Vector2.MoveTowards

描述

将一个点 current 移动到 target。

这与 Vector2.Lerp 类似，但该函数会确保距离永远不会超过 maxDistanceDelta。 maxDistanceDelta 的负值会将向量推离 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;
        }
    }
}