效果圖：
20200319.gif
參數(shù)配置：
background: rgb(0, 0, 0); //背景色
var text_arr = ['page', 'Not Found', '404', '找不到頁(yè)面'];//顯示文字
var text_num = 50; //頁(yè)面要顯示的文字個(gè)數(shù)
var word_arr = []; //儲(chǔ)存文字坐標(biāo)等屬性的數(shù)組
var txt_min_size = 10; //文字最小大小
var txt_max_size = 50; //文字最大大小
var keypress = false; //默認(rèn)鍵盤(pán)未點(diǎn)擊狀態(tài)，點(diǎn)擊鍵盤(pán)實(shí)現(xiàn)加速效果
var acclerate = 3; //點(diǎn)擊鍵盤(pán)加速速率
代碼如下：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
body {
margin: 0;
padding: 0;
overflow: hidden;
}
canvas {
display: block;
background: rgb(0, 0, 0);
}
</style>
</head>
<body>
<canvas id="canvas"></canvas>
</body>
<script>
var w = window.innerWidth;
var h = window.innerHeight;
var canvas = document.getElementById("canvas");
canvas.width = w;
canvas.height = h;
var ctx = canvas.getContext("2d");
var text_arr = ['page', 'Not Found', '404', '找不到頁(yè)面'];//顯示文字
var text_num = 50; //頁(yè)面要顯示的文字個(gè)數(shù)
var word_arr = []; //儲(chǔ)存文字坐標(biāo)等屬性的數(shù)組
var txt_min_size = 10; //文字最小大小
var txt_max_size = 50; //文字最大大小
var keypress = false; //默認(rèn)鍵盤(pán)未點(diǎn)擊狀態(tài)蹦掐，點(diǎn)擊鍵盤(pán)實(shí)現(xiàn)加速效果
var acclerate = 3; //點(diǎn)擊鍵盤(pán)加速速率
window.addEventListener('keydown', function () {
keypress = true;
}, true);
window.addEventListener('keyup', function () {
keypress = false;
}, true);
//生成一個(gè)隨機(jī)隨
function random(min, max) {
return Math.random() * (max - min + 1) + min;
}
//實(shí)現(xiàn)不同大小文字的移動(dòng)速度不同
//out_min 最小速度
//out_max 最大速度
function range_map(value, in_min, in_max, out_min, out_max) {
return (value - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}
// 返回一個(gè)數(shù)的平方根
function distance(x, y, x1, y1) {
// sqrt() 方法可返回一個(gè)數(shù)的平方根。
// a2 + b2 = c2
return Math.sqrt((x1 - x) * (x1 - x) + (y1 - y) * (y1 - y));
}
//儲(chǔ)存文字坐標(biāo)位置
function saveText() {
for (let i = 0; i < text_num; i++) {
let t = {
x: random(0, w),
y: random(0, h),
text: text_arr[~~random(0, text_arr.length)],
size: ~~random(txt_min_size, txt_max_size)
}
word_arr.push(t)
}
console.log(word_arr)
}
//在canvas繪制文字移動(dòng)效果
function draw() {
ctx.clearRect(0, 0, w, h);
ctx.fillStyle = "#fff";
for (let i = 0; i < word_arr.length; i++) {
//文字大小卧抗，樣式
ctx.font = word_arr[i].size + "px sans-serif";
//文字寬度
var t_w = ctx.measureText(word_arr[i].text);
ctx.fillText(word_arr[i].text, word_arr[i].x, word_arr[i].y);
if (keypress) {
word_arr[i].x += range_map(word_arr[i].size, txt_min_size, txt_max_size, 2, 4) * acclerate;
} else {
word_arr[i].x += range_map(word_arr[i].size, txt_min_size, txt_max_size, 2, 3);
}
//如果大于窗口寬度，那么重新返回社裆，并且隨機(jī)y軸位置和大小
if (word_arr[i].x >= w) {
word_arr[i].x = -t_w.width * 5;
word_arr[i].y = random(0, h);
word_arr[i].size = ~~random(txt_min_size, txt_max_size);
}
}
ctx.fill()
window.requestAnimationFrame(draw)
}
saveText()
draw()
</script>
</html>
