Identify Texture DataCategory from original client serialization

Source/ACE.DatLoader.Tests/TextureDataCategoryTests.cs

@@ -0,0 +1,121 @@
+
+using System.IO;
+using ACE.DatLoader.FileTypes;
+using ACE.Entity.Enum;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace ACE.DatLoader.Tests
+{
+    [TestClass]
+    public class TextureDataCategoryTests
+    {
+        [TestMethod]
+        public void Unpack_DataCategory_PreservesUnsignedValuesAndFollowingFields()
+        {
+            // Include observed category values and synthetic UInt32
+            // boundary cases. The meanings of the values remain unknown.
+            var categories = new uint[]
+            {
+                0u, 7u, 0x80000000u, uint.MaxValue
+            };
+
+            var pixels = new byte[]
+            {
+                1, 2, 3, 4, 5, 6, 7, 8
+            };
+
+            foreach (var category in categories)
+            {
+                var bytes = BuildRecord(
+                    0x06000001u,
+                    category,
+                    2,
+                    1,
+                    SurfacePixelFormat.PFID_A8R8G8B8,
+                    pixels);
+
+                var texture = UnpackCompletely(bytes);
+
+                Assert.AreEqual(0x06000001u, texture.Id);
+                Assert.AreEqual(category, texture.DataCategory);
+                Assert.AreEqual(2, texture.Width);
+                Assert.AreEqual(1, texture.Height);
+                Assert.AreEqual(SurfacePixelFormat.PFID_A8R8G8B8,
+                    texture.Format);
+                Assert.AreEqual(pixels.Length, texture.Length);
+                CollectionAssert.AreEqual(pixels, texture.SourceData);
+                Assert.IsNull(texture.DefaultPaletteId);
+            }
+        }
+
+        [TestMethod]
+        public void Unpack_PalettizedTexture_PreservesPaletteAndAlignment()
+        {
+            var pixels = new byte[] { 3, 7 };
+
+            var bytes = BuildRecord(
+                0x06000002u,
+                10u,
+                2,
+                1,
+                SurfacePixelFormat.PFID_P8,
+                pixels,
+                0x04000001u);
+
+            var texture = UnpackCompletely(bytes);
+
+            Assert.AreEqual(0x06000002u, texture.Id);
+            Assert.AreEqual(10u, texture.DataCategory);
+            Assert.AreEqual(2, texture.Width);
+            Assert.AreEqual(1, texture.Height);
+            Assert.AreEqual(SurfacePixelFormat.PFID_P8, texture.Format);
+            Assert.AreEqual(2, texture.Length);
+            CollectionAssert.AreEqual(pixels, texture.SourceData);
+            Assert.AreEqual((uint?)0x04000001u,
+                texture.DefaultPaletteId);
+        }
+
+        private static Texture UnpackCompletely(byte[] bytes)
+        {
+            using var stream = new MemoryStream(bytes, writable: false);
+            using var reader = new BinaryReader(stream);
+
+            var texture = new Texture();
+            texture.Unpack(reader);
+
+            Assert.AreEqual(stream.Length, stream.Position,
+                "The parser must consume the complete texture record.");
+
+            return texture;
+        }
+
+        private static byte[] BuildRecord(
+            uint id,
+            uint category,
+            int width,
+            int height,
+            SurfacePixelFormat format,
+            byte[] pixels,
+            uint? paletteId = null)
+        {
+            using var stream = new MemoryStream();
+
+            using (var writer = new BinaryWriter(
+                stream, System.Text.Encoding.UTF8, leaveOpen: true))
+            {
+                writer.Write(id);
+                writer.Write(category);
+                writer.Write(width);
+                writer.Write(height);
+                writer.Write((uint)format);
+                writer.Write(pixels.Length);
+                writer.Write(pixels);
+
+                if (paletteId.HasValue)
+                    writer.Write(paletteId.Value);
+            }
+
+            return stream.ToArray();
+        }
+    }
+}

Source/ACE.DatLoader/FileTypes/Texture.cs

@@ -17,7 +17,10 @@ namespace ACE.DatLoader.FileTypes
     [DatFileType(DatFileType.Texture)]
     public class Texture : FileType
     {
-        public int Unknown { get; set; }
+        // RenderSurface inherits m_dataCategory from DBObj.
+        // The original client serializes this field for categorized resources.
+        // The meaning of individual category values has not yet been established.
+        public uint DataCategory { get; set; }
         public int Width { get; set; }
         public int Height { get; set; }
         public SurfacePixelFormat Format { get; set; }
@@ -32,7 +35,7 @@ public class Texture : FileType
         public override void Unpack(BinaryReader reader)
         {
             Id = reader.ReadUInt32();
-            Unknown = reader.ReadInt32();
+            DataCategory = reader.ReadUInt32();
             Width = reader.ReadInt32();
             Height = reader.ReadInt32();
             Format = (SurfacePixelFormat)reader.ReadUInt32();