Shooter.cs

using System.Collections;
using UnityEngine;

public class Shooter : MonoBehaviour {

        public LayerMask layerMask;
        public Camera mainCamera;

        public Transform target;
        public Rigidbody bullet;
        public Transform muzzle;

        public int fireCount = 1;

        public float speed = 10f;
        public float threshold = 1f;

        public float fireDelay = 0.14f;
        public float bulletPower = 10f;
        public float bulletLifeTime = 2f;
        public float bulletAngle = 15f;

        Vector3 targetPosition;
        bool isMoving;
        bool isFiring;

        // Update is called once per frame
        void Update()
        {
            RaycastHit hit;
            Vector3 mos = Input.mousePosition;
            mos.z = mainCamera.farClipPlane;

            Vector3 dir = mainCamera.ScreenToWorldPoint(mos);

            Debug.DrawRay(mainCamera.transform.position, mainCamera.transform.position + mos.z * 2 * dir);

            if (Physics.Raycast(mainCamera.transform.position, dir, out hit, 2 * mos.z, layerMask)) {
                transform.LookAt(hit.point);
            }

            if (Input.GetMouseButtonDown(1)) {
                target.position = hit.point;
                targetPosition = hit.point;
                isMoving = true;
            }

            if (Input.GetMouseButtonDown(0)) {
                isFiring = true;
                StartCoroutine(nameof(Fire));
            }

            if (Input.GetMouseButtonUp(0)) {
                isFiring = false;
                StopCoroutine(nameof(Fire));
            }
        }

        IEnumerator Fire()
        {
            while (isFiring) {
                yield return null;
                DoFire();
                yield return new WaitForSeconds(fireDelay);
            }
        }

        void DoFire()
        {
            for (int i = 0; i < fireCount; i++) {

                Rigidbody bulletInstance2 = Instantiate(bullet);
                bulletInstance2.gameObject.SetActive(true);
                bulletInstance2.transform.position = muzzle.position;
                
                // 홀 짝 구분
                Vector3 angle = transform.rotation.eulerAngles +
                                (i - fireCount / 2 + (fireCount % 2 == 0 ? 0.5f : 0.0f)) * bulletAngle * Vector3.up;

                bulletInstance2.transform.rotation = Quaternion.Euler(angle);
                bulletInstance2.AddForce(bulletInstance2.transform.forward * bulletPower);
                Destroy(bulletInstance2.gameObject, bulletLifeTime);
            }
        }

        void FixedUpdate()
        {
            if (isMoving) {

                transform.position = Vector3.Lerp(new Vector3(transform.position.x, 0, transform.position.z),
                    targetPosition, Mathf.Clamp(speed * Time.fixedDeltaTime, 0, 1f));

                float sqr = Vector3.SqrMagnitude(transform.position - targetPosition);
                if (sqr < threshold) {
                    isMoving = false;
                }
            }
        }
    }