Question

椭圆

我们可以通过实例化一个 McDbEllipse() 对象创建椭圆。通过设置 McDbEllipse() 实例对象的圆心 center 、主轴向量 majorAxis、副轴向量 minorAxis 或短轴与长轴的比例 radiusRatio 绘制椭圆，也可以通过设置实例对象的开始角度 startAngle 和结束角度 endAngle 绘制椭圆弧。

此外，还可以通过 mxcad 实例对象提供的 drawEllipse() 方法直接绘制椭圆，drawEllipseArc() 方法直接绘制椭圆弧。

点击 McDbEllipse() 查看详细属性和方法说明。

点击 drawEllipse()、drawEllipseArc() 查看详细属性和方法说明。

import { MxCpp, McGePoint3d, McDbEllipse, McCmColor, McGeVector3d } from "mxcad"

const mxcad = MxCpp.getCurrentMxCAD()
const ellipse = new McDbEllipse()
ellipse.center = new McGePoint3d(-200, -200),
ellipse.majorAxis = new McGeVector3d(0, 300, 0)
ellipse.minorAxis = new McGeVector3d(33, 0, 0)
ellipse.radiusRatio = 0.5
ellipse.startAngle = Math.PI / 2
ellipse.endAngle = Math.PI * 3 / 2
ellipse.trueColor = new McCmColor(255, 233, 0)
mxcad.drawEntity(ellipse)

mxcad.drawEllipse(0, -200, 200, 0, 1.5)

mxcad.drawEllipseArc(200, -200, 200, 0, 1.5, 100, 650)

:::demo

import {  McObject, McDbEllipse, McGePoint3d, McCmColor, McGeVector3d } from "mxcad"

export default () => {
    const mxcad = new McObject()
    mxcad.create({
      canvas: "#myCanvas",
      locateFile: (fileName: string)=> {
            // CDN 加载必须使用wasm/2d-st中的资源、因为github的限制无法使用wasm/2d 资源
            // 需要使用wasm/2d需要遵循浏览器同源策略或使用其他手段规避浏览器同源策略
            return "https://unpkg.com/mxcad/dist/wasm/2d-st/" + fileName
      },
      // 加载字体的目录位置
      fontspath: self.location.origin + "/mxcad_docs/fonts",
      // 加载转换后的图纸文件
      fileUrl: self.location.origin + "/mxcad_docs/test.mxweb",
      onOpenFileComplete: ()=>{
            const ellipse = new McDbEllipse()
            ellipse.center = new McGePoint3d(-200, -200),
            ellipse.majorAxis = new McGeVector3d(0, 300, 0)
            ellipse.radiusRatio = 0.5
            ellipse.trueColor = new McCmColor(255, 233, 0)
            mxcad.drawEntity(ellipse)

            const ellipse_arc = new McDbEllipse()
            ellipse_arc.center = new McGePoint3d(-380, -200),
            ellipse_arc.majorAxis = new McGeVector3d(0, 150, 0)
            ellipse_arc.minorAxis = new McGeVector3d(280, 0, 0)
            ellipse_arc.startAngle = Math.PI / 2
            ellipse_arc.endAngle = Math.PI * 3 / 2
            ellipse_arc.trueColor = new McCmColor(0, 255, 255)
            mxcad.drawEntity(ellipse_arc)

            mxcad.drawEllipse(0, -200, 200, 0, 1.5)

            mxcad.drawColor = new McCmColor(0, 255, 0)       
            mxcad.drawEllipseArc(200, -200, 200, 0, 1.5, 100, 650)

            mxcad.zoomAll()
            mxcad.zoomScale(0.8)
      }
    })
    return (<div style="height: 500px; overflow: hidden;"><canvas id="myCanvas" ></canvas>
    </div>)
}

:::