using System.Collections;
using System.Collections.Generic;
using UnityEngine;
 
public class MeshCreater : MonoBehaviour
{
 Mesh mesh;
 public Material mat;//mesh材质
 public GameObject game;
 
 // Start is called before the first frame update
 void Start()
 {
  mesh = new Mesh();
  mesh.Clear();
  SetVertivesUV();
  SetTriangles();
  mesh.vertices = vertices.ToArray();
  mesh.triangles = triangles;
  GameObject obj_cell = new GameObject();
  obj_cell.name = "cell";
 
  mesh.RecalculateNormals();//重置法线
 
  mesh.RecalculateBounds(); //重置范围
 
  obj_cell.AddComponent<MeshFilter>().mesh = mesh;
  obj_cell.AddComponent<MeshRenderer>();
  obj_cell.GetComponent<MeshRenderer>().material = mat;
  
  MeshCaluate mesh_caluate = new MeshCaluate();
  mesh_caluate.CalculateMesh(mesh);
 }
 
 // Update is called once per frame
 void Update()
 {
  
 }
 
 public List<Vector3> vertices = new List<Vector3>();
 
 private float angle = 10;
 
 private float max_angle = 120;
 // 设置顶点信息
 void SetVertivesUV()
 {
  Vector3 dir1 = new Vector3(Mathf.Sqrt(3f), -1, 0);
  Vector3 dir2 = dir1 * 0.8f;
  
  List<Vector3> points1 = new List<Vector3>();
  List<Vector3> points2 = new List<Vector3>();
 
  int count = (int)((360 - max_angle) / angle);
 
  for (int i = 0; i < count; i++)
  {
   Quaternion q= Quaternion.AngleAxis(i * angle, Vector3.forward);
   
   Vector3 point1 = q* dir1;
   Vector3 point2 = q* dir2;
   points1.Add(point1);
   points2.Add(point2);
  }
  points1.Add(points1[0]);
  points2.Add(points2[0]);
 
  for (int i = 0; i < points1.Count; i++)
  {
   var v1 = points1[i];
   var v2 = points2[i];
   var v3 = points1[i];
   v3.z = 10;
   var v4 = points2[i];
   v4.z = 10;
   
   vertices.Add(v1);
   vertices.Add(v3);
   vertices.Add(v2);
   vertices.Add(v4);
  }
 }
 
 private int[] triangles;//索引
 // 设置索引
 void SetTriangles()
 {
  triangles = new int[vertices.Count * 3];
  int c = 0;
  for (int i = 0; i < triangles.Length -12 ; i += 12)
  {
   var v1 = c;
   var v2 = c + 1;
   var v3 = c + 4;
   var v4 = c + 5;
   
   var v5 = c + 2;
   var v6 = c + 3;
   var v7 = c + 6;
   var v8 = c + 7;
   
   triangles[i] = v4;
   triangles[i + 1] = v2;
   triangles[i + 2] = v1;
 
   triangles[i + 3] = v3;
   triangles[i + 4] = v4;
   triangles[i + 5] = v1;
 
   triangles[i + 6] = v5;
   triangles[i + 7] = v6;
   triangles[i + 8] = v8;
   
   triangles[i + 9] = v5;
   triangles[i + 10] = v8;
   triangles[i + 11] = v7;
 
   c += 4;
  }
 }
}