Jani´s Firsperson Control

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

public class Firstperson_Control : MonoBehaviour
{
    Camera mainCamera;

    [Header("Mouse")]
    public float mouseSensitivity = 100f;
    float mouseX, mouseY;
    float xRotation = 0f;

    Rigidbody rb;
    CapsuleCollider cc;
    bool isGrounded;

    bool cantStand;
    bool isCrouching;
    float orginalHeight;
    float wantedHeight;

    [Header("Abilities")]
    public float gravity = 10.0f;
    public bool canMove;

    float movingSpeed;
    float inputX, inputZ;
    Vector3 movingDirection;

    public float walkSpeed = 3.2f;
    public float crouchSpeed = 2.4f;
    public float runSpeed = 4.6f;

    public bool canJump;
    public float jumpForce;

    [Header("Pick & Drop gameObject")]
    public float smooth;
    public float holdingdDistance;
    bool isCarrying;

    //[HideInInspector]
    public GameObject carriedObject;

    [Header("Cursor")]
    public Image cursor;
    public Sprite Default, Active;

    private void Awake()
    {
        mainCamera = GameObject.FindGameObjectWithTag("MainCamera").GetComponent<Camera>();

        if(mainCamera == null)
        {
            Debug.LogError("MainCamera tagged camera was not found");
        }

        mainCamera.transform.position = transform.position + new Vector3(0, 1.5f, 0);
        mainCamera.transform.parent = transform;

        rb = GetComponent<Rigidbody>();

        if(rb == null)
        {
            rb = gameObject.AddComponent<Rigidbody>();
        }

        rb.freezeRotation = true;
        rb.useGravity = false;

        cc = GetComponent<CapsuleCollider>();

        orginalHeight = cc.height;
        wantedHeight = orginalHeight / 2;
    }

    private void Start()
    {
        Cursor.lockState = CursorLockMode.Locked;
    }

    private void Update()
    {
        isGrounded = Physics.Raycast(transform.position + new Vector3(0,0.2f,0), -Vector3.up, 0.5f);

        if (isCrouching)
        {
            cantStand = Physics.Raycast(transform.position + new Vector3(0, 1.6f, 0), Vector3.up, 0.5f);
        }

        Inputs();
        Rotate();
        Speed();
        Crouching();
    }

    private void FixedUpdate()
    {
        Move();

        if(isCarrying)
        {
            Carry(carriedObject);
        }

        if(!isCarrying)
        {
            PickUp();
        }
    }

    void Inputs()
    {
        //Mouse
        mouseX = Input.GetAxis("Mouse X") * mouseSensitivity * Time.deltaTime;
        mouseY = Input.GetAxis("Mouse Y") * mouseSensitivity * Time.deltaTime;

        //Camera
        xRotation -= mouseY;
        xRotation = Mathf.Clamp(xRotation, -90f, 90f);

        if (isGrounded && canMove)
        {
            //Player
            inputX = Input.GetAxis("Horizontal");
            inputZ = Input.GetAxis("Vertical");
        }

        //Calculate + Speed
        movingDirection = transform.right * inputX + transform.forward * inputZ;
        movingDirection = movingDirection.normalized * movingSpeed;
    }

    void Rotate()
    {
        //Player
        transform.Rotate(Vector3.up * mouseX);

        //Camera
        mainCamera.transform.localRotation = Quaternion.Euler(xRotation, 0f, 0f);
    }

    void Move()
    {

        //Player
        Vector3 velocity = rb.velocity;
        Vector3 velocityChange = (movingDirection - velocity);
        velocityChange.y = 0;
        rb.AddForce(velocityChange, ForceMode.VelocityChange);

        //Jump
        if (isGrounded && canJump && !isCrouching)
        {
            if (Input.GetKeyDown(KeyCode.Space))
            {
                rb.velocity = new Vector3(velocity.x, Mathf.Sqrt(2 * jumpForce * gravity), velocity.z);
            }
        }


        // We apply gravity manually for more tuning control
        rb.AddForce(new Vector3(0, -gravity * rb.mass, 0));
    }

    void Speed()
    {
        if(movingSpeed != crouchSpeed && isCrouching)
        {
            movingSpeed = crouchSpeed;
        }

        if(movingSpeed != walkSpeed && !isCrouching)
        {
            movingSpeed = walkSpeed;
        }

        if(movingSpeed != runSpeed && !isCrouching && Input.GetKey(KeyCode.LeftShift))
        {
            movingSpeed = runSpeed;
        }
    }

    void Crouching()
    {
        if (Input.GetKeyDown(KeyCode.V) && !cantStand)
        {
            isCrouching = !isCrouching;
        }

        if (!cantStand && !isCrouching)
        {
            cc.height = Mathf.Lerp(cc.height, orginalHeight, 5f * Time.deltaTime);
            cc.center = Vector3.Lerp(cc.center, new Vector3(0, orginalHeight / 2 , 0), 5f * Time.deltaTime);
            mainCamera.transform.position = Vector3.Slerp(mainCamera.transform.position, transform.position + new Vector3(0, 1.5f, 0), 5f * Time.deltaTime);
        }

        if (!cantStand && isCrouching)
        {
            cc.height = Mathf.Lerp(cc.height, wantedHeight, 5f * Time.deltaTime);
            cc.center = Vector3.Lerp(cc.center, new Vector3(0, wantedHeight / 2, 0), 5f * Time.deltaTime);
            mainCamera.transform.position = Vector3.Slerp(mainCamera.transform.position, transform.position + new Vector3(0, 1f, 0), 5f * Time.deltaTime);
        }
    }

    void Carry(GameObject o)
    {
        o.transform.position = Vector3.Lerp(o.transform.position, mainCamera.transform.position + mainCamera.transform.forward * holdingdDistance, 5f * Time.deltaTime);
    }

    void PickUp()
    {
        if(Input.GetKeyDown(KeyCode.F))
        {
            int x = Screen.width / 2;
            int y = Screen.height / 2;

            Ray ray = mainCamera.ScreenPointToRay(new Vector3(x, y));
            RaycastHit hit;
            if(Physics.Raycast(ray, out hit))
            {
                if(hit.transform.tag == "Pickable")
                {
                    carriedObject = hit.transform.gameObject;
                    isCarrying = true;
                }
            }
        }
    }
}