voxel-building-system/Runtime/VoxelBuildingRule.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using Sirenix.OdinInspector;
using KairoEngine.Chunks;

namespace KairoEngine.VoxelBuildingSystem
{
    public enum RuleType
    {
        EmptyVoxels
    }

    [System.Serializable]
    public class VoxelBuildingRule
    {
        private string title 
        {
            get 
            {
                switch (rule)
                {
                    case RuleType.EmptyVoxels: return $"Empty voxels";
                    default: return "?";
                }
            }
        }

        [SerializeField, FoldoutGroup("@title")] private RuleType rule;
        public bool Evaluate(VoxelBuildingSystem buildingSystem, int templateIndex, Vector3Int position, int rotationIndex)
        {
            switch (rule)
            {
                case RuleType.EmptyVoxels: return EvaluateEmptyVoxels(buildingSystem, templateIndex, position, rotationIndex);
                default: return false;
            }
        }

        public bool EvaluateEmptyVoxels(VoxelBuildingSystem buildingSystem, int templateIndex, Vector3Int position, int rotationIndex)
        {
            List<Vector3Int> voxelPositions = buildingSystem.GetBuildingVoxelList(position, templateIndex, rotationIndex);
            for (int i = 0; i < voxelPositions.Count; i++)
            {
                VoxelBuildData block = buildingSystem.chunkSystem.GetBlock(voxelPositions[i]);
                if(block.buildingIndex != -1) 
                {
                    return false;
                }
            }
            return true;
        }
    }

}