source: binary-improvements/7dtd-server-fixes/src/MapRendering/MapRenderBlockBuffer.cs@ 180

using System;
using System.IO;
using System.Threading;
using UnityEngine;

namespace AllocsFixes.MapRendering
{
        public class MapRenderBlockBuffer
        {
                private int zoomLevel;
                private string currentBlockMap = string.Empty;
                private Texture2D blockMap = new Texture2D (Constants.MAP_BLOCK_SIZE, Constants.MAP_BLOCK_SIZE);
                private Texture2D zoomBuffer = new Texture2D (1, 1);
                private Color nullColor = new Color (0, 0, 0, 0);

                public MapRenderBlockBuffer (int level)
                {
                        zoomLevel = level;
                }

                public void ResetBlock ()
                {
                        currentBlockMap = string.Empty;
                }

                public void SaveBlock ()
                {
                        try {
                                if (currentBlockMap.Length > 0)
                                        saveTextureToFile (currentBlockMap);
                        } catch (Exception e) {
                                Log.Out ("Exception in MapRenderBlockBuffer.SaveBlock(): " + e);
                        }
                }

                public bool LoadBlock (Vector2i block)
                {
                        bool res = false;
                        Monitor.Enter (blockMap);
                        try {
                                string folder = Constants.MAP_DIRECTORY + "/" + (zoomLevel) + "/" + block.x;
                                string fileName = folder + "/" + block.y + ".png";
                                Directory.CreateDirectory (folder);
                                if (!fileName.Equals (currentBlockMap)) {
                                        res = true;
                                        SaveBlock ();
                                        loadTextureFromFile (fileName);
                                }
                                currentBlockMap = fileName;
                        } finally {
                                Monitor.Exit (blockMap);
                        }
                        return res;
                }

                public void SetPart (Vector2i offset, int partSize, Color[] pixels)
                {
                        blockMap.SetPixels (offset.x, offset.y, partSize, partSize, pixels);
                }

                public Color[] GetHalfScaled ()
                {
                        zoomBuffer.Resize (Constants.MAP_BLOCK_SIZE, Constants.MAP_BLOCK_SIZE);
                        zoomBuffer.SetPixels (blockMap.GetPixels ());

                        TextureScale.Point (zoomBuffer, Constants.MAP_BLOCK_SIZE / 2, Constants.MAP_BLOCK_SIZE / 2);

                        return zoomBuffer.GetPixels ();
                }

                private void loadTextureFromFile (string _fileName)
                {
                        try {
                                byte[] array = File.ReadAllBytes (_fileName);
                                blockMap.LoadImage (array);
                        } catch (Exception) {
                                for (int x = 0; x < Constants.MAP_BLOCK_SIZE; x++) {
                                        for (int y = 0; y < Constants.MAP_BLOCK_SIZE; y++) {
                                                blockMap.SetPixel (x, y, nullColor);
                                        }
                                }
                        }
                }

                private void saveTextureToFile (string _fileName)
                {
                        try {
                                byte[] array = blockMap.EncodeToPNG ();
                                File.WriteAllBytes (_fileName, array);
                        } catch (Exception e) {
                                Log.Out ("Exception in MapRenderBlockBuffer.saveTextureToFile(): " + e);
                        }
                }

        }
}