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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>
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>
<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>
This article ends here
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