Merge pull request #6 from dcronqvist/dev

Merge dev into master

DotTiled.Benchmark/DotTiled.Benchmark.csproj

@@ -0,0 +1,20 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="BenchmarkDotNet" Version="0.13.12" />
+    <PackageReference Include="TiledCSPlus" Version="4.2.0" />
+    <PackageReference Include="TiledLib" Version="4.0.3" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\DotTiled\DotTiled.csproj" />
+  </ItemGroup>
+
+</Project>

DotTiled.Benchmark/Program.cs

@@ -0,0 +1,94 @@
+using System;
+using System.Collections.Immutable;
+using System.Runtime.CompilerServices;
+using System.Security.Cryptography;
+using System.Text;
+using System.Xml;
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Columns;
+using BenchmarkDotNet.Configs;
+using BenchmarkDotNet.Order;
+using BenchmarkDotNet.Reports;
+using BenchmarkDotNet.Running;
+
+namespace MyBenchmarks
+{
+  [GroupBenchmarksBy(BenchmarkLogicalGroupRule.ByCategory)]
+  [CategoriesColumn]
+  [Orderer(SummaryOrderPolicy.FastestToSlowest)]
+  [HideColumns(["StdDev", "Error", "RatioSD"])]
+  public class MapLoading
+  {
+    private string _tmxPath = @"DotTiled.Tests/Serialization/TestData/Map/default-map/default-map.tmx";
+    private string _tmxContents = "";
+
+    private string _tmjPath = @"DotTiled.Tests/Serialization/TestData/Map/default-map/default-map.tmj";
+    private string _tmjContents = "";
+
+    public MapLoading()
+    {
+      var basePath = Path.GetDirectoryName(WhereAmI())!;
+      var tmxPath = Path.Combine(basePath, $"../{_tmxPath}");
+      var tmjPath = Path.Combine(basePath, $"../{_tmjPath}");
+
+      _tmxContents = System.IO.File.ReadAllText(tmxPath);
+      _tmjContents = System.IO.File.ReadAllText(tmjPath);
+    }
+
+    static string WhereAmI([CallerFilePath] string callerFilePath = "") => callerFilePath;
+
+    [BenchmarkCategory("MapFromInMemoryTmxString")]
+    [Benchmark(Baseline = true, Description = "DotTiled")]
+    public DotTiled.Map LoadWithDotTiledFromInMemoryTmxString()
+    {
+      using var stringReader = new StringReader(_tmxContents);
+      using var xmlReader = XmlReader.Create(stringReader);
+      using var mapReader = new DotTiled.TmxMapReader(xmlReader, _ => throw new Exception(), _ => throw new Exception(), []);
+      return mapReader.ReadMap();
+    }
+
+    [BenchmarkCategory("MapFromInMemoryTmjString")]
+    [Benchmark(Baseline = true, Description = "DotTiled")]
+    public DotTiled.Map LoadWithDotTiledFromInMemoryTmjString()
+    {
+      using var mapReader = new DotTiled.TmjMapReader(_tmjContents, _ => throw new Exception(), _ => throw new Exception(), []);
+      return mapReader.ReadMap();
+    }
+
+    [BenchmarkCategory("MapFromInMemoryTmxString")]
+    [Benchmark(Description = "TiledLib")]
+    public TiledLib.Map LoadWithTiledLibFromInMemoryTmxString()
+    {
+      using var memStream = new MemoryStream(Encoding.UTF8.GetBytes(_tmxContents));
+      return TiledLib.Map.FromStream(memStream);
+    }
+
+    [BenchmarkCategory("MapFromInMemoryTmjString")]
+    [Benchmark(Description = "TiledLib")]
+    public TiledLib.Map LoadWithTiledLibFromInMemoryTmjString()
+    {
+      using var memStream = new MemoryStream(Encoding.UTF8.GetBytes(_tmjContents));
+      return TiledLib.Map.FromStream(memStream);
+    }
+
+    [BenchmarkCategory("MapFromInMemoryTmxString")]
+    [Benchmark(Description = "TiledCSPlus")]
+    public TiledCSPlus.TiledMap LoadWithTiledCSPlusFromInMemoryTmxString()
+    {
+      using var memStream = new MemoryStream(Encoding.UTF8.GetBytes(_tmxContents));
+      return new TiledCSPlus.TiledMap(memStream);
+    }
+  }
+
+  public class Program
+  {
+    public static void Main(string[] args)
+    {
+      var config = BenchmarkDotNet.Configs.DefaultConfig.Instance
+        .WithArtifactsPath(args[0])
+        .WithOptions(ConfigOptions.DisableOptimizationsValidator)
+        .AddDiagnoser(BenchmarkDotNet.Diagnosers.MemoryDiagnoser.Default);
+      var summary = BenchmarkRunner.Run<MapLoading>(config);
+    }
+  }
+}

DotTiled.Tests/Assert/AssertData.cs

@@ -0,0 +1,43 @@
+namespace DotTiled.Tests;
+
+public static partial class DotTiledAssert
+{
+  internal static void AssertData(Data? expected, Data? actual)
+  {
+    if (expected is null)
+    {
+      Assert.Null(actual);
+      return;
+    }
+
+    // Attributes
+    Assert.NotNull(actual);
+    AssertEqual(expected.Encoding, actual.Encoding, nameof(Data.Encoding));
+    AssertEqual(expected.Compression, actual.Compression, nameof(Data.Compression));
+
+    // Data
+    AssertEqual(expected.GlobalTileIDs, actual.GlobalTileIDs, nameof(Data.GlobalTileIDs));
+    AssertEqual(expected.FlippingFlags, actual.FlippingFlags, nameof(Data.FlippingFlags));
+
+    if (expected.Chunks is not null)
+    {
+      Assert.NotNull(actual.Chunks);
+      AssertEqual(expected.Chunks.Length, actual.Chunks.Length, "Chunks.Length");
+      for (var i = 0; i < expected.Chunks.Length; i++)
+        AssertChunk(expected.Chunks[i], actual.Chunks[i]);
+    }
+  }
+
+  private static void AssertChunk(Chunk expected, Chunk actual)
+  {
+    // Attributes
+    AssertEqual(expected.X, actual.X, nameof(Chunk.X));
+    AssertEqual(expected.Y, actual.Y, nameof(Chunk.Y));
+    AssertEqual(expected.Width, actual.Width, nameof(Chunk.Width));
+    AssertEqual(expected.Height, actual.Height, nameof(Chunk.Height));
+
+    // Data
+    AssertEqual(expected.GlobalTileIDs, actual.GlobalTileIDs, nameof(Chunk.GlobalTileIDs));
+    AssertEqual(expected.FlippingFlags, actual.FlippingFlags, nameof(Chunk.FlippingFlags));
+  }
+}

DotTiled.Tests/Assert/AssertImage.cs

@@ -0,0 +1,21 @@
+namespace DotTiled.Tests;
+
+public static partial class DotTiledAssert
+{
+  internal static void AssertImage(Image? expected, Image? actual)
+  {
+    if (expected is null)
+    {
+      Assert.Null(actual);
+      return;
+    }
+
+    // Attributes
+    Assert.NotNull(actual);
+    AssertEqual(expected.Format, actual.Format, nameof(Image.Format));
+    AssertEqual(expected.Source, actual.Source, nameof(Image.Source));
+    AssertEqual(expected.TransparentColor, actual.TransparentColor, nameof(Image.TransparentColor));
+    AssertEqual(expected.Width, actual.Width, nameof(Image.Width));
+    AssertEqual(expected.Height, actual.Height, nameof(Image.Height));
+  }
+}

DotTiled.Tests/Assert/AssertLayer.cs

@@ -0,0 +1,75 @@
+namespace DotTiled.Tests;
+
+public static partial class DotTiledAssert
+{
+  internal static void AssertLayer(BaseLayer? expected, BaseLayer? actual)
+  {
+    if (expected is null)
+    {
+      Assert.Null(actual);
+      return;
+    }
+
+    // Attributes
+    Assert.NotNull(actual);
+    AssertEqual(expected.ID, actual.ID, nameof(BaseLayer.ID));
+    AssertEqual(expected.Name, actual.Name, nameof(BaseLayer.Name));
+    AssertEqual(expected.Class, actual.Class, nameof(BaseLayer.Class));
+    AssertEqual(expected.Opacity, actual.Opacity, nameof(BaseLayer.Opacity));
+    AssertEqual(expected.Visible, actual.Visible, nameof(BaseLayer.Visible));
+    AssertEqual(expected.TintColor, actual.TintColor, nameof(BaseLayer.TintColor));
+    AssertEqual(expected.OffsetX, actual.OffsetX, nameof(BaseLayer.OffsetX));
+    AssertEqual(expected.OffsetY, actual.OffsetY, nameof(BaseLayer.OffsetY));
+    AssertEqual(expected.ParallaxX, actual.ParallaxX, nameof(BaseLayer.ParallaxX));
+    AssertEqual(expected.ParallaxY, actual.ParallaxY, nameof(BaseLayer.ParallaxY));
+
+    AssertProperties(expected.Properties, actual.Properties);
+    AssertLayer((dynamic)expected, (dynamic)actual);
+  }
+
+  private static void AssertLayer(TileLayer expected, TileLayer actual)
+  {
+    // Attributes
+    AssertEqual(expected.Width, actual.Width, nameof(TileLayer.Width));
+    AssertEqual(expected.Height, actual.Height, nameof(TileLayer.Height));
+    AssertEqual(expected.X, actual.X, nameof(TileLayer.X));
+    AssertEqual(expected.Y, actual.Y, nameof(TileLayer.Y));
+
+    Assert.NotNull(actual.Data);
+    AssertData(expected.Data, actual.Data);
+  }
+
+  private static void AssertLayer(ObjectLayer expected, ObjectLayer actual)
+  {
+    // Attributes
+    AssertEqual(expected.DrawOrder, actual.DrawOrder, nameof(ObjectLayer.DrawOrder));
+    AssertEqual(expected.X, actual.X, nameof(ObjectLayer.X));
+    AssertEqual(expected.Y, actual.Y, nameof(ObjectLayer.Y));
+
+    Assert.NotNull(actual.Objects);
+    AssertEqual(expected.Objects.Count, actual.Objects.Count, "Objects.Count");
+    for (var i = 0; i < expected.Objects.Count; i++)
+      AssertObject(expected.Objects[i], actual.Objects[i]);
+  }
+
+  private static void AssertLayer(ImageLayer expected, ImageLayer actual)
+  {
+    // Attributes
+    AssertEqual(expected.RepeatX, actual.RepeatX, nameof(ImageLayer.RepeatX));
+    AssertEqual(expected.RepeatY, actual.RepeatY, nameof(ImageLayer.RepeatY));
+    AssertEqual(expected.X, actual.X, nameof(ImageLayer.X));
+    AssertEqual(expected.Y, actual.Y, nameof(ImageLayer.Y));
+
+    Assert.NotNull(actual.Image);
+    AssertImage(expected.Image, actual.Image);
+  }
+
+  private static void AssertLayer(Group expected, Group actual)
+  {
+    // Attributes
+    Assert.NotNull(actual.Layers);
+    AssertEqual(expected.Layers.Count, actual.Layers.Count, "Layers.Count");
+    for (var i = 0; i < expected.Layers.Count; i++)
+      AssertLayer(expected.Layers[i], actual.Layers[i]);
+  }
+}

DotTiled.Tests/Assert/AssertMap.cs

@@ -0,0 +1,105 @@
+using System.Collections;
+using System.Numerics;
+
+namespace DotTiled.Tests;
+
+public static partial class DotTiledAssert
+{
+  private static void AssertEqual<T>(T expected, T actual, string nameof)
+  {
+    if (expected == null)
+    {
+      Assert.Null(actual);
+      return;
+    }
+
+    if (typeof(T) == typeof(float))
+    {
+      var expectedFloat = (float)(object)expected;
+      var actualFloat = (float)(object)actual!;
+
+      var expecRounded = MathF.Round(expectedFloat, 3);
+      var actRounded = MathF.Round(actualFloat, 3);
+
+      Assert.True(expecRounded == actRounded, $"Expected {nameof} '{expecRounded}' but got '{actRounded}'");
+      return;
+    }
+
+    if (expected is Vector2)
+    {
+      var expectedVector = (Vector2)(object)expected;
+      var actualVector = (Vector2)(object)actual!;
+
+      AssertEqual(expectedVector.X, actualVector.X, $"{nameof}.X");
+      AssertEqual(expectedVector.Y, actualVector.Y, $"{nameof}.Y");
+
+      return;
+    }
+
+    if (typeof(T).IsArray)
+    {
+      var expectedArray = (Array)(object)expected;
+      var actualArray = (Array)(object)actual!;
+
+      Assert.NotNull(actualArray);
+      AssertEqual(expectedArray.Length, actualArray.Length, $"{nameof}.Length");
+
+      for (var i = 0; i < expectedArray.Length; i++)
+        AssertEqual(expectedArray.GetValue(i), actualArray.GetValue(i), $"{nameof}[{i}]");
+
+      return;
+    }
+
+    if (typeof(T).IsGenericType && typeof(T).GetGenericTypeDefinition() == typeof(List<>))
+    {
+      var expectedList = (IList)(object)expected;
+      var actualList = (IList)(object)actual!;
+
+      Assert.NotNull(actualList);
+      AssertEqual(expectedList.Count, actualList.Count, $"{nameof}.Count");
+
+      for (var i = 0; i < expectedList.Count; i++)
+        AssertEqual(expectedList[i], actualList[i], $"{nameof}[{i}]");
+
+      return;
+    }
+
+    Assert.True(expected.Equals(actual), $"Expected {nameof} '{expected}' but got '{actual}'");
+  }
+
+  internal static void AssertMap(Map expected, Map actual)
+  {
+    // Attributes
+    AssertEqual(expected.Version, actual.Version, nameof(Map.Version));
+    AssertEqual(expected.TiledVersion, actual.TiledVersion, nameof(Map.TiledVersion));
+    AssertEqual(expected.Class, actual.Class, nameof(Map.Class));
+    AssertEqual(expected.Orientation, actual.Orientation, nameof(Map.Orientation));
+    AssertEqual(expected.RenderOrder, actual.RenderOrder, nameof(Map.RenderOrder));
+    AssertEqual(expected.CompressionLevel, actual.CompressionLevel, nameof(Map.CompressionLevel));
+    AssertEqual(expected.Width, actual.Width, nameof(Map.Width));
+    AssertEqual(expected.Height, actual.Height, nameof(Map.Height));
+    AssertEqual(expected.TileWidth, actual.TileWidth, nameof(Map.TileWidth));
+    AssertEqual(expected.TileHeight, actual.TileHeight, nameof(Map.TileHeight));
+    AssertEqual(expected.HexSideLength, actual.HexSideLength, nameof(Map.HexSideLength));
+    AssertEqual(expected.StaggerAxis, actual.StaggerAxis, nameof(Map.StaggerAxis));
+    AssertEqual(expected.StaggerIndex, actual.StaggerIndex, nameof(Map.StaggerIndex));
+    AssertEqual(expected.ParallaxOriginX, actual.ParallaxOriginX, nameof(Map.ParallaxOriginX));
+    AssertEqual(expected.ParallaxOriginY, actual.ParallaxOriginY, nameof(Map.ParallaxOriginY));
+    AssertEqual(expected.BackgroundColor, actual.BackgroundColor, nameof(Map.BackgroundColor));
+    AssertEqual(expected.NextLayerID, actual.NextLayerID, nameof(Map.NextLayerID));
+    AssertEqual(expected.NextObjectID, actual.NextObjectID, nameof(Map.NextObjectID));
+    AssertEqual(expected.Infinite, actual.Infinite, nameof(Map.Infinite));
+
+    AssertProperties(actual.Properties, expected.Properties);
+
+    Assert.NotNull(actual.Tilesets);
+    AssertEqual(expected.Tilesets.Count, actual.Tilesets.Count, "Tilesets.Count");
+    for (var i = 0; i < expected.Tilesets.Count; i++)
+      AssertTileset(expected.Tilesets[i], actual.Tilesets[i]);
+
+    Assert.NotNull(actual.Layers);
+    AssertEqual(expected.Layers.Count, actual.Layers.Count, "Layers.Count");
+    for (var i = 0; i < expected.Layers.Count; i++)
+      AssertLayer(expected.Layers[i], actual.Layers[i]);
+  }
+}

DotTiled.Tests/Assert/AssertObject.cs

@@ -0,0 +1,73 @@
+namespace DotTiled.Tests;
+
+public static partial class DotTiledAssert
+{
+  internal static void AssertObject(Object expected, Object actual)
+  {
+    // Attributes
+    AssertEqual(expected.ID, actual.ID, nameof(Object.ID));
+    AssertEqual(expected.Name, actual.Name, nameof(Object.Name));
+    AssertEqual(expected.Type, actual.Type, nameof(Object.Type));
+    AssertEqual(expected.X, actual.X, nameof(Object.X));
+    AssertEqual(expected.Y, actual.Y, nameof(Object.Y));
+    AssertEqual(expected.Width, actual.Width, nameof(Object.Width));
+    AssertEqual(expected.Height, actual.Height, nameof(Object.Height));
+    AssertEqual(expected.Rotation, actual.Rotation, nameof(Object.Rotation));
+    AssertEqual(expected.Visible, actual.Visible, nameof(Object.Visible));
+    AssertEqual(expected.Template, actual.Template, nameof(Object.Template));
+
+    AssertProperties(expected.Properties, actual.Properties);
+
+    Assert.True(expected.GetType() == actual.GetType(), $"Expected object type {expected.GetType()} but got {actual.GetType()}");
+    AssertObject((dynamic)expected, (dynamic)actual);
+  }
+
+  private static void AssertObject(RectangleObject expected, RectangleObject actual)
+  {
+    Assert.True(true); // A rectangle object is the same as the abstract Object
+  }
+
+  private static void AssertObject(EllipseObject expected, EllipseObject actual)
+  {
+    Assert.True(true); // An ellipse object is the same as the abstract Object
+  }
+
+  private static void AssertObject(PointObject expected, PointObject actual)
+  {
+    Assert.True(true); // A point object is the same as the abstract Object
+  }
+
+  private static void AssertObject(PolygonObject expected, PolygonObject actual)
+  {
+    AssertEqual(expected.Points, actual.Points, nameof(PolygonObject.Points));
+  }
+
+  private static void AssertObject(PolylineObject expected, PolylineObject actual)
+  {
+    AssertEqual(expected.Points, actual.Points, nameof(PolylineObject.Points));
+  }
+
+  private static void AssertObject(TextObject expected, TextObject actual)
+  {
+    // Attributes
+    AssertEqual(expected.FontFamily, actual.FontFamily, nameof(TextObject.FontFamily));
+    AssertEqual(expected.PixelSize, actual.PixelSize, nameof(TextObject.PixelSize));
+    AssertEqual(expected.Wrap, actual.Wrap, nameof(TextObject.Wrap));
+    AssertEqual(expected.Color, actual.Color, nameof(TextObject.Color));
+    AssertEqual(expected.Bold, actual.Bold, nameof(TextObject.Bold));
+    AssertEqual(expected.Italic, actual.Italic, nameof(TextObject.Italic));
+    AssertEqual(expected.Underline, actual.Underline, nameof(TextObject.Underline));
+    AssertEqual(expected.Strikeout, actual.Strikeout, nameof(TextObject.Strikeout));
+    AssertEqual(expected.Kerning, actual.Kerning, nameof(TextObject.Kerning));
+    AssertEqual(expected.HorizontalAlignment, actual.HorizontalAlignment, nameof(TextObject.HorizontalAlignment));
+    AssertEqual(expected.VerticalAlignment, actual.VerticalAlignment, nameof(TextObject.VerticalAlignment));
+
+    AssertEqual(expected.Text, actual.Text, nameof(TextObject.Text));
+  }
+
+  private static void AssertObject(TileObject expected, TileObject actual)
+  {
+    // Attributes
+    AssertEqual(expected.GID, actual.GID, nameof(TileObject.GID));
+  }
+}

DotTiled.Tests/Assert/AssertProperties.cs

@@ -0,0 +1,69 @@
+namespace DotTiled.Tests;
+
+public static partial class DotTiledAssert
+{
+  internal static void AssertProperties(Dictionary<string, IProperty>? expected, Dictionary<string, IProperty>? actual)
+  {
+    if (expected is null)
+    {
+      Assert.Null(actual);
+      return;
+    }
+
+    Assert.NotNull(actual);
+    AssertEqual(expected.Count, actual.Count, "Properties.Count");
+    foreach (var kvp in expected)
+    {
+      Assert.Contains(kvp.Key, actual.Keys);
+      AssertProperty((dynamic)kvp.Value, (dynamic)actual[kvp.Key]);
+    }
+  }
+
+  private static void AssertProperty(IProperty expected, IProperty actual)
+  {
+    AssertEqual(expected.Type, actual.Type, "Property.Type");
+    AssertEqual(expected.Name, actual.Name, "Property.Name");
+    AssertProperties((dynamic)actual, (dynamic)expected);
+  }
+
+  private static void AssertProperty(StringProperty expected, StringProperty actual)
+  {
+    AssertEqual(expected.Value, actual.Value, "StringProperty.Value");
+  }
+
+  private static void AssertProperty(IntProperty expected, IntProperty actual)
+  {
+    AssertEqual(expected.Value, actual.Value, "IntProperty.Value");
+  }
+
+  private static void AssertProperty(FloatProperty expected, FloatProperty actual)
+  {
+    AssertEqual(expected.Value, actual.Value, "FloatProperty.Value");
+  }
+
+  private static void AssertProperty(BoolProperty expected, BoolProperty actual)
+  {
+    AssertEqual(expected.Value, actual.Value, "BoolProperty.Value");
+  }
+
+  private static void AssertProperty(ColorProperty expected, ColorProperty actual)
+  {
+    AssertEqual(expected.Value, actual.Value, "ColorProperty.Value");
+  }
+
+  private static void AssertProperty(FileProperty expected, FileProperty actual)
+  {
+    AssertEqual(expected.Value, actual.Value, "FileProperty.Value");
+  }
+
+  private static void AssertProperty(ObjectProperty expected, ObjectProperty actual)
+  {
+    AssertEqual(expected.Value, actual.Value, "ObjectProperty.Value");
+  }
+
+  private static void AssertProperty(ClassProperty expected, ClassProperty actual)
+  {
+    AssertEqual(expected.PropertyType, actual.PropertyType, "ClassProperty.PropertyType");
+    AssertProperties(expected.Properties, actual.Properties);
+  }
+}

DotTiled.Tests/Assert/AssertTileset.cs

@@ -0,0 +1,160 @@
+namespace DotTiled.Tests;
+
+public static partial class DotTiledAssert
+{
+  internal static void AssertTileset(Tileset expected, Tileset actual)
+  {
+    // Attributes
+    AssertEqual(expected.Version, actual.Version, nameof(Tileset.Version));
+    AssertEqual(expected.TiledVersion, actual.TiledVersion, nameof(Tileset.TiledVersion));
+    AssertEqual(expected.FirstGID, actual.FirstGID, nameof(Tileset.FirstGID));
+    AssertEqual(expected.Source, actual.Source, nameof(Tileset.Source));
+    AssertEqual(expected.Name, actual.Name, nameof(Tileset.Name));
+    AssertEqual(expected.Class, actual.Class, nameof(Tileset.Class));
+    AssertEqual(expected.TileWidth, actual.TileWidth, nameof(Tileset.TileWidth));
+    AssertEqual(expected.TileHeight, actual.TileHeight, nameof(Tileset.TileHeight));
+    AssertEqual(expected.Spacing, actual.Spacing, nameof(Tileset.Spacing));
+    AssertEqual(expected.Margin, actual.Margin, nameof(Tileset.Margin));
+    AssertEqual(expected.TileCount, actual.TileCount, nameof(Tileset.TileCount));
+    AssertEqual(expected.Columns, actual.Columns, nameof(Tileset.Columns));
+    AssertEqual(expected.ObjectAlignment, actual.ObjectAlignment, nameof(Tileset.ObjectAlignment));
+    AssertEqual(expected.RenderSize, actual.RenderSize, nameof(Tileset.RenderSize));
+    AssertEqual(expected.FillMode, actual.FillMode, nameof(Tileset.FillMode));
+
+    // At most one of
+    AssertImage(expected.Image, actual.Image);
+    AssertTileOffset(expected.TileOffset, actual.TileOffset);
+    AssertGrid(expected.Grid, actual.Grid);
+    AssertProperties(expected.Properties, actual.Properties);
+    // TODO: AssertTerrainTypes(actual.TerrainTypes, expected.TerrainTypes);
+    if (expected.Wangsets is not null)
+    {
+      Assert.NotNull(actual.Wangsets);
+      AssertEqual(expected.Wangsets.Count, actual.Wangsets.Count, "Wangsets.Count");
+      for (var i = 0; i < expected.Wangsets.Count; i++)
+        AssertWangset(expected.Wangsets[i], actual.Wangsets[i]);
+    }
+    AssertTransformations(expected.Transformations, actual.Transformations);
+
+    // Any number of
+    Assert.NotNull(actual.Tiles);
+    AssertEqual(expected.Tiles.Count, actual.Tiles.Count, "Tiles.Count");
+    for (var i = 0; i < expected.Tiles.Count; i++)
+      AssertTile(expected.Tiles[i], actual.Tiles[i]);
+  }
+
+  private static void AssertTileOffset(TileOffset? expected, TileOffset? actual)
+  {
+    if (expected is null)
+    {
+      Assert.Null(actual);
+      return;
+    }
+
+    // Attributes
+    Assert.NotNull(actual);
+    AssertEqual(expected.X, actual.X, nameof(TileOffset.X));
+    AssertEqual(expected.Y, actual.Y, nameof(TileOffset.Y));
+  }
+
+  private static void AssertGrid(Grid? expected, Grid? actual)
+  {
+    if (expected is null)
+    {
+      Assert.Null(actual);
+      return;
+    }
+
+    // Attributes
+    Assert.NotNull(actual);
+    AssertEqual(expected.Orientation, actual.Orientation, nameof(Grid.Orientation));
+    AssertEqual(expected.Width, actual.Width, nameof(Grid.Width));
+    AssertEqual(expected.Height, actual.Height, nameof(Grid.Height));
+  }
+
+  private static void AssertWangset(Wangset expected, Wangset actual)
+  {
+    // Attributes
+    AssertEqual(expected.Name, actual.Name, nameof(Wangset.Name));
+    AssertEqual(expected.Class, actual.Class, nameof(Wangset.Class));
+    AssertEqual(expected.Tile, actual.Tile, nameof(Wangset.Tile));
+
+    // At most one of
+    AssertProperties(expected.Properties, actual.Properties);
+    if (expected.WangColors is not null)
+    {
+      Assert.NotNull(actual.WangColors);
+      AssertEqual(expected.WangColors.Count, actual.WangColors.Count, "WangColors.Count");
+      for (var i = 0; i < expected.WangColors.Count; i++)
+        AssertWangColor(expected.WangColors[i], actual.WangColors[i]);
+    }
+    for (var i = 0; i < expected.WangTiles.Count; i++)
+      AssertWangTile(expected.WangTiles[i], actual.WangTiles[i]);
+  }
+
+  private static void AssertWangColor(WangColor expected, WangColor actual)
+  {
+    // Attributes
+    AssertEqual(expected.Name, actual.Name, nameof(WangColor.Name));
+    AssertEqual(expected.Class, actual.Class, nameof(WangColor.Class));
+    AssertEqual(expected.Color, actual.Color, nameof(WangColor.Color));
+    AssertEqual(expected.Tile, actual.Tile, nameof(WangColor.Tile));
+    AssertEqual(expected.Probability, actual.Probability, nameof(WangColor.Probability));
+
+    AssertProperties(expected.Properties, actual.Properties);
+  }
+
+  private static void AssertWangTile(WangTile expected, WangTile actual)
+  {
+    // Attributes
+    AssertEqual(expected.TileID, actual.TileID, nameof(WangTile.TileID));
+    AssertEqual(expected.WangID, actual.WangID, nameof(WangTile.WangID));
+  }
+
+  private static void AssertTransformations(Transformations? expected, Transformations? actual)
+  {
+    if (expected is null)
+    {
+      Assert.Null(actual);
+      return;
+    }
+
+    // Attributes
+    Assert.NotNull(actual);
+    AssertEqual(expected.HFlip, actual.HFlip, nameof(Transformations.HFlip));
+    AssertEqual(expected.VFlip, actual.VFlip, nameof(Transformations.VFlip));
+    AssertEqual(expected.Rotate, actual.Rotate, nameof(Transformations.Rotate));
+    AssertEqual(expected.PreferUntransformed, actual.PreferUntransformed, nameof(Transformations.PreferUntransformed));
+  }
+
+  private static void AssertTile(Tile expected, Tile actual)
+  {
+    // Attributes
+    AssertEqual(expected.ID, actual.ID, nameof(Tile.ID));
+    AssertEqual(expected.Type, actual.Type, nameof(Tile.Type));
+    AssertEqual(expected.Probability, actual.Probability, nameof(Tile.Probability));
+    AssertEqual(expected.X, actual.X, nameof(Tile.X));
+    AssertEqual(expected.Y, actual.Y, nameof(Tile.Y));
+    AssertEqual(expected.Width, actual.Width, nameof(Tile.Width));
+    AssertEqual(expected.Height, actual.Height, nameof(Tile.Height));
+
+    // Elements
+    AssertProperties(actual.Properties, expected.Properties);
+    AssertImage(actual.Image, expected.Image);
+    AssertLayer((BaseLayer?)actual.ObjectLayer, (BaseLayer?)expected.ObjectLayer);
+    if (expected.Animation is not null)
+    {
+      Assert.NotNull(actual.Animation);
+      AssertEqual(expected.Animation.Count, actual.Animation.Count, "Animation.Count");
+      for (var i = 0; i < expected.Animation.Count; i++)
+        AssertFrame(expected.Animation[i], actual.Animation[i]);
+    }
+  }
+
+  private static void AssertFrame(Frame expected, Frame actual)
+  {
+    // Attributes
+    AssertEqual(expected.TileID, actual.TileID, nameof(Frame.TileID));
+    AssertEqual(expected.Duration, actual.Duration, nameof(Frame.Duration));
+  }
+}

DotTiled.Tests/DotTiled.Tests.csproj

@@ -25,8 +25,8 @@
   </ItemGroup>
 
   <ItemGroup>
-    <!-- TmxSerializer test data -->
+    <!-- Test data -->
-    <EmbeddedResource Include="TmxSerializer/TestData/**/*.tmx" />
+    <EmbeddedResource Include="Serialization/TestData/**/*" />
   </ItemGroup>
 
 </Project>

DotTiled.Tests/Serialization/TestData.cs

@@ -0,0 +1,79 @@
+using System.Xml;
+
+namespace DotTiled.Tests;
+
+public static partial class TestData
+{
+  public static XmlReader GetXmlReaderFor(string testDataFile)
+  {
+    var fullyQualifiedTestDataFile = $"DotTiled.Tests.{ConvertPathToAssemblyResourcePath(testDataFile)}";
+    using var stream = typeof(TestData).Assembly.GetManifestResourceStream(fullyQualifiedTestDataFile)
+                       ?? throw new ArgumentException($"Test data file '{fullyQualifiedTestDataFile}' not found");
+
+    using var stringReader = new StreamReader(stream);
+    var xml = stringReader.ReadToEnd();
+    var xmlStringReader = new StringReader(xml);
+    return XmlReader.Create(xmlStringReader);
+  }
+
+  public static string GetRawStringFor(string testDataFile)
+  {
+    var fullyQualifiedTestDataFile = $"DotTiled.Tests.{ConvertPathToAssemblyResourcePath(testDataFile)}";
+    using var stream = typeof(TestData).Assembly.GetManifestResourceStream(fullyQualifiedTestDataFile)
+                       ?? throw new ArgumentException($"Test data file '{fullyQualifiedTestDataFile}' not found");
+
+    using var stringReader = new StreamReader(stream);
+    return stringReader.ReadToEnd();
+  }
+
+  private static string ConvertPathToAssemblyResourcePath(string path) =>
+    path.Replace("/", ".").Replace("\\", ".").Replace(" ", "_");
+
+  public static IEnumerable<object[]> MapTests =>
+  [
+    ["Serialization/TestData/Map/default_map/default-map", (string f) => TestData.DefaultMap(), Array.Empty<CustomTypeDefinition>()],
+    ["Serialization/TestData/Map/map_with_common_props/map-with-common-props", (string f) => TestData.MapWithCommonProps(), Array.Empty<CustomTypeDefinition>()],
+    ["Serialization/TestData/Map/map_with_custom_type_props/map-with-custom-type-props", (string f) => TestData.MapWithCustomTypeProps(), TestData.MapWithCustomTypePropsCustomTypeDefinitions()],
+    ["Serialization/TestData/Map/map_with_embedded_tileset/map-with-embedded-tileset", (string f) => TestData.MapWithEmbeddedTileset(), Array.Empty<CustomTypeDefinition>()],
+    ["Serialization/TestData/Map/map_with_external_tileset/map-with-external-tileset", (string f) => TestData.MapWithExternalTileset(f), Array.Empty<CustomTypeDefinition>()],
+    ["Serialization/TestData/Map/map_with_flippingflags/map-with-flippingflags", (string f) => TestData.MapWithFlippingFlags(f), Array.Empty<CustomTypeDefinition>()],
+    ["Serialization/TestData/Map/map_external_tileset_multi/map-external-tileset-multi", (string f) => TestData.MapExternalTilesetMulti(f), Array.Empty<CustomTypeDefinition>()],
+    ["Serialization/TestData/Map/map_external_tileset_wangset/map-external-tileset-wangset", (string f) => TestData.MapExternalTilesetWangset(f), Array.Empty<CustomTypeDefinition>()],
+    ["Serialization/TestData/Map/map_with_many_layers/map-with-many-layers", (string f) => TestData.MapWithManyLayers(f), Array.Empty<CustomTypeDefinition>()],
+  ];
+
+  private static CustomTypeDefinition[] typedefs = [
+    new CustomClassDefinition
+    {
+      Name = "TestClass",
+      ID = 1,
+      UseAs = CustomClassUseAs.Property,
+      Members = [
+        new StringProperty
+        {
+          Name = "Name",
+          Value = ""
+        },
+        new FloatProperty
+        {
+          Name = "Amount",
+          Value = 0f
+        }
+      ]
+    },
+    new CustomClassDefinition
+    {
+      Name = "Test",
+      ID = 2,
+      UseAs = CustomClassUseAs.All,
+      Members = [
+        new ClassProperty
+        {
+          Name = "Yep",
+          PropertyType = "TestClass",
+          Properties = []
+        }
+      ]
+    }
+  ];
+}

DotTiled.Tests/Serialization/TestData/Map/default-map/default-map.cs

@@ -1,37 +1,28 @@
 namespace DotTiled.Tests;
 
-public partial class TmxSerializerMapTests
+public partial class TestData
 {
-  private static Map SimpleMapWithEmbeddedTileset() => new Map
+  public static Map DefaultMap() => new Map
   {
-    Version = "1.10",
+    Class = "",
-    TiledVersion = "1.11.0",
     Orientation = MapOrientation.Orthogonal,
-    RenderOrder = RenderOrder.RightDown,
     Width = 5,
     Height = 5,
     TileWidth = 32,
     TileHeight = 32,
     Infinite = false,
+    HexSideLength = null,
+    StaggerAxis = null,
+    StaggerIndex = null,
+    ParallaxOriginX = 0,
+    ParallaxOriginY = 0,
+    RenderOrder = RenderOrder.RightDown,
+    CompressionLevel = -1,
+    BackgroundColor = new Color { R = 0, G = 0, B = 0, A = 0 },
+    Version = "1.10",
+    TiledVersion = "1.11.0",
     NextLayerID = 2,
     NextObjectID = 1,
-    Tilesets = [
-      new Tileset
-      {
-        FirstGID = 1,
-        Name = "Tileset 1",
-        TileWidth = 32,
-        TileHeight = 32,
-        TileCount = 8,
-        Columns = 4,
-        Image = new Image
-        {
-          Source = "tiles.png",
-          Width = 128,
-          Height = 64
-        }
-      }
-    ],
     Layers = [
       new TileLayer
       {
@@ -42,13 +33,14 @@ public partial class TmxSerializerMapTests
         Data = new Data
         {
           Encoding = DataEncoding.Csv,
+          Chunks = null,
           Compression = null,
           GlobalTileIDs = [
-            1,1,1,1,1,
+            0, 0, 0, 0, 0,
-            1,1,1,1,1,
+            0, 0, 0, 0, 0,
-            1,1,1,1,1,
+            0, 0, 0, 0, 0,
-            2,2,2,2,2,
+            0, 0, 0, 0, 0,
-            2,2,2,2,2
+            0, 0, 0, 0, 0
           ],
           FlippingFlags = [
             FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
@@ -57,7 +49,7 @@ public partial class TmxSerializerMapTests
             FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
             FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None
           ]
-        },
+        }
       }
     ]
   };

DotTiled.Tests/Serialization/TestData/Map/default-map/default-map.tmj

@@ -0,0 +1,32 @@
+{ "compressionlevel":-1,
+ "height":5,
+ "infinite":false,
+ "layers":[
+        {
+         "data":[0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0],
+         "height":5,
+         "id":1,
+         "name":"Tile Layer 1",
+         "opacity":1,
+         "type":"tilelayer",
+         "visible":true,
+         "width":5,
+         "x":0,
+         "y":0
+        }],
+ "nextlayerid":2,
+ "nextobjectid":1,
+ "orientation":"orthogonal",
+ "renderorder":"right-down",
+ "tiledversion":"1.11.0",
+ "tileheight":32,
+ "tilesets":[],
+ "tilewidth":32,
+ "type":"map",
+ "version":"1.10",
+ "width":5
+}

DotTiled.Tests/Serialization/TestData/Map/map-external-tileset-multi/map-external-tileset-multi.cs

@@ -0,0 +1,121 @@
+using System.Globalization;
+
+namespace DotTiled.Tests;
+
+public partial class TestData
+{
+  public static Map MapExternalTilesetMulti(string fileExt) => new Map
+  {
+    Class = "",
+    Orientation = MapOrientation.Orthogonal,
+    Width = 5,
+    Height = 5,
+    TileWidth = 32,
+    TileHeight = 32,
+    Infinite = false,
+    HexSideLength = null,
+    StaggerAxis = null,
+    StaggerIndex = null,
+    ParallaxOriginX = 0,
+    ParallaxOriginY = 0,
+    RenderOrder = RenderOrder.RightDown,
+    CompressionLevel = -1,
+    BackgroundColor = Color.Parse("#00000000", CultureInfo.InvariantCulture),
+    Version = "1.10",
+    TiledVersion = "1.11.0",
+    NextLayerID = 2,
+    NextObjectID = 1,
+    Tilesets = [
+      new Tileset
+      {
+        TileOffset = new TileOffset
+        {
+          X = 1,
+          Y = 5
+        },
+        Version = "1.10",
+        TiledVersion = "1.11.0",
+        FirstGID = 1,
+        Name = "multi-tileset",
+        TileWidth = 256,
+        TileHeight = 96,
+        TileCount = 2,
+        Columns = 0,
+        Source = $"multi-tileset.{(fileExt == "tmx" ? "tsx" : "tsj")}",
+        Grid = new Grid
+        {
+          Orientation = GridOrientation.Orthogonal,
+          Width = 1,
+          Height = 1
+        },
+        Properties = new Dictionary<string, IProperty>
+        {
+          ["tilesetbool"] = new BoolProperty { Name = "tilesetbool", Value = true },
+          ["tilesetcolor"] = new ColorProperty { Name = "tilesetcolor", Value = Color.Parse("#ffff0000", CultureInfo.InvariantCulture) },
+          ["tilesetfile"] = new FileProperty { Name = "tilesetfile", Value = "" },
+          ["tilesetfloat"] = new FloatProperty { Name = "tilesetfloat", Value = 5.2f },
+          ["tilesetint"] = new IntProperty { Name = "tilesetint", Value = 9 },
+          ["tilesetobject"] = new ObjectProperty { Name = "tilesetobject", Value = 0 },
+          ["tilesetstring"] = new StringProperty { Name = "tilesetstring", Value = "hello world!" }
+        },
+        Tiles = [
+          new Tile
+          {
+            ID = 0,
+            Width = 256,
+            Height = 96,
+            Image = new Image
+            {
+              Format = ImageFormat.Png,
+              Source = "tileset.png",
+              Width = 256,
+              Height = 96
+            }
+          },
+          new Tile
+          {
+            ID = 1,
+            Width = 256,
+            Height = 96,
+            Image = new Image
+            {
+              Format = ImageFormat.Png,
+              Source = "tileset.png",
+              Width = 256,
+              Height = 96
+            }
+          }
+        ]
+      }
+    ],
+    Layers = [
+      new TileLayer
+      {
+        ID = 1,
+        Name = "Tile Layer 1",
+        Width = 5,
+        Height = 5,
+        Data = new Data
+        {
+          Encoding = DataEncoding.Csv,
+          Chunks = null,
+          Compression = null,
+          GlobalTileIDs = [
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            1, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            0, 2, 0, 0, 0
+          ],
+          FlippingFlags = [
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None
+          ]
+        }
+      }
+    ]
+  };
+}

DotTiled.Tests/Serialization/TestData/Map/map-external-tileset-multi/map-external-tileset-multi.tmj

@@ -0,0 +1,36 @@
+{ "compressionlevel":-1,
+ "height":5,
+ "infinite":false,
+ "layers":[
+        {
+         "data":[0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            1, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            0, 2, 0, 0, 0],
+         "height":5,
+         "id":1,
+         "name":"Tile Layer 1",
+         "opacity":1,
+         "type":"tilelayer",
+         "visible":true,
+         "width":5,
+         "x":0,
+         "y":0
+        }],
+ "nextlayerid":2,
+ "nextobjectid":1,
+ "orientation":"orthogonal",
+ "renderorder":"right-down",
+ "tiledversion":"1.11.0",
+ "tileheight":32,
+ "tilesets":[
+        {
+         "firstgid":1,
+         "source":"multi-tileset.tsj"
+        }],
+ "tilewidth":32,
+ "type":"map",
+ "version":"1.10",
+ "width":5
+}

DotTiled.Tests/Serialization/TestData/Map/map-external-tileset-multi/map-external-tileset-multi.tmx

@@ -1,8 +1,13 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <map version="1.10" tiledversion="1.11.0" orientation="orthogonal" renderorder="right-down" width="5" height="5" tilewidth="32" tileheight="32" infinite="0" nextlayerid="2" nextobjectid="1">
+ <tileset firstgid="1" source="multi-tileset.tsx"/>
  <layer id="1" name="Tile Layer 1" width="5" height="5">
-  <data encoding="base64" compression="zlib">
+  <data encoding="csv">
-   eJxjYKA9AAAAZAAB
+0,0,0,0,0,
-  </data>
+0,0,0,0,0,
+1,0,0,0,0,
+0,0,0,0,0,
+0,2,0,0,0
+</data>
  </layer>
 </map>

DotTiled.Tests/Serialization/TestData/Map/map-external-tileset-multi/multi-tileset.tsj

@@ -0,0 +1,71 @@
+{ "columns":0,
+ "grid":
+    {
+     "height":1,
+     "orientation":"orthogonal",
+     "width":1
+    },
+ "margin":0,
+ "name":"multi-tileset",
+ "properties":[
+        {
+         "name":"tilesetbool",
+         "type":"bool",
+         "value":true
+        }, 
+        {
+         "name":"tilesetcolor",
+         "type":"color",
+         "value":"#ffff0000"
+        }, 
+        {
+         "name":"tilesetfile",
+         "type":"file",
+         "value":""
+        }, 
+        {
+         "name":"tilesetfloat",
+         "type":"float",
+         "value":5.2
+        }, 
+        {
+         "name":"tilesetint",
+         "type":"int",
+         "value":9
+        }, 
+        {
+         "name":"tilesetobject",
+         "type":"object",
+         "value":0
+        }, 
+        {
+         "name":"tilesetstring",
+         "type":"string",
+         "value":"hello world!"
+        }],
+ "spacing":0,
+ "tilecount":2,
+ "tiledversion":"1.11.0",
+ "tileheight":96,
+ "tileoffset":
+    {
+     "x":1,
+     "y":5
+    },
+ "tiles":[
+        {
+         "id":0,
+         "image":"tileset.png",
+         "imageheight":96,
+         "imagewidth":256
+        }, 
+        {
+         "id":1,
+         "image":"tileset.png",
+         "imageheight":96,
+         "imagewidth":256
+        }],
+ "tilewidth":256,
+ "type":"tileset",
+ "version":"1.10"
+}

DotTiled.Tests/Serialization/TestData/Map/map-external-tileset-multi/multi-tileset.tsx

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<tileset version="1.10" tiledversion="1.11.0" name="multi-tileset" tilewidth="256" tileheight="96" tilecount="2" columns="0">
+ <tileoffset x="1" y="5"/>
+ <grid orientation="orthogonal" width="1" height="1"/>
+ <properties>
+  <property name="tilesetbool" type="bool" value="true"/>
+  <property name="tilesetcolor" type="color" value="#ffff0000"/>
+  <property name="tilesetfile" type="file" value=""/>
+  <property name="tilesetfloat" type="float" value="5.2"/>
+  <property name="tilesetint" type="int" value="9"/>
+  <property name="tilesetobject" type="object" value="0"/>
+  <property name="tilesetstring" value="hello world!"/>
+ </properties>
+ <tile id="0">
+  <image source="tileset.png" width="256" height="96"/>
+ </tile>
+ <tile id="1">
+  <image source="tileset.png" width="256" height="96"/>
+ </tile>
+</tileset>

DotTiled.Tests/Serialization/TestData/Map/map-external-tileset-wangset/map-external-tileset-wangset.cs

@@ -0,0 +1,92 @@
+using System.Globalization;
+
+namespace DotTiled.Tests;
+
+public partial class TestData
+{
+  public static Map MapExternalTilesetWangset(string fileExt) => new Map
+  {
+    Class = "",
+    Orientation = MapOrientation.Orthogonal,
+    Width = 5,
+    Height = 5,
+    TileWidth = 24,
+    TileHeight = 24,
+    Infinite = false,
+    HexSideLength = null,
+    StaggerAxis = null,
+    StaggerIndex = null,
+    ParallaxOriginX = 0,
+    ParallaxOriginY = 0,
+    RenderOrder = RenderOrder.RightDown,
+    CompressionLevel = -1,
+    BackgroundColor = Color.Parse("#00000000", CultureInfo.InvariantCulture),
+    Version = "1.10",
+    TiledVersion = "1.11.0",
+    NextLayerID = 2,
+    NextObjectID = 1,
+    Tilesets = [
+      new Tileset
+      {
+        Version = "1.10",
+        TiledVersion = "1.11.0",
+        FirstGID = 1,
+        Name = "tileset",
+        TileWidth = 24,
+        TileHeight = 24,
+        TileCount = 48,
+        Columns = 10,
+        Source = $"wangset-tileset.{(fileExt == "tmx" ? "tsx" : "tsj")}",
+        Transformations = new Transformations
+        {
+          HFlip = true,
+          VFlip = true,
+          Rotate = false,
+          PreferUntransformed = false
+        },
+        Grid = new Grid
+        {
+          Orientation = GridOrientation.Orthogonal,
+          Width = 32,
+          Height = 32
+        },
+        Image = new Image
+        {
+          Format = ImageFormat.Png,
+          Source = "tileset.png",
+          Width = 256,
+          Height = 96,
+        }
+      }
+    ],
+    Layers = [
+      new TileLayer
+      {
+        ID = 1,
+        Name = "Tile Layer 1",
+        Width = 5,
+        Height = 5,
+        Data = new Data
+        {
+          Encoding = DataEncoding.Csv,
+          Chunks = null,
+          Compression = null,
+          GlobalTileIDs = [
+            2, 2, 12, 11, 0,
+            1, 12, 1, 11, 0,
+            2, 1, 0, 1, 0,
+            12, 11, 12, 2, 0,
+            0, 0, 0, 0, 0
+          ],
+          FlippingFlags = [
+            FlippingFlags.FlippedHorizontally, FlippingFlags.None, FlippingFlags.FlippedHorizontally, FlippingFlags.FlippedHorizontally, FlippingFlags.None,
+            FlippingFlags.FlippedVertically, FlippingFlags.None, FlippingFlags.None, FlippingFlags.FlippedVertically | FlippingFlags.FlippedHorizontally, FlippingFlags.None,
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.FlippedVertically | FlippingFlags.FlippedHorizontally, FlippingFlags.None,
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.FlippedHorizontally, FlippingFlags.None,
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None
+          ]
+        }
+      }
+    ]
+  };
+}

DotTiled.Tests/Serialization/TestData/Map/map-external-tileset-wangset/map-external-tileset-wangset.tmj

@@ -0,0 +1,36 @@
+{ "compressionlevel":-1,
+ "height":5,
+ "infinite":false,
+ "layers":[
+        {
+         "data":[2147483650, 2, 2147483660, 2147483659, 0,
+            1073741825, 12, 1, 3221225483, 0,
+            2, 1, 0, 3221225473, 0,
+            12, 11, 12, 2147483650, 0,
+            0, 0, 0, 0, 0],
+         "height":5,
+         "id":1,
+         "name":"Tile Layer 1",
+         "opacity":1,
+         "type":"tilelayer",
+         "visible":true,
+         "width":5,
+         "x":0,
+         "y":0
+        }],
+ "nextlayerid":2,
+ "nextobjectid":1,
+ "orientation":"orthogonal",
+ "renderorder":"right-down",
+ "tiledversion":"1.11.0",
+ "tileheight":24,
+ "tilesets":[
+        {
+         "firstgid":1,
+         "source":"wangset-tileset.tsj"
+        }],
+ "tilewidth":24,
+ "type":"map",
+ "version":"1.10",
+ "width":5
+}

DotTiled.Tests/Serialization/TestData/Map/map-external-tileset-wangset/map-external-tileset-wangset.tmx

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<map version="1.10" tiledversion="1.11.0" orientation="orthogonal" renderorder="right-down" width="5" height="5" tilewidth="24" tileheight="24" infinite="0" nextlayerid="2" nextobjectid="1">
+ <tileset firstgid="1" source="wangset-tileset.tsx"/>
+ <layer id="1" name="Tile Layer 1" width="5" height="5">
+  <data encoding="csv">
+2147483650,2,2147483660,2147483659,0,
+1073741825,12,1,3221225483,0,
+2,1,0,3221225473,0,
+12,11,12,2147483650,0,
+0,0,0,0,0
+</data>
+ </layer>
+</map>

DotTiled.Tests/Serialization/TestData/Map/map-external-tileset-wangset/wangset-tileset.tsj

@@ -0,0 +1,69 @@
+{ "columns":10,
+ "grid":
+    {
+     "height":32,
+     "orientation":"orthogonal",
+     "width":32
+    },
+ "image":"tileset.png",
+ "imageheight":96,
+ "imagewidth":256,
+ "margin":0,
+ "name":"tileset",
+ "spacing":0,
+ "tilecount":48,
+ "tiledversion":"1.11.0",
+ "tileheight":24,
+ "tilewidth":24,
+ "transformations":
+    {
+     "hflip":true,
+     "preferuntransformed":false,
+     "rotate":false,
+     "vflip":true
+    },
+ "type":"tileset",
+ "version":"1.10",
+ "wangsets":[
+        {
+         "colors":[
+                {
+                 "color":"#ff0000",
+                 "name":"Water",
+                 "probability":1,
+                 "tile":0
+                }, 
+                {
+                 "color":"#00ff00",
+                 "name":"Grass",
+                 "probability":1,
+                 "tile":-1
+                }, 
+                {
+                 "color":"#0000ff",
+                 "name":"Stone",
+                 "probability":1,
+                 "tile":29
+                }],
+         "name":"test-terrain",
+         "tile":-1,
+         "type":"mixed",
+         "wangtiles":[
+                {
+                 "tileid":0,
+                 "wangid":[1, 1, 0, 0, 0, 1, 1, 1]
+                }, 
+                {
+                 "tileid":1,
+                 "wangid":[1, 1, 1, 1, 0, 0, 0, 1]
+                }, 
+                {
+                 "tileid":10,
+                 "wangid":[0, 0, 0, 1, 1, 1, 1, 1]
+                }, 
+                {
+                 "tileid":11,
+                 "wangid":[0, 1, 1, 1, 1, 1, 0, 0]
+                }]
+        }]
+}

DotTiled.Tests/Serialization/TestData/Map/map-external-tileset-wangset/wangset-tileset.tsx

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<tileset version="1.10" tiledversion="1.11.0" name="tileset" tilewidth="24" tileheight="24" tilecount="48" columns="10">
+ <grid orientation="orthogonal" width="32" height="32"/>
+ <transformations hflip="1" vflip="1" rotate="0" preferuntransformed="0"/>
+ <image source="tileset.png" width="256" height="96"/>
+ <wangsets>
+  <wangset name="test-terrain" type="mixed" tile="-1">
+   <wangcolor name="Water" color="#ff0000" tile="0" probability="1"/>
+   <wangcolor name="Grass" color="#00ff00" tile="-1" probability="1"/>
+   <wangcolor name="Stone" color="#0000ff" tile="29" probability="1"/>
+   <wangtile tileid="0" wangid="1,1,0,0,0,1,1,1"/>
+   <wangtile tileid="1" wangid="1,1,1,1,0,0,0,1"/>
+   <wangtile tileid="10" wangid="0,0,0,1,1,1,1,1"/>
+   <wangtile tileid="11" wangid="0,1,1,1,1,1,0,0"/>
+  </wangset>
+ </wangsets>
+</tileset>

DotTiled.Tests/Serialization/TestData/Map/map-with-common-props/map-with-common-props.cs

@@ -0,0 +1,68 @@
+using System.Globalization;
+
+namespace DotTiled.Tests;
+
+public partial class TestData
+{
+  public static Map MapWithCommonProps() => new Map
+  {
+    Class = "",
+    Orientation = MapOrientation.Isometric,
+    Width = 5,
+    Height = 5,
+    TileWidth = 32,
+    TileHeight = 16,
+    Infinite = false,
+    HexSideLength = null,
+    StaggerAxis = null,
+    StaggerIndex = null,
+    ParallaxOriginX = 0,
+    ParallaxOriginY = 0,
+    RenderOrder = RenderOrder.RightDown,
+    CompressionLevel = -1,
+    BackgroundColor = Color.Parse("#00ff00", CultureInfo.InvariantCulture),
+    Version = "1.10",
+    TiledVersion = "1.11.0",
+    NextLayerID = 2,
+    NextObjectID = 1,
+    Layers = [
+      new TileLayer
+      {
+        ID = 1,
+        Name = "Tile Layer 1",
+        Width = 5,
+        Height = 5,
+        Data = new Data
+        {
+          Encoding = DataEncoding.Csv,
+          Chunks = null,
+          Compression = null,
+          GlobalTileIDs = [
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0
+          ],
+          FlippingFlags = [
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None
+          ]
+        }
+      }
+    ],
+    Properties = new Dictionary<string, IProperty>
+    {
+      ["boolprop"] = new BoolProperty { Name = "boolprop", Value = true },
+      ["colorprop"] = new ColorProperty { Name = "colorprop", Value = Color.Parse("#ff55ffff", CultureInfo.InvariantCulture) },
+      ["fileprop"] = new FileProperty { Name = "fileprop", Value = "file.txt" },
+      ["floatprop"] = new FloatProperty { Name = "floatprop", Value = 4.2f },
+      ["intprop"] = new IntProperty { Name = "intprop", Value = 8 },
+      ["objectprop"] = new ObjectProperty { Name = "objectprop", Value = 5 },
+      ["stringprop"] = new StringProperty { Name = "stringprop", Value = "This is a string, hello world!" }
+    }
+  };
+}

DotTiled.Tests/Serialization/TestData/Map/map-with-common-props/map-with-common-props.tmj

@@ -0,0 +1,70 @@
+{ "backgroundcolor":"#00ff00",
+ "compressionlevel":-1,
+ "height":5,
+ "infinite":false,
+ "layers":[
+        {
+         "data":[0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0],
+         "height":5,
+         "id":1,
+         "name":"Tile Layer 1",
+         "opacity":1,
+         "type":"tilelayer",
+         "visible":true,
+         "width":5,
+         "x":0,
+         "y":0
+        }],
+ "nextlayerid":2,
+ "nextobjectid":1,
+ "orientation":"isometric",
+ "properties":[
+        {
+         "name":"boolprop",
+         "type":"bool",
+         "value":true
+        }, 
+        {
+         "name":"colorprop",
+         "type":"color",
+         "value":"#ff55ffff"
+        }, 
+        {
+         "name":"fileprop",
+         "type":"file",
+         "value":"file.txt"
+        }, 
+        {
+         "name":"floatprop",
+         "type":"float",
+         "value":4.2
+        }, 
+        {
+         "name":"intprop",
+         "type":"int",
+         "value":8
+        },
+    
+        {
+         "name":"objectprop",
+         "type":"object",
+         "value":5
+        }, 
+        {
+         "name":"stringprop",
+         "type":"string",
+         "value":"This is a string, hello world!"
+        }],
+ "renderorder":"right-down",
+ "tiledversion":"1.11.0",
+ "tileheight":16,
+ "tilesets":[],
+ "tilewidth":32,
+ "type":"map",
+ "version":"1.10",
+ "width":5
+}

DotTiled.Tests/Serialization/TestData/Map/map-with-common-props/map-with-common-props.tmx

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<map version="1.10" tiledversion="1.11.0" orientation="isometric" renderorder="right-down" width="5" height="5" tilewidth="32" tileheight="16" infinite="0" backgroundcolor="#00ff00" nextlayerid="2" nextobjectid="1">
+ <properties>
+  <property name="boolprop" type="bool" value="true"/>
+  <property name="colorprop" type="color" value="#ff55ffff"/>
+  <property name="fileprop" type="file" value="file.txt"/>
+  <property name="floatprop" type="float" value="4.2"/>
+  <property name="intprop" type="int" value="8"/>
+  <property name="objectprop" type="object" value="5"/>
+  <property name="stringprop" value="This is a string, hello world!"/>
+ </properties>
+ <layer id="1" name="Tile Layer 1" width="5" height="5">
+  <data encoding="csv">
+0,0,0,0,0,
+0,0,0,0,0,
+0,0,0,0,0,
+0,0,0,0,0,
+0,0,0,0,0
+</data>
+ </layer>
+</map>

DotTiled.Tests/Serialization/TestData/Map/map-with-custom-type-props/map-with-custom-type-props.cs

@@ -0,0 +1,122 @@
+using System.Globalization;
+
+namespace DotTiled.Tests;
+
+public partial class TestData
+{
+  public static Map MapWithCustomTypeProps() => new Map
+  {
+    Class = "",
+    Orientation = MapOrientation.Orthogonal,
+    Width = 5,
+    Height = 5,
+    TileWidth = 32,
+    TileHeight = 32,
+    Infinite = false,
+    HexSideLength = null,
+    StaggerAxis = null,
+    StaggerIndex = null,
+    ParallaxOriginX = 0,
+    ParallaxOriginY = 0,
+    RenderOrder = RenderOrder.RightDown,
+    CompressionLevel = -1,
+    BackgroundColor = Color.Parse("#00000000", CultureInfo.InvariantCulture),
+    Version = "1.10",
+    TiledVersion = "1.11.0",
+    NextLayerID = 2,
+    NextObjectID = 1,
+    Layers = [
+      new TileLayer
+      {
+        ID = 1,
+        Name = "Tile Layer 1",
+        Width = 5,
+        Height = 5,
+        Data = new Data
+        {
+          Encoding = DataEncoding.Csv,
+          Chunks = null,
+          Compression = null,
+          GlobalTileIDs = [
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0
+          ],
+          FlippingFlags = [
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None
+          ]
+        }
+      }
+    ],
+    Properties = new Dictionary<string, IProperty>
+    {
+      ["customclassprop"] = new ClassProperty
+      {
+        Name = "customclassprop",
+        PropertyType = "CustomClass",
+        Properties = new Dictionary<string, IProperty>
+        {
+          ["boolinclass"] = new BoolProperty { Name = "boolinclass", Value = true },
+          ["colorinclass"] = new ColorProperty { Name = "colorinclass", Value = Color.Parse("#000000ff", CultureInfo.InvariantCulture) },
+          ["fileinclass"] = new FileProperty { Name = "fileinclass", Value = "" },
+          ["floatinclass"] = new FloatProperty { Name = "floatinclass", Value = 13.37f },
+          ["intinclass"] = new IntProperty { Name = "intinclass", Value = 0 },
+          ["objectinclass"] = new ObjectProperty { Name = "objectinclass", Value = 0 },
+          ["stringinclass"] = new StringProperty { Name = "stringinclass", Value = "This is a set string" }
+        }
+      }
+    }
+  };
+
+  // This comes from map-with-custom-type-props/propertytypes.json
+  public static IReadOnlyCollection<CustomTypeDefinition> MapWithCustomTypePropsCustomTypeDefinitions() => [
+    new CustomClassDefinition
+    {
+      Name = "CustomClass",
+      UseAs = CustomClassUseAs.Property,
+      Members = [
+        new BoolProperty
+        {
+          Name = "boolinclass",
+          Value = false
+        },
+        new ColorProperty
+        {
+          Name = "colorinclass",
+          Value = Color.Parse("#000000ff", CultureInfo.InvariantCulture)
+        },
+        new FileProperty
+        {
+          Name = "fileinclass",
+          Value = ""
+        },
+        new FloatProperty
+        {
+          Name = "floatinclass",
+          Value = 0f
+        },
+        new IntProperty
+        {
+          Name = "intinclass",
+          Value = 0
+        },
+        new ObjectProperty
+        {
+          Name = "objectinclass",
+          Value = 0
+        },
+        new StringProperty
+        {
+          Name = "stringinclass",
+          Value = ""
+        }
+      ]
+    }
+  ];
+}

DotTiled.Tests/Serialization/TestData/Map/map-with-custom-type-props/map-with-custom-type-props.tmj

@@ -0,0 +1,44 @@
+{ "compressionlevel":-1,
+ "height":5,
+ "infinite":false,
+ "layers":[
+        {
+         "data":[0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0,
+            0, 0, 0, 0, 0],
+         "height":5,
+         "id":1,
+         "name":"Tile Layer 1",
+         "opacity":1,
+         "type":"tilelayer",
+         "visible":true,
+         "width":5,
+         "x":0,
+         "y":0
+        }],
+ "nextlayerid":2,
+ "nextobjectid":1,
+ "orientation":"orthogonal",
+ "properties":[
+        {
+         "name":"customclassprop",
+         "propertytype":"CustomClass",
+         "type":"class",
+         "value":
+            {
+             "boolinclass":true,
+             "floatinclass":13.37,
+             "stringinclass":"This is a set string"
+            }
+        }],
+ "renderorder":"right-down",
+ "tiledversion":"1.11.0",
+ "tileheight":32,
+ "tilesets":[],
+ "tilewidth":32,
+ "type":"map",
+ "version":"1.10",
+ "width":5
+}

DotTiled.Tests/Serialization/TestData/Map/map-with-custom-type-props/map-with-custom-type-props.tmx

@@ -1,13 +1,13 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <map version="1.10" tiledversion="1.11.0" orientation="orthogonal" renderorder="right-down" width="5" height="5" tilewidth="32" tileheight="32" infinite="0" nextlayerid="2" nextobjectid="1">
  <properties>
-  <property name="MapBool" type="bool" value="true"/>
+  <property name="customclassprop" type="class" propertytype="CustomClass">
-  <property name="MapColor" type="color" value="#ffff0000"/>
+   <properties>
-  <property name="MapFile" type="file" value="file.png"/>
+    <property name="boolinclass" type="bool" value="true"/>
-  <property name="MapFloat" type="float" value="5.2"/>
+    <property name="floatinclass" type="float" value="13.37"/>
-  <property name="MapInt" type="int" value="42"/>
+    <property name="stringinclass" value="This is a set string"/>
-  <property name="MapObject" type="object" value="5"/>
+   </properties>
-  <property name="MapString" value="string in map"/>
+  </property>
  </properties>
  <layer id="1" name="Tile Layer 1" width="5" height="5">
   <data encoding="csv">

DotTiled.Tests/Serialization/TestData/Map/map-with-custom-type-props/propertytypes.json

@@ -0,0 +1,49 @@
+[
+    {
+        "color": "#ffa0a0a4",
+        "drawFill": true,
+        "id": 8,
+        "members": [
+            {
+                "name": "boolinclass",
+                "type": "bool",
+                "value": false
+            },
+            {
+                "name": "colorinclass",
+                "type": "color",
+                "value": ""
+            },
+            {
+                "name": "fileinclass",
+                "type": "file",
+                "value": ""
+            },
+            {
+                "name": "floatinclass",
+                "type": "float",
+                "value": 0
+            },
+            {
+                "name": "intinclass",
+                "type": "int",
+                "value": 0
+            },
+            {
+                "name": "objectinclass",
+                "type": "object",
+                "value": 0
+            },
+            {
+                "name": "stringinclass",
+                "type": "string",
+                "value": ""
+            }
+        ],
+        "name": "CustomClass",
+        "type": "class",
+        "useAs": [
+            "property"
+        ]
+    }
+]

DotTiled.Tests/Serialization/TestData/Map/map-with-embedded-tileset/map-with-embedded-tileset.cs

@@ -1,20 +1,48 @@
+using System.Globalization;
+
 namespace DotTiled.Tests;
 
-public partial class TmxSerializerMapTests
+public partial class TestData
 {
-  private static Map EmptyMapWithProperties() => new Map
+  public static Map MapWithEmbeddedTileset() => new Map
   {
-    Version = "1.10",
+    Class = "",
-    TiledVersion = "1.11.0",
     Orientation = MapOrientation.Orthogonal,
-    RenderOrder = RenderOrder.RightDown,
     Width = 5,
     Height = 5,
     TileWidth = 32,
     TileHeight = 32,
     Infinite = false,
+    HexSideLength = null,
+    StaggerAxis = null,
+    StaggerIndex = null,
+    ParallaxOriginX = 0,
+    ParallaxOriginY = 0,
+    RenderOrder = RenderOrder.RightDown,
+    CompressionLevel = -1,
+    BackgroundColor = Color.Parse("#00000000", CultureInfo.InvariantCulture),
+    Version = "1.10",
+    TiledVersion = "1.11.0",
     NextLayerID = 2,
     NextObjectID = 1,
+    Tilesets = [
+      new Tileset
+      {
+        FirstGID = 1,
+        Name = "tileset",
+        TileWidth = 32,
+        TileHeight = 32,
+        TileCount = 24,
+        Columns = 8,
+        Image = new Image
+        {
+          Format = ImageFormat.Png,
+          Source = "tileset.png",
+          Width = 256,
+          Height = 96,
+        }
+      }
+    ],
     Layers = [
       new TileLayer
       {
@@ -25,12 +53,14 @@ public partial class TmxSerializerMapTests
         Data = new Data
         {
           Encoding = DataEncoding.Csv,
+          Chunks = null,
+          Compression = null,
           GlobalTileIDs = [
-            0,0,0,0,0,
+            1, 1, 0, 0, 7,
-            0,0,0,0,0,
+            1, 1, 0, 0, 7,
-            0,0,0,0,0,
+            0, 0, 0, 0, 7,
-            0,0,0,0,0,
+            9, 10, 0, 0, 7,
-            0,0,0,0,0
+            17, 18, 0, 0, 0
           ],
           FlippingFlags = [
             FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
@@ -41,16 +71,6 @@ public partial class TmxSerializerMapTests
           ]
         }
       }
-    ],
+    ]
-    Properties = new Dictionary<string, IProperty>
-    {
-      ["MapBool"] = new BoolProperty { Name = "MapBool", Value = true },
-      ["MapColor"] = new ColorProperty { Name = "MapColor", Value = new Color { R = 255, G = 0, B = 0, A = 255 } },
-      ["MapFile"] = new FileProperty { Name = "MapFile", Value = "file.png" },
-      ["MapFloat"] = new FloatProperty { Name = "MapFloat", Value = 5.2f },
-      ["MapInt"] = new IntProperty { Name = "MapInt", Value = 42 },
-      ["MapObject"] = new ObjectProperty { Name = "MapObject", Value = 5 },
-      ["MapString"] = new StringProperty { Name = "MapString", Value = "string in map" }
-    }
   };
 }

DotTiled.Tests/Serialization/TestData/Map/map-with-embedded-tileset/map-with-embedded-tileset.tmj

@@ -0,0 +1,45 @@
+{ "compressionlevel":-1,
+ "height":5,
+ "infinite":false,
+ "layers":[
+        {
+         "data":[1, 1, 0, 0, 7,
+            1, 1, 0, 0, 7,
+            0, 0, 0, 0, 7,
+            9, 10, 0, 0, 7,
+            17, 18, 0, 0, 0],
+         "height":5,
+         "id":1,
+         "name":"Tile Layer 1",
+         "opacity":1,
+         "type":"tilelayer",
+         "visible":true,
+         "width":5,
+         "x":0,
+         "y":0
+        }],
+ "nextlayerid":2,
+ "nextobjectid":1,
+ "orientation":"orthogonal",
+ "renderorder":"right-down",
+ "tiledversion":"1.11.0",
+ "tileheight":32,
+ "tilesets":[
+        {
+         "columns":8,
+         "firstgid":1,
+         "image":"tileset.png",
+         "imageheight":96,
+         "imagewidth":256,
+         "margin":0,
+         "name":"tileset",
+         "spacing":0,
+         "tilecount":24,
+         "tileheight":32,
+         "tilewidth":32
+        }],
+ "tilewidth":32,
+ "type":"map",
+ "version":"1.10",
+ "width":5
+}

DotTiled.Tests/Serialization/TestData/Map/map-with-embedded-tileset/map-with-embedded-tileset.tmx

@@ -1,15 +1,15 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <map version="1.10" tiledversion="1.11.0" orientation="orthogonal" renderorder="right-down" width="5" height="5" tilewidth="32" tileheight="32" infinite="0" nextlayerid="2" nextobjectid="1">
- <tileset firstgid="1" name="Tileset 1" tilewidth="32" tileheight="32" tilecount="8" columns="4">
+ <tileset firstgid="1" name="tileset" tilewidth="32" tileheight="32" tilecount="24" columns="8">
-  <image source="tiles.png" width="128" height="64"/>
+  <image source="tileset.png" width="256" height="96"/>
  </tileset>
  <layer id="1" name="Tile Layer 1" width="5" height="5">
   <data encoding="csv">
-1,1,1,1,1,
+1,1,0,0,7,
-1,1,1,1,1,
+1,1,0,0,7,
-1,1,1,1,1,
+0,0,0,0,7,
-2,2,2,2,2,
+9,10,0,0,7,
-2,2,2,2,2
+17,18,0,0,0
 </data>
  </layer>
 </map>

DotTiled.Tests/Serialization/TestData/Map/map-with-external-tileset/map-with-external-tileset.cs

@@ -1,20 +1,51 @@
+using System.Globalization;
+
 namespace DotTiled.Tests;
 
-public partial class TmxSerializerMapTests
+public partial class TestData
 {
-  private static Map EmptyMapWithEncodingAndCompression(DataEncoding dataEncoding, DataCompression? compression) => new Map
+  public static Map MapWithExternalTileset(string fileExt) => new Map
   {
-    Version = "1.10",
+    Class = "",
-    TiledVersion = "1.11.0",
     Orientation = MapOrientation.Orthogonal,
-    RenderOrder = RenderOrder.RightDown,
     Width = 5,
     Height = 5,
     TileWidth = 32,
     TileHeight = 32,
     Infinite = false,
+    HexSideLength = null,
+    StaggerAxis = null,
+    StaggerIndex = null,
+    ParallaxOriginX = 0,
+    ParallaxOriginY = 0,
+    RenderOrder = RenderOrder.RightDown,
+    CompressionLevel = -1,
+    BackgroundColor = Color.Parse("#00000000", CultureInfo.InvariantCulture),
+    Version = "1.10",
+    TiledVersion = "1.11.0",
     NextLayerID = 2,
     NextObjectID = 1,
+    Tilesets = [
+      new Tileset
+      {
+        Version = "1.10",
+        TiledVersion = "1.11.0",
+        FirstGID = 1,
+        Name = "tileset",
+        TileWidth = 32,
+        TileHeight = 32,
+        TileCount = 24,
+        Columns = 8,
+        Source = $"tileset.{(fileExt == "tmx" ? "tsx" : "tsj")}",
+        Image = new Image
+        {
+          Format = ImageFormat.Png,
+          Source = "tileset.png",
+          Width = 256,
+          Height = 96,
+        }
+      }
+    ],
     Layers = [
       new TileLayer
       {
@@ -24,14 +55,15 @@ public partial class TmxSerializerMapTests
         Height = 5,
         Data = new Data
         {
-          Encoding = dataEncoding,
+          Encoding = DataEncoding.Csv,
-          Compression = compression,
+          Chunks = null,
+          Compression = null,
           GlobalTileIDs = [
-            0,0,0,0,0,
+            1, 1, 0, 0, 7,
-            0,0,0,0,0,
+            1, 1, 0, 0, 7,
-            0,0,0,0,0,
+            0, 0, 1, 0, 7,
-            0,0,0,0,0,
+            0, 0, 0, 1, 7,
-            0,0,0,0,0
+            21, 21, 21, 21, 1
           ],
           FlippingFlags = [
             FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,

DotTiled.Tests/Serialization/TestData/Map/map-with-external-tileset/map-with-external-tileset.tmj

@@ -0,0 +1,36 @@
+{ "compressionlevel":-1,
+ "height":5,
+ "infinite":false,
+ "layers":[
+        {
+         "data":[1, 1, 0, 0, 7,
+            1, 1, 0, 0, 7,
+            0, 0, 1, 0, 7,
+            0, 0, 0, 1, 7,
+            21, 21, 21, 21, 1],
+         "height":5,
+         "id":1,
+         "name":"Tile Layer 1",
+         "opacity":1,
+         "type":"tilelayer",
+         "visible":true,
+         "width":5,
+         "x":0,
+         "y":0
+        }],
+ "nextlayerid":2,
+ "nextobjectid":1,
+ "orientation":"orthogonal",
+ "renderorder":"right-down",
+ "tiledversion":"1.11.0",
+ "tileheight":32,
+ "tilesets":[
+        {
+         "firstgid":1,
+         "source":"tileset.tsj"
+        }],
+ "tilewidth":32,
+ "type":"map",
+ "version":"1.10",
+ "width":5
+}

DotTiled.Tests/Serialization/TestData/Map/map-with-external-tileset/map-with-external-tileset.tmx

@@ -1,8 +1,13 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <map version="1.10" tiledversion="1.11.0" orientation="orthogonal" renderorder="right-down" width="5" height="5" tilewidth="32" tileheight="32" infinite="0" nextlayerid="2" nextobjectid="1">
+ <tileset firstgid="1" source="tileset.tsx"/>
  <layer id="1" name="Tile Layer 1" width="5" height="5">
-  <data encoding="base64" compression="gzip">
+  <data encoding="csv">
-   H4sIAAAAAAAACmNgoD0AAMrGiJlkAAAA
+1,1,0,0,7,
-  </data>
+1,1,0,0,7,
+0,0,1,0,7,
+0,0,0,1,7,
+21,21,21,21,1
+</data>
  </layer>
 </map>

DotTiled.Tests/Serialization/TestData/Map/map-with-external-tileset/tileset.tsj

@@ -0,0 +1,14 @@
+{ "columns":8,
+ "image":"tileset.png",
+ "imageheight":96,
+ "imagewidth":256,
+ "margin":0,
+ "name":"tileset",
+ "spacing":0,
+ "tilecount":24,
+ "tiledversion":"1.11.0",
+ "tileheight":32,
+ "tilewidth":32,
+ "type":"tileset",
+ "version":"1.10"
+}

DotTiled.Tests/Serialization/TestData/Map/map-with-external-tileset/tileset.tsx

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<tileset version="1.10" tiledversion="1.11.0" name="tileset" tilewidth="32" tileheight="32" tilecount="24" columns="8">
+ <image source="tileset.png" width="256" height="96"/>
+</tileset>

DotTiled.Tests/Serialization/TestData/Map/map-with-flippingflags/map-with-flippingflags.cs

@@ -0,0 +1,79 @@
+using System.Globalization;
+
+namespace DotTiled.Tests;
+
+public partial class TestData
+{
+  public static Map MapWithFlippingFlags(string fileExt) => new Map
+  {
+    Class = "",
+    Orientation = MapOrientation.Orthogonal,
+    Width = 5,
+    Height = 5,
+    TileWidth = 32,
+    TileHeight = 32,
+    Infinite = false,
+    HexSideLength = null,
+    StaggerAxis = null,
+    StaggerIndex = null,
+    ParallaxOriginX = 0,
+    ParallaxOriginY = 0,
+    RenderOrder = RenderOrder.RightDown,
+    CompressionLevel = -1,
+    BackgroundColor = Color.Parse("#00000000", CultureInfo.InvariantCulture),
+    Version = "1.10",
+    TiledVersion = "1.11.0",
+    NextLayerID = 2,
+    NextObjectID = 1,
+    Tilesets = [
+      new Tileset
+      {
+        Version = "1.10",
+        TiledVersion = "1.11.0",
+        FirstGID = 1,
+        Name = "tileset",
+        TileWidth = 32,
+        TileHeight = 32,
+        TileCount = 24,
+        Columns = 8,
+        Source = $"tileset.{(fileExt == "tmx" ? "tsx" : "tsj")}",
+        Image = new Image
+        {
+          Format = ImageFormat.Png,
+          Source = "tileset.png",
+          Width = 256,
+          Height = 96,
+        }
+      }
+    ],
+    Layers = [
+      new TileLayer
+      {
+        ID = 1,
+        Name = "Tile Layer 1",
+        Width = 5,
+        Height = 5,
+        Data = new Data
+        {
+          Encoding = DataEncoding.Csv,
+          Chunks = null,
+          Compression = null,
+          GlobalTileIDs = [
+            1, 1, 0, 0, 7,
+            1, 1, 0, 0, 7,
+            0, 0, 1, 0, 7,
+            0, 0, 0, 1, 7,
+            21, 21, 21, 21, 1
+          ],
+          FlippingFlags = [
+            FlippingFlags.None, FlippingFlags.FlippedDiagonally | FlippingFlags.FlippedHorizontally, FlippingFlags.None, FlippingFlags.None, FlippingFlags.FlippedVertically,
+            FlippingFlags.FlippedDiagonally | FlippingFlags.FlippedVertically, FlippingFlags.FlippedVertically | FlippingFlags.FlippedHorizontally, FlippingFlags.None, FlippingFlags.None, FlippingFlags.FlippedVertically,
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.FlippedVertically,
+            FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.FlippedVertically,
+            FlippingFlags.FlippedHorizontally, FlippingFlags.FlippedHorizontally, FlippingFlags.FlippedHorizontally, FlippingFlags.FlippedHorizontally, FlippingFlags.None
+          ]
+        }
+      }
+    ]
+  };
+}

DotTiled.Tests/Serialization/TestData/Map/map-with-flippingflags/map-with-flippingflags.tmj

@@ -0,0 +1,36 @@
+{ "compressionlevel":-1,
+ "height":5,
+ "infinite":false,
+ "layers":[
+        {
+         "data":[1, 2684354561, 0, 0, 1073741831,
+            1610612737, 3221225473, 0, 0, 1073741831,
+            0, 0, 1, 0, 1073741831,
+            0, 0, 0, 1, 1073741831,
+            2147483669, 2147483669, 2147483669, 2147483669, 1],
+         "height":5,
+         "id":1,
+         "name":"Tile Layer 1",
+         "opacity":1,
+         "type":"tilelayer",
+         "visible":true,
+         "width":5,
+         "x":0,
+         "y":0
+        }],
+ "nextlayerid":2,
+ "nextobjectid":1,
+ "orientation":"orthogonal",
+ "renderorder":"right-down",
+ "tiledversion":"1.11.0",
+ "tileheight":32,
+ "tilesets":[
+        {
+         "firstgid":1,
+         "source":"tileset.tsj"
+        }],
+ "tilewidth":32,
+ "type":"map",
+ "version":"1.10",
+ "width":5
+}

DotTiled.Tests/Serialization/TestData/Map/map-with-flippingflags/map-with-flippingflags.tmx

@@ -1,8 +1,13 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <map version="1.10" tiledversion="1.11.0" orientation="orthogonal" renderorder="right-down" width="5" height="5" tilewidth="32" tileheight="32" infinite="0" nextlayerid="2" nextobjectid="1">
+ <tileset firstgid="1" source="tileset.tsx"/>
  <layer id="1" name="Tile Layer 1" width="5" height="5">
-  <data encoding="base64">
+  <data encoding="csv">
-   AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA==
+1,2684354561,0,0,1073741831,
-  </data>
+1610612737,3221225473,0,0,1073741831,
+0,0,1,0,1073741831,
+0,0,0,1,1073741831,
+2147483669,2147483669,2147483669,2147483669,1
+</data>
  </layer>
 </map>

DotTiled.Tests/Serialization/TestData/Map/map-with-flippingflags/tileset.tsj

@@ -0,0 +1,14 @@
+{ "columns":8,
+ "image":"tileset.png",
+ "imageheight":96,
+ "imagewidth":256,
+ "margin":0,
+ "name":"tileset",
+ "spacing":0,
+ "tilecount":24,
+ "tiledversion":"1.11.0",
+ "tileheight":32,
+ "tilewidth":32,
+ "type":"tileset",
+ "version":"1.10"
+}

DotTiled.Tests/Serialization/TestData/Map/map-with-flippingflags/tileset.tsx

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<tileset version="1.10" tiledversion="1.11.0" name="tileset" tilewidth="32" tileheight="32" tilecount="24" columns="8">
+ <image source="tileset.png" width="256" height="96"/>
+</tileset>

DotTiled.Tests/Serialization/TestData/Map/map-with-many-layers/map-with-many-layers.cs

@@ -0,0 +1,219 @@
+using System.Numerics;
+
+namespace DotTiled.Tests;
+
+public partial class TestData
+{
+  public static Map MapWithManyLayers(string fileExt) => new Map
+  {
+    Class = "",
+    Orientation = MapOrientation.Orthogonal,
+    Width = 5,
+    Height = 5,
+    TileWidth = 32,
+    TileHeight = 32,
+    Infinite = false,
+    HexSideLength = null,
+    StaggerAxis = null,
+    StaggerIndex = null,
+    ParallaxOriginX = 0,
+    ParallaxOriginY = 0,
+    RenderOrder = RenderOrder.RightDown,
+    CompressionLevel = -1,
+    BackgroundColor = new Color { R = 0, G = 0, B = 0, A = 0 },
+    Version = "1.10",
+    TiledVersion = "1.11.0",
+    NextLayerID = 8,
+    NextObjectID = 7,
+    Tilesets = [
+      new Tileset
+      {
+        Version = "1.10",
+        TiledVersion = "1.11.0",
+        FirstGID = 1,
+        Name = "tileset",
+        TileWidth = 32,
+        TileHeight = 32,
+        TileCount = 24,
+        Columns = 8,
+        Source = $"tileset.{(fileExt == "tmx" ? "tsx" : "tsj")}",
+        Image = new Image
+        {
+          Format = ImageFormat.Png,
+          Source = "tileset.png",
+          Width = 256,
+          Height = 96,
+        }
+      }
+    ],
+    Layers = [
+      new Group
+      {
+        ID = 2,
+        Name = "Root",
+        Layers = [
+          new ObjectLayer
+          {
+            ID = 3,
+            Name = "Objects",
+            Objects = [
+              new RectangleObject
+              {
+                ID = 1,
+                Name = "Object 1",
+                X = 25.6667f,
+                Y = 28.6667f,
+                Width = 31.3333f,
+                Height = 31.3333f
+              },
+              new PointObject
+              {
+                ID = 3,
+                Name = "P1",
+                X = 117.667f,
+                Y = 48.6667f
+              },
+              new EllipseObject
+              {
+                ID = 4,
+                Name = "Circle1",
+                X = 77f,
+                Y = 72.3333f,
+                Width = 34.6667f,
+                Height = 34.6667f
+              },
+              new PolygonObject
+              {
+                ID = 5,
+                Name = "Poly",
+                X = 20.6667f,
+                Y = 114.667f,
+                Points = [
+                  new Vector2(0, 0),
+                  new Vector2(104,20),
+                  new Vector2(35.6667f, 32.3333f)
+                ],
+                Template = fileExt == "tmx" ? "poly.tx" : "poly.tj",
+                Properties = new Dictionary<string, IProperty>
+                {
+                  ["templateprop"] = new StringProperty { Name = "templateprop", Value = "helo there" }
+                }
+              },
+              new TileObject
+              {
+                ID = 6,
+                Name = "TileObj",
+                GID = 7,
+                X = -35,
+                Y = 110.333f,
+                Width = 64,
+                Height = 146
+              }
+            ]
+          },
+          new Group
+          {
+            ID = 5,
+            Name = "Sub",
+            Layers = [
+              new TileLayer
+              {
+                ID = 7,
+                Name = "Tile 3",
+                Width = 5,
+                Height = 5,
+                Data = new Data
+                {
+                  Encoding = DataEncoding.Csv,
+                  Chunks = null,
+                  Compression = null,
+                  GlobalTileIDs = [
+                    0, 0, 0, 0, 0,
+                    0, 0, 0, 0, 0,
+                    0, 0, 0, 0, 0,
+                    0, 0, 0, 0, 0,
+                    0, 0, 0, 0, 0
+                  ],
+                  FlippingFlags = [
+                    FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+                    FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+                    FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+                    FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+                    FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None
+                  ]
+                }
+              },
+              new TileLayer
+              {
+                ID = 6,
+                Name = "Tile 2",
+                Width = 5,
+                Height = 5,
+                Data = new Data
+                {
+                  Encoding = DataEncoding.Csv,
+                  Chunks = null,
+                  Compression = null,
+                  GlobalTileIDs = [
+                    0, 15, 15, 0, 0,
+                    0, 15, 15, 0, 0,
+                    0, 15, 15, 15, 0,
+                    15, 15, 15, 0, 0,
+                    0, 0, 0, 0, 0
+                  ],
+                  FlippingFlags = [
+                    FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+                    FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+                    FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+                    FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+                    FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None
+                  ]
+                }
+              }
+            ]
+          },
+          new ImageLayer
+          {
+            ID = 4,
+            Name = "ImageLayer",
+            Image = new Image
+            {
+              Format = ImageFormat.Png,
+              Source = "tileset.png",
+              Width = fileExt == "tmx" ? 256u : 0, // Currently, json format does not
+              Height = fileExt == "tmx" ? 96u : 0  // include image dimensions in image layer https://github.com/mapeditor/tiled/issues/4028
+            },
+            RepeatX = true
+          },
+          new TileLayer
+          {
+            ID = 1,
+            Name = "Tile Layer 1",
+            Width = 5,
+            Height = 5,
+            Data = new Data
+            {
+              Encoding = DataEncoding.Csv,
+              Chunks = null,
+              Compression = null,
+              GlobalTileIDs = [
+                1, 1, 1, 1, 1,
+                0, 0, 0, 0, 0,
+                0, 0, 0, 0, 0,
+                0, 0, 0, 0, 0,
+                0, 0, 0, 0, 0
+              ],
+              FlippingFlags = [
+                FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+                FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+                FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+                FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None,
+                FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None, FlippingFlags.None
+              ]
+            }
+          }
+        ]
+      }
+    ]
+  };
+}

DotTiled.Tests/Serialization/TestData/Map/map-with-many-layers/map-with-many-layers.tmj

@@ -0,0 +1,163 @@
+{ "compressionlevel":-1,
+ "height":5,
+ "infinite":false,
+ "layers":[
+        {
+         "id":2,
+         "layers":[
+                {
+                 "draworder":"topdown",
+                 "id":3,
+                 "name":"Objects",
+                 "objects":[
+                        {
+                         "height":31.3333,
+                         "id":1,
+                         "name":"Object 1",
+                         "rotation":0,
+                         "type":"",
+                         "visible":true,
+                         "width":31.3333,
+                         "x":25.6667,
+                         "y":28.6667
+                        }, 
+                        {
+                         "height":0,
+                         "id":3,
+                         "name":"P1",
+                         "point":true,
+                         "rotation":0,
+                         "type":"",
+                         "visible":true,
+                         "width":0,
+                         "x":117.667,
+                         "y":48.6667
+                        }, 
+                        {
+                         "ellipse":true,
+                         "height":34.6667,
+                         "id":4,
+                         "name":"Circle1",
+                         "rotation":0,
+                         "type":"",
+                         "visible":true,
+                         "width":34.6667,
+                         "x":77,
+                         "y":72.3333
+                        }, 
+                        {
+                         "id":5,
+                         "template":"poly.tj",
+                         "x":20.6667,
+                         "y":114.667
+                        }, 
+                        {
+                         "gid":7,
+                         "height":146,
+                         "id":6,
+                         "name":"TileObj",
+                         "rotation":0,
+                         "type":"",
+                         "visible":true,
+                         "width":64,
+                         "x":-35,
+                         "y":110.333
+                        }],
+                 "opacity":1,
+                 "type":"objectgroup",
+                 "visible":true,
+                 "x":0,
+                 "y":0
+                }, 
+                {
+                 "id":5,
+                 "layers":[
+                        {
+                         "data":[0, 0, 0, 0, 0,
+                            0, 0, 0, 0, 0,
+                            0, 0, 0, 0, 0,
+                            0, 0, 0, 0, 0,
+                            0, 0, 0, 0, 0],
+                         "height":5,
+                         "id":7,
+                         "name":"Tile 3",
+                         "opacity":1,
+                         "type":"tilelayer",
+                         "visible":true,
+                         "width":5,
+                         "x":0,
+                         "y":0
+                        }, 
+                        {
+                         "data":[0, 15, 15, 0, 0,
+                            0, 15, 15, 0, 0,
+                            0, 15, 15, 15, 0,
+                            15, 15, 15, 0, 0,
+                            0, 0, 0, 0, 0],
+                         "height":5,
+                         "id":6,
+                         "name":"Tile 2",
+                         "opacity":1,
+                         "type":"tilelayer",
+                         "visible":true,
+                         "width":5,
+                         "x":0,
+                         "y":0
+                        }],
+                 "name":"Sub",
+                 "opacity":1,
+                 "type":"group",
+                 "visible":true,
+                 "x":0,
+                 "y":0
+                }, 
+                {
+                 "id":4,
+                 "image":"tileset.png",
+                 "name":"ImageLayer",
+                 "opacity":1,
+                 "repeatx":true,
+                 "type":"imagelayer",
+                 "visible":true,
+                 "x":0,
+                 "y":0
+                }, 
+                {
+                 "data":[1, 1, 1, 1, 1,
+                    0, 0, 0, 0, 0,
+                    0, 0, 0, 0, 0,
+                    0, 0, 0, 0, 0,
+                    0, 0, 0, 0, 0],
+                 "height":5,
+                 "id":1,
+                 "name":"Tile Layer 1",
+                 "opacity":1,
+                 "type":"tilelayer",
+                 "visible":true,
+                 "width":5,
+                 "x":0,
+                 "y":0
+                }],
+         "name":"Root",
+         "opacity":1,
+         "type":"group",
+         "visible":true,
+         "x":0,
+         "y":0
+        }],
+ "nextlayerid":8,
+ "nextobjectid":7,
+ "orientation":"orthogonal",
+ "renderorder":"right-down",
+ "tiledversion":"1.11.0",
+ "tileheight":32,
+ "tilesets":[
+        {
+         "firstgid":1,
+         "source":"tileset.tsj"
+        }],
+ "tilewidth":32,
+ "type":"map",
+ "version":"1.10",
+ "width":5
+}

DotTiled.Tests/Serialization/TestData/Map/map-with-many-layers/map-with-many-layers.tmx

@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<map version="1.10" tiledversion="1.11.0" orientation="orthogonal" renderorder="right-down" width="5" height="5" tilewidth="32" tileheight="32" infinite="0" nextlayerid="8" nextobjectid="7">
+ <tileset firstgid="1" source="tileset.tsx"/>
+ <group id="2" name="Root">
+  <objectgroup id="3" name="Objects">
+   <object id="1" name="Object 1" x="25.6667" y="28.6667" width="31.3333" height="31.3333"/>
+   <object id="3" name="P1" x="117.667" y="48.6667">
+    <point/>
+   </object>
+   <object id="4" name="Circle1" x="77" y="72.3333" width="34.6667" height="34.6667">
+    <ellipse/>
+   </object>
+   <object id="5" template="poly.tx" x="20.6667" y="114.667"/>
+   <object id="6" name="TileObj" gid="7" x="-35" y="110.333" width="64" height="146"/>
+  </objectgroup>
+  <group id="5" name="Sub">
+   <layer id="7" name="Tile 3" width="5" height="5">
+    <data encoding="csv">
+0,0,0,0,0,
+0,0,0,0,0,
+0,0,0,0,0,
+0,0,0,0,0,
+0,0,0,0,0
+</data>
+   </layer>
+   <layer id="6" name="Tile 2" width="5" height="5">
+    <data encoding="csv">
+0,15,15,0,0,
+0,15,15,0,0,
+0,15,15,15,0,
+15,15,15,0,0,
+0,0,0,0,0
+</data>
+   </layer>
+  </group>
+  <imagelayer id="4" name="ImageLayer" repeatx="1">
+   <image source="tileset.png" width="256" height="96"/>
+  </imagelayer>
+  <layer id="1" name="Tile Layer 1" width="5" height="5">
+   <data encoding="csv">
+1,1,1,1,1,
+0,0,0,0,0,
+0,0,0,0,0,
+0,0,0,0,0,
+0,0,0,0,0
+</data>
+  </layer>
+ </group>
+</map>

DotTiled.Tests/Serialization/TestData/Map/map-with-many-layers/poly.tj

@@ -0,0 +1,31 @@
+{ "object":
+    {
+     "height":0,
+     "id":5,
+     "name":"Poly",
+     "polygon":[
+            {
+             "x":0,
+             "y":0
+            }, 
+            {
+             "x":104,
+             "y":20
+            }, 
+            {
+             "x":35.6667,
+             "y":32.3333
+            }],
+     "properties":[
+            {
+             "name":"templateprop",
+             "type":"string",
+             "value":"helo there"
+            }],
+     "rotation":0,
+     "type":"",
+     "visible":true,
+     "width":0
+    },
+ "type":"template"
+}

DotTiled.Tests/Serialization/TestData/Map/map-with-many-layers/poly.tx

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<template>
+ <object name="Poly">
+  <properties>
+   <property name="templateprop" value="helo there"/>
+  </properties>
+  <polygon points="0,0 104,20 35.6667,32.3333"/>
+ </object>
+</template>

DotTiled.Tests/Serialization/TestData/Map/map-with-many-layers/tileset.tsj

@@ -0,0 +1,14 @@
+{ "columns":8,
+ "image":"tileset.png",
+ "imageheight":96,
+ "imagewidth":256,
+ "margin":0,
+ "name":"tileset",
+ "spacing":0,
+ "tilecount":24,
+ "tiledversion":"1.11.0",
+ "tileheight":32,
+ "tilewidth":32,
+ "type":"tileset",
+ "version":"1.10"
+}

DotTiled.Tests/Serialization/TestData/Map/map-with-many-layers/tileset.tsx

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<tileset version="1.10" tiledversion="1.11.0" name="tileset" tilewidth="32" tileheight="32" tilecount="24" columns="8">
+ <image source="tileset.png" width="256" height="96"/>
+</tileset>

DotTiled.Tests/Serialization/Tmj/TmjMapReaderTests.cs

@@ -0,0 +1,38 @@
+namespace DotTiled.Tests;
+
+public partial class TmjMapReaderTests
+{
+  public static IEnumerable<object[]> Maps => TestData.MapTests;
+  [Theory]
+  [MemberData(nameof(Maps))]
+  public void TmxMapReaderReadMap_ValidTmjExternalTilesetsAndTemplates_ReturnsMapThatEqualsExpected(
+    string testDataFile,
+    Func<string, Map> expectedMap,
+    IReadOnlyCollection<CustomTypeDefinition> customTypeDefinitions)
+  {
+    // Arrange
+    testDataFile += ".tmj";
+    var fileDir = Path.GetDirectoryName(testDataFile);
+    var json = TestData.GetRawStringFor(testDataFile);
+    Template ResolveTemplate(string source)
+    {
+      var templateJson = TestData.GetRawStringFor($"{fileDir}/{source}");
+      using var templateReader = new TjTemplateReader(templateJson, ResolveTileset, ResolveTemplate, customTypeDefinitions);
+      return templateReader.ReadTemplate();
+    }
+    Tileset ResolveTileset(string source)
+    {
+      var tilesetJson = TestData.GetRawStringFor($"{fileDir}/{source}");
+      using var tilesetReader = new TsjTilesetReader(tilesetJson, ResolveTemplate, customTypeDefinitions);
+      return tilesetReader.ReadTileset();
+    }
+    using var mapReader = new TmjMapReader(json, ResolveTileset, ResolveTemplate, customTypeDefinitions);
+
+    // Act
+    var map = mapReader.ReadMap();
+
+    // Assert
+    Assert.NotNull(map);
+    DotTiledAssert.AssertMap(expectedMap("tmj"), map);
+  }
+}

DotTiled.Tests/Serialization/Tmx/TmxMapReaderTests.cs

@@ -0,0 +1,40 @@
+using System.Xml;
+
+namespace DotTiled.Tests;
+
+public partial class TmxMapReaderTests
+{
+  public static IEnumerable<object[]> Maps => TestData.MapTests;
+  [Theory]
+  [MemberData(nameof(Maps))]
+  public void TmxMapReaderReadMap_ValidXmlExternalTilesetsAndTemplates_ReturnsMapThatEqualsExpected(
+    string testDataFile,
+    Func<string, Map> expectedMap,
+    IReadOnlyCollection<CustomTypeDefinition> customTypeDefinitions)
+  {
+    // Arrange
+    testDataFile += ".tmx";
+    var fileDir = Path.GetDirectoryName(testDataFile);
+    using var reader = TestData.GetXmlReaderFor(testDataFile);
+    Template ResolveTemplate(string source)
+    {
+      using var xmlTemplateReader = TestData.GetXmlReaderFor($"{fileDir}/{source}");
+      using var templateReader = new TxTemplateReader(xmlTemplateReader, ResolveTileset, ResolveTemplate, customTypeDefinitions);
+      return templateReader.ReadTemplate();
+    }
+    Tileset ResolveTileset(string source)
+    {
+      using var xmlTilesetReader = TestData.GetXmlReaderFor($"{fileDir}/{source}");
+      using var tilesetReader = new TsxTilesetReader(xmlTilesetReader, ResolveTemplate, customTypeDefinitions);
+      return tilesetReader.ReadTileset();
+    }
+    using var mapReader = new TmxMapReader(reader, ResolveTileset, ResolveTemplate, customTypeDefinitions);
+
+    // Act
+    var map = mapReader.ReadMap();
+
+    // Assert
+    Assert.NotNull(map);
+    DotTiledAssert.AssertMap(expectedMap("tmx"), map);
+  }
+}

DotTiled.Tests/TmxSerializer/TestData/TestData.cs

@@ -1,18 +0,0 @@
-using System.Xml;
-
-namespace DotTiled.Tests;
-
-public static class TmxSerializerTestData
-{
-  public static XmlReader GetReaderFor(string testDataFile)
-  {
-    var fullyQualifiedTestDataFile = $"DotTiled.Tests.{testDataFile}";
-    using var stream = typeof(TmxSerializerTestData).Assembly.GetManifestResourceStream(fullyQualifiedTestDataFile)
-                       ?? throw new ArgumentException($"Test data file '{fullyQualifiedTestDataFile}' not found");
-
-    using var stringReader = new StreamReader(stream);
-    var xml = stringReader.ReadToEnd();
-    var xmlStringReader = new StringReader(xml);
-    return XmlReader.Create(xmlStringReader);
-  }
-}

DotTiled.Tests/TmxSerializer/TmxSerializer.DataTests.cs

@@ -1,43 +0,0 @@
-namespace DotTiled.Tests;
-
-public partial class TmxSerializerDataTests
-{
-  public static void AssertData(Data? actual, Data? expected)
-  {
-    if (expected is null)
-    {
-      Assert.Null(actual);
-      return;
-    }
-
-    // Attributes
-    Assert.NotNull(actual);
-    Assert.Equal(expected.Encoding, actual.Encoding);
-    Assert.Equal(expected.Compression, actual.Compression);
-
-    // Data
-    Assert.Equal(expected.GlobalTileIDs, actual.GlobalTileIDs);
-    Assert.Equal(expected.FlippingFlags, actual.FlippingFlags);
-
-    if (expected.Chunks is not null)
-    {
-      Assert.NotNull(actual.Chunks);
-      Assert.Equal(expected.Chunks.Length, actual.Chunks.Length);
-      for (var i = 0; i < expected.Chunks.Length; i++)
-        AssertChunk(actual.Chunks[i], expected.Chunks[i]);
-    }
-  }
-
-  private static void AssertChunk(Chunk actual, Chunk expected)
-  {
-    // Attributes
-    Assert.Equal(expected.X, actual.X);
-    Assert.Equal(expected.Y, actual.Y);
-    Assert.Equal(expected.Width, actual.Width);
-    Assert.Equal(expected.Height, actual.Height);
-
-    // Data
-    Assert.Equal(expected.GlobalTileIDs, actual.GlobalTileIDs);
-    Assert.Equal(expected.FlippingFlags, actual.FlippingFlags);
-  }
-}

DotTiled.Tests/TmxSerializer/TmxSerializer.ImageTests.cs

@@ -1,21 +0,0 @@
-namespace DotTiled.Tests;
-
-public partial class TmxSerializerImageTests
-{
-  public static void AssertImage(Image? actual, Image? expected)
-  {
-    if (expected is null)
-    {
-      Assert.Null(actual);
-      return;
-    }
-
-    // Attributes
-    Assert.NotNull(actual);
-    Assert.Equal(expected.Format, actual.Format);
-    Assert.Equal(expected.Source, actual.Source);
-    Assert.Equal(expected.TransparentColor, actual.TransparentColor);
-    Assert.Equal(expected.Width, actual.Width);
-    Assert.Equal(expected.Height, actual.Height);
-  }
-}

DotTiled.Tests/TmxSerializer/TmxSerializer.LayerTests.cs

@@ -1,62 +0,0 @@
-namespace DotTiled.Tests;
-
-public partial class TmxSerializerLayerTests
-{
-  public static void AssertLayer(BaseLayer? actual, BaseLayer? expected)
-  {
-    if (expected is null)
-    {
-      Assert.Null(actual);
-      return;
-    }
-
-    // Attributes
-    Assert.NotNull(actual);
-    Assert.Equal(expected.ID, actual.ID);
-    Assert.Equal(expected.Name, actual.Name);
-    Assert.Equal(expected.Class, actual.Class);
-    Assert.Equal(expected.X, actual.X);
-    Assert.Equal(expected.Y, actual.Y);
-    Assert.Equal(expected.Opacity, actual.Opacity);
-    Assert.Equal(expected.Visible, actual.Visible);
-    Assert.Equal(expected.TintColor, actual.TintColor);
-    Assert.Equal(expected.OffsetX, actual.OffsetX);
-    Assert.Equal(expected.OffsetY, actual.OffsetY);
-    Assert.Equal(expected.ParallaxX, actual.ParallaxX);
-    Assert.Equal(expected.ParallaxY, actual.ParallaxY);
-
-    TmxSerializerPropertiesTests.AssertProperties(actual.Properties, expected.Properties);
-    AssertLayer((dynamic)actual, (dynamic)expected);
-  }
-
-  private static void AssertLayer(TileLayer actual, TileLayer expected)
-  {
-    // Attributes
-    Assert.Equal(expected.Width, actual.Width);
-    Assert.Equal(expected.Height, actual.Height);
-
-    Assert.NotNull(actual.Data);
-    TmxSerializerDataTests.AssertData(actual.Data, expected.Data);
-  }
-
-  private static void AssertLayer(ObjectLayer actual, ObjectLayer expected)
-  {
-    // Attributes
-    Assert.Equal(expected.DrawOrder, actual.DrawOrder);
-
-    Assert.NotNull(actual.Objects);
-    Assert.Equal(expected.Objects.Count, actual.Objects.Count);
-    for (var i = 0; i < expected.Objects.Count; i++)
-      TmxSerializerObjectTests.AssertObject(actual.Objects[i], expected.Objects[i]);
-  }
-
-  private static void AssertLayer(ImageLayer actual, ImageLayer expected)
-  {
-    // Attributes
-    Assert.Equal(expected.RepeatX, actual.RepeatX);
-    Assert.Equal(expected.RepeatY, actual.RepeatY);
-
-    Assert.NotNull(actual.Image);
-    TmxSerializerImageTests.AssertImage(actual.Image, expected.Image);
-  }
-}

DotTiled.Tests/TmxSerializer/TmxSerializer.MapTests.cs

@@ -1,67 +0,0 @@
-namespace DotTiled.Tests;
-
-public partial class TmxSerializerMapTests
-{
-  private static void AssertMap(Map actual, Map expected)
-  {
-    // Attributes
-    Assert.Equal(expected.Version, actual.Version);
-    Assert.Equal(expected.TiledVersion, actual.TiledVersion);
-    Assert.Equal(expected.Class, actual.Class);
-    Assert.Equal(expected.Orientation, actual.Orientation);
-    Assert.Equal(expected.RenderOrder, actual.RenderOrder);
-    Assert.Equal(expected.CompressionLevel, actual.CompressionLevel);
-    Assert.Equal(expected.Width, actual.Width);
-    Assert.Equal(expected.Height, actual.Height);
-    Assert.Equal(expected.TileWidth, actual.TileWidth);
-    Assert.Equal(expected.TileHeight, actual.TileHeight);
-    Assert.Equal(expected.HexSideLength, actual.HexSideLength);
-    Assert.Equal(expected.StaggerAxis, actual.StaggerAxis);
-    Assert.Equal(expected.StaggerIndex, actual.StaggerIndex);
-    Assert.Equal(expected.ParallaxOriginX, actual.ParallaxOriginX);
-    Assert.Equal(expected.ParallaxOriginY, actual.ParallaxOriginY);
-    Assert.Equal(expected.BackgroundColor, actual.BackgroundColor);
-    Assert.Equal(expected.NextLayerID, actual.NextLayerID);
-    Assert.Equal(expected.NextObjectID, actual.NextObjectID);
-    Assert.Equal(expected.Infinite, actual.Infinite);
-
-    TmxSerializerPropertiesTests.AssertProperties(actual.Properties, expected.Properties);
-
-    Assert.NotNull(actual.Tilesets);
-    Assert.Equal(expected.Tilesets.Count, actual.Tilesets.Count);
-    for (var i = 0; i < expected.Tilesets.Count; i++)
-      TmxSerializerTilesetTests.AssertTileset(actual.Tilesets[i], expected.Tilesets[i]);
-
-    Assert.NotNull(actual.Layers);
-    Assert.Equal(expected.Layers.Count, actual.Layers.Count);
-    for (var i = 0; i < expected.Layers.Count; i++)
-      TmxSerializerLayerTests.AssertLayer(actual.Layers[i], expected.Layers[i]);
-  }
-
-  public static IEnumerable<object[]> DeserializeMap_ValidXmlNoExternalTilesets_ReturnsMapWithoutThrowing_Data =>
-    [
-      ["TmxSerializer.TestData.Map.empty-map-csv.tmx", EmptyMapWithEncodingAndCompression(DataEncoding.Csv, null)],
-      ["TmxSerializer.TestData.Map.empty-map-base64.tmx", EmptyMapWithEncodingAndCompression(DataEncoding.Base64, null)],
-      ["TmxSerializer.TestData.Map.empty-map-base64-gzip.tmx", EmptyMapWithEncodingAndCompression(DataEncoding.Base64, DataCompression.GZip)],
-      ["TmxSerializer.TestData.Map.empty-map-base64-zlib.tmx", EmptyMapWithEncodingAndCompression(DataEncoding.Base64, DataCompression.ZLib)],
-      ["TmxSerializer.TestData.Map.simple-tileset-embed.tmx", SimpleMapWithEmbeddedTileset()],
-      ["TmxSerializer.TestData.Map.empty-map-properties.tmx", EmptyMapWithProperties()],
-    ];
-
-  [Theory]
-  [MemberData(nameof(DeserializeMap_ValidXmlNoExternalTilesets_ReturnsMapWithoutThrowing_Data))]
-  public void DeserializeMap_ValidXmlNoExternalTilesets_ReturnsMapThatEqualsExpected(string testDataFile, Map expectedMap)
-  {
-    // Arrange
-    using var reader = TmxSerializerTestData.GetReaderFor(testDataFile);
-    Func<string, Tileset> externalTilesetResolver = (string s) => throw new NotSupportedException("External tilesets are not supported in this test");
-    var tmxSerializer = new TmxSerializer(externalTilesetResolver);
-
-    // Act
-    var map = tmxSerializer.DeserializeMap(reader);
-
-    // Assert
-    Assert.NotNull(map);
-    AssertMap(map, expectedMap);
-  }
-}

DotTiled.Tests/TmxSerializer/TmxSerializer.ObjectTests.cs

@@ -1,66 +0,0 @@
-namespace DotTiled.Tests;
-
-public partial class TmxSerializerObjectTests
-{
-  public static void AssertObject(Object actual, Object expected)
-  {
-    // Attributes
-    Assert.Equal(expected.ID, actual.ID);
-    Assert.Equal(expected.Name, actual.Name);
-    Assert.Equal(expected.Type, actual.Type);
-    Assert.Equal(expected.X, actual.X);
-    Assert.Equal(expected.Y, actual.Y);
-    Assert.Equal(expected.Width, actual.Width);
-    Assert.Equal(expected.Height, actual.Height);
-    Assert.Equal(expected.Rotation, actual.Rotation);
-    Assert.Equal(expected.GID, actual.GID);
-    Assert.Equal(expected.Visible, actual.Visible);
-    Assert.Equal(expected.Template, actual.Template);
-
-    TmxSerializerPropertiesTests.AssertProperties(actual.Properties, expected.Properties);
-    AssertObject((dynamic)actual, (dynamic)expected);
-  }
-
-  private static void AssertObject(RectangleObject actual, RectangleObject expected)
-  {
-    Assert.True(true); // A rectangle object is the same as the abstract Object
-  }
-
-  private static void AssertObject(EllipseObject actual, EllipseObject expected)
-  {
-    Assert.True(true); // An ellipse object is the same as the abstract Object
-  }
-
-  private static void AssertObject(PointObject actual, PointObject expected)
-  {
-    Assert.True(true); // A point object is the same as the abstract Object
-  }
-
-  private static void AssertObject(PolygonObject actual, PolygonObject expected)
-  {
-    Assert.Equal(expected.Points, actual.Points);
-  }
-
-  private static void AssertObject(PolylineObject actual, PolylineObject expected)
-  {
-    Assert.Equal(expected.Points, actual.Points);
-  }
-
-  private static void AssertObject(TextObject actual, TextObject expected)
-  {
-    // Attributes
-    Assert.Equal(expected.FontFamily, actual.FontFamily);
-    Assert.Equal(expected.PixelSize, actual.PixelSize);
-    Assert.Equal(expected.Wrap, actual.Wrap);
-    Assert.Equal(expected.Color, actual.Color);
-    Assert.Equal(expected.Bold, actual.Bold);
-    Assert.Equal(expected.Italic, actual.Italic);
-    Assert.Equal(expected.Underline, actual.Underline);
-    Assert.Equal(expected.Strikeout, actual.Strikeout);
-    Assert.Equal(expected.Kerning, actual.Kerning);
-    Assert.Equal(expected.HorizontalAlignment, actual.HorizontalAlignment);
-    Assert.Equal(expected.VerticalAlignment, actual.VerticalAlignment);
-
-    Assert.Equal(expected.Text, actual.Text);
-  }
-}

DotTiled.Tests/TmxSerializer/TmxSerializer.PropertiesTests.cs

@@ -1,69 +0,0 @@
-namespace DotTiled.Tests;
-
-public partial class TmxSerializerPropertiesTests
-{
-  public static void AssertProperties(Dictionary<string, IProperty>? actual, Dictionary<string, IProperty>? expected)
-  {
-    if (expected is null)
-    {
-      Assert.Null(actual);
-      return;
-    }
-
-    Assert.NotNull(actual);
-    Assert.Equal(expected.Count, actual.Count);
-    foreach (var kvp in expected)
-    {
-      Assert.Contains(kvp.Key, actual.Keys);
-      AssertProperty((dynamic)kvp.Value, (dynamic)actual[kvp.Key]);
-    }
-  }
-
-  private static void AssertProperty(IProperty actual, IProperty expected)
-  {
-    Assert.Equal(expected.Type, actual.Type);
-    Assert.Equal(expected.Name, actual.Name);
-    AssertProperties((dynamic)actual, (dynamic)expected);
-  }
-
-  private static void AssertProperty(StringProperty actual, StringProperty expected)
-  {
-    Assert.Equal(expected.Value, actual.Value);
-  }
-
-  private static void AssertProperty(IntProperty actual, IntProperty expected)
-  {
-    Assert.Equal(expected.Value, actual.Value);
-  }
-
-  private static void AssertProperty(FloatProperty actual, FloatProperty expected)
-  {
-    Assert.Equal(expected.Value, actual.Value);
-  }
-
-  private static void AssertProperty(BoolProperty actual, BoolProperty expected)
-  {
-    Assert.Equal(expected.Value, actual.Value);
-  }
-
-  private static void AssertProperty(ColorProperty actual, ColorProperty expected)
-  {
-    Assert.Equal(expected.Value, actual.Value);
-  }
-
-  private static void AssertProperty(FileProperty actual, FileProperty expected)
-  {
-    Assert.Equal(expected.Value, actual.Value);
-  }
-
-  private static void AssertProperty(ObjectProperty actual, ObjectProperty expected)
-  {
-    Assert.Equal(expected.Value, actual.Value);
-  }
-
-  private static void AssertProperty(ClassProperty actual, ClassProperty expected)
-  {
-    Assert.Equal(expected.PropertyType, actual.PropertyType);
-    AssertProperties(actual.Properties, expected.Properties);
-  }
-}

DotTiled.Tests/TmxSerializer/TmxSerializer.TilesetTests.cs

@@ -1,160 +0,0 @@
-namespace DotTiled.Tests;
-
-public partial class TmxSerializerTilesetTests
-{
-  public static void AssertTileset(Tileset actual, Tileset expected)
-  {
-    // Attributes
-    Assert.Equal(expected.Version, actual.Version);
-    Assert.Equal(expected.TiledVersion, actual.TiledVersion);
-    Assert.Equal(expected.FirstGID, actual.FirstGID);
-    Assert.Equal(expected.Source, actual.Source);
-    Assert.Equal(expected.Name, actual.Name);
-    Assert.Equal(expected.Class, actual.Class);
-    Assert.Equal(expected.TileWidth, actual.TileWidth);
-    Assert.Equal(expected.TileHeight, actual.TileHeight);
-    Assert.Equal(expected.Spacing, actual.Spacing);
-    Assert.Equal(expected.Margin, actual.Margin);
-    Assert.Equal(expected.TileCount, actual.TileCount);
-    Assert.Equal(expected.Columns, actual.Columns);
-    Assert.Equal(expected.ObjectAlignment, actual.ObjectAlignment);
-    Assert.Equal(expected.RenderSize, actual.RenderSize);
-    Assert.Equal(expected.FillMode, actual.FillMode);
-
-    // At most one of
-    TmxSerializerImageTests.AssertImage(actual.Image, expected.Image);
-    AssertTileOffset(actual.TileOffset, expected.TileOffset);
-    AssertGrid(actual.Grid, expected.Grid);
-    TmxSerializerPropertiesTests.AssertProperties(actual.Properties, expected.Properties);
-    // TODO: AssertTerrainTypes(actual.TerrainTypes, expected.TerrainTypes);
-    if (expected.Wangsets is not null)
-    {
-      Assert.NotNull(actual.Wangsets);
-      Assert.Equal(expected.Wangsets.Count, actual.Wangsets.Count);
-      for (var i = 0; i < expected.Wangsets.Count; i++)
-        AssertWangset(actual.Wangsets[i], expected.Wangsets[i]);
-    }
-    AssertTransformations(actual.Transformations, expected.Transformations);
-
-    // Any number of
-    Assert.NotNull(actual.Tiles);
-    Assert.Equal(expected.Tiles.Count, actual.Tiles.Count);
-    for (var i = 0; i < expected.Tiles.Count; i++)
-      AssertTile(actual.Tiles[i], expected.Tiles[i]);
-  }
-
-  private static void AssertTileOffset(TileOffset? actual, TileOffset? expected)
-  {
-    if (expected is null)
-    {
-      Assert.Null(actual);
-      return;
-    }
-
-    // Attributes
-    Assert.NotNull(actual);
-    Assert.Equal(expected.X, actual.X);
-    Assert.Equal(expected.Y, actual.Y);
-  }
-
-  private static void AssertGrid(Grid? actual, Grid? expected)
-  {
-    if (expected is null)
-    {
-      Assert.Null(actual);
-      return;
-    }
-
-    // Attributes
-    Assert.NotNull(actual);
-    Assert.Equal(expected.Orientation, actual.Orientation);
-    Assert.Equal(expected.Width, actual.Width);
-    Assert.Equal(expected.Height, actual.Height);
-  }
-
-  private static void AssertWangset(Wangset actual, Wangset expected)
-  {
-    // Attributes
-    Assert.Equal(expected.Name, actual.Name);
-    Assert.Equal(expected.Class, actual.Class);
-    Assert.Equal(expected.Tile, actual.Tile);
-
-    // At most one of
-    TmxSerializerPropertiesTests.AssertProperties(actual.Properties, expected.Properties);
-    if (expected.WangColors is not null)
-    {
-      Assert.NotNull(actual.WangColors);
-      Assert.Equal(expected.WangColors.Count, actual.WangColors.Count);
-      for (var i = 0; i < expected.WangColors.Count; i++)
-        AssertWangColor(actual.WangColors[i], expected.WangColors[i]);
-    }
-    for (var i = 0; i < expected.WangTiles.Count; i++)
-      AssertWangTile(actual.WangTiles[i], expected.WangTiles[i]);
-  }
-
-  private static void AssertWangColor(WangColor actual, WangColor expected)
-  {
-    // Attributes
-    Assert.Equal(expected.Name, actual.Name);
-    Assert.Equal(expected.Class, actual.Class);
-    Assert.Equal(expected.Color, actual.Color);
-    Assert.Equal(expected.Tile, actual.Tile);
-    Assert.Equal(expected.Probability, actual.Probability);
-
-    TmxSerializerPropertiesTests.AssertProperties(actual.Properties, expected.Properties);
-  }
-
-  private static void AssertWangTile(WangTile actual, WangTile expected)
-  {
-    // Attributes
-    Assert.Equal(expected.TileID, actual.TileID);
-    Assert.Equal(expected.WangID, actual.WangID);
-  }
-
-  private static void AssertTransformations(Transformations? actual, Transformations? expected)
-  {
-    if (expected is null)
-    {
-      Assert.Null(actual);
-      return;
-    }
-
-    // Attributes
-    Assert.NotNull(actual);
-    Assert.Equal(expected.HFlip, actual.HFlip);
-    Assert.Equal(expected.VFlip, actual.VFlip);
-    Assert.Equal(expected.Rotate, actual.Rotate);
-    Assert.Equal(expected.PreferUntransformed, actual.PreferUntransformed);
-  }
-
-  private static void AssertTile(Tile actual, Tile expected)
-  {
-    // Attributes
-    Assert.Equal(expected.ID, actual.ID);
-    Assert.Equal(expected.Type, actual.Type);
-    Assert.Equal(expected.Probability, actual.Probability);
-    Assert.Equal(expected.X, actual.X);
-    Assert.Equal(expected.Y, actual.Y);
-    Assert.Equal(expected.Width, actual.Width);
-    Assert.Equal(expected.Height, actual.Height);
-
-    // Elements
-    TmxSerializerPropertiesTests.AssertProperties(actual.Properties, expected.Properties);
-    TmxSerializerImageTests.AssertImage(actual.Image, expected.Image);
-    TmxSerializerLayerTests.AssertLayer(actual.ObjectLayer, expected.ObjectLayer);
-    if (expected.Animation is not null)
-    {
-      Assert.NotNull(actual.Animation);
-      Assert.Equal(expected.Animation.Count, actual.Animation.Count);
-      for (var i = 0; i < expected.Animation.Count; i++)
-        AssertFrame(actual.Animation[i], expected.Animation[i]);
-    }
-  }
-
-  private static void AssertFrame(Frame actual, Frame expected)
-  {
-    // Attributes
-    Assert.Equal(expected.TileID, actual.TileID);
-    Assert.Equal(expected.Duration, actual.Duration);
-  }
-}

DotTiled.Tests/TmxSerializer/TmxSerializerTests.cs

@@ -1,30 +0,0 @@
-namespace DotTiled.Tests;
-
-public class TmxSerializerTests
-{
-  [Fact]
-  public void TmxSerializerConstructor_ExternalTilesetResolverIsNull_ThrowsArgumentNullException()
-  {
-    // Arrange
-    Func<string, Tileset> externalTilesetResolver = null!;
-
-    // Act
-    Action act = () => _ = new TmxSerializer(externalTilesetResolver);
-
-    // Assert
-    Assert.Throws<ArgumentNullException>(act);
-  }
-
-  [Fact]
-  public void TmxSerializerConstructor_ExternalTilesetResolverIsNotNull_DoesNotThrow()
-  {
-    // Arrange
-    Func<string, Tileset> externalTilesetResolver = _ => new Tileset();
-
-    // Act
-    var tmxSerializer = new TmxSerializer(externalTilesetResolver);
-
-    // Assert
-    Assert.NotNull(tmxSerializer);
-  }
-}

DotTiled.sln

@@ -7,6 +7,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "DotTiled", "DotTiled\DotTil
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "DotTiled.Tests", "DotTiled.Tests\DotTiled.Tests.csproj", "{C1311A5A-5206-467C-B323-B131CA11FDB8}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "DotTiled.Benchmark", "DotTiled.Benchmark\DotTiled.Benchmark.csproj", "{510F3077-8EA4-47D1-8D01-E2D538F1B899}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -24,5 +26,9 @@ Global
 		{C1311A5A-5206-467C-B323-B131CA11FDB8}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{C1311A5A-5206-467C-B323-B131CA11FDB8}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{C1311A5A-5206-467C-B323-B131CA11FDB8}.Release|Any CPU.Build.0 = Release|Any CPU
+		{510F3077-8EA4-47D1-8D01-E2D538F1B899}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{510F3077-8EA4-47D1-8D01-E2D538F1B899}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{510F3077-8EA4-47D1-8D01-E2D538F1B899}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{510F3077-8EA4-47D1-8D01-E2D538F1B899}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal

DotTiled/Model/Color.cs

@@ -66,4 +66,6 @@ public class Color : IParsable<Color>, IEquatable<Color>
   public override bool Equals(object? obj) => obj is Color other && Equals(other);
 
   public override int GetHashCode() => HashCode.Combine(R, G, B, A);
+
+  public override string ToString() => $"#{A:x2}{R:x2}{G:x2}{B:x2}";
 }

DotTiled/Model/IProperty.cs

@@ -1,78 +0,0 @@
-using System.Collections.Generic;
-
-namespace DotTiled;
-
-public enum PropertyType
-{
-  String,
-  Int,
-  Float,
-  Bool,
-  Color,
-  File,
-  Object,
-  Class
-}
-
-public interface IProperty
-{
-  public string Name { get; set; }
-  public PropertyType Type { get; }
-}
-
-public class StringProperty : IProperty
-{
-  public required string Name { get; set; }
-  public PropertyType Type => PropertyType.String;
-  public required string Value { get; set; }
-}
-
-public class IntProperty : IProperty
-{
-  public required string Name { get; set; }
-  public PropertyType Type => PropertyType.Int;
-  public required int Value { get; set; }
-}
-
-public class FloatProperty : IProperty
-{
-  public required string Name { get; set; }
-  public PropertyType Type => PropertyType.Float;
-  public required float Value { get; set; }
-}
-
-public class BoolProperty : IProperty
-{
-  public required string Name { get; set; }
-  public PropertyType Type => PropertyType.Bool;
-  public required bool Value { get; set; }
-}
-
-public class ColorProperty : IProperty
-{
-  public required string Name { get; set; }
-  public PropertyType Type => PropertyType.Color;
-  public required Color Value { get; set; }
-}
-
-public class FileProperty : IProperty
-{
-  public required string Name { get; set; }
-  public PropertyType Type => PropertyType.File;
-  public required string Value { get; set; }
-}
-
-public class ObjectProperty : IProperty
-{
-  public required string Name { get; set; }
-  public PropertyType Type => PropertyType.Object;
-  public required uint Value { get; set; }
-}
-
-public class ClassProperty : IProperty
-{
-  public required string Name { get; set; }
-  public PropertyType Type => DotTiled.PropertyType.Class;
-  public required string PropertyType { get; set; }
-  public required Dictionary<string, IProperty> Properties { get; set; }
-}

DotTiled/Model/Layers/BaseLayer.cs

@@ -8,8 +8,6 @@ public abstract class BaseLayer
   public required uint ID { get; set; }
   public string Name { get; set; } = "";
   public string Class { get; set; } = "";
-  public uint X { get; set; } = 0;
-  public uint Y { get; set; } = 0;
   public float Opacity { get; set; } = 1.0f;
   public bool Visible { get; set; } = true;
   public Color? TintColor { get; set; }

DotTiled/Model/Layers/Group.cs

@@ -0,0 +1,11 @@
+using System.Collections.Generic;
+
+namespace DotTiled;
+
+public class Group : BaseLayer
+{
+  // Uses same attributes as BaseLayer
+
+  // Any number of
+  public List<BaseLayer> Layers { get; set; } = [];
+}

DotTiled/Model/Layers/ImageLayer.cs

@@ -3,8 +3,10 @@ namespace DotTiled;
 public class ImageLayer : BaseLayer
 {
   // Attributes
-  public required bool RepeatX { get; set; }
+  public uint X { get; set; } = 0;
-  public required bool RepeatY { get; set; }
+  public uint Y { get; set; } = 0;
+  public bool RepeatX { get; set; } = false;
+  public bool RepeatY { get; set; } = false;
 
   // At most one of
   public Image? Image { get; set; }

DotTiled/Model/Layers/ObjectLayer.cs

@@ -11,10 +11,12 @@ public enum DrawOrder
 public class ObjectLayer : BaseLayer
 {
   // Attributes
+  public uint X { get; set; } = 0;
+  public uint Y { get; set; } = 0;
   public uint? Width { get; set; }
   public uint? Height { get; set; }
-  public required Color? Color { get; set; }
+  public Color? Color { get; set; }
-  public required DrawOrder DrawOrder { get; set; } = DrawOrder.TopDown;
+  public DrawOrder DrawOrder { get; set; } = DrawOrder.TopDown;
 
   // Elements
   public required List<Object> Objects { get; set; }

DotTiled/Model/Layers/Objects/Object.cs

@@ -5,7 +5,7 @@ namespace DotTiled;
 public abstract class Object
 {
   // Attributes
-  public required uint ID { get; set; }
+  public uint? ID { get; set; }
   public string Name { get; set; } = "";
   public string Type { get; set; } = "";
   public float X { get; set; } = 0f;
@@ -13,7 +13,6 @@ public abstract class Object
   public float Width { get; set; } = 0f;
   public float Height { get; set; } = 0f;
   public float Rotation { get; set; } = 0f;
-  public uint? GID { get; set; }
   public bool Visible { get; set; } = true;
   public string? Template { get; set; }
 

DotTiled/Model/Layers/Objects/TileObject.cs

@@ -0,0 +1,6 @@
+namespace DotTiled;
+
+public class TileObject : Object
+{
+  public uint GID { get; set; }
+}

DotTiled/Model/Layers/TileLayer.cs

@@ -3,6 +3,8 @@ namespace DotTiled;
 public class TileLayer : BaseLayer
 {
   // Attributes
+  public uint X { get; set; } = 0;
+  public uint Y { get; set; } = 0;
   public required uint Width { get; set; }
   public required uint Height { get; set; }
 

DotTiled/Model/Map.cs

@@ -60,5 +60,4 @@ public class Map
   // Any number of
   public List<Tileset> Tilesets { get; set; } = [];
   public List<BaseLayer> Layers { get; set; } = [];
-  // public List<Group> Groups { get; set; } = [];
 }

DotTiled/Model/Properties/BoolProperty.cs

@@ -0,0 +1,14 @@
+namespace DotTiled;
+
+public class BoolProperty : IProperty
+{
+  public required string Name { get; set; }
+  public PropertyType Type => PropertyType.Bool;
+  public required bool Value { get; set; }
+
+  public IProperty Clone() => new BoolProperty
+  {
+    Name = Name,
+    Value = Value
+  };
+}

DotTiled/Model/Properties/ClassProperty.cs

@@ -0,0 +1,19 @@
+using System.Collections.Generic;
+using System.Linq;
+
+namespace DotTiled;
+
+public class ClassProperty : IProperty
+{
+  public required string Name { get; set; }
+  public PropertyType Type => DotTiled.PropertyType.Class;
+  public required string PropertyType { get; set; }
+  public required Dictionary<string, IProperty> Properties { get; set; }
+
+  public IProperty Clone() => new ClassProperty
+  {
+    Name = Name,
+    PropertyType = PropertyType,
+    Properties = Properties.ToDictionary(p => p.Key, p => p.Value.Clone())
+  };
+}

DotTiled/Model/Properties/ColorProperty.cs

@@ -0,0 +1,14 @@
+namespace DotTiled;
+
+public class ColorProperty : IProperty
+{
+  public required string Name { get; set; }
+  public PropertyType Type => PropertyType.Color;
+  public required Color Value { get; set; }
+
+  public IProperty Clone() => new ColorProperty
+  {
+    Name = Name,
+    Value = Value
+  };
+}

DotTiled/Model/Properties/CustomTypes/CustomClassDefinition.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Collections.Generic;
+
+namespace DotTiled;
+
+[Flags]
+public enum CustomClassUseAs
+{
+  Property,
+  Map,
+  Layer,
+  Object,
+  Tile,
+  Tileset,
+  WangColor,
+  Wangset,
+  Project,
+  All = Property | Map | Layer | Object | Tile | Tileset | WangColor | Wangset | Project
+}
+
+public class CustomClassDefinition : CustomTypeDefinition
+{
+  public Color? Color { get; set; }
+  public bool DrawFill { get; set; }
+  public CustomClassUseAs UseAs { get; set; }
+  public List<IProperty> Members { get; set; } = [];
+}

DotTiled/Model/Properties/CustomTypes/CustomEnumDefinition.cs

@@ -0,0 +1,16 @@
+using System.Collections.Generic;
+
+namespace DotTiled;
+
+public enum CustomEnumStorageType
+{
+  Int,
+  String
+}
+
+public class CustomEnumDefinition : CustomTypeDefinition
+{
+  public CustomEnumStorageType StorageType { get; set; }
+  public List<string> Values { get; set; } = [];
+  public bool ValueAsFlags { get; set; }
+}

DotTiled/Model/Properties/CustomTypes/CustomTypeDefinition.cs

@@ -0,0 +1,7 @@
+namespace DotTiled;
+
+public abstract class CustomTypeDefinition
+{
+  public uint ID { get; set; }
+  public string Name { get; set; } = "";
+}

DotTiled/Model/Properties/FileProperty.cs

@@ -0,0 +1,14 @@
+namespace DotTiled;
+
+public class FileProperty : IProperty
+{
+  public required string Name { get; set; }
+  public PropertyType Type => PropertyType.File;
+  public required string Value { get; set; }
+
+  public IProperty Clone() => new FileProperty
+  {
+    Name = Name,
+    Value = Value
+  };
+}

DotTiled/Model/Properties/FloatProperty.cs

@@ -0,0 +1,14 @@
+namespace DotTiled;
+
+public class FloatProperty : IProperty
+{
+  public required string Name { get; set; }
+  public PropertyType Type => PropertyType.Float;
+  public required float Value { get; set; }
+
+  public IProperty Clone() => new FloatProperty
+  {
+    Name = Name,
+    Value = Value
+  };
+}

DotTiled/Model/Properties/IProperty.cs

@@ -0,0 +1,9 @@
+namespace DotTiled;
+
+public interface IProperty
+{
+  public string Name { get; set; }
+  public PropertyType Type { get; }
+
+  IProperty Clone();
+}

DotTiled/Model/Properties/IntProperty.cs

@@ -0,0 +1,14 @@
+namespace DotTiled;
+
+public class IntProperty : IProperty
+{
+  public required string Name { get; set; }
+  public PropertyType Type => PropertyType.Int;
+  public required int Value { get; set; }
+
+  public IProperty Clone() => new IntProperty
+  {
+    Name = Name,
+    Value = Value
+  };
+}

DotTiled/Model/Properties/ObjectProperty.cs

@@ -0,0 +1,14 @@
+namespace DotTiled;
+
+public class ObjectProperty : IProperty
+{
+  public required string Name { get; set; }
+  public PropertyType Type => PropertyType.Object;
+  public required uint Value { get; set; }
+
+  public IProperty Clone() => new ObjectProperty
+  {
+    Name = Name,
+    Value = Value
+  };
+}

DotTiled/Model/Properties/PropertyType.cs

@@ -0,0 +1,13 @@
+namespace DotTiled;
+
+public enum PropertyType
+{
+  String,
+  Int,
+  Float,
+  Bool,
+  Color,
+  File,
+  Object,
+  Class
+}

DotTiled/Model/Properties/StringProperty.cs

@@ -0,0 +1,14 @@
+namespace DotTiled;
+
+public class StringProperty : IProperty
+{
+  public required string Name { get; set; }
+  public PropertyType Type => PropertyType.String;
+  public required string Value { get; set; }
+
+  public IProperty Clone() => new StringProperty
+  {
+    Name = Name,
+    Value = Value
+  };
+}

DotTiled/Model/Template.cs

@@ -0,0 +1,8 @@
+namespace DotTiled;
+
+public class Template
+{
+  // At most one of (if the template is a tile object)
+  public Tileset? Tileset { get; set; }
+  public required Object Object { get; set; }
+}

DotTiled/Model/Tileset/Tileset.cs

@@ -39,8 +39,8 @@ public class Tileset
   public string Class { get; set; } = "";
   public uint? TileWidth { get; set; }
   public uint? TileHeight { get; set; }
-  public float? Spacing { get; set; }
+  public float? Spacing { get; set; } = 0f;
-  public float? Margin { get; set; }
+  public float? Margin { get; set; } = 0f;
   public uint? TileCount { get; set; }
   public uint? Columns { get; set; }
   public ObjectAlignment ObjectAlignment { get; set; } = ObjectAlignment.Unspecified;

DotTiled/Model/Tileset/WangColor.cs

@@ -8,7 +8,7 @@ public class WangColor
   public required string Name { get; set; }
   public string Class { get; set; } = "";
   public required Color Color { get; set; }
-  public required uint Tile { get; set; }
+  public required int Tile { get; set; }
   public float Probability { get; set; } = 0f;
 
   // Elements

DotTiled/Model/Tileset/Wangset.cs

@@ -7,7 +7,7 @@ public class Wangset
   // Attributes
   public required string Name { get; set; }
   public string Class { get; set; } = "";
-  public required uint Tile { get; set; }
+  public required int Tile { get; set; }
 
   // Elements
   // At most one of

DotTiled/Serialization/Helpers.cs

@@ -0,0 +1,123 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.IO.Compression;
+using System.Linq;
+
+namespace DotTiled;
+
+internal static partial class Helpers
+{
+  internal static uint[] ReadMemoryStreamAsInt32Array(Stream stream)
+  {
+    var finalValues = new List<uint>();
+    var int32Bytes = new byte[4];
+    while (stream.Read(int32Bytes, 0, 4) == 4)
+    {
+      var value = BitConverter.ToUInt32(int32Bytes, 0);
+      finalValues.Add(value);
+    }
+    return [.. finalValues];
+  }
+
+  internal static uint[] DecompressGZip(MemoryStream stream)
+  {
+    using var decompressedStream = new GZipStream(stream, CompressionMode.Decompress);
+    return ReadMemoryStreamAsInt32Array(decompressedStream);
+  }
+
+  internal static uint[] DecompressZLib(MemoryStream stream)
+  {
+    using var decompressedStream = new ZLibStream(stream, CompressionMode.Decompress);
+    return ReadMemoryStreamAsInt32Array(decompressedStream);
+  }
+
+  internal static uint[] ReadBytesAsInt32Array(byte[] bytes)
+  {
+    var intArray = new uint[bytes.Length / 4];
+    for (var i = 0; i < intArray.Length; i++)
+    {
+      intArray[i] = BitConverter.ToUInt32(bytes, i * 4);
+    }
+
+    return intArray;
+  }
+
+  internal static (uint[] GlobalTileIDs, FlippingFlags[] FlippingFlags) ReadAndClearFlippingFlagsFromGIDs(uint[] globalTileIDs)
+  {
+    var clearedGlobalTileIDs = new uint[globalTileIDs.Length];
+    var flippingFlags = new FlippingFlags[globalTileIDs.Length];
+    for (var i = 0; i < globalTileIDs.Length; i++)
+    {
+      var gid = globalTileIDs[i];
+      var flags = gid & 0xF0000000u;
+      flippingFlags[i] = (FlippingFlags)flags;
+      clearedGlobalTileIDs[i] = gid & 0x0FFFFFFFu;
+    }
+
+    return (clearedGlobalTileIDs, flippingFlags);
+  }
+
+  internal static ImageFormat ParseImageFormatFromSource(string source)
+  {
+    var extension = Path.GetExtension(source).ToLowerInvariant();
+    return extension switch
+    {
+      ".png" => ImageFormat.Png,
+      ".gif" => ImageFormat.Gif,
+      ".jpg" => ImageFormat.Jpg,
+      ".jpeg" => ImageFormat.Jpg,
+      ".bmp" => ImageFormat.Bmp,
+      _ => throw new NotSupportedException($"Unsupported image format '{extension}'")
+    };
+  }
+
+  internal static Dictionary<string, IProperty> MergeProperties(Dictionary<string, IProperty>? baseProperties, Dictionary<string, IProperty>? overrideProperties)
+  {
+    if (baseProperties is null)
+      return overrideProperties ?? new Dictionary<string, IProperty>();
+
+    if (overrideProperties is null)
+      return baseProperties;
+
+    var result = baseProperties.ToDictionary(kvp => kvp.Key, kvp => kvp.Value.Clone());
+    foreach (var (key, value) in overrideProperties)
+    {
+      if (!result.TryGetValue(key, out var baseProp))
+      {
+        result[key] = value;
+        continue;
+      }
+      else
+      {
+        if (value is ClassProperty classProp)
+        {
+          ((ClassProperty)baseProp).Properties = MergeProperties(((ClassProperty)baseProp).Properties, classProp.Properties);
+        }
+        else
+        {
+          result[key] = value;
+        }
+      }
+    }
+
+    return result;
+  }
+
+  internal static void SetAtMostOnce<T>(ref T? field, T value, string fieldName)
+  {
+    if (field is not null)
+      throw new InvalidOperationException($"{fieldName} already set");
+
+    field = value;
+  }
+
+  internal static void SetAtMostOnceUsingCounter<T>(ref T? field, T value, string fieldName, ref int counter)
+  {
+    if (counter > 0)
+      throw new InvalidOperationException($"{fieldName} already set");
+
+    field = value;
+    counter++;
+  }
+}

DotTiled/Serialization/IMapReader.cs

@@ -0,0 +1,8 @@
+using System;
+
+namespace DotTiled;
+
+public interface IMapReader : IDisposable
+{
+  Map ReadMap();
+}

DotTiled/Serialization/ITemplateReader.cs

@@ -0,0 +1,8 @@
+using System;
+
+namespace DotTiled;
+
+public interface ITemplateReader : IDisposable
+{
+  Template ReadTemplate();
+}

DotTiled/Serialization/ITilesetReader.cs

@@ -0,0 +1,8 @@
+using System;
+
+namespace DotTiled;
+
+public interface ITilesetReader : IDisposable
+{
+  Tileset ReadTileset();
+}