HTMLcanvas rectangle shower-H5 Tutorial-php.cn

HTMLcanvas rectangle shower

大家讲道理

Release： 2017-05-28 10:40:48

Original

1585 people have browsed it

HTMLcanvasRectangle Shower

Execute on canvas
Get the drawing environment
Get full screen Screen Width and Screen Height
Determine the width of each text to determine the columns
LoopOutput
TimerCall

##HTML part

<!DOCTYPE HTML><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>HTMLcanvas矩形阵雨</title></head><body><canvas id="c">您的浏览器不支持 请升级</canvas></body></html>

Copy after login

CSS Part

<style type="text/css">/* 基本的复位 */* {
    margin:0;
    padding:0;}/* 给body一个背景 使画布看起来更清晰 */body {
    background-color:#000;}canvas {
    display:block;}</style>

Copy after login

##Javascript Part

<script type="text/jscript">
 var c = document.getElementById("c"); //获取id
 var ctx = c.getContext("2d"); //2d制图 
 c.width = window.innerWidth; //获取屏幕宽度 c.height = window.innerHeight; //获取屏幕高度
 
 var chinese = "abcdefghijklmnopqrstuvwxyz"; //canvas 阵雨文字 chinese = chinese.split(""); //split 分离
 
 var font_size = 10; //字体大小 10px
 var columns = c.width/font_size; 
 //获取列 屏幕宽度/字体大小
 var drops = []; // drop 落下 新建数组
 for(n=0; n < columns; n++) //控制列输出     drops[n] = 1; //draw
 function draw(){
     ctx.fillStyle = "rgba(0,0,0,0.05)"; //绘制矩形     ctx.fillRect(0,0,c.width,c.height); //以(0,0)为坐标 画制矩形     
     ctx.fillStyle = "#0F0"; //绿色字体     ctx.font = font_size + "px arial"; //以像素为单位 宋体
          
     for(var i=0; i< drops.length; i++)
     {         var text = chinese[Math.floor(Math.random()*chinese.length)];         // Math.floor 对浮点数向下取整         ctx.fillText(text, i*font_size, drops[i]*font_size);         // 规定在画布上输出的文本 开始绘制文本的x坐标 y坐标
         if(drops[i]*font_size > c.height && Math.random() > 0.975)         // 如果下落的文本大于屏幕高度 或者 随机数大于0.975             drops[i] = 0;         // 重置下落         drops[i]++;         // 继续执行     }
 }
 setInterval(draw,33); //33 执行一次draw()</script>

Copy after login

This article ends here

I always believe that this world is full of beauty and Hope to come on!

The above is the detailed content of HTMLcanvas rectangle shower. For more information, please follow other related articles on the PHP Chinese website!