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canvas效果

知识库编程技巧CSSSJavaScript大约 2 分钟

时钟

[vanilla]
<html>
<div><canvas id="drawing" style="margin: auto;display: block;"></canvas></div>
</html>
<script>
var drawing=document.getElementById('drawing');if(drawing.getContext){var cxt=drawing.getContext('2d');var W=drawing.width=200;var H=drawing.height=200;var R=W/2;var cw=cxt.lineWidth=0.1*R;function drawStatics(){cxt.save();cxt.translate(R,R);cxt.beginPath();cxt.lineWidth=0.1*R;cxt.arc(0,0,R-cw/2,0,2*Math.PI,false);cxt.stroke();cxt.beginPath();cxt.font=0.2*R+'px 宋体';cxt.textAlign='center';cxt.textBaseline='middle';var r1=0.8*R-cw/2;for(var i=12;i>0;i--){var radius=2*Math.PI/12*i+1.5*Math.PI;var x=Math.cos(radius)*r1;var y=Math.sin(radius)*r1;cxt.fillText(i,x,y)}cxt.beginPath();var r2=0.9*R-cw/2;for(var i=0;i<60;i++){var radius=2*Math.PI/60*i+1.5*Math.PI;var x=Math.cos(radius)*r2;var y=Math.sin(radius)*r2;cxt.beginPath();if(i%5===0){cxt.arc(x,y,cw/5,0,2*Math.PI,false)}else{cxt.arc(x,y,cw/8,0,2*Math.PI,false)}cxt.fill()}cxt.restore()}function drawDot(){cxt.save();cxt.translate(R,R);cxt.beginPath();cxt.arc(0,0,cw/3,0,2*Math.PI,false);cxt.fillStyle='#fff';cxt.fill();cxt.restore()}function drawSecond(second){cxt.save();cxt.translate(R,R);cxt.beginPath();var radius=2*Math.PI/60*second;cxt.rotate(radius);cxt.lineWidth=2;cxt.moveTo(0,cw*2);cxt.lineTo(0,-0.8*R);cxt.strokeStyle='red';cxt.stroke();cxt.restore()}function drawMinute(minute,second){cxt.save();cxt.translate(R,R);cxt.beginPath();var radius=2*Math.PI/60*minute;var sRaiuds=2*Math.PI/60/60*second;cxt.rotate(radius+sRaiuds);cxt.lineWidth=4;cxt.lineCap='round';cxt.moveTo(0,cw);cxt.lineTo(0,-(0.8*R-cw/2));cxt.stroke();cxt.restore()}function drawHour(hour,minute){cxt.save();cxt.translate(R,R);cxt.beginPath();var radius=2*Math.PI/12*hour;var mRaiuds=2*Math.PI/12/60*minute;cxt.rotate(radius+mRaiuds);cxt.lineWidth=6;cxt.lineCap='round';cxt.moveTo(0,cw/2);cxt.lineTo(0,-(0.8*R-cw*2));cxt.stroke();cxt.restore()}function draw(){cxt.clearRect(0,0,W,H);drawStatics();var now=new Date();drawHour(now.getHours(),now.getMinutes());drawMinute(now.getMinutes(),now.getSeconds());drawSecond(now.getSeconds());drawDot()}draw();setInterval(draw,500)}
</script>

玫瑰花

[vanilla]
<html>
<div><canvas id="canvas-rose" style="margin: auto;display: block;"></canvas></div>
</html>
<script>
var c=document.getElementById('canvas-rose');
var b=c.parentElement;var a=c.getContext('2d');
with(m=Math)C=cos,S=sin,P=pow,R=random;c.width=c.height=f=600;h=-250;
function p(a,b,c){if(c>60)return[S(a*7)*(13+5/(.2+P(b*4,4)))-S(b)*50,b*f+50,625+C(a*7)*(13+5/(.2+P(b*4,4)))+b*400,a*1-b/2,a];A=a*2-1;B=b*2-1;if(A*A+B*B<1){if(c>37){n=(j=c&1)?6:4;o=.5/(a+.01)+C(b*125)*3-a*300;w=b*h;return[o*C(n)+w*S(n)+j*610-390,o*S(n)-w*C(n)+550-j*350,1180+C(B+A)*99-j*300,.4-a*.1+P(1-B*B,-h*6)*.15-a*b*.4+C(a+b)/5+P(C((o*(a+1)+(B>0?w:-w))/25),30)*.1*(1-B*B),o/1e3+.7-o*w*3e-6]}if(c>32){c=c*1.16-.15;o=a*45-20;w=b*b*h;z=o*S(c)+w*C(c)+620;return[o*C(c)-w*S(c),28+C(B*.5)*99-b*b*b*60-z/2-h,z,(b*b*.3+P((1-(A*A)),7)*.15+.3)*b,b*.7]}o=A*(2-b)*(80-c*2);w=99-C(A)*120-C(b)*(-h-c*4.9)+C(P(1-b,7))*50+c*2;z=o*S(c)+w*C(c)+700;return[o*C(c)-w*S(c),B*99-C(P(b,7))*50-c/3-z/1.35+450,z,(1-b/1.2)*.9+a*.1,P((1-b),20)/4+.05]}};
setInterval(function(){for(i=0;i<1e4;i++){if(s=p(R(),R(),i%46/.74)){z=s[2];x=~~(s[0]*f/z-h);y=~~(s[1]*f/z-h);if(!m[q=y*f+x]|m[q]>z)m[q]=z,a.fillStyle="rgb("+~(s[3]*h)+","+~(s[4]*h)+","+~(s[3]*s[3]*-80)+")",a.fillRect(x,y,1,1)}}});
</script>