BallControl

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

public class BallControl : MonoBehaviour
{

    private GameObject cueBall;
    public float power = 10.0f;
    public float maxDrag = 5.0f;

    private LineRenderer lr;
    private Rigidbody rb;


    Vector3 dragStartPos;
    Touch touch;

    private void Start()
    {
        cueBall = GameObject.Find("CueBall");
        rb = cueBall.GetComponent<Rigidbody>();
        lr = cueBall.GetComponent <LineRenderer>();
    }

    private void Update()
    {
        TouchActions();
    }

    void TouchActions()
    {
        if (Input.touchCount > 0)
        {
            touch = Input.GetTouch(0);
            if (touch.phase == TouchPhase.Began)
            {
                DragStart();
            }
            if (touch.phase == TouchPhase.Moved)
            {
                Dragging();
            }
            if (touch.phase == TouchPhase.Ended)
            {
                DragRelease();
            }
        }
    }
    void DragStart()
    {
        dragStartPos = Camera.main.ScreenToWorldPoint(touch.position);
        dragStartPos.y = 0;
        lr.positionCount = 1;
        lr.SetPosition(0,dragStartPos);

    }
    void Dragging()
    {
        Vector3 draggingPos = Camera.main.ScreenToWorldPoint(touch.position);
        draggingPos.y = 0;
        lr.positionCount = 2;
        lr.SetPosition(1,draggingPos);
    }

    void DragRelease()
    {
        lr.positionCount = 0;
        Vector3 dragReleasePos = Camera.main.ScreenToWorldPoint(touch.position);
        dragReleasePos.y = 0;
        Vector3 force = dragStartPos - dragReleasePos;
        Vector3 clampedForce = Vector3.ClampMagnitude(force, maxDrag) * power;
        Debug.Log(clampedForce);
        rb.AddForce(clampedForce,ForceMode.Impulse);
    }
}