MoveDirection

描述

这是一个 8 方向移动枚举。

MoveDirection 提供了一种在移动状态之间切换的方式。您必须将这些状态分配给操作，例如，处于 Up 状态时，通过向上矢量移动游戏对象。

与必须始终包含大量矢量和计算相比，具有此类状态更容易识别。相反，您只需在一个部分中定义希望状态执行的操作，并在需要时切换到相应状态即可。

//This is a full example of how a GameObject changes direction using MoveDirection states
//Assign this script to a visible GameObject (with a Rigidbody attached) to see it in action

using UnityEngine;
using UnityEngine.EventSystems;

public class Example : MonoBehaviour
{
    Vector3 m_StartPosition, m_StartForce;
    Rigidbody m_Rigidbody;
    //Use Enum for easy switching between direction states
    MoveDirection m_MoveDirection;

    //Use these Vectors for moving Rigidbody components
    Vector3 m_ResetVector;
    Vector3 m_UpVector;
    Vector3 m_RightVector;
    const float speed = 5.0f;

    void Start()
    {
        //You get the Rigidbody component attached to the GameObject
        m_Rigidbody = GetComponent<Rigidbody>();
        //This starts with the Rigidbody not moving in any direction at all
        m_MoveDirection = MoveDirection.None;

        //These are the GameObject’s starting position and Rigidbody position
        m_StartPosition = transform.position;
        m_StartForce = m_Rigidbody.transform.position;

        //This Vector is set to 1 in the y axis (for moving upwards)
        m_UpVector = Vector3.up;
        //This Vector is set to 1 in the x axis (for moving in the right direction)
        m_RightVector = Vector3.right;
        //This Vector is zeroed out for when the Rigidbody should not move
        m_ResetVector = Vector3.zero;
    }

    void Update()
    {
        //This switches the direction depending on button presses
        switch (m_MoveDirection)
        {
            //The starting state which resets the object
            case MoveDirection.None:
                //Reset to the starting position of the GameObject and Rigidbody
                transform.position = m_StartPosition;
                m_Rigidbody.transform.position = m_StartForce;
                //This resets the velocity of the Rigidbody
                m_Rigidbody.velocity = m_ResetVector;
                break;

            //This is for moving in an upwards direction
            case MoveDirection.Up:
                //Change the velocity so that the Rigidbody travels upwards
                m_Rigidbody.velocity = m_UpVector * speed;
                break;

            //This is for moving left
            case MoveDirection.Left:
                //This moves the Rigidbody to the left (minus right Vector)
                m_Rigidbody.velocity = -m_RightVector * speed;
                break;

            //This is for moving right
            case MoveDirection.Right:
                //This moves the Rigidbody to the right
                m_Rigidbody.velocity = m_RightVector * speed;
                break;

            //This is for moving down
            case MoveDirection.Down:
                //This moves the Rigidbody down
                m_Rigidbody.velocity = -m_UpVector * speed;
                break;
        }
    }

    void OnGUI()
    {
        //Press the reset Button to switch to no mode
        if (GUI.Button(new Rect(100, 0, 150, 30), "Reset"))
        {
            //Switch to start/reset case
            m_MoveDirection = MoveDirection.None;
        }

        //Press the Left button to switch the Rigidbody direction to the left
        if (GUI.Button(new Rect(100, 30, 150, 30), "Move Left"))
        {
            //Switch to the left direction
            m_MoveDirection = MoveDirection.Left;
        }

        //Press the Up button to switch the Rigidbody direction to upwards
        if (GUI.Button(new Rect(100, 60, 150, 30), "Move Up"))
        {
            //Switch to Up Direction
            m_MoveDirection = MoveDirection.Up;
        }

        //Press the Down button to switch the direction to down
        if (GUI.Button(new Rect(100, 90, 150, 30), "Move Down"))
        {
            //Switch to Down Direction
            m_MoveDirection = MoveDirection.Down;
        }

        //Press the right button to switch to the right direction
        if (GUI.Button(new Rect(100, 120, 150, 30), "Move Right"))
        {
            //Switch to Right Direction
            m_MoveDirection = MoveDirection.Right;
        }
    }
}

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