function getCirclePoint(x, y, radius) {
    var pointArr = []
    for (var i = 0; i < 361; i++) {
        if (i < 360) {
            pointArr.push({
                x: x + radius * Math.cos(i * 2 * Math.PI / 360),
                y: y + radius * Math.sin(i * 2 * Math.PI / 360)
            })
        } else {
            pointArr.push({
                x: x + radius * Math.cos(0 * 2 * Math.PI / 360),
                y: y + radius * Math.sin(0 * 2 * Math.PI / 360)
            })
        }
    }
    return pointArr; //x - y
};

function addCircleToPolygon(options, allCirclePoint, extrudes) {
    var altitudes = [];
    var guid = [];
    var guidArr = [];
    for (var n = 0; n < allCirclePoint.length; n++) {
        var curExtrude = extrudes[n];
        altitudes = [];
        for (var j = 0; j < allCirclePoint[n].length; j++) {
            altitudes.push(curExtrude);
        }
        if (n == 0) { 
            if (options.display.show2D) {
                map2DViewer.polygon({
                    action: 'add',
                    groupId:options.groupId,
                    geojson: {
                        "type": "Feature",
                        "properties": {
                            title: options.properties.title,
                            color: options.properties.color,
                            weight: options.properties.weight,
                            fillColor: options.properties.fillColor,
                            opacity: options.properties.opacity,
                            fillOpacity: options.properties.fillOpacity,
                            popupContent: '',
                            extrude: 0, //拉伸高度
                            altitude: altitudes, //点海拔高度
                            altitudeMode: 0 //海拔模式
                        },
                        "geometry": {
                            "type": "Polygon",
                            "coordinates": [
                                allCirclePoint[n]
                            ]
                        }
                    }
                })
            }
            if (options.altitudeMode === 1) {
                if (options.display.show3D) {
                    map3DViewer.polyline({
                        action: 'add',
                        groupId:options.groupId,
                        geojson: {
                            "type": "Feature",
                            "properties": {
                                title: options.properties.title,
                                color: options.properties.color,
                                weight: options.properties.weight,
                                fillColor: options.properties.fillColor,
                                opacity: options.properties.opacity,
                                popupContent: '',
                                extrude: 0, //拉伸高度
                                altitude: altitudes, //点海拔高度
                                altitudeMode: 0 //海拔模式
                            },
                            "geometry": {
                                "type": "Polyline",
                                "coordinates": allCirclePoint[n]

                            }
                        }
                    })
                }
            }
        } else {
            if (options.display.show3D) {
                map3DViewer.polyline({
                    action: 'add',
                    groupId:options.groupId,
                    geojson: {
                        "type": "Feature",
                        "properties": {
                            title: options.properties.title,
                            color: options.properties.color,
                            weight: options.properties.weight,
                            fillColor: options.properties.fillColor,
                            opacity: options.properties.opacity,
                            popupContent: '',
                            extrude: 0, //拉伸高度
                            altitude: altitudes, //点海拔高度
                            altitudeMode: 1 //海拔模式
                        },
                        "geometry": {
                            "type": "Polyline",
                            "coordinates": allCirclePoint[n]
                        }
                    }
                })
            }
        }
    }
};
L.addLD = function(options) {
    //圆心
    var allCirclePoint = [];
    var center_lat = options.center.lat;
    var center_lon = options.center.lng;
    //半径
    var radius = options.radius; //米
    //计算圆心到极点的距离
    if (center_lat < 0) {
        var centerToPole = new L.LatLng(center_lat, center_lon).distanceTo(new L.LatLng(-90, center_lon));
    } else {
        var centerToPole = new L.LatLng(center_lat, center_lon).distanceTo(new L.LatLng(90, center_lon));
    }
    //转换定义 核心
    var epsg_4326 = "+proj=longlat +datum=WGS84 +no_defs "
    var esri_102016 = "+proj=aeqd +lat_0=90 +lon_0=0 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m no_defs"
    var self_defined = "+proj=aeqd +lat_0=" + center_lat + "+lon_0=" + center_lon + "+x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m no_defs"
    var circleTangle = options.circleTangle || 5;
    var extrudes = [];
    var minExtrudes = map23DUtil.getLDCircleExtrude(radius);
    for (var i = 0; i <= 90; i += circleTangle) {
        if (i == 90) {
            var curHeight = radius;
        } else {
            var ral = (i * Math.PI) / 180;
            var curHeight = radius * Math.sin(ral);
        }
        if (i != 0) {
            if (curHeight < minExtrudes) {
                curHeight = minExtrudes;
            }
        }
        var curBRedius = Math.sqrt(Math.pow(radius, 2) - Math.pow(curHeight, 2));
        //生成圆平面点；
        var pointArr = getCirclePoint(0, 0, curBRedius);
        //圆的轮廓点转换为经纬度，当做GeoJSON来使用。
        var circlePoints = [];

        extrudes.push(curHeight);
        for (var k = 0; k < pointArr.length; k++) {
            var item = pointArr[k];
            //核心 将平面坐标转经纬度坐标
            var xy = proj4(self_defined, epsg_4326, [item.x, item.y]);
            circlePoints.push([
                xy[0],
                xy[1]
            ])
        }
        if (i == 0) { //二维雷达显示坐标处理
            if (curBRedius >= centerToPole) {
                if (center_lat < 0) {
                    circlePoints = map23DUtil.southHeightLatLD(map23DUtil.southHeightLatLD(map23DUtil.lnglatsToDateLineLnglats(circlePoints)));
                    circlePoints.push([circlePoints[circlePoints.length - 1][0], -90])
                    circlePoints[circlePoints.length - 2] = [circlePoints[circlePoints.length - 3][0], -90];
                } else {
                    circlePoints = map23DUtil.northHeightLatLD(map23DUtil.northHeightLatLD(map23DUtil.lnglatsToDateLineLnglats(circlePoints)));
                    circlePoints.push([circlePoints[circlePoints.length - 1][0], 90])
                    circlePoints[circlePoints.length - 2] = [circlePoints[circlePoints.length - 3][0], 90];
                }
            } else {
                circlePoints = map23DUtil.lnglatsToDateLineLnglats(circlePoints);
            }
        } else { //三维雷达显示坐标处理
            if (curBRedius > centerToPole) {
                //判断中心点是在南半球还是北半球
                if (center_lat < 0) {
                    circlePoints = map23DUtil.southHeightLatLD(map23DUtil.southHeightLatLD(map23DUtil.lnglatsToDateLineLnglats(circlePoints)))
                } else {
                    circlePoints = map23DUtil.northHeightLatLD(map23DUtil.northHeightLatLD(map23DUtil.lnglatsToDateLineLnglats(circlePoints)))
                }
            }
        }
        allCirclePoint.push(circlePoints)
        if (i == 90) {
            addCircleToPolygon(options, allCirclePoint, extrudes);
        }
    }
};