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

[RequireComponent(typeof(LineRenderer))]
public class SingleWaveLineRenderer : MonoBehaviour
{
    public LineRenderer lineRenderer;

    public int pointCount = 100;
    public float lineLength = 6f;

    public float amplitude = 0.5f;
    public float wavelength = 2f;
    public float waveSpeed = 2f;
    public float phaseOffset = 0f;

    public Transform startPointTransform; // ✅ 控制起点位置和方向的锚点

    private float frequency;

    void Start()
    {
        frequency = 2 * Mathf.PI / wavelength;
        lineRenderer.positionCount = pointCount;

        if (lineRenderer.material != null)
            lineRenderer.material.color = Color.cyan;
    }

    void Update()
    {
        float step = lineLength / (pointCount - 1);
        float time = Time.time;

        Vector3 startPos = startPointTransform.position;
        Vector3 direction = startPointTransform.right; // ✅ 方向：起点 Transform 的右方向

        for (int j = 0; j < pointCount; j++)
        {
            float x = j * step;
            float y = amplitude * Mathf.Sin(frequency * x - waveSpeed * time + phaseOffset);

            // ✅ 构建偏移：方向 + 垂直扰动（up 方向）
            Vector3 offset = direction.normalized * x + startPointTransform.up * y;

            lineRenderer.SetPosition(j, startPos + offset);
        }
    }
}