cesium-长度测量和面积测量
（更新）多谢网友的提醒，面积测量的小问题已经修改，经测试可正常使用
网上找的大神的实现方法有点问题，实现有一些bug，作为cesium新手一个，弃之不忍，只好硬着头皮修改了，不过还好问题不大，再次mark一下，下次就可以直接用了
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import Cesium from "cesium/Cesium";
import widgets from "cesium/Widgets/widgets.css";
export default {
//测量空间直线距离
/******************************************* */
measureLineSpace(viewer, handler) {
// 取消双击事件-追踪该位置
viewer.cesiumWidget.screenSpaceEventHandler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK);
handler = new Cesium.ScreenSpaceEventHandler(viewer.scene._imageryLayerCollection);
var positions = [];
var poly = null;
// var tooltip = document.getElementById("toolTip");
var distance = 0;
var cartesian = null;
var floatingPoint;
// tooltip.style.display = "block";
handler.setInputAction(function (movement) {
// tooltip.style.left = movement.endPosition.x + 3 + "px";
// tooltip.style.top = movement.endPosition.y - 25 + "px";
// tooltip.innerHTML = '<p>单击开始，右击结束</p>';
// cartesian = viewer.scene.pickPosition(movement.endPosition);
let ray = viewer.camera.getPickRay(movement.endPosition);
cartesian = viewer.scene.globe.pick(ray, viewer.scene);
//cartesian = viewer.scene.camera.pickEllipsoid(movement.endPosition, viewer.scene.globe.ellipsoid);
if (positions.length >= 2) {
if (!Cesium.defined(poly)) {
poly = new PolyLinePrimitive(positions);
} else {
positions.pop();
// cartesian.y += (1 + Math.random());
positions.push(cartesian);
}
distance = getSpaceDistance(positions);
// console.log("distance: " + distance);
// tooltip.innerHTML='<p>'+distance+'米</p>';
}
}, Cesium.ScreenSpaceEventType.MOUSE_MOVE);
handler.setInputAction(function (movement) {
// tooltip.style.display = "none";
// cartesian = viewer.scene.camera.pickEllipsoid(movement.position, viewer.scene.globe.ellipsoid);
// cartesian = viewer.scene.pickPosition(movement.position);
let ray = viewer.camera.getPickRay(movement.position);
cartesian = viewer.scene.globe.pick(ray, viewer.scene);
if (positions.length == 0) {
positions.push(cartesian.clone());
}
positions.push(cartesian);
//在三维场景中添加Label
// var cartographic = Cesium.Cartographic.fromCartesian(cartesian);
var textDisance = distance + "米";
// console.log(textDisance + ",lng:" + cartographic.longitude/Math.PI*180.0);
floatingPoint = viewer.entities.add({
name: '空间直线距离',
// position: Cesium.Cartesian3.fromDegrees(cartographic.longitude / Math.PI * 180, cartographic.latitude / Math.PI * 180,cartographic.height),
position: positions[positions.length - 1],
point: {
pixelSize: 5,
color: Cesium.Color.RED,
outlineColor: Cesium.Color.WHITE,
outlineWidth: 2,
},
label: {
text: textDisance,
font: '18px sans-serif',
fillColor: Cesium.Color.GOLD,
style: Cesium.LabelStyle.FILL_AND_OUTLINE,
outlineWidth: 2,
verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
pixelOffset: new Cesium.Cartesian2(20, -20),
}
});
}, Cesium.ScreenSpaceEventType.LEFT_CLICK);
handler.setInputAction(function (movement) {
handler.destroy(); //关闭事件句柄
positions.pop(); //最后一个点无效
// viewer.entities.remove(floatingPoint);
// tooltip.style.display = "none";
}, Cesium.ScreenSpaceEventType.RIGHT_CLICK);
var PolyLinePrimitive = (function () {
function _(positions) {
this.options = {
name: '直线',
polyline: {
show: true,
positions: [],
material: Cesium.Color.CHARTREUSE,
width: 10,
clampToGround: true
}
};
this.positions = positions;
this._init();
}
_.prototype._init = function () {
var _self = this;
var _update = function () {
return _self.positions;
};
//实时更新polyline.positions
this.options.polyline.positions = new Cesium.CallbackProperty(_update, false);
viewer.entities.add(this.options);
};
return _;
})();
//空间两点距离计算函数
function getSpaceDistance(positions) {
var distance = 0;
for (var i = 0; i < positions.length - 1; i++) {
var point1cartographic = Cesium.Cartographic.fromCartesian(positions[i]);
var point2cartographic = Cesium.Cartographic.fromCartesian(positions[i + 1]);
/**根据经纬度计算出距离**/
var geodesic = new Cesium.EllipsoidGeodesic();
geodesic.setEndPoints(point1cartographic, point2cartographic);
var s = geodesic.surfaceDistance;
//console.log(Math.sqrt(Math.pow(distance, 2) + Math.pow(endheight, 2)));
//返回两点之间的距离
s = Math.sqrt(Math.pow(s, 2) + Math.pow(point2cartographic.height - point1cartographic.height, 2));
distance = distance + s;
}
return distance.toFixed(2);
}
},
//****************************测量空间面积************************************************//
measureAreaSpace(viewer, handler){
// 取消双击事件-追踪该位置
viewer.cesiumWidget.screenSpaceEventHandler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK);
// 鼠标事件
handler = new Cesium.ScreenSpaceEventHandler(viewer.scene._imageryLayerCollection);
var positions = [];
var tempPoints = [];
var polygon = null;
// var tooltip = document.getElementById("toolTip");
var cartesian = null;
var floatingPoint;//浮动点
// tooltip.style.display = "block";
handler.setInputAction(function(movement){
// tooltip.style.left = movement.endPosition.x + 3 + "px";
// tooltip.style.top = movement.endPosition.y - 25 + "px";
// tooltip.innerHTML ='<p>单击开始，右击结束</p>';
// cartesian = viewer.scene.pickPosition(movement.endPosition);
let ray = viewer.camera.getPickRay(movement.endPosition);
cartesian = viewer.scene.globe.pick(ray, viewer.scene);
//cartesian = viewer.scene.camera.pickEllipsoid(movement.endPosition, viewer.scene.globe.ellipsoid);
if(positions.length >= 2){
if (!Cesium.defined(polygon)) {
polygon = new PolygonPrimitive(positions);
}else{
positions.pop();
// cartesian.y += (1 + Math.random());
positions.push(cartesian);
}
// tooltip.innerHTML='<p>'+distance+'米</p>';
}
},Cesium.ScreenSpaceEventType.MOUSE_MOVE);
handler.setInputAction(function(movement){
// tooltip.style.display = "none";
// cartesian = viewer.scene.pickPosition(movement.position);
let ray = viewer.camera.getPickRay(movement.position);
cartesian = viewer.scene.globe.pick(ray, viewer.scene);
// cartesian = viewer.scene.camera.pickEllipsoid(movement.position, viewer.scene.globe.ellipsoid);
if(positions.length == 0) {
positions.push(cartesian.clone());
}
//positions.pop();
positions.push(cartesian);
//在三维场景中添加点
var cartographic = Cesium.Cartographic.fromCartesian(positions[positions.length - 1]);
var longitudeString = Cesium.Math.toDegrees(cartographic.longitude);
var latitudeString = Cesium.Math.toDegrees(cartographic.latitude);
var heightString = cartographic.height;
tempPoints.push({ lon: longitudeString, lat: latitudeString ,hei:heightString});
floatingPoint = viewer.entities.add({
name : '多边形面积',
position : positions[positions.length - 1],
point : {
pixelSize : 5,
color : Cesium.Color.RED,
outlineColor : Cesium.Color.WHITE,
outlineWidth : 2,
heightReference:Cesium.HeightReference.CLAMP_TO_GROUND
}
});
},Cesium.ScreenSpaceEventType.LEFT_CLICK);
handler.setInputAction(function(movement){
handler.destroy();
positions.pop();
//tempPoints.pop();
// viewer.entities.remove(floatingPoint);
// tooltip.style.display = "none";
//在三维场景中添加点
// var cartographic = Cesium.Cartographic.fromCartesian(positions[positions.length - 1]);
// var longitudeString = Cesium.Math.toDegrees(cartographic.longitude);
// var latitudeString = Cesium.Math.toDegrees(cartographic.latitude);
// var heightString = cartographic.height;
// tempPoints.push({ lon: longitudeString, lat: latitudeString ,hei:heightString});
var textArea = getArea(tempPoints) + "平方公里";
viewer.entities.add({
name : '多边形面积',
position : positions[positions.length - 1],
// point : {
// pixelSize : 5,
// color : Cesium.Color.RED,
// outlineColor : Cesium.Color.WHITE,
// outlineWidth : 2,
// heightReference:Cesium.HeightReference.CLAMP_TO_GROUND
// },
label : {
text : textArea,
font : '18px sans-serif',
fillColor : Cesium.Color.GOLD,
style: Cesium.LabelStyle.FILL_AND_OUTLINE,
outlineWidth : 2,
verticalOrigin : Cesium.VerticalOrigin.BOTTOM,
pixelOffset : new Cesium.Cartesian2(20, -40),
heightReference:Cesium.HeightReference.CLAMP_TO_GROUND
}
});
}, Cesium.ScreenSpaceEventType.RIGHT_CLICK );
var radiansPerDegree = Math.PI / 180.0;//角度转化为弧度(rad)
var degreesPerRadian = 180.0 / Math.PI;//弧度转化为角度
//计算多边形面积
function getArea(points) {
var res = 0;
//拆分三角曲面
for (var i = 0; i < points.length - 2; i++) {
var j = (i + 1) % points.length;
var k = (i + 2) % points.length;
var totalAngle = Angle(points[i], points[j], points[k]);
var dis_temp1 = distance(positions[i], positions[j]);
var dis_temp2 = distance(positions[j], positions[k]);
res += dis_temp1 * dis_temp2 * Math.abs(Math.sin(totalAngle)) ;
console.log(res);
}
return (res/1000000.0).toFixed(4);
}
/*角度*/
function Angle(p1, p2, p3) {
var bearing21 = Bearing(p2, p1);
var bearing23 = Bearing(p2, p3);
var angle = bearing21 - bearing23;
if (angle < 0) {
angle += 360;
}
return angle;
}
/*方向*/
function Bearing(from, to) {
var lat1 = from.lat * radiansPerDegree;
var lon1 = from.lon * radiansPerDegree;
var lat2 = to.lat * radiansPerDegree;
var lon2 = to.lon * radiansPerDegree;
var angle = -Math.atan2(Math.sin(lon1 - lon2) * Math.cos(lat2), Math.cos(lat1) * Math.sin(lat2) - Math.sin(lat1) * Math.cos(lat2) * Math.cos(lon1 - lon2));
if (angle < 0) {
angle += Math.PI * 2.0;
}
angle = angle * degreesPerRadian;//角度
return angle;
}
var PolygonPrimitive = (function(){
function _(positions){
this.options = {
name:'多边形',
polygon : {
hierarchy : [],
// perPositionHeight : true,
material : Cesium.Color.GREEN.withAlpha(0.5),
// heightReference:20000
}
};
this.hierarchy = {positions};
this._init();
}
_.prototype._init = function(){
var _self = this;
var _update = function(){
return _self.hierarchy;
};
//实时更新polygon.hierarchy
this.options.polygon.hierarchy = new Cesium.CallbackProperty(_update,false);
viewer.entities.add(this.options);
};
return _;
})();
function distance(point1,point2){
var point1cartographic = Cesium.Cartographic.fromCartesian(point1);
var point2cartographic = Cesium.Cartographic.fromCartesian(point2);
/**根据经纬度计算出距离**/
var geodesic = new Cesium.EllipsoidGeodesic();
geodesic.setEndPoints(point1cartographic, point2cartographic);
var s = geodesic.surfaceDistance;
//console.log(Math.sqrt(Math.pow(distance, 2) + Math.pow(endheight, 2)));
//返回两点之间的距离
s = Math.sqrt(Math.pow(s, 2) + Math.pow(point2cartographic.height - point1cartographic.height, 2));
return s;
}
}
}