canvas时钟效果
作者：59580
本文主要介绍了canvas实现时钟效果的代码。具有很好的参考价值，下面跟着小编一起来看下吧
效果如下：
代码如下：
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>canvas时钟</title>
<style type="text/css">
*{
margin: 0;
padding: 0;
}
</style>
<script>
window.onload = function(){
var WINDOW_WIDTH = document.body.scrollWidth;
var WINDOW_HEIGHT = document.body.scrollHeight-10;
var RADIUS = 7; //球半径
var NUMBER_GAP = 10; //数字之间的间隙
var u = 0.65; //碰撞能量损耗系数
var context; //Canvas绘制上下文
var balls = []; //存储彩色的小球
const colors = ["#33B5E5", "#0099CC", "#AA66CC", "#9933CC", "#99CC00", "#669900", "#FFBB33", "#FF8800", "#FF4444", "#CC0000"]; //彩色小球的颜色
var currentNums = []; //屏幕显示的8个字符
var digit = [
[
[0, 0, 1, 1, 1, 0, 0],
[0, 1, 1, 0, 1, 1, 0],
[1, 1, 0, 0, 0, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[0, 1, 1, 0, 1, 1, 0],
[0, 0, 1, 1, 1, 0, 0]
], //0
[
[0, 0, 0, 1, 1, 0, 0],
[0, 1, 1, 1, 1, 0, 0],
[0, 0, 0, 1, 1, 0, 0],
[0, 0, 0, 1, 1, 0, 0],
[0, 0, 0, 1, 1, 0, 0],
[0, 0, 0, 1, 1, 0, 0],
[0, 0, 0, 1, 1, 0, 0],
[0, 0, 0, 1, 1, 0, 0],
[0, 0, 0, 1, 1, 0, 0],
[1, 1, 1, 1, 1, 1, 1]
], //1
[
[0, 1, 1, 1, 1, 1, 0],
[1, 1, 0, 0, 0, 1, 1],
[0, 0, 0, 0, 0, 1, 1],
[0, 0, 0, 0, 1, 1, 0],
[0, 0, 0, 1, 1, 0, 0],
[0, 0, 1, 1, 0, 0, 0],
[0, 1, 1, 0, 0, 0, 0],
[1, 1, 0, 0, 0, 0, 0],
[1, 1, 0, 0, 0, 1, 1],
[1, 1, 1, 1, 1, 1, 1]
], //2
[
[1, 1, 1, 1, 1, 1, 1],
[0, 0, 0, 0, 0, 1, 1],
[0, 0, 0, 0, 1, 1, 0],
[0, 0, 0, 1, 1, 0, 0],
[0, 0, 1, 1, 1, 0, 0],
[0, 0, 0, 0, 1, 1, 0],
[0, 0, 0, 0, 0, 1, 1],
[0, 0, 0, 0, 0, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[0, 1, 1, 1, 1, 1, 0]
], //3
[
[0, 0, 0, 0, 1, 1, 0],
[0, 0, 0, 1, 1, 1, 0],
[0, 0, 1, 1, 1, 1, 0],
[0, 1, 1, 0, 1, 1, 0],
[1, 1, 0, 0, 1, 1, 0],
[1, 1, 1, 1, 1, 1, 1],
[0, 0, 0, 0, 1, 1, 0],
[0, 0, 0, 0, 1, 1, 0],
[0, 0, 0, 0, 1, 1, 0],
[0, 0, 0, 1, 1, 1, 1]
], //4
[
[1, 1, 1, 1, 1, 1, 1],
[1, 1, 0, 0, 0, 0, 0],
[1, 1, 0, 0, 0, 0, 0],
[1, 1, 1, 1, 1, 1, 0],
[0, 0, 0, 0, 0, 1, 1],
[0, 0, 0, 0, 0, 1, 1],
[0, 0, 0, 0, 0, 1, 1],
[0, 0, 0, 0, 0, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[0, 1, 1, 1, 1, 1, 0]
], //5
[
[0, 0, 0, 0, 1, 1, 0],
[0, 0, 1, 1, 0, 0, 0],
[0, 1, 1, 0, 0, 0, 0],
[1, 1, 0, 0, 0, 0, 0],
[1, 1, 0, 1, 1, 1, 0],
[1, 1, 0, 0, 0, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[0, 1, 1, 1, 1, 1, 0]
], //6
[
[1, 1, 1, 1, 1, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[0, 0, 0, 0, 1, 1, 0],
[0, 0, 0, 0, 1, 1, 0],
[0, 0, 0, 1, 1, 0, 0],
[0, 0, 0, 1, 1, 0, 0],
[0, 0, 1, 1, 0, 0, 0],
[0, 0, 1, 1, 0, 0, 0],
[0, 0, 1, 1, 0, 0, 0],
[0, 0, 1, 1, 0, 0, 0]
], //7
[
[0, 1, 1, 1, 1, 1, 0],
[1, 1, 0, 0, 0, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[0, 1, 1, 1, 1, 1, 0],
[1, 1, 0, 0, 0, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[0, 1, 1, 1, 1, 1, 0]
], //8
[
[0, 1, 1, 1, 1, 1, 0],
[1, 1, 0, 0, 0, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[1, 1, 0, 0, 0, 1, 1],
[0, 1, 1, 1, 0, 1, 1],
[0, 0, 0, 0, 0, 1, 1],
[0, 0, 0, 0, 0, 1, 1],
[0, 0, 0, 0, 1, 1, 0],
[0, 0, 0, 1, 1, 0, 0],
[0, 1, 1, 0, 0, 0, 0]
], //9
[
[0, 0, 0, 0],
[0, 0, 0, 0],
[0, 1, 1, 0],
[0, 1, 1, 0],
[0, 0, 0, 0],
[0, 0, 0, 0],
[0, 1, 1, 0],
[0, 1, 1, 0],
[0, 0, 0, 0],
[0, 0, 0, 0]
] //:
];
function drawDatetime(cxt) {
var nums = [];
var date = new Date();
var hours = date.getHours();
var num1 = Math.floor(hours / 10);
var num2 = hours % 10;
context.fillStyle = colors[(date.getSeconds()%10)];
var offsetX = WINDOW_WIDTH/4,
offsetY = 30;
nums.push({
num: num1
});
nums.push({
num: num2
});
nums.push({
num: 10
}); //冒号
var minutes = date.getMinutes();
var num1 = Math.floor(minutes / 10);
var num2 = minutes % 10;
nums.push({
num: num1
});
nums.push({
num: num2
});
nums.push({
num: 10
}); //冒号
var seconds = date.getSeconds();
var num1 = Math.floor(seconds / 10);
var num2 = seconds % 10;
nums.push({
num: num1
});
nums.push({
num: num2
});
for(var x = 0; x < nums.length; x++) {
nums[x].offsetX = offsetX;
offsetX = drawSingleNumber(offsetX, offsetY, nums[x].num, cxt);
//两个数字连一块，应该间隔一些距离
if(x < nums.length - 1) {
if((nums[x].num != 10) && (nums[x + 1].num != 10)) {
offsetX += NUMBER_GAP;
}
}
}
//说明这是初始化
if(currentNums.length == 0) {
currentNums = nums;
} else {
//进行比较
for(var index = 0; index < currentNums.length; index++) {
if(currentNums[index].num != nums[index].num) {
//不一样时，添加彩色小球
addBalls(nums[index]);
currentNums[index].num = nums[index].num;
}
}
}
renderBalls(cxt);
updateBalls();
return date;
}
function addBalls(item) {
var num = item.num;
var numMatrix = digit[num];
for(var y = 0; y < numMatrix.length; y++) {
for(var x = 0; x < numMatrix[y].length; x++) {
if(numMatrix[y][x] == 1) {
var ball = {
offsetX: item.offsetX + RADIUS + RADIUS * 2 * x,
offsetY: 30 + RADIUS + RADIUS * 2 * y,
color: colors[Math.floor(Math.random() * colors.length)],
g: 1.5 + Math.random(),
vx: Math.pow(-1, Math.ceil(Math.random() * 10)) * 4 + Math.random(),
vy: -5
}
balls.push(ball);
}
}
}
}
function renderBalls(cxt) {
for(var index = 0; index < balls.length; index++) {
cxt.beginPath();
cxt.fillStyle = balls[index].color;
cxt.arc(balls[index].offsetX, balls[index].offsetY, RADIUS, 0, 2 * Math.PI);
cxt.fill();
}
}
function updateBalls() {
var i = 0;
for(var index = 0; index < balls.length; index++) {
var ball = balls[index];
ball.offsetX += ball.vx;
ball.offsetY += ball.vy;
ball.vy += ball.g;
if(ball.offsetY > (WINDOW_HEIGHT - RADIUS)) {
ball.offsetY = WINDOW_HEIGHT - RADIUS;
ball.vy = -ball.vy * u;
}
if(ball.offsetX > RADIUS && ball.offsetX < (WINDOW_WIDTH - RADIUS)) {
balls[i] = balls[index];
i++;
}
}
//去除出边界的球
for(; i < balls.length; i++) {
balls.pop();
}
}
function drawSingleNumber(offsetX, offsetY, num, cxt) {
var numMatrix = digit[num];
for(var y = 0; y < numMatrix.length; y++) {
for(var x = 0; x < numMatrix[y].length; x++) {
if(numMatrix[y][x] == 1) {
cxt.beginPath();
cxt.arc(offsetX + RADIUS + RADIUS * 2 * x, offsetY + RADIUS + RADIUS * 2 * y, RADIUS, 0, 2 * Math.PI);
cxt.fill();
}
}
}
cxt.beginPath();
offsetX += numMatrix[0].length * RADIUS * 2;
return offsetX;
}
var canvas = document.getElementById("canvas");
canvas.width = WINDOW_WIDTH;
canvas.height = WINDOW_HEIGHT;
context = canvas.getContext("2d");
//记录当前绘制的时刻
var currentDate = new Date();
setInterval(function() {
//清空整个Canvas，重新绘制内容
context.clearRect(0, 0, context.canvas.width, context.canvas.height);
drawDatetime(context);
}, 50)
}
</script>
</head>
<body>
<canvas id="canvas"></canvas>
</body>
</html>
以上就是本文的全部内容，希望本文的内容对大家的学习或者工作能带来一定的帮助，同时也希望多多支持脚本之家！