How can i set a Range values min/max according to another variable value?

Question

In one script:

using System.Collections;
using System.Collections.Generic;
using System.Linq;
using UnityEditor;
using UnityEngine;
using UnityEngine.UI;

public class LevelGenerator : MonoBehaviour
{
    public GameObject Node;
    public Vector3 nodeScale = new Vector3(4, 1, 4);
    [Range(3, 100)]
    public int mapSize = 10;
    public float Spacing = 10;

    private List<GameObject> Nodes = new List<GameObject>();
    private List<GameObject> EndStartPoints = new List<GameObject>();
    private int currentMapSize;

    private void Start()
    {
        currentMapSize = mapSize;
        GenerateNew();
        GenerateRandom(mapSize);
    }

    public void Generate()
    {
        if (Nodes.Count > 0)
            Nodes = new List<GameObject>();

        if (Node == null)
            Node = UnityEngine.GameObject.FindGameObjectWithTag("Main Node");

        for (int x = 0; x < mapSize; x++)
        {
            float positionWidth = Spacing * (float)x;

            for (int z = 0; z < mapSize; z++)
            {
                float positionHieght = Spacing * (float)z;
                GameObject Node = Instantiate(this.Node, Vector3.zero, this.Node.transform.rotation) as GameObject;
                Node.transform.parent = transform;
                Node.transform.localPosition = new Vector3(positionWidth, 0, positionHieght);
                Node.transform.localScale = new Vector3(nodeScale.x, nodeScale.y, nodeScale.z);
                Node.tag = "Node";
                Node.name = "Node";
                Nodes.Add(Node);
            }
        }
    }

    public void GenerateNew()
    {
        currentMapSize = mapSize;
        DestroyNodes();

        Node = UnityEngine.GameObject.FindGameObjectWithTag("Main Node");
        Generate();
        GenerateRandom(mapSize);
    }

    public void DestroyNodes()
    {
        GameObject[] nodes = UnityEngine.GameObject.FindGameObjectsWithTag("Node");

        if (nodes.Length == 0)
        {
            //Debug.Log("No nodes to destroy found");
        }
        else
        {
            for (int i = 0; i < nodes.Length; i++)
            {
                DestroyImmediate(nodes[i]);
            }
        }
    }

    private void Update()
    {
        Erase();
    }

    private void Erase()
    {
        if (Input.GetMouseButton(0))
        {
            Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
            RaycastHit hit;
            if (Physics.Raycast(ray, out hit))
            {
                if (hit.collider.tag == "Node")
                {
                    Destroy(hit.collider.gameObject);
                }
            }
        }
    }

    private void GenerateRandom(int gridSize)
    {
        List<int> selectedIndexes = new List<int>();

        //Create an array for indexes of the TOP side
        var arr = new int[gridSize];
        for (int i = 0; i < gridSize; i++)
        {
            arr[i] = i;
        }
        int mynum = arr[Random.Range(0, arr.Length)];
        GameObject Top = Nodes[mynum];
        selectedIndexes.Add(mynum);

        //Create an array for indexes of the LEFT side
        int mynum1 = 0;
        var arr1 = new int[gridSize];
        for (int i = 0; i < gridSize; i++)
        {
            arr1[i] = i * gridSize;
        }
        do
        {
            mynum1 = arr1[Random.Range(0, arr1.Length)];
        }
        while (selectedIndexes.Contains(mynum1));
        GameObject Left = Nodes[mynum1];
        selectedIndexes.Add(mynum1);


        //Create an array for indexes of the BOTTOM side
        int mynum2 = 0;
        var arr2 = new int[gridSize];
        for (int i = 0; i < gridSize; i++)
        {
            arr2[i] = (gridSize * (gridSize - 1)) + i;   //Reach the last row and iterate with i.
        }
        do
        {
            mynum2 = arr2[Random.Range(0, arr2.Length)];
        }
        while (selectedIndexes.Contains(mynum2));
        GameObject Bottom = Nodes[mynum2];
        selectedIndexes.Add(mynum2);

        //Create an array for indexes of the RIGHT side
        int mynum3 = 0;
        var arr3 = new int[gridSize];
        for (int i = 0; i < gridSize; i++)
        {
            arr3[i] = (i * gridSize) + gridSize - 1;
        }
        do
        {
            mynum3 = arr3[Random.Range(0, arr3.Length)];
        }
        while (selectedIndexes.Contains(mynum3));
        GameObject Right = Nodes[mynum3];
        selectedIndexes.Add(mynum3);

        /*DestroyImmediate(Right);
        DestroyImmediate(Left);
        DestroyImmediate(Top);
        DestroyImmediate(Bottom);*/

        EndStartPoints = new List<GameObject>();
        EndStartPoints.Add(Left);
        EndStartPoints.Add(Right);

        selectedIndexes.Clear();
    }

    private void OnValidate()
    {
        if (currentMapSize != mapSize)
        {
            UnityEditor.EditorApplication.delayCall += () =>
            {
                GenerateNew();
            };
        }
    }
}

Then i'm creating a grid of gameobjects and it will be always 10x10 if it was 11 then 11x11 or 9x9.

In another script:

using UnityEngine.UI;
using System;

public class WayPoints : MonoBehaviour
{
    public GameObject[] wayPoints;

    [Range(5, 50)]
    public int waypointsCount = 44;

    private System.Random random = new System.Random();

    // Use this for initialization
    void Start ()
    {
        var Nodes = UnityEngine.GameObject.FindGameObjectsWithTag("Node");



    }

    // Update is called once per frame
    void Update ()
    {

    }
}

I set the Range min to 5 and max to 50 But i know that the map size is 10 so there will be 100 gameobjects. So the range should be min 5 max 90 or maybe min 5 and max 50.

The problem is how can i make sure i will not set the Range max to be more then the map size ? If the map size will be 5 so it's 25 gameobjects i can't set the Range max to 50.

Answer 1

Usually I do it something like this:

[Range(0, 1)]
public float proportionToPick;

public int maxItems = 50;

int _numberToPick;

void Start() {
     _numberToPick = Mathf.FloorToInt(maxItems * proportionToPick);

     ...
}

This way you can tune proportionToPick to 0.2 if you want to grab about a fifth of the items in the collection, no matter if that collection is 50 items or 5 or 5000. It will automatically scale in proportion to your count.

If you need to be able to set the number of items more explicitly, you can do this with a Custom Editor, where you can manually control every detail of how the script looks & works in the Inspector. This is a fair bit of extra code though so I usually work around it with what I can do in a single script unless I need something complicated.