using System;
using UnityEngine;
using System.Collections.Generic;

public class ThePixelgon : MonoBehaviour
{
  public List<Vector3> vertices;

  public Mesh meshPoint;
  public Material mat;
  // just edit in the inspector (arrays and such)


  void Start()
  {

  }

  void Update()
  {
    Mesh mesh = new Mesh();
    mesh.SetVertices(vertices);

    // triangle 
    // clock wise
    // 0 1 2, 1 2 3 ?
    List<int> tris = new List<int>();//{ 0, 1, 2 };

    int trav = 1;
    int numSides = vertices.Count;


    for (int i = 0; i < numSides - 2; i++)
    {
      tris.Add(0);
      tris.Add(trav);
      tris.Add(trav + 1);
      trav++;
    }

    /*
    */

    mesh.SetTriangles(tris, 0);
    // pixelgon
    // ngon
    // vertices, tris, uvs

    List<Vector2> uvs = new List<Vector2>();
    // uvs
    Vector3 cv = Vector3.zero;
    for (int i = 0; i < vertices.Count; i++)
    {
      cv += vertices[i];
    }

    cv = cv / vertices.Count;

    Vector3 farthest = cv;
    for (int i = 0; i < vertices.Count; i++)
    {
      if (Vector3.Distance(cv, vertices[i]) > Vector3.Distance(cv, farthest))
      {
        farthest = vertices[i];
      }
    }
    float radius = Vector3.Distance(cv, farthest);

    Vector3 normal = Vector3.Cross(vertices[1] - vertices[0], vertices[vertices.Count - 1] - vertices[0]).normalized;

    for (int i = 0; i < vertices.Count; i++)
    {
      Vector3 local = vertices[i] - cv;
      local = Quaternion.Inverse(Quaternion.LookRotation(normal)) * local;
      Vector3 uvPos = new Vector2(local.x + radius, local.y + radius);
      // scaling
      Debug.Log(uvPos);
      uvs.Add(uvPos);
    }
    mesh.SetUVs(0, uvs);

    Graphics.DrawMesh(meshPoint, cv, Quaternion.identity, mat, 0);
    Graphics.DrawMesh(meshPoint, farthest, Quaternion.identity, mat, 0);
    Graphics.DrawMesh(meshPoint, cv + normal, Quaternion.identity, mat, 0);


    int width = 4, height = 4;

    var texture = new Texture2D(width, height, TextureFormat.ARGB32, false);

    bool black = true;

    for (int j = 0; j < width; j++)
    {
      for (int k = 0; k < height; k++)
      {
        if (black)
          texture.SetPixel(j, k, Color.black);
        else
          texture.SetPixel(j, k, Color.white);
        black = !black;
      }
      black = !black;
    }
    /*
        var texture = new Texture2D(2, 2, TextureFormat.ARGB32, false);
        texture.SetPixel(0, 0, Color.black);
        texture.SetPixel(1, 0, Color.white);
        texture.SetPixel(1, 1, Color.black);
        texture.SetPixel(0, 1, Color.white);
        */
    texture.Apply();

    texture.filterMode = FilterMode.Point;
    mat.mainTexture = texture;


    // pixels
    // texture, scale, rotation, rendering options(point filtering, and cutout transparency)

    // just reference a 2d texture for now

    Graphics.DrawMesh(mesh,
      Vector3.zero,
      Quaternion.identity,
      mat, 0
    );
  }
}