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ParkanPlayground/Msh0x05.cs

@@ -0,0 +1,51 @@
+using System.Buffers.Binary;
+using NResLib;
+
+namespace ParkanPlayground;
+
+/// <summary>
+/// MSH-компонент 0x05: упакованные UV0. component / 1024.0.
+/// </summary>
+public static class Msh0x05
+{
+    public static List<Msh05Uv> ReadComponent(FileStream mshFs, NResArchive archive)
+    {
+        var entry = archive.Files.FirstOrDefault(x => x.FileType == "05 00 00 00");
+
+        if (entry is null)
+        {
+            throw new Exception("Archive doesn't contain file (05)");
+        }
+
+        if (entry.ElementSize != 4)
+        {
+            throw new Exception("Packed UV file (05) element size is not 4");
+        }
+
+        if (entry.FileLength % entry.ElementSize != 0)
+        {
+            throw new Exception("Packed UV component (0x05) payload size is not divisible by element size");
+        }
+
+        var data = new byte[entry.FileLength];
+        mshFs.Seek(entry.OffsetInFile, SeekOrigin.Begin);
+        mshFs.ReadExactly(data, 0, data.Length);
+
+        var elements = new List<Msh05Uv>(entry.FileLength / entry.ElementSize);
+        for (var i = 0; i < entry.FileLength / entry.ElementSize; i++)
+        {
+            var span = data.AsSpan(i * 4, 4);
+            elements.Add(new Msh05Uv(
+                BinaryPrimitives.ReadInt16LittleEndian(span[0..2]),
+                BinaryPrimitives.ReadInt16LittleEndian(span[2..4])));
+        }
+
+        return elements;
+    }
+}
+
+/// <summary>Упакованные UV0: две int16-компоненты (length = 4).</summary>
+/// <param name="U">[0x00..0x02] U-компонента, uv = U / 1024.0.</param>
+/// <param name="V">[0x02..0x04] V-компонента, uv = V / 1024.0.</param>
+public readonly record struct Msh05Uv(short U, short V)
+;