依旧在学习道路上的小白
分类: HTML5
2015-09-21 12:07:30
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 | <!DOCTYPE html> <html lang= "en" > <head> <meta charset= "UTF-8" > <title>二进制雨</title> </head> <body> <div style= "color:red;text-align: center;font-size: 20px;" >二进制雨</div> <canvas id= "myCanvas" width= "1000px" height= "600px" style= "background-color: black;" ></canvas> <script> var draw= function (ctx,x,y,size){ this .ctx=ctx; this .x=x; this .y=y; this .size=size; var y1= this .y; this .drawText= function (){ var str=Math.ceil(Math.random()*10000).toString(2); var grd= this .ctx.createLinearGradient( this .x, this .y, this .x, this .y- this .ctx.measureText(str).width); grd.addColorStop(0, "#00FF00" ); grd.addColorStop(1, "#004400" ); this .ctx.fillStyle=grd; this .ctx.font= this .size+ "px Arial" ; for ( var i=str.length-1;i>=0;i--) { this .ctx.fillText(str.charAt(i), this .x, y1-=15); } y1= this .y+=10; if (y1-720+ this .ctx.measureText(str).width>0){ this .x=Math.ceil(Math.random()*1000); y1= this .y=Math.ceil(Math.random()*100); } } }; var rain= function (ctx,length){ this .length=length; this .ctx=ctx; var x=[]; var y=[]; var size=[]; var texts=[]; var i=0; for (;i<length;i++){ x[i]=Math.ceil(Math.random()*1000); y[i]=Math.ceil(Math.random()*500); size[i]=Math.ceil(Math.random()*15); texts[i]= new draw( this .ctx,x[i],y[i],size[i]); } this .run= function (){ ctx.clearRect(0,0,1000,600); for ( var j=0;j<length;j++){ texts[j].drawText(); } }; }; var canvas=document.getElementById( "myCanvas" ); var ctx=canvas.getContext( "2d" ); var rain0= new rain(ctx,100); setInterval(rain0.run,50); </script> </body> </html> |