Spawner

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PrefabScatterSpawner : MonoBehaviour
{
    [System.Serializable]
    public struct SpawnInfo
    {
        public float frequency;
        public GameObject prefab;
    }

    public List<GameObject> spawnList = new List<GameObject>();

    public int minSpawnCount, maxSpawnCount;

    public Vector2 spawnArea = Vector2.one;

    [Range(0,1)]
    public float minSafeSpawnRadius= .5f;

    public float castStartHeight = 5;
    [Range(0, 5)]
    public float castOvershoot = 2;

    public int gizmoRaySamples = 4;
    public float sampleRate = 2;

    public LayerMask RaycastHitMask;

    [System.Serializable]
    public class GizmoColors
    {
        public Color areaColor = new Color(1f, 0.92f, 0.02f, 0.25f);
        public Color areaOvershootColor = new Color(1f, 0.56f, 0.02f, 0.25f);
        public Color raycastOriginColor = new Color(1f, 0f, 0f, 0.25f);
        public Color raycastHitColor = new Color(1f, 0f, 0f, 0.52f);
        public Color rayColor = new Color(0f, 1f, 0f, 0.25f);
    }

    [SerializeField] GizmoColors gizmoColors = new GizmoColors();

    // Start is called before the first frame update
    void Start()
    {

    }

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

    }

    private void OnValidate()
    {
        t = sampleRate;
    }

    public Vector3 GetRandomOffsetInSpawnArea()
    {
        float halfAreaY = spawnArea.y / 2;
        float halfAreaX = spawnArea.x / 2;

        return new Vector3(Random.Range(-halfAreaX, halfAreaX), 0, Random.Range(-halfAreaY, halfAreaY));
    }

    private float t = 0;
    private List<Vector3> samplePoints = new List<Vector3>();
    private void OnDrawGizmos()
    {
        Gizmos.color = gizmoColors.areaOvershootColor;
        Gizmos.DrawWireCube(transform.position + Vector3.up * castStartHeight / 2, new Vector3(spawnArea.x, castStartHeight, spawnArea.y));

        Gizmos.color = gizmoColors.areaColor;
        Gizmos.DrawWireCube(transform.position + Vector3.up * (castStartHeight - castOvershoot) / 2, new Vector3(spawnArea.x, castStartHeight + castOvershoot, spawnArea.y));

        Gizmos.color = gizmoColors.raycastOriginColor;
        Gizmos.DrawWireSphere(transform.position + Vector3.up * castStartHeight, .1f);


        foreach (var samplePoint in samplePoints)
        {
            Gizmos.color = gizmoColors.rayColor;
            Gizmos.DrawRay(samplePoint, Vector3.down * (castStartHeight + castOvershoot));
            if (Physics.Raycast(samplePoint, Vector3.down, out RaycastHit hit, castOvershoot + castStartHeight, RaycastHitMask))
            {
                Gizmos.color = gizmoColors.raycastHitColor;
                //Gizmos.DrawWireSphere(hit.point, .1f);
                CookieGizmo.DrawWireCircle(hit.point + Vector3.up * .01f, minSafeSpawnRadius, Vector3.up, Vector3.forward );
            }
        }

        t += Time.deltaTime;
        if (t < sampleRate)
            return;

        t -= sampleRate;

        samplePoints.Clear();

        for (int i = 0; i < gizmoRaySamples; i++)
        {
            for (int attempt = 0; attempt < 10; attempt++)
            {
                var randOffset = GetRandomOffsetInSpawnArea();
                var randomPosition = transform.position + Vector3.up * castStartHeight + randOffset;

                bool tooClose = false;
                foreach (var validPoints in samplePoints)
                {
                    if (Vector3.Distance(randomPosition, validPoints) < minSafeSpawnRadius*2)
                    {
                        tooClose = true;
                        break;
                    }
                }

                if (!tooClose)
                {
                    samplePoints.Add(randomPosition);
                }
            }
        }
    }
}