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

public class Parallax : MonoBehaviour
{
    [SerializeField] private new GameObject camera;
    [SerializeField] private float parallaxScale;
    [SerializeField] private float PixelsPerUnit;

    private float startPos, length;
    private void Start()
    {
        startPos = transform.position.x;
        length = GetComponent<SpriteRenderer>().bounds.size.x;
    }

    private void Update()
    {
        float temp = camera.transform.position.x * (1 - parallaxScale);
        float dist = camera.transform.position.x * parallaxScale;

        transform.position = Clamp(new Vector2(startPos + dist, transform.position.y), PixelsPerUnit);

        if (temp > startPos + length / 2)
            startPos += length;
        else if (temp < startPos - length / 2)
            startPos -= length;
    }

    private Vector2 Clamp(Vector2 location, float ppu)
    {
        return new Vector2(Mathf.CeilToInt(location.x * ppu), Mathf.CeilToInt(location.y * ppu)) / ppu;
    }
}