SHI-Cesium/Assets/Scripts/PolygonMeasureGroup.cs

using CesiumForUnity;
using System;
using System.Collections.Generic;
using TMPro;
using Unity.Mathematics;
using UnityEngine;
using UnityEngine.UI;

public class PolygonMeasureGroup : MeasureGroup
{
    private PolygonMeasureGroupInfoPopup polygonMeasureGroupInfoPopup;
    private float baseCloseDistance = 10f;

    public override void AddPoint(Vector3 pos)
    {
        if (!polygonMeasureGroupInfoPopup)
        {
            polygonMeasureGroupInfoPopup = Instantiate(polygonInfoPopupPrefab).GetComponent<PolygonMeasureGroupInfoPopup>();
            polygonMeasureGroupInfoPopup.InitUI(infoPopupRoot);
            polygonMeasureGroupInfoPopup.transform.position = pos + new Vector3(20, 0, 20);
        }

        if (points.Count >= 3 && Vector3.Distance(points[0], pos) < baseCloseDistance)
        {
            ClosePolygon();
            return;
        }

        points.Add(pos);
        line.positionCount = points.Count;
        line.SetPosition(points.Count - 1, pos);

        GameObject label = Instantiate(labelPrefab, pos, Quaternion.identity, labelRoot);
        labels.Add(label);

        if (points.Count >= 2)
        {
            Vector3 a = points[points.Count - 2];
            Vector3 b = points[points.Count - 1];

            double3 llh_a = GeoUtils.GetLonLatHeight(cesiumGeoreference, a);
            double3 llh_b = GeoUtils.GetLonLatHeight(cesiumGeoreference, b);

            double dist = GeoUtils.Haversine(llh_a.x, llh_a.y, llh_b.x, llh_b.y);
            totalDistance += dist;
        }

        UpdateInfo();
    }

    private void ClosePolygon()
    {
        line.positionCount = points.Count + 1;
        for (int i = 0; i < points.Count; i++)
            line.SetPosition(i, points[i]);
        line.SetPosition(points.Count, points[0]);

        double3[] llhs = new double3[points.Count];
        for (int i = 0; i < points.Count; i++)
            llhs[i] = GeoUtils.GetLonLatHeight(cesiumGeoreference, points[i]);

        double totalDistance = 0;
        for (int i = 0; i < points.Count; i++)
        {
            int j = (i + 1) % points.Count;
            double dist = GeoUtils.Haversine(llhs[i].x, llhs[i].y, llhs[j].x, llhs[j].y);
            totalDistance += dist;

            Vector3 mid = (points[i] + points[j]) * 0.5f;
            labels[i].transform.position = mid;
            labels[i].GetComponentInChildren<TextMeshProUGUI>().text = $"{dist:F1} m";
        }

        double area = GetPolygonArea();
        polygonMeasureGroupInfoPopup.UpdateInfo("(¾øÀ½)", llhs[0].x, llhs[0].y, totalDistance, area);

        deleteButton = Instantiate(deleteButtonPrefab, points[0], Quaternion.identity, infoPopupRoot);
        deleteButton.GetComponentInChildren<Button>().onClick.AddListener(() => DestroyAll());
        deleteButton.transform.position = points[0] + new Vector3(-20, 0, 20);

        FindAnyObjectByType<MeasureManager>().isMeasuring = false;
    }

    private void UpdateInfo()
    {
        if (polygonMeasureGroupInfoPopup == null) return;

        double totalDistance = 0;
        for (int i = 0; i < points.Count - 1; i++)
        {
            double3 llh_a = GeoUtils.GetLonLatHeight(cesiumGeoreference, points[i]);
            double3 llh_b = GeoUtils.GetLonLatHeight(cesiumGeoreference, points[i + 1]);
            totalDistance += GeoUtils.Haversine(llh_a.x, llh_a.y, llh_b.x, llh_b.y);
        }

        double3 llh_last = GeoUtils.GetLonLatHeight(cesiumGeoreference, points[points.Count - 1]);
        polygonMeasureGroupInfoPopup.UpdateInfo("(¾øÀ½)", llh_last.x, llh_last.y, totalDistance, 0);
    }

    public override void EndMeasure()
    {
        if (line == null) return;
        DestroyAll();
    }

    public override void DestroyAll()
    {
        base.DestroyAll();
        if (polygonMeasureGroupInfoPopup)
            Destroy(polygonMeasureGroupInfoPopup.gameObject);
        Destroy(this);
    }

    public override void LateUpdate()
    {
        base.LateUpdate();

        if (polygonMeasureGroupInfoPopup)
        {
            polygonMeasureGroupInfoPopup.transform.LookAt(polygonMeasureGroupInfoPopup.transform.position + cam.transform.forward);
            float heightDiff = Mathf.Abs(cam.transform.position.y - polygonMeasureGroupInfoPopup.transform.position.y);
            polygonMeasureGroupInfoPopup.transform.localScale = Vector3.one * (heightDiff * lineScaleMultiplier);
        }
    }

    public override void UpdatePreviewLine(Vector3 mousePos)
    {
        if (points.Count == 0 || line == null) return;

        if (line.positionCount == points.Count)
            line.positionCount++;

        line.SetPosition(line.positionCount - 1, mousePos);

        Vector3 last = points[points.Count - 1];
        Vector3 mid = (last + mousePos) * 0.5f;
        labels[labels.Count - 1].transform.position = mid;

        double3 llh_a = GeoUtils.GetLonLatHeight(cesiumGeoreference, last);
        double3 llh_b = GeoUtils.GetLonLatHeight(cesiumGeoreference, mousePos);
        double dist = GeoUtils.Haversine(llh_a.x, llh_a.y, llh_b.x, llh_b.y);

        labels[labels.Count - 1].GetComponentInChildren<TextMeshProUGUI>().text = $"{dist:F1} m";

        double previewTotal = totalDistance + dist;
        polygonMeasureGroupInfoPopup?.UpdateInfo("(¾øÀ½)", llh_b.x, llh_b.y, previewTotal, 0);
    }

    private double GetPolygonArea()
    {
        double sum1 = 0, sum2 = 0;
        for (int i = 0; i < points.Count - 1; i++)
        {
            sum1 += points[i].x * points[i + 1].z;
            sum2 += points[i + 1].x * points[i].z;
        }
        sum1 += points[points.Count - 1].x * points[0].z;
        sum2 += points[0].x * points[points.Count - 1].z;
        return Math.Abs((sum1 - sum2) / 2.0);
    }
}