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

public class MeshImage : Image
{
    private Vector2[] pos;
    private Vector2[] uvs;

    public int rotatePointIndex;
    [SerializeField]
    private bool isErrorReset;

    public void SetPos(Vector2[] pos, bool referesh)
    {
        this.pos = pos;
        this.uvs = SetUvs(pos);
        if (referesh)
        {
            SetAllDirty();
        }
    }

    public void SetSize(float width, float height, bool adaptPointToSize)
    {
        rectTransform.sizeDelta = new Vector2(width, height);
        if (adaptPointToSize)
        {
            float minW = 9999;
            float minH = 9999;
            float maxW = -1;
            float maxH = -1;
            foreach (var po in pos)
            {
                if (po.x < minW)
                {
                    minW = po.x;
                }

                if (po.x > maxW)
                {
                    maxW = po.x;
                }

                if (po.y < minH)
                {
                    minH = po.y;
                }

                if (po.y > maxH)
                {
                    maxH = po.y;
                }
            }

            float w = maxW - minW;
            float h = maxH - minH;

            float sw = w / width;
            float sh = h / height;

            float s = sw > sh ? sw : sh;
            for (int i = 0; i < pos.Length; i++)
            {
                pos[i] /= s;
            }

            SetPos(pos, true);
        }
    }

    public void SetRotatePointIndex(int index)
    {
        rotatePointIndex = index;
    }


    public Vector2[] GetPos()
    {
        return pos;
    }

    private Vector2[] SetUvs(Vector2[] tempPos)
    {
        Vector2[] tempUvs = new Vector2[tempPos.Length];
        for (int i = 0; i < tempPos.Length; i++)
        {
            tempUvs[i] = new Vector2(tempPos[i].x / rectTransform.rect.width + 0.5f,
                tempPos[i].y / rectTransform.rect.height + 0.5f);
        }

        return tempUvs;
    }

    protected override void OnPopulateMesh(VertexHelper vh)
    {
        Vector2[] tempPos = pos;
        Vector2[] tempUvs = uvs;
        if (tempPos == null)
        {
            base.OnPopulateMesh(vh);
            return;
        }

        Color32 color32 = color;
        vh.Clear();

        try
        {
            for (int i = 0; i < tempPos.Length; i++)
            {
                vh.AddVert(tempPos[i], color32, tempUvs[i]);
            }



            Triangulator triangular = new Triangulator(tempPos); //计算三角面的类
            int[] indices = triangular.Triangulate(); //得到三角面

            for (int i = 0; i < indices.Length - 2; i += 3)
            {
                vh.AddTriangle(indices[i], indices[i + 1], indices[i + 2]);
            }
        }
        catch (Exception e)
        {
            Debug.LogError(e.ToString());
            base.OnPopulateMesh(vh);
        }
    }
}