CrowdControl/Assets/Feel/MMTools/Tools/MMTilemaps/MMTilemapShadow.cs

using UnityEngine;
using UnityEngine.UI;
using System.Collections;
using MoreMountains.Tools;
using System;
using System.Collections.Generic;
using UnityEngine.Tilemaps;

namespace MoreMountains.Tools
{
	/// <summary>
	/// A class to put on a tilemap so it acts as a shadow/copy of another reference tilemap.
	/// Useful for wall shadows for example.
	/// Offsetting the tilemap and changing its sorting order etc is done via the regular components
	/// </summary>
	[ExecuteAlways]
	[AddComponentMenu("More Mountains/Tools/Tilemaps/MMTilemapShadow")]
	[RequireComponent(typeof(Tilemap))]
	public class MMTilemapShadow : MonoBehaviour
	{        
		/// the tilemap to copy
		public Tilemap ReferenceTilemap;
        
		[MMInspectorButton("UpdateShadows")]
		public bool UpdateShadowButton;

		protected Tilemap _tilemap;

		/// <summary>
		/// This method will copy the reference tilemap into the one on this gameobject
		/// </summary>
		public virtual void UpdateShadows()
		{
			if (ReferenceTilemap == null)
			{
				return;
			}

			_tilemap = this.gameObject.GetComponent<Tilemap>();
           
			Copy(ReferenceTilemap, _tilemap);
		}

		/// <summary>
		/// Copies the source tilemap on the destination tilemap
		/// </summary>
		/// <param name="source"></param>
		/// <param name="destination"></param>
		public static void Copy(Tilemap source, Tilemap destination)
		{
			source.RefreshAllTiles();
			destination.RefreshAllTiles();
            
			List<Vector3Int> referenceTilemapPositions = new List<Vector3Int>();
            
			// we grab all filled positions from the ref tilemap
			foreach (Vector3Int pos in source.cellBounds.allPositionsWithin)
			{
				Vector3Int localPlace = new Vector3Int(pos.x, pos.y, pos.z);
				if (source.HasTile(localPlace))
				{
					referenceTilemapPositions.Add(localPlace);
				}
			}
            
			// we turn our list into an array
			Vector3Int[] positions = new Vector3Int[referenceTilemapPositions.Count];
			TileBase[] allTiles = new TileBase[referenceTilemapPositions.Count];
			int i = 0;
			foreach(Vector3Int tilePosition in referenceTilemapPositions)
			{
				positions[i] = tilePosition;
				allTiles[i] = source.GetTile(tilePosition);
				i++;
			}

			// we clear our tilemap and resize it
			destination.ClearAllTiles();
			destination.RefreshAllTiles();
			destination.size = source.size;
			destination.origin = source.origin;
			destination.ResizeBounds();
            
			// we feed it our positions
			destination.SetTiles(positions, allTiles);
		}
		
	}
}