前端js特效—实现代码雨
程序员文章站
2024-01-03 08:45:40
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参考：https://www.cnblogs.com/myvin/p/4775152.html
有改动
彩色代码雨
<html lang="en"> <head> <meta charset="UTF-8"> <title>The Matrix for Practice</title> <style type="text/css"> *{margin: 0 auto;padding: 0 auto;} body{background: black;overflow: hidden;} h1{text-align: center;color: green;text-transform: uppercase;} </style> </head> <body> <h1>the matrix</h1> <canvas id="matrix"></canvas> <script type="text/javascript"> var matrix=document.getElementById("matrix"); var context=matrix.getContext("2d"); matrix.height=window.innerHeight; matrix.width=window.innerWidth; var drop=[]; var font_size=16; var columns=matrix.width/font_size; for(var i=0;i<columns;i++) drop[i]=1; function get_random_color(){ var color="#"; for(var i=0;i<6;i++){ color += (Math.random()*16 | 0).toString(16); } return color; } function drawMatrix(){ context.fillStyle="rgba(0, 0, 0, 0.1)"; context.fillRect(0,0,matrix.width,matrix.height); context.fillStyle=get_random_color(); //颜色变化在这里 context.font=font_size+"px"; for(var i=0;i<columns;i++){ context.fillText(Math.floor(Math.random()*2),i*font_size,drop[i]*font_size);/*get 0 and 1*/ if(drop[i]*font_size>(matrix.height*2/3)&&Math.random()>0.85)/*reset*/ drop[i]=0; drop[i]++; } } setInterval(drawMatrix,40); </script> </body> </html>
纯绿色代码雨
<html lang="en"> <head> <meta charset="UTF-8"> <title>The Matrix for Practice</title> <style type="text/css"> *{margin: 0 auto;padding: 0 auto;} body{background: black;overflow: hidden;} h1{text-align: center;color: green;text-transform: uppercase;} </style> </head> <body> <h1>the matrix</h1> <canvas id="matrix"></canvas> <script type="text/javascript"> var matrix=document.getElementById("matrix"); var context=matrix.getContext("2d"); matrix.height=window.innerHeight; matrix.width=window.innerWidth; var drop=[]; var font_size=16; var columns=matrix.width/font_size; for(var i=0;i<columns;i++) drop[i]=1; function drawMatrix(){ context.fillStyle="rgba(0, 0, 0, 0.1)"; context.fillRect(0,0,matrix.width,matrix.height); context.fillStyle="green"; context.font=font_size+"px"; for(var i=0;i<columns;i++){ context.fillText(Math.floor(Math.random()*2),i*font_size,drop[i]*font_size);/*get 0 and 1*/ if(drop[i]*font_size>(matrix.height*2/3)&&Math.random()>0.85)/*reset*/ drop[i]=0; drop[i]++; } } setInterval(drawMatrix,40); </script> </body> </html>
显示特定文字
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>Document</title> <style> * { padding: 0; margin: 0; } body { overflow: hidden; } </style> </head> <body> <canvas id="mom" style="background-image: linear-gradient(red,green,yellow)"></canvas> <script> //获取画布对象 var canvas = document.getElementById("mom"); //获取画布的上下文 //getContext() 方法返回一个用于在画布上绘图的环境。 var context = canvas.getContext("2d"); //获取浏览器屏幕的宽度和高度 var W = window.innerWidth; var H = window.innerHeight; //设置canvas的宽度和高度 canvas.width = W; canvas.height = H; //每个文字的字体大小 var fontSize = 16; //计算列 var colunms = Math.floor(W / fontSize); //记录每列文字的y轴坐标 var drops = []; //给每一个文字初始化一个起始点的位置 //计算每一个文字所谓坐标 存储y轴的坐标 for (var i = 0; i < colunms; i++) { drops[i] = 1; } //运动的文字JavaScript function(){} var str = "hxx"; //4:fillText(str,x,y);原理就是去更改y的坐标位置 //绘画的函数 function draw() { context.fillStyle = "rgba(0,0,0,0.05)"; //fillRect() 方法绘制“已填色”的矩形。默认的填充颜色是黑色。 context.fillRect(0, 0, W, H); //给字体设置样式 context.font = "700 " + fontSize + "px 微软雅黑"; //给字体添加颜色 context.fillStyle = "#00cc33";//可以rgb,hsl, 标准色，十六进制颜色 //写入画布中 for (var i = 0; i < colunms; i++) { var index = Math.floor(Math.random() * str.length);//设置文字出发时间随机 Math.floor(Math.random()*str.length)让数组里面的文字索引随机出现 var x = i * fontSize; var y = drops[i] * fontSize;//也让y轴方向也向下掉一个文字的距离 context.fillText(str[index], x, y); // //如果要改变时间，肯定就是改变每次他的起点 if (y >= canvas.height && Math.random() > 0.99) { drops[i] = 0; } drops[i]++;//让数组里面的值每次加一，用于上面的y轴下掉 } }; function randColor() { var r = Math.floor(Math.random() * 256); var g = Math.floor(Math.random() * 256); var b = Math.floor(Math.random() * 256); return "rgb(" + r + "," + g + "," + b + ")"; } draw(); setInterval(draw, 20); </script> </body> </html>