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){
    let truncatedSplitter = turf.truncate(turf.lineString(outerPolygon.geometry.coordinates[0]), {precision: 7});
 
    //求交点
    let intersectCollection = turf.lineIntersect(line, truncatedSplitter);
    if (intersectCollection.features.length < 2) {
        return null;
    }
    
    //将点合并成MultiPoint
    let intersectCombined = turf.combine(intersectCollection).features[0];
 
    //分别获取切割线
    let outerPieceCollection = turf.lineSplit(line, intersectCombined);
    let splitterPieceCollection = turf.lineSplit(truncatedSplitter, intersectCombined);
 
    //将所有的线段放到一起
    let pieceCollection = turf.featureCollection(outerPieceCollection.features.concat(splitterPieceCollection.features));
 
    //使用turf将闭合线组成多边形
    let polygonCollection = turf.polygonize(pieceCollection);
    

    //对多边形进行判断，切割外的多边形丢弃
    // let innerPolygons = polygonCollection.features.filter(polygon => {
    //     let center = turf.centroid(polygon);
    //     return turf.booleanWithin(center, outerPolygon);
    // });

    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;
        });
    }
    innerPolygons.forEach((item,index)=>{
        innerPolygons[index].properties.id = generateUUID();
    })
    return innerPolygons;
}


export function splitPolygonByFill(fill,outerPolygon){
    var polygon1 = turf.polygon(fill.geometry.coordinates);
    // var polygon1 = turf.polygon(
    //     [
    //         [
    //             [
    //                 118.08246593377775,
    //                 35.22214906870923
    //             ],
    //             [
    //                 118.0824468053414,
    //                 35.2221025269492
    //             ],
    //             [
    //                 118.08255783344151,
    //                 35.22206277960647
    //             ],
    //             [
    //                 118.08258527859043,
    //                 35.22213378126961
    //             ],
    //             [
    //                 118.08246593377775,
    //                 35.22214906870923
    //             ]
    //         ]
    //     ]
    // )

    var polygon2 = turf.polygon(outerPolygon.geometry.coordinates);
    // var polygon2 = turf.polygon(
    //     [
    //         [
    //             [
    //                 118.082358,
    //                 35.222126
    //             ],
    //             [
    //                 118.082517,
    //                 35.222061
    //             ],
    //             [
    //                 118.082535,
    //                 35.222098
    //             ],
    //             [
    //                 118.082372,
    //                 35.222163
    //             ],
    //             [
    //                 118.082358,
    //                 35.222126
    //             ]
    //         ]
    //     ]
    // )

    var difference = turf.difference(polygon1, polygon2);
    
    console.log("difference123",difference);
    return difference;
}