c;o+=a)bezier3(o,this.start,this.anchor_1,this.anchor_2,this.goal,1,y),perspective(y,e,p)&&(s=y.z-e.z,l=1-(1-o+c)/r,this.color_f(t,l,s),t.lineTo(p.x,p.y),t.stroke(),t.beginPath(),t.moveTo(p.x,p.y),a=s/n+.01);perspective(this.pos,e,p)&&(s=this.pos.z-e.z,l=1-1/r,this.color_f(t,l,s),t.lineTo(p.x,p.y),t.stroke())},bezier3=function(t,e,i,h,s,o,r){t/=o,r.x=e.x*(1-t)*(1-t)*(1-t)+3*i.x*t*(1-t)*(1-t)+3*h.x*t*t*(1-t)+s.x*t*t*t,r.y=e.y*(1-t)*(1-t)*(1-t)+3*i.y*t*(1-t)*(1-t)+3*h.y*t*t*(1-t)+s.y*t*t*t,r.z=e.z*(1-t)*(1-t)*(1-t)+3*i.z*t*(1-t)*(1-t)+3*h.z*t*t*(1-t)+s.z*t*t*t},perspective=function(t,e,i){var h=t.x-e.x,o=t.y-e.y,r=t.z-e.z;return r>0&&(i.x=s*h/r,i.y=s*o/r,!0)},updateScene=function(t){var e,i=(u=(new Date).getTime())-z;for(_[0].update(u),e=1;e<_.length;e++)_[e].update(u,_[e-1].pos);d.x+=5e-4*(_[0].pos.x-d.x)*i,d.y+=5e-4*(_[0].pos.y-d.y)*i,d.z+=5e-4*(_[0].pos.z-d.z-100)*i,z=u},drawScene=function(t){var e;for(t.clearRect(-p.width/2,-p.height/2,p.width,p.height),e=0;e<_.length;e++)_[e].draw(t,d,u)};var l,y=c(0,20),p=t.getElementById("world"),x=p.getContext("2d"),_=[],u=(new Date).getTime(),z=u,d={x:0,y:0,z:-200};for(l=0;l<o;l++)_.push(new Trail({x:y(),y:y(),z:y()},u,function(t,e){return"#FFFFFF"}));for(l=0;l<o;l++)switch(l%3){case 0:_[l].color_f=function(t,e,i){var h=i<10?0:e*s/i;h=(h>1?1:h)*(i<30?(i-10)/20:1),t.strokeStyle="rgba(255,"+Math.floor(255*e)+",0,"+h+")",t.lineWidth=s/i,t.lineCap=h>.8?"round":"butt"};break;case 1:_[l].color_f=function(t,e,i){var h=i<10?0:e*s/i;h=(h>1?1:h)*(i<30?(i-10)/20:1),t.strokeStyle="rgba(0, 255,"+Math.floor(255*e)+","+h+")",t.lineWidth=s/i,t.lineCap=h>.8?"round":"butt"};break;default:_[l].color_f=function(t,e,i){var h=i<10?0:e*s/i;h=(h>1?1:h)*(i<30?(i-10)/20:1),t.strokeStyle="rgba("+Math.floor(255*e)+",0,255,"+h+")",t.lineWidth=s/i,t.lineCap=h>.8?"round":"butt"}}p.width=e.innerWidth,p.height=e.innerHeight,x.translate(p.width/2,p.height/2),setInterval(function(){updateScene(),drawScene(x)},1e3/h)}(document,window);