canvas 實現簡單的圖像擴散
<!DOCTYPE HTML>
<html>
<body>
<canvas id="myCanvas" width="800" height="800" style="border:1px solid #c3c3c3;">
Your browser does not support the canvas element.
</canvas>
<script type="text/javascript">
var c=document.getElementById("myCanvas");
var cxt=c.getContext("2d");
var x1=200,x2=400,x3=600,y1=400,y2=400,y3=400,lr1=10,lr2=10,lr3=10;
var lc1="#EE7942";lc2="#EE2C2C";lc3="#CD6839";
var lr1,lr2,lr3;
drawarc(15,"#CAE1FF",1);
drawarc(25,"#98FB98",2);
drawarc(25,"#757575",3);
drawarc(30,"#000000",1);
drawarc(35,"#32CD32",2);
drawarc(50,"#6959CD",3);
drawarc(45,"red",1);
drawarc(50,"#fff",2);
drawarc(65,"#000",3);
function drawarc(radiu,ecolor,type){
var grd;
var x,y,r;
var scolor;
switch(type){
case 1:
x=x1;
y=y1;
r=lr1;
lr1=radiu;
scolor=lc1;
break;
case 2:
x=x2;
y=y2;
r=lr2;
lr2=radiu;
scolor=lc2;
break;
case 3:
x=x3;
y=y3;
r=lr3;
lr3=radiu;
scolor=lc3;
break;
default:
}
grd=cxt.createRadialGradient(x,y,r,x,y,radiu);
grd.addColorStop(0,scolor);
grd.addColorStop(1,ecolor);
cxt.fillStyle=grd;
cxt.beginPath();
cxt.arc(x,y,radiu,0,360,false);
cxt.closePath();
cxt.fill();
}
</script>
</body>
</html>
