JS+canvas画一个圆锥实例代码

以下是我们给大家分享是实例代码:

<html>
<head>
<title>我的第一个 HTML 页面</title>
</head>
<body>
<canvas id=\'cvs\' width=\'1000\' height=\"800\">
</canvas>
<script>
const cvs =document.getElementById(\'cvs\');

 // 计算画布的宽度
  const width = cvs.offsetWidth;
  // 计算画布的高度
 const  height = cvs.offsetHeight;
const ctx = cvs.getContext(\'2d\');
  // 设置宽高
  cvs.width = width;
  cvs.height = height;
/**
ctx:context
x,y:偏移 纵横坐标
w:度
h:高
color:颜色 数组,可以把颜色提取出来方便自定义
*/
var Cone = function(ctx,x,y,w,h,d,color){
ctx.save();
ctx.translate(x, y);
var blockHeight=h;
// 中点
var x2 = 0;
var y2 = 20;
var k2 = 10;
var w2 = w;
var h2 = h;
// 递减度
var decrease = d; 
 ctx.beginPath();
ctx.moveTo(x2+w2,y2);
// 椭圆加了边框,所以加1减1
ctx.bezierCurveTo(x2+w2, y2+k2, x2-w2, y2+k2, x2-w2-1, y2);

ctx.lineTo(x2-w2+decrease,y2+blockHeight);
ctx.bezierCurveTo(x2-w2+decrease, y2+blockHeight+k2, x2+w2-decrease, y2+blockHeight+k2, x2+w2-decrease, y2+blockHeight);
ctx.lineTo(x2+w2+1,y2);
var linear = ctx.createLinearGradient(x2-w2, y2,x2+w2-decrease, y2+blockHeight);
linear.addColorStop(0,color[0]);
linear.addColorStop(1,color[1]);
ctx.fillStyle = linear ; 
ctx.strokeStyle=linear 
ctx.fill();
//ctx.stroke();
ctx.closePath();
//画椭圆
ctx.beginPath();
ctx.moveTo(x2-w2, y2);
ctx.bezierCurveTo(x2-w2, y2-k2, x2+w2, y2-k2, x2+w2, y2);
ctx.bezierCurveTo(x2+w2, y2+k2, x2-w2, y2+k2, x2-w2, y2);
var linear = ctx.createLinearGradient(x2-w2, y2,x2+w2-decrease, y2+blockHeight);
linear.addColorStop(1,color[0]);
linear.addColorStop(0,color[1]);
ctx.fillStyle = linear ; 
ctx.strokeStyle=linear 
ctx.closePath();

ctx.fill();
ctx.stroke();

ctx.restore();
};
function dr(m){
const colorList =[
{
color:[\'#76e3ff\',\'#2895ea\'],
height:60
},
{
color:[\'#17ead9\',\'#5d7ce9\'],
height:30
},
{
color:[\'#1ca5e5\',\'#d381ff\'],
height:40
},
{
color:[\'#ffa867\',\'#ff599e\'],
height:70
},
{
color:[\'#ffa6e3\',\'#ec6a70\'],
height:50
},
{
color:[\'#f9c298\',\'#d9436a\'],
height:30
},
{
color:[\'#eb767b\',\'#9971dc\'],
height:30
},
{
color:[\'#f06af9\',\'#5983ff\'],
height:100
},
];
const space = 20;
let coneHeight = 0;
// 间隔
const gap = 20;
const x = 380;
const y = 20;
const angle = 30;
let coneWidth=0;
colorList.forEach((item)=>{
coneHeight += item.height +space;
});
// 最下面的先画(层级)
colorList.reverse().forEach((item,index)=>{
const decrease =Math.tan(Math.PI*angle/180)*(item.height+space);
coneWidth=coneWidth + decrease;
coneHeight = coneHeight-item.height - space;
//圆锥
Cone(ctx,x,coneHeight ,coneWidth ,item.height,decrease,item.color);
// 中点
const cX =parseInt(x)+0.5;
const cY = parseInt(coneHeight + space+ item.height/2)+0.5;
//文字
ctx.save();
ctx.translate(cX , cY );
ctx.textBaseline=\'top\';
ctx.textAlign=\'center\';
const fontSize = item.height/2>=40?40:item.height/2;
ctx.font = fontSize + \'px serif\';
//const textMetrics = ctx.measureText(\'Hello World\');
ctx.fillStyle = \'#ffffff\';
ctx.fillText(\'5000\',0,-fontSize/3);
ctx.restore();
const xLineA =parseInt(coneWidth-decrease/2)+10;
const xLine =parseInt(m+xLineA )>=x?x:m+xLineA ;
//线
ctx.save();
ctx.translate(cX , cY );
ctx.setLineDash([3,2]); 
ctx.strokeStyle = \'#a4a4a4\'; 
ctx.beginPath(); 
ctx.moveTo(xLineA , 0); 
ctx.lineTo(xLine +20, 0); 
ctx.stroke();
ctx.restore();
//描述文字
ctx.save();
ctx.translate(cX , cY );
ctx.textBaseline=\'middle\';
ctx.textAlign=\'left\';
ctx.font = \'22px serif\';
//const textMetrics = ctx.measureText(\'Hello World\');
ctx.fillStyle = \'#4a4a4a\';
ctx.fillText(\'进入收件列表2\',xLine+gap ,0);
ctx.restore();
//转化率文字
ctx.save();
ctx.translate(cX , cY );
ctx.textBaseline=\'middle\';
ctx.textAlign=\'left\';
ctx.font = \'28px bold serif \';
ctx.fillStyle = \'#007dfd\';
ctx.fillText(\'20%\',xLine+gap ,(item.height+gap)/2 );
ctx.restore();
});
}
let m=0;  
let gravity =10;   
(function drawFrame(){
      window.requestAnimationFrame(drawFrame,cvs);
      ctx.clearRect(0,0,cvs.width,cvs.height);
m += gravity;
      dr(m);
})();
</script>
</body>
</html>

这是测试后的完成图:

JS+canvas画一个圆锥实例代码

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