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canvas基础绘制-绚丽倒计时的实例

程序员文章站 2022-09-08 13:49:45
效果图： html：

效果图：

canvas基础绘制-绚丽倒计时的实例

html：

<!doctype html>
<html lang="en">
<head>
 <meta charset="utf-8">
 <title>ball</title>
 <script src="digit_1.js"></script>
 <script src="countdown.js"></script>
</head>
<body >
<canvas id="canvas" ></canvas>
</body>
</html>

digit_1.js在之前的 canvas基础绘制-倒计时 中有贴

countdown.js:

var window_width = 1024;
var window_height = 768;
var radius = 8;
var margin_top = 60;
var margin_left = 30;

var endtime = new date();//const声明变量，不可修改，必须声明时赋值；
endtime.settime( endtime.gettime() + 3600*1000);//当前时间向后一小时；
var curshowtimeseconds = 0;

var balls =[];
const colors = ["#33b5e5","#0099cc","#aa66cc","#9933cc","#99cc00","#669900","#ffbb33","#ff8800","#ff4444","#cc0000"];

window.onload = function () {
 //屏幕自适应
 window_width = document.body.clientwidth;
 window_height = document.body.clientheight;

 radius = math.round(window_width*4/5/108)-1;

 margin_top = math.round(window_height/5);
 margin_left = math.round(window_width/10);

 var canvas = document.getelementbyid("canvas");
 var context = canvas.getcontext("2d");

 canvas.width = window_width;
 canvas.height = window_height;

 curshowtimeseconds = getcurrentshowtimeseconds();
 setinterval(
  function () {
   update();
   render(context);
 },50)

};

function getcurrentshowtimeseconds() {
 var curtime = new date();//获取目前时间；
 var ret = endtime.gettime()-curtime.gettime();
 ret = math.round(ret/1000);//获取秒数差值；
 return ret>=0?ret:0;
}
function update() {

 var nextshowtimeseconds = getcurrentshowtimeseconds();

 var nexthours = parseint(nextshowtimeseconds/3600);
 var nextminutes = parseint((nextshowtimeseconds-nexthours*3600)/60);
 var nextseconds = nextshowtimeseconds%60;

 var curhours = parseint(curshowtimeseconds/3600);
 var curminutes = parseint((curshowtimeseconds-curhours*3600)/60);
 var curseconds = curshowtimeseconds%60;

 if(nextseconds!=curseconds){
  if(parseint(curhours/10)!=parseint(nexthours/10)){
   addballs(margin_left+0,margin_top,parseint(curhours/10));
  }
  if(parseint(curhours%10)!=parseint(nexthours%10)){
   addballs(margin_left+15*(radius+1),margin_top,parseint(curhours%10));
  }

  if(parseint(curminutes/10)!=parseint(nextminutes/10)){
   addballs(margin_left+39*(radius+1),margin_top,parseint(curminutes/10));
  }
  if(parseint(curminutes%10)!=parseint(nextminutes%10)){
   addballs(margin_left+54*(radius+1),margin_top,parseint(curminutes%10));
  }

  if(parseint(curseconds/10)!=parseint(nextseconds/10)){
   addballs(margin_left+78*(radius+1),margin_top,parseint(curseconds/10));
  }
  if(parseint(curseconds%10)!=parseint(nextseconds%10)){
   addballs(margin_left+93*(radius+1),margin_top,parseint(curseconds%10));
  }

  curshowtimeseconds = nextshowtimeseconds;
 }
 
 updateballs();
}
function updateballs() {

 //循环遍历每一个彩色动画小球
 for(var i=0;i<balls.length;i++){
  balls[i].x+=balls[i].vx;
  balls[i].y+=balls[i].vy;
  balls[i].vy+=balls[i].g;
  //落到画布最底部时反弹起来
  if(balls[i].y>=window_height){
   balls[i].y = window_height-radius;
   balls[i].vy = -balls[i].vy*0.75;
  }
 }

 // 如果小球出了画布，就清除小球,性能优化
 var cnt = 0;
 for(var i=0;i<balls.length;i++){
  if(balls[i].x-radius>0&&balls[i].x+radius<window_width){
   balls[cnt++] = balls[i];
  }
 }

 while (balls.length>math.min(300,cnt)){
  balls.pop();
 }
}
function addballs(x,y,num) {


 for (var i = 0; i < digit[num].length; i++) {//数组行
  for (var j = 0; j < digit[num][i].length; j++) {//数组列
   if (digit[num][i][j] == 1) {
    var aball = {
     x: x + j * 2 * (radius + 1) + (radius + 1),
     y: y + i * 2 * (radius + 1) + (radius + 1),
     g: 1.5 + math.random(),
     vx: math.pow(-1, math.ceil(math.random() * 1000)) * 4,//pow(x,y),x 的 y 次幂;ceil()可对一个数进行上舍入;
     vy: -5,
     color: colors[math.floor(math.random() * colors.length)]//floor()对一个数进行下舍入
    };
    balls.push(aball);
   }
  }
 }
}
function render(cxt) {
 //每一帧都要对动画进行刷新，不然就会新的旧的叠在一起；
 cxt.clearrect(0,0,window_width,window_height);//对一个矩形空间里的动画进行刷新；
 //倒计时的时间绘制
 var hours = parseint(curshowtimeseconds/3600);
 var minutes = parseint((curshowtimeseconds-hours*3600)/60);
 var seconds = curshowtimeseconds%60;

 renderdigit(margin_left,margin_top,parseint(hours/10),cxt);
 renderdigit(margin_left+15*(radius+1),margin_top,parseint(hours%10),cxt);
 renderdigit(margin_left+30*(radius+1),margin_top,10,cxt);
 renderdigit(margin_left+39*(radius+1),margin_top,parseint(minutes/10),cxt);
 renderdigit(margin_left+54*(radius+1),margin_top,parseint(minutes%10),cxt);
 renderdigit(margin_left+69*(radius+1),margin_top,10,cxt);
 renderdigit(margin_left+78*(radius+1),margin_top,parseint(seconds/10),cxt);
 renderdigit(margin_left+93*(radius+1),margin_top,parseint(seconds%10),cxt);
 //彩色动画小球的绘制
 for(var i=0;i<balls.length;i++){
  cxt.fillstyle = balls[i].color;

  cxt.beginpath();
  cxt.arc(balls[i].x,balls[i].y,radius,0,2*math.pi,true);
  cxt.closepath();

  cxt.fill();
 }
}

function renderdigit(x,y,num,cxt) {

 cxt.fillstyle = "rgb(0,102,153)";

 for (var i = 0; i < digit[num].length; i++) {//数组行
  for (var j = 0; j < digit[num][i].length; j++) {//数组列
   if (digit[num][i][j] == 1) {
    cxt.beginpath();
    cxt.arc(x + j * 2 * (radius + 1) + (radius + 1), y + i * 2 * (radius + 1) + (radius + 1), radius, 0, 2 * math.pi);
    cxt.closepath();

    cxt.fill();
   }
  }
 }
}

以上这篇canvas基础绘制-绚丽倒计时的实例就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持。

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