[游戏开发]Unity 获取屏幕点击对象二

框选屏幕中的gameobject，或者点选（处理当场景中的物体可以重叠的时候）屏幕中的gameobject

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using Unity.Mathematics;

public class SelectControl : MonoBehaviour
{
    private float3 startPos;
    private float3 endPos;

    public void OnUpdate()
    {
        if (Input.GetMouseButtonDown(0))
        {
            startPos = WorldTouchPos();
        }

        if (Input.GetMouseButtonUp(0))
        {
            endPos = WorldTouchPos();

            float3 downLeftPos = new float3(math.min(startPos.x, endPos.x), 0, math.min(startPos.z, endPos.z));
            float3 upRightPos = new float3(math.max(startPos.x, endPos.x), 0, math.max(startPos.z, endPos.z));

            //设置点选（点选只选中，重叠的多个目标中的一个目标）
            float minDis = 2;//点选范围
            float dis = math.distance(downLeftPos, upRightPos);
            int clickNum = dis < minDis ? 1: -1;
            if (clickNum > 0)
            {
                downLeftPos += new float3(-1, 0, -1) * (minDis - dis) * 1f;
                upRightPos += new float3(1, 0, 1) * (minDis - dis) * 1f;
            }

			List<GameObject> allObject = new List<GameObject>();//这里设置你想搜索的目标
			for(int index =0; index < allObject.Count; index ++)
			{
				var pos = allObject[index].transform.position;
                if (clickNum > 0)//点选直选中一个
                {
                    if (pos.x >= downLeftPos.x && pos.z >= downLeftPos.z && pos.x <= upRightPos.x && pos.z <= upRightPos.z)
                    {
                    	//这里是你点选到的目标
                        clickNum--;
                    }
                }
                else if(clickNum == -1)
                {
                    if (pos.x >= downLeftPos.x && pos.z >= downLeftPos.z && pos.x <= upRightPos.x && pos.z <= upRightPos.z)
                    {
                    	//这里是你框选的到目标
                    }
                }
			}
        }
    }

    public static Vector3 WorldTouchPos()
    {
        return Camera.main.ScreenToWorldPoint(GetTouchPosition());
    }

    public static Vector3 GetTouchPosition()
    {
#if UNITY_EDITOR || UNITY_STANDALONE_WIN
        return Input.mousePosition;
#else
         return Input.touches[0].position;
#endif
    }
}