canvas小案列-绚丽多彩的倒计时
本次随笔中，我将实现一个绚丽的倒计时效果，这个效果主要是结合canvas和js实现的，具体代码如下
index.html文件
<!DOCTYPE html> <html> <head> </head> <body style="height:100%"> <canvas id="canvas" style="height:100%"> </canvas> <script src="digit.js"></script> <script src="countdown.js"></script> </body> </html>
接着书写digit.js文件，这个文件中主要是一个三维数组，观察可以发现，总共有十个二维数组，分别对应1...9和：
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] ]//: ];
最后实现整个效果的代码书写在countdown.js中
var WINDOW_WIDTH=1024; var WINDOW_HEIGHT=768; var RADIUS=8; var MARGIN_TOP=60; var MARGIN_LEFT=30; var endTime=new Date(); endTime.setTime(endTime.getTime()+3600*1000); var curShowTimeSeconds=0; var balls=[]; const colors=["#33b5E5","#0099cc","#aa66cc","#9933cc","#99cc00","#669900","#FFBB33","#FF8800","#FF4444","#cc0000"]; window.onload=function(){ WINDOW_WIDTH=document.body.clientWidth; WINDOW_HEIGHT=768; MARGIN_LEFT=Math.round(WINDOW_WIDTH/10); RADIUS=Math.round(WINDOW_WIDTH*4/5/108)-1; MARGIN_TOP=Math.round(WINDOW_HEIGHT/5); var canvas=document.getElementById("canvas"); var context=canvas.getContext("2d"); canvas.width=WINDOW_WIDTH;; canvas.height=WINDOW_HEIGHT; curShowTimeSeconds=getCurrentShowTimeSeconds(); setInterval( function(){ render(context); update(); }, 50 ); } function getCurrentShowTimeSeconds(){ var curTime=new Date(); var ret=endTime.getTime()-curTime.getTime(); ret=Math.round(ret/1000); return ret>0? ret:0; } function update(){ var nextShowTimeSeconds=getCurrentShowTimeSeconds(); var nextHours=parseInt(nextShowTimeSeconds/3600); var nextMinutes=parseInt(nextShowTimeSeconds/60%60); var nextSeconds=parseInt(nextShowTimeSeconds%60); var curHours=parseInt(curShowTimeSeconds/3600); var curMinutes=parseInt(curShowTimeSeconds/60%60); var curSeconds=parseInt(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(){ 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; if(balls[i].y>=WINDOW_HEIGHT-RADIUS){ balls[i].y=WINDOW_HEIGHT-RADIUS; balls[i].vy=-balls[i].vy*0.75; } } 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>cnt){ balls.pop(); } } function addBalls(x,y,num){ for(var i=0;i<digit[num].length;i++) for(var j=0;j<digit[num][i].length;j++) 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, vy:-5, color:colors[Math.floor(Math.random()*colors.length)] } balls.push(aBall); } } function render(cxt){ cxt.clearRect(0,0,WINDOW_WIDTH,WINDOW_HEIGHT); var hours=parseInt(curShowTimeSeconds/3600); var minutes=parseInt(curShowTimeSeconds/60%60); var seconds=parseInt(curShowTimeSeconds%60); //var hours=12; //var minutes=34; // var seconds=56; 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); 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 ++ ) for(var j = 0 ; j < digit[num][i].length ; j ++ ) 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() } }
大家赶快来试验一下吧！
