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| "use strict";
var Clock = (function () {
let clock = {
now: new Date(),
hr: 0,
minu: 0,
sec: 0
}
// 初始化钟表对象
function init(el) {
clock.canvas = document.querySelector(el)
clock.ctx = clock.canvas.getContext('2d')
clock.canvas.width = clock.canvas.height = 400
clock.ctx.translate(clock.canvas.width / 2, clock.canvas.width / 2)
}
// 画指针的方法
function _pointer(length, width, base, num) {
clock.ctx.beginPath()
clock.ctx.moveTo(0, 0)
clock.ctx.lineTo(length * Math.sin(2 * Math.PI * num / base), -length * Math.cos(2 * Math.PI * num / base))
clock.ctx.lineWidth = width
clock.ctx.stroke()
}
function Hour(hr) {
_pointer(80, 5.5, 12, hr)
}
function Minu(minu) {
_pointer(110, 2.5, 60, minu)
}
function Sec(sec) {
_pointer(150, 1.5, 60, sec)
}
// 更新时间
function update() {
clock.now = new Date()
clock.hr = clock.now.getHours()
clock.minu = clock.now.getMinutes()
clock.sec = clock.now.getSeconds()
// 中点
clock.ctx.beginPath()
clock.ctx.arc(0, 0, 5, 0, 2 * Math.PI)
clock.ctx.fill()
// 表盘
clock.ctx.beginPath()
clock.ctx.arc(0, 0, 180, 0, 2 * Math.PI)
clock.ctx.lineWidth = "7"
clock.ctx.stroke()
// 画刻度
clock.ctx.beginPath()
for (let i = 0; i < 12; i++) {
let angle = Math.PI * i / 6
clock.ctx.moveTo(180 * Math.sin(angle), 180 * Math.cos(angle))
clock.ctx.lineTo(160 * Math.sin(angle), 160 * Math.cos(angle))
}
clock.ctx.lineWidth = "1.5"
clock.ctx.stroke()
// 执行函数
Hour(clock.hr)
Minu(clock.minu)
Sec(clock.sec)
}
// 循环动画
function loop() {
clock.ctx.clearRect(-1 / 2 * clock.canvas.width, -1 / 2 * clock.canvas.height, clock.canvas.width, clock.canvas.height)
update()
window.requestAnimationFrame(loop.bind(this));
}
return { init, loop }
})();
|
