Automap/Subsystems/Snapshot.cs

   1 using System;
   2 using System.Collections.Generic;
   3 using System.Diagnostics;
   4 using System.IO;
   5 using System.Linq;
   6 using System.Threading;
   7 using System.Threading.Tasks;
   8
   9 using Hjg.Pngcs;
  10 using Hjg.Pngcs.Chunks;
  11
  12 namespace Automap
  13 {
  14         public class Snapshotter
  15         {
  16                 public readonly int chunkSize;
  17                 public string fileName;
  18                 public string chunkPath;
  19                 public ColumnsMetadata cols;
  20                 //TODO: Refactor - so Edges are set at construction time, as ColumnsMetadata is async updating in real time!
  21                 public int NorthEdge => cols.North_mostChunk;
  22                 public int WestEdge => cols.West_mostChunk;
  23                 public int Width => (cols.East_mostChunk - WestEdge + 1);
  24                 public int Height => (cols.South_mostChunk - NorthEdge + 1);
  25
  26
  27                 public Snapshotter(string path, ColumnsMetadata cols, int chunkSize, int worldSeed)
  28                 {
  29                         this.fileName = Path.Combine(path, $"snapshot_{worldSeed}_{DateTime.UtcNow:u}.png");
  30                         this.chunkPath = Path.Combine(path, AutomapSystem._chunkPath);
  31                         this.cols = cols;
  32                         this.chunkSize = chunkSize;
  33                 }
  34
  35                 /// <summary>
  36                 /// takes a snapshot. this should be called from an extra thread.
  37                 /// </summary>
  38                 /// <param name="path">path to the map dir</param>
  39                 /// <param name="chunkPath">name of the chunks dir part thing</param>
  40                 /// <param name="cols"></param>
  41                 /// <param name="chunkSize"></param>
  42                 public async void Take()
  43                 {
  44                         var t = new Stopwatch();
  45                         t.Start();
  46
  47                         Console.WriteLine("snapshot started");
  48
  49                         ImageInfo info = new ImageInfo(Width * chunkSize, Height * chunkSize, 8, false);
  50                         PngWriter snapWriter = FileHelper.CreatePngWriter(fileName, info, true);
  51                         PngMetadata meta = snapWriter.GetMetadata( );
  52                         meta.SetTimeNow( );
  53                         var transparencyChunk = meta.CreateTRNSChunk( );
  54                         transparencyChunk.SetRGB(0, 0, 0);//CHECK: This is pure black.
  55                         meta.SetText("Northmost", NorthEdge.ToString("D"));
  56                         meta.SetText("Eastmost", WestEdge.ToString("D"));
  57                         meta.SetText("Width", Width.ToString("D"));
  58                         meta.SetText("Height", Height.ToString("D"));
  59
  60
  61
  62                         /*
  63                         Red:   2 bytes, range 0 .. (2^bitdepth)-1
  64                         Green: 2 bytes, range 0 .. (2^bitdepth)-1
  65                         Blue:  2 bytes, range 0 .. (2^bitdepth)-1
  66                         */
  67
  68
  69                         snapWriter.CompLevel = 5;
  70                         snapWriter.CompressionStrategy = Hjg.Pngcs.Zlib.EDeflateCompressStrategy.Filtered;
  71
  72
  73
  74                         var orderedList =
  75                                 from ch in cols
  76                                 group ch by ch.Location.Y into g
  77                                 orderby g.Key
  78                                 select g;
  79                         // that sorts things in ascending order so we can only create (chunkSize) lines at once
  80                         int row = 0, lastPosY = 0, posY = 0;
  81                         foreach (var chunkGroup in orderedList)
  82                         {
  83                                 // oh god here we go...
  84                                 posY = chunkGroup.Key - NorthEdge;
  85                                 var delta = posY - lastPosY;
  86                                 lastPosY = posY;
  87
  88                                 // if there is more than 1 blank step then the gap needs to be filled.
  89                                 for (int i = 1; i < delta; i++)
  90                                 {
  91                                         byte[] blankLine = new byte[info.BytesPerRow];
  92                                         for (int j = 0; j < chunkSize; j++)
  93                                                 snapWriter.WriteRowByte(blankLine, row++);
  94                                 }
  95
  96                                 var inGroup = (await ReadAllInGroup(chunkGroup)).ToArray();
  97
  98                                 for (int r = 0; r < chunkSize; r++)
  99                                 {
 100                                         var line = new byte[info.BytesPerRow];
 101                                         for (int chunk = 0; chunk < inGroup.Length; chunk++)
 102                                         {
 103                                                 var posX = inGroup[chunk].Key * chunkSize * info.BytesPixel;
 104                                                 inGroup[chunk].Value?[r].CopyTo(line, posX);
 105                                         }
 106                                         snapWriter.WriteRowByte(line, row++);
 107                                 }
 108                         }
 109                         snapWriter.ShouldCloseStream = true;
 110                         try
 111                         {
 112                                 snapWriter.End();
 113                         }
 114                         catch (Exception)
 115                         {
 116                                 Console.WriteLine("Snapshot exception!");
 117                         }
 118                         Console.WriteLine($"snapshot finished in {t.ElapsedMilliseconds}");
 119                 }
 120
 121                 private async Task<Dictionary<int, byte[][]>> ReadAllInGroup(IGrouping<int, ColumnMeta> group)
 122                 {
 123                         var taskGroup = new Dictionary<int, byte[][]>(group.Count());
 124                         foreach (var shardMeta in group)
 125                         {
 126                                 var shardPath = Path.Combine(chunkPath, $"{shardMeta.Location.X}_{shardMeta.Location.Y}.png");
 127                                 taskGroup.Add(shardMeta.Location.X - WestEdge, await ReadNoThrow(shardPath));
 128                         }
 129                         return taskGroup;
 130                 }
 131
 132                 private async Task<byte[][]> ReadNoThrow(string readPath)
 133                 {
 134                         try
 135                         {
 136                                 return await Task.Run(() => FileHelper.CreatePngReader(readPath).ReadRowsByte().ScanlinesB);
 137                         }
 138                         catch (Exception e)
 139                         {
 140                                 Console.WriteLine(e.Message);
 141                                 return null;
 142                         } // do nothing on error
 143                 }
 144         }
 145 }