parse PAL file

PalLib/PalParser.cs

@@ -0,0 +1,37 @@
+using System.Text;
+
+namespace PalLib;
+
+public class PalParser
+{
+    public static PalFile ReadFromStream(Stream stream, string filename)
+    {
+        // Expected size: 1024 (palette) + 4 ("Ipol") + 65536 (indices) = 66564
+        if (stream.Length != 66564)
+        {
+            throw new InvalidDataException($"Invalid PAL file size. Expected 66564 bytes, got {stream.Length}.");
+        }
+
+        var palette = new byte[1024];
+        stream.ReadExactly(palette, 0, 1024);
+
+        var signatureBytes = new byte[4];
+        stream.ReadExactly(signatureBytes, 0, 4);
+        var signature = Encoding.ASCII.GetString(signatureBytes);
+
+        if (signature != "Ipol")
+        {
+            throw new InvalidDataException($"Invalid PAL file signature. Expected 'Ipol', got '{signature}'.");
+        }
+
+        var indices = new byte[65536];
+        stream.ReadExactly(indices, 0, 65536);
+
+        return new PalFile
+        {
+            FileName = filename,
+            Palette = palette,
+            Indices = indices
+        };
+    }
+}