ZStd Support

src/DotTiled/Serialization/Helpers.cs

@@ -46,6 +46,12 @@ internal static partial class Helpers
     return ReadMemoryStreamAsInt32Array(decompressedStream);
   }
 
+  internal static uint[] DecompressZStd(MemoryStream stream)
+  {
+    using var decompressedStream = new ZstdSharp.DecompressionStream(stream);
+    return ReadMemoryStreamAsInt32Array(decompressedStream);
+  }
+
   internal static uint[] ReadBytesAsInt32Array(byte[] bytes)
   {
     var intArray = new uint[bytes.Length / 4];

src/DotTiled/Serialization/Tmj/TmjReaderBase.Data.cs

@@ -61,7 +61,7 @@ public abstract partial class TmjReaderBase
       {
         DataCompression.GZip => Helpers.DecompressGZip(stream),
         DataCompression.ZLib => Helpers.DecompressZLib(stream),
-        DataCompression.ZStd => throw new NotSupportedException("ZStd compression is not supported."),
+        DataCompression.ZStd => Helpers.DecompressZStd(stream),
         _ => throw new InvalidOperationException($"Unsupported compression '{compression}'.")
       };
 

src/DotTiled/Serialization/Tmj/TmjReaderBase.TileLayer.cs

@@ -16,6 +16,7 @@ public abstract partial class TmjReaderBase
     {
       "zlib" => DataCompression.ZLib,
       "gzip" => DataCompression.GZip,
+      "zstd" => DataCompression.ZStd,
       "" => Optional.Empty,
       _ => throw new JsonException($"Unsupported compression '{s}'.")
     });

src/DotTiled/Serialization/Tmx/TmxReaderBase.Data.cs

@@ -77,7 +77,7 @@ public abstract partial class TmxReaderBase
     {
       DataCompression.GZip => Helpers.DecompressGZip(bytes),
       DataCompression.ZLib => Helpers.DecompressZLib(bytes),
-      DataCompression.ZStd => throw new NotSupportedException("ZStd compression is not supported."),
+      DataCompression.ZStd => Helpers.DecompressZStd(bytes),
       _ => throw new XmlException("Invalid compression")
     };