CaiYuanYiTiHua/src/components/MapboxMaps/lib/splitpolygon.ts

import { generateUUID } from '../src/tool';

/**
 * 使用turf工具进行切割面
 * @param line 线段数据
 * @param outerPolygon 面数据
 * return  返回切割的面数据
 */
export function splitPolygonByLine(line, outerPolygon) {
  console.log("************** 分割开始 start **************")
  console.log("第1步：传入的分割线数据",line);
  console.log("第2步：传入的分割面数据",outerPolygon)

  // 处理被分割的面数据坐标小数点保留多少位
  let truncatedSplitter = turf.truncate(turf.lineString(outerPolygon.geometry.coordinates[0]), {
    precision: 7,
  });
  console.log("第3步：分割面转换为线数据",truncatedSplitter);
  //求交点
  let intersectCollection = turf.lineIntersect(line, truncatedSplitter);
  console.log("第4步：与分割面的交点",intersectCollection);
  // printLngLat(intersectCollection.geometry.coordinates);
  // 交点小于2个 返回null
  if (intersectCollection.features.length < 2) {
    return null;
  }
  //将点合并成MultiPoint
  let intersectCombined = turf.combine(intersectCollection).features[0];
  
  console.log("第5步：分割后所有点数据",intersectCombined)


  //分别获取切割线
  let outerPieceCollection = turf.lineSplit(line, intersectCombined);
  let splitterPieceCollection = turf.lineSplit(truncatedSplitter, intersectCombined);

  console.log("第6步：切割线被分割后所有线段",outerPieceCollection);

  console.log("第7步：切割面被分割后所有线段",splitterPieceCollection);
  
  //将所有的线段放到一起
  let pieceCollection = turf.featureCollection(
    outerPieceCollection.features.concat(splitterPieceCollection.features),
  );
  console.log("第8步：所有分割线段",pieceCollection);
  //使用turf将闭合线组成多边形
  let polygonCollection = turf.polygonize(pieceCollection);

  console.log("第9步：分割线合并面数据",polygonCollection)

  //对多边形进行判断，切割外的多边形丢弃
  let innerPolygons = polygonCollection.features.filter((polygon) => {
    // 获取多边形质心 多边形不规则时有问题
    // let newcenter = turf.centroid(polygon);
    let randomCenterPoint =  getRandomPointInPolygon(polygon);

    // 获取多边形表面一点
    let newcenter = turf.pointOnFeature(polygon);
    // 图斑中心点 
    let centerPoint = turf.point(randomCenterPoint.geometry.coordinates);
    console.log('第10步：封闭图形中心点数据',randomCenterPoint,centerPoint)
    return turf.booleanWithin(centerPoint, outerPolygon);

  });

  console.log("第11步：返回最终处理后的数据",innerPolygons)
  //   let innerPolygons = polygonCollection.features;

  //处理镂空数据（多处镂空数据会导致计算错误，因为polygonize方法无法正常的返回数据）
  if (outerPolygon.geometry.coordinates?.length > 1) {
    //获取镂空的面数据
    let holeCollection = turf.featureCollection(
      outerPolygon.geometry.coordinates.slice(1).map((item) => turf.polygon([item])),
    );

    //剔除掉镂空的部分数据
    innerPolygons = innerPolygons.map((polygon) => {
      let diff = polygon;
      turf.featureEach(holeCollection, (hole) => {
        diff = turf.difference(diff, hole);
      });
      return diff;
    });
  }

  // 每个图斑配置UUID
  innerPolygons.forEach((item, index) => {
    innerPolygons[index].properties.id = generateUUID();
  });
  console.log("************** 分割结束 end **************")
  return innerPolygons;
}

function getRandomPointInPolygon(polygon) {
  const bbox = turf.bbox(polygon); // 获取多边形的边界框
  let point;

  do {
      point = turf.randomPoint(1, {bbox: bbox}).features[0]; // 从边界框中生成一个随机点
  } while (!turf.booleanWithin(point, polygon)); // 检查点是否在多边形内部
  // 直到找到在内部的点再返回数据
  return point;
}

// 单个面数据分割
export function splitPolygonByFill(drawPolygon, outerPolygon) {

  console.log("drawPolygon",drawPolygon);
  console.log("outerPolygon",outerPolygon)
  
  var polygon1 = turf.polygon(drawPolygon.geometry.coordinates)
  var polygon2 = turf.polygon(outerPolygon.geometry.coordinates);
  var difference = turf.difference(polygon2,polygon1);
  var intersection = turf.intersect(polygon2, polygon1);

  intersection.properties.id = generateUUID();
  difference.properties.id = generateUUID();

  let splitAfterFeatures = [intersection,difference];

  // splitAfterFeatures?.forEach((item,index)=>{
  //   splitAfterFeatures[index].properties?.id = generateUUID();
  // })

  return splitAfterFeatures;

}

export function printLngLat(arr){
  arr.forEach((item,index)=>{
    console.log(item[1]+","+item[0]+"\n");
  })
}