Vector2.MoveTowards

Description

将点 current 移向 /target/。

This is essentially the same as Vector2.Lerp but instead the function will ensure that the distance never exceeds maxDistanceDelta. Negative values of maxDistanceDelta pushes the vector away from target.

using UnityEngine;

// 2D MoveTowards example
// Move the sprite to where the mouse is clicked
//
// Set speed to -1.0f and the sprite will move
// away from the mouse click position forever

public class ExampleClass : MonoBehaviour
{
    private float speed = 10.0f;
    private Vector2 target;
    private Vector2 position;
    private Camera cam;

    void Start()
    {
        target = new Vector2(0.0f, 0.0f);
        position = gameObject.transform.position;

        cam = Camera.main;
    }

    void Update()
    {
        float step = speed * Time.deltaTime;

        // move sprite towards the target location
        transform.position = Vector2.MoveTowards(transform.position, target, step);
    }

    void OnGUI()
    {
        Event currentEvent = Event.current;
        Vector2 mousePos = new Vector2();
        Vector2 point = new Vector2();

        // compute where the mouse is in world space
        mousePos.x = currentEvent.mousePosition.x;
        mousePos.y = cam.pixelHeight - currentEvent.mousePosition.y;
        point = cam.ScreenToWorldPoint(new Vector3(mousePos.x, mousePos.y, 0.0f));

        if (Input.GetMouseButtonDown(0))
        {
            // set the target to the mouse click location
            target = point;
        }
    }
}