<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no"> <meta http-equiv="X-UA-Compatible" content="IE=Edge,chrome=1"> </head> <body> <canvas id="content" width="1250px" height="602px"></canvas> </body> </html> <script> var cav = document.getElementById('content'); var w = window.screen.width; var h = window.screen.height; var yPositions = Array(300).join(0).split(''); var ctx = cav.getContext('2d'); var draw = function(){ ctx.fillStyle = 'rgba(0,0,0,.05)'; ctx.fillRect(0,0,w,h); ctx.fillStyle = 'green'; ctx.font = '20px'; yPositions.map(function(y,index){ text = String.fromCharCode(1e2+Math.random()*330); x = index*10; cav.getContext('2d').fillText(text,x,y); if(y>Math.random()*1e4){ yPositions[index]=0; }else{ yPositions[index]=y+10; } }); } setInterval('draw()',30); </script>