Add some start for Evp Data.

Penumbra/Meta/Files/EvpFile.cs

@@ -0,0 +1,68 @@
+using System;
+
+namespace Penumbra.Meta.Files;
+
+
+// EVP file structure:
+// [Identifier:3 bytes, EVP]
+// [NumModels:ushort]
+// NumModels x [ModelId:ushort]
+//     Containing the relevant model IDs. Seems to be sorted.
+// NumModels x [DataArray]:512 Byte]
+// Containing Flags in each byte, 0x01 set for Body, 0x02 set for Helmet. Unsure where the index into this array comes from.
+public unsafe class EvpFile : MetaBaseFile
+{
+    public const int FlagArraySize = 512;
+
+    [Flags]
+    public enum EvpFlag : byte
+    {
+        None = 0x00,
+        Body = 0x01,
+        Head = 0x02,
+        Both = Body | Head,
+    }
+
+    public int NumModels
+        => Data[ 3 ];
+
+    public ReadOnlySpan< ushort > ModelSetIds
+        => new(Data + 4, NumModels);
+
+    public ushort ModelSetId( int idx )
+        => idx >= 0 && idx < NumModels ? ( ( ushort* )( Data + 4 ) )[ idx ] : ushort.MaxValue;
+
+    public ReadOnlySpan< EvpFlag > Flags( int idx )
+        => new(Data + 4 + idx * FlagArraySize, FlagArraySize);
+
+    public EvpFlag Flag( ushort modelSet, int arrayIndex )
+    {
+        if( arrayIndex is >= FlagArraySize or < 0 )
+        {
+            return EvpFlag.None;
+        }
+
+        var ids = ModelSetIds;
+        for( var i = 0; i < ids.Length; ++i )
+        {
+            var model = ids[ i ];
+            if( model < modelSet )
+            {
+                continue;
+            }
+
+            if( model > modelSet )
+            {
+                break;
+            }
+
+            return Flags( i )[ arrayIndex ];
+        }
+
+        return EvpFlag.None;
+    }
+
+    public EvpFile()
+        : base( ( Interop.Structs.CharacterUtility.Index )1 ) // TODO: Name
+    { }
+}

Penumbra/Meta/Files/MetaBaseFile.cs

@@ -12,7 +12,7 @@ public unsafe class MetaBaseFile : IDisposable
     public CharacterUtility.InternalIndex Index { get; }
 
     public MetaBaseFile( Interop.Structs.CharacterUtility.Index idx )
-        => Index = CharacterUtility.ReverseIndices[(int) idx];
+        => Index = CharacterUtility.ReverseIndices[ ( int )idx ];
 
     protected (IntPtr Data, int Length) DefaultData
         => Penumbra.CharacterUtility.DefaultResource( Index );