using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
// using Sirenix.OdinInspector;

[ExecuteAlways]
public class NBShaderSpriteHelper : MonoBehaviour
{
    public Sprite sprite;
    // [ReadOnly]
    public SpriteRenderer spRenderer;
    // [ReadOnly]
    public Image image;

    [InspectorButton("初始化","Init")]
    public bool ButtomInspector;

    private Material mat;
    
    
    
    // Start is called before the first frame update
    void Start()
    {
        Init();
    }
    
    void Init()
    {
        if (TryGetComponent<SpriteRenderer>(out SpriteRenderer spr))
        {
            spRenderer = spr;
            sprite = spr.sprite;
        }
        else
        {
            if (TryGetComponent<Image>(out Image im))
            {
                image = im;
                sprite = im.sprite;
            }
        }

        

        if (sprite)
        {
           Texture texture = sprite.texture;
           Rect rect = sprite.textureRect;
           // sharedMaterial.SetVector("_BaseMapReverseST",CalScaleOffset(spRenderer.sprite.textureRect,spRenderer.sprite.texture));

            if (spRenderer)
            {
                if (Application.isPlaying)
                {
                    mat = spRenderer.material;
                }
                else
                {
                    mat = spRenderer.sharedMaterial;
                }
            }
            else if(image)
            {
                mat = image.material;
            }

            if (mat && mat.shader.name == "XuanXuan/Effects/Particle_NiuBi")
            {
                mat.SetVector("_MainTex_Reverse_ST",CalScaleOffset(rect,texture));
                Debug.Log(mat.name);
            }
        }
     
        
   
    }

    Vector4 CalScaleOffset(Rect textureRect,Texture texture)
    {
        //这是一个反向的scale offset。
        //算法：如果原scale offset。转换后会是 scaleAfter= 1 / scale , offsetAfter = - offset/scale;
        Vector2 scaleAfter = new Vector2(texture.width / textureRect.width, texture.height / textureRect.height);
        Vector2 offsetAfter = new Vector2(-(textureRect.x / texture.width) * scaleAfter.x,
            -(textureRect.y / texture.height) * scaleAfter.y);
        Vector4 scaleOffset = new Vector4(scaleAfter.x,scaleAfter.y,offsetAfter.x,offsetAfter.y);
        return scaleOffset;
    }
}