using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;
/// <summary>
/// 摇杆脚本【挂到可以设定的拖拽区域UI上】
/// </summary>
public class M_Touch : MonoBehaviour,IPointerDownHandler,IPointerUpHandler,IDragHandler {
public Transform TouchBack;//摇杆背景圈
public Transform Touch;//摇杆图标
//摇杆最大位移【应根据屏幕变化比例变化】
private const float MaxLen = 100;
public Vector2 starVec = Vector2.zero;
void Start()
{
starVec = Touch.position;//记录摇杆本来屏幕的位置
}
public void OnPointerDown(PointerEventData eventData)
{
DoMove(eventData);
}
public void OnPointerUp(PointerEventData eventData)
{
Touch.localPosition = Vector2.zero;//抬起手指回最初点
}
public void OnDrag(PointerEventData eventData)
{
DoMove(eventData);
}
private void DoMove(PointerEventData eventData)
{
Vector2 dir = eventData.position - starVec;
float len = dir.magnitude;
if (len > MaxLen)
{
//限定向量长度
Vector2 clampDir = Vector2.ClampMagnitude(dir, MaxLen);
Touch.position = starVec + clampDir;
}
else
{
Touch.position = eventData.position;
}
}
}