Unity3d 札记-Tanks Tutorial 知识点汇总---如何发射子弹

using UnityEngine;
using UnityEngine.UI;

public class TankShooting : MonoBehaviour
{
    public int m_PlayerNumber = 1;       
    public Rigidbody m_Shell;            
    public Transform m_FireTransform;    
    public Slider m_AimSlider;           
    public AudioSource m_ShootingAudio;  
    public AudioClip m_ChargingClip;     
    public AudioClip m_FireClip;         
    public float m_MinLaunchForce = 15f; 
    public float m_MaxLaunchForce = 30f; 
    public float m_MaxChargeTime = 0.75f;

    
    private string m_FireButton;         
    private float m_CurrentLaunchForce;  
    private float m_ChargeSpeed;         
    private bool m_Fired;                


    private void OnEnable()
    {
        m_CurrentLaunchForce = m_MinLaunchForce;
        m_AimSlider.value = m_MinLaunchForce;
    }


    private void Start()
    {
        m_FireButton = "Fire" + m_PlayerNumber;

        m_ChargeSpeed = (m_MaxLaunchForce - m_MinLaunchForce) / m_MaxChargeTime;
    }
    

    private void Update()
    {
        // Track the current state of the fire button and make decisions based on the current launch force.
        m_AimSlider.value = m_CurrentLaunchForce;

        if (m_CurrentLaunchForce >= m_MaxLaunchForce && !m_Fired) {
            m_CurrentLaunchForce = m_MaxLaunchForce;
            Fire ();
        } else if (Input.GetButtonDown (m_FireButton)) {
            m_Fired = false;
            m_CurrentLaunchForce = m_MinLaunchForce;
            m_ShootingAudio.clip = m_ChargingClip;
            m_ShootingAudio.Play ();
        } else if (Input.GetButton (m_FireButton) && !m_Fired) {
            m_CurrentLaunchForce += m_ChargeSpeed * Time.deltaTime;
            m_AimSlider.value = m_CurrentLaunchForce;
        } else if (Input.GetButtonUp (m_FireButton)&& !m_Fired) {
            Fire ();
        }
    }


    private void Fire()
    {
        // Set the fired flag so only Fire is only called once.
        m_Fired = true;

        // Create an instance of the shell and store a reference to it‘s rigidbody.
        Rigidbody shellInstance =
            Instantiate (m_Shell, m_FireTransform.position, m_FireTransform.rotation) as Rigidbody;

        // Set the shell‘s velocity to the launch force in the fire position‘s forward direction.
        shellInstance.velocity = m_CurrentLaunchForce * m_FireTransform.forward; ;

        // Change the clip to the firing clip and play it.
        m_ShootingAudio.clip = m_FireClip;
        m_ShootingAudio.Play ();

        // Reset the launch force.  This is a precaution in case of missing button events.
        m_CurrentLaunchForce = m_MinLaunchForce;
    }
}