using UnityEngine;

public class ElectricLineController : MonoBehaviour
{
    public Transform pointA;
    public Transform pointB;
    public Material electricMaterial;

    public int columns = 2;  // 帧列数
    public int rows = 8;     // 帧行数
    public float frameRate = 0.05f;

    private LineRenderer lineRenderer;
    private int currentFrame = 0;
    private float timer = 0f;

    void Start()
    {
        lineRenderer = GetComponent<LineRenderer>();
        lineRenderer.positionCount = 2;

        Vector2 scale = new Vector2(1f / columns, 1f / rows);
        electricMaterial.SetTextureScale("_MainTex", scale);

        /*electricMaterial.SetInt("_ZWrite", 0); // 不写入深度
        electricMaterial.SetInt("_ZTest", (int)UnityEngine.Rendering.CompareFunction.Always); // 永远显示
        electricMaterial.renderQueue = 5000; // Overlay*/

    }


    void Update()
    {
        // 实时更新两点位置
        if (pointA && pointB)
        {
            lineRenderer.SetPosition(0, pointA.position);
            lineRenderer.SetPosition(1, pointB.position);
        }

        // 播放序列帧
        timer += Time.deltaTime;
        if (timer >= frameRate)
        {
            timer -= frameRate;
            currentFrame = (currentFrame + 1) % (columns * rows);

            int col = currentFrame % columns;
            int row = currentFrame / columns;

            // Y 要倒着来
            Vector2 offset = new Vector2((float)col / columns, 1f - ((float)(row + 1) / rows));
            electricMaterial.SetTextureOffset("_MainTex", offset);
        }
    }
}