ArcGIS JavaScript 4.x之点生成矩形缓冲区

记录自己用ArcGIS JavaScript 4.x实现以点(Point)为中心生成任意长宽的矩形缓冲区的效果。关键是通过中心点坐标，长，宽作为条件计算出各顶点坐标来绘制出一个类型为矩形多边形(polygon)的图形。下图是演示效果:

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绘制矩形缓冲相关代码:

/**
 * 绘制长方形缓冲的方法
 * 中心点-[lon,lat]
 * 长-width
 * 宽-height 
 */
function getRectangleBuffer (centerPt, width, height) {
  var xieLineDis = Math.sqrt(width * width + height * height);
  var Tdegs = deg(Math.atan(width / height)); //弧度转换为度数
  var coordTopLeft = distanceAngle({ lon: centerPt[0], lat: centerPt[1] }, -Tdegs, xieLineDis / 2); //左上角坐标
  var coordTopRight = distanceAngle({ lon: centerPt[0], lat: centerPt[1] }, Tdegs, xieLineDis / 2); //右上角
  var coordBottomLeft = distanceAngle({ lon: centerPt[0], lat: centerPt[1] }, -(180 - Tdegs), xieLineDis / 2); //左下角
  var coordBootomRight = distanceAngle({ lon: centerPt[0], lat: centerPt[1] }, 180 - Tdegs, xieLineDis / 2); //右下角
  //构建一个polygon所需的环形数组
  var points = [
    [coordTopLeft.lon, coordTopLeft.lat],
    [coordTopRight.lon, coordTopRight.lat],
    [coordBootomRight.lon, coordBootomRight.lat],
    [coordBottomLeft.lon, coordBottomLeft.lat]
  ]
  //右上角的点，用来同步放大矩形
  var scalePt = new Point({
    longitude: coordTopRight.lon,
    latitude: coordTopRight.lat,
    spatialReference: view.spatialReference
  })
  var scaleSym = {
    type: "simple-marker",
    color: [266, 266, 266, 0.8]
  }
  scaleGp = new Graphic({
    geometry: scalePt,
    symbol: scaleSym,
    attributes: {
      name: "rectangleGp"
    }
  })
  view.graphics.add(scaleGp)
  var polygon = new Polygon({
    rings: points
  })
  var recsymbol = {
    type: "simple-fill",
    color: [267, 267, 0]
  }
  var rectangleGp = new Graphic({
    geometry: polygon,
    symbol: recsymbol
  })
  return rectangleGp;
}

image.gif

完整demo下载地址:https://download.csdn.net/download/lf5566fl/12089174