Havok.cs

using System;
using System.IO;
using System.Runtime.InteropServices;
using Dalamud.Data;
using Dalamud.Game;
using FFXIVClientStructs.Havok;

namespace Toolkitty.Utils;

// shoutouts aers, winter, perch, couldn't have done it without you besties
// supported:
// sklb->hkx (SklbToHkx)
// sklb->xml (SklbToXml)
// hkx->xml (HkxToXml)
// xml->hkx (XmlToHkx)
// hkx->sklb (SpliceSklb)

public unsafe class Havok {
    [Flags]
    internal enum hkSerializeUtil_SaveOptionBits : int {
        SAVE_DEFAULT = 0x0,
        SAVE_TEXT_FORMAT = 0x1,
        SAVE_SERIALIZE_IGNORED_MEMBERS = 0x2,
        SAVE_WRITE_ATTRIBUTES = 0x4,
        SAVE_CONCISE = 0x8
    }

    internal enum hkSerializeUtil_LoadOptionBits : int {
        LOAD_DEFAULT = 0,
        LOAD_FAIL_IF_VERSIONING = 1,
        LOAD_FORCED = 2
    }

    internal struct hkTypeInfoRegistry { }

    internal struct hkClassNameRegistry { }

    [StructLayout(LayoutKind.Explicit, Size = 0x18)]
    internal struct hkSerializeUtil_LoadOptions {
        [FieldOffset(0x0)]
        internal hkEnum<hkSerializeUtil_LoadOptionBits, int> options;

        [FieldOffset(0x8)]
        internal hkClassNameRegistry* m_classNameReg;

        [FieldOffset(0x10)]
        internal hkTypeInfoRegistry* m_typeInfoReg;
    }

    [StructLayout(LayoutKind.Explicit, Size = 0x18)]
    internal struct hkOStream {
        [FieldOffset(0x10)]
        internal hkRefPtr<hkStreamWriter> m_writer;
    }

    [StructLayout(LayoutKind.Explicit, Size = 0x10)]
    internal struct hkStreamWriter { }

    [StructLayout(LayoutKind.Explicit, Size = 0x10)]
    internal struct hkStreamReader { }

    [StructLayout(LayoutKind.Explicit, Size = 0x50)]
    internal struct hkClass { }

    [StructLayout(LayoutKind.Explicit, Size = 0x48)]
    internal struct hkResourceVtbl {
        [FieldOffset(0x38)]
        internal delegate* unmanaged[Stdcall] <void*, byte*, void*, void*> getContentsPointer;
    }

    [StructLayout(LayoutKind.Explicit, Size = 0x8)] // larger
    internal struct hkBuiltinTypeRegistry {
        [FieldOffset(0x0)]
        internal hkBuiltinTypeRegistryVtbl* vtbl;
    }

    [StructLayout(LayoutKind.Explicit, Size = 0x48)]
    internal struct hkBuiltinTypeRegistryVtbl {
        [FieldOffset(0x20)]
        internal delegate* unmanaged[Stdcall] <hkBuiltinTypeRegistry*, hkTypeInfoRegistry*> GetTypeInfoRegistry;

        [FieldOffset(0x28)]
        internal delegate* unmanaged[Stdcall] <hkBuiltinTypeRegistry*, hkClassNameRegistry*> GetClassNameRegistry;
    }

    private delegate hkResource* hkSerializeUtil_LoadDelegate(
        char* path,
        void* idk,
        hkSerializeUtil_LoadOptions* options
    );

    private delegate hkResult* hkSerializeUtil_SaveDelegate(
        hkResult* result,
        void* obj,
        hkClass* klass,
        hkStreamWriter* writer,
        hkFlags<hkSerializeUtil_SaveOptionBits, uint> flags
    );

    private delegate void hkOstream_CtorDelegate(hkOStream* self, byte* streamWriter);

    private delegate void hkOstream_DtorDelegate(hkOStream* self);

    private hkSerializeUtil_LoadDelegate hkSerializeUtil_Load;
    private hkSerializeUtil_SaveDelegate hkSerializeUtil_Save;
    private hkOstream_CtorDelegate hkOstream_Ctor;
    private hkOstream_DtorDelegate hkOstream_Dtor;

    private hkClass* hkRootLevelContainerClass;
    private hkBuiltinTypeRegistry* hkBuiltinTypeRegistrySingleton;

    private SigScanner sigScanner;
    private DataManager dataManager;

    private T GetDelegate<T>(string sig) {
        var addr = this.sigScanner.ScanText(sig);
        return Marshal.GetDelegateForFunctionPointer<T>(addr);
    }

    public Havok(SigScanner scanner, DataManager dataManager) {
        this.sigScanner = scanner;
        this.dataManager = dataManager;

        // FIXME: sigs look unstable
        // last updated 2023.02.28.0000.0000
        this.hkSerializeUtil_Load = this.GetDelegate<hkSerializeUtil_LoadDelegate>(
            "40 53 48 83 EC 60 41 0F 10 00 48 8B DA 48 8B D1 F2 41 0F 10 48 ?? 48 8D 4C 24 ?? 0F 29 44 24 ?? F2 0F 11 4C 24 ?? E8 ?? ?? ?? ?? 4C 8D 44 24 ?? 48 8B D3 48 8B 48 10 E8 ?? ?? ?? ?? 48 8D 4C 24 ?? 48 8B D8 E8 ?? ?? ?? ?? 48 8B C3 48 83 C4 60 5B C3 CC CC CC CC CC CC CC CC CC CC CC CC CC CC 48 89 5C 24 ??"
        );
        this.hkSerializeUtil_Save = this.GetDelegate<hkSerializeUtil_SaveDelegate>(
            "40 53 48 83 EC 30 8B 44 24 60 48 8B D9 89 44 24 28"
        );
        this.hkOstream_Ctor = this.GetDelegate<hkOstream_CtorDelegate>(
            "48 89 5C 24 ?? 57 48 83 EC 20 C7 41 ?? ?? ?? ?? ?? 48 8D 05 ?? ?? ?? ?? 48 89 01 48 8B F9 48 C7 41 ?? ?? ?? ?? ?? 4C 8B C2 48 8B 0D ?? ?? ?? ?? 48 8D 54 24 ?? 41 B9 ?? ?? ?? ?? 48 8B 01 FF 50 28"
        );
        this.hkOstream_Dtor = this.GetDelegate<hkOstream_DtorDelegate>(
            "E8 ?? ?? ?? ?? 44 8B 44 24 ?? 4C 8B 7C 24 ??"
        );

        this.hkRootLevelContainerClass = (hkClass*) this.sigScanner.GetStaticAddressFromSig(
            "48 8D 0D ?? ?? ?? ?? E8 ?? ?? ?? ?? 48 83 C4 78 C3 CC CC CC 48 83 EC 78 33 C9 C7 44 24 ?? ?? ?? ?? ?? 89 4C 24 60 48 8D 05 ?? ?? ?? ?? 48 89 4C 24 ?? 48 8D 15 ?? ?? ?? ?? 48 89 4C 24 ?? 45 33 C0 C7 44 24 ?? ?? ?? ?? ?? 44 8D 49 18"
        );

        // My formatter hates this line so i'm splitting it into two
        var typeRegistry = this.sigScanner.GetStaticAddressFromSig(
            "48 8B 0D ?? ?? ?? ?? 48 8B 01 FF 50 20 4C 8B 0F 48 8B D3 4C 8B C0 48 8B CF 48 8B 5C 24 ?? 48 83 C4 20 5F 49 FF 61 48"
        );
        this.hkBuiltinTypeRegistrySingleton = *(hkBuiltinTypeRegistry**) typeRegistry;
    }

    private string CreateTempFile() {
        var s = File.Create(Path.GetTempFileName());
        s.Close();
        return s.Name;
    }

    private int? GetHavokOffset(byte[] bytes) {
        var reader = new BinaryReader(new MemoryStream(bytes));
        var magic = reader.ReadInt32();
        if (magic != 0x736B6C62) {
            return null;
        }

        var version = reader.ReadInt32();

        if (version != 0x31333030) {
            // version one
            reader.ReadInt16(); // skip unkOffset
            return reader.ReadInt16();
        } else {
            // version two
            reader.ReadInt32(); // skip unkOffset
            return reader.ReadInt32();
        }
    }

    public byte[]? SklbToHkx(byte[] sklb) {
        var offset = this.GetHavokOffset(sklb);
        if (offset == null) return null;

        var offsetValue = offset.Value;
        return sklb[offsetValue..];
    }

    public string? SklbToXml(byte[] sklb) {
        var hkx = this.SklbToHkx(sklb);
        if (hkx == null) return null;

        return HkxToXml(hkx);
    }

    public string? HkxToXml(byte[] xml) {
        var tempHkx = this.CreateTempFile();

        File.WriteAllBytes(tempHkx, xml);
        var resource = this.Read(tempHkx);

        File.Delete(tempHkx);
        if (resource == null) return null;

        var options = (uint) (hkSerializeUtil_SaveOptionBits.SAVE_SERIALIZE_IGNORED_MEMBERS
                              | hkSerializeUtil_SaveOptionBits.SAVE_TEXT_FORMAT
                              | hkSerializeUtil_SaveOptionBits.SAVE_WRITE_ATTRIBUTES);

        var file = this.Write(resource, options);
        if (file == null) return null;

        file.Close();
        var bytes = File.ReadAllText(file.Name);
        File.Delete(file.Name);

        return bytes;
    }

    public byte[]? XmlToHkx(string xml) {
        var tempXml = this.CreateTempFile();

        File.WriteAllText(tempXml, xml);
        var resource = this.Read(tempXml);

        File.Delete(tempXml);
        if (resource == null) return null;

        var options = (uint) (hkSerializeUtil_SaveOptionBits.SAVE_SERIALIZE_IGNORED_MEMBERS
                              | hkSerializeUtil_SaveOptionBits.SAVE_WRITE_ATTRIBUTES);

        var file = this.Write(resource, options);
        if (file == null) return null;

        file.Close();
        var bytes = File.ReadAllBytes(file.Name);
        File.Delete(file.Name);

        return bytes;
    }

    public byte[]? SpliceSklb(string origPath, byte[] hkx) {
        var file = this.dataManager.GetFile(origPath);
        if (file == null) return null;

        var offset = this.GetHavokOffset(file.Data);
        if (offset == null) return null;

        var header = file.Data[..offset.Value];

        var newFile = new byte[header.Length + hkx.Length];
        header.CopyTo(newFile, 0);
        hkx.CopyTo(newFile, header.Length);

        return newFile;
    }

    private hkResource* Read(string filePath) {
        var path = Marshal.StringToHGlobalAnsi(filePath);

        hkSerializeUtil_LoadOptions* loadOptions = stackalloc hkSerializeUtil_LoadOptions[1];
        loadOptions->m_typeInfoReg =
            hkBuiltinTypeRegistrySingleton->vtbl->GetTypeInfoRegistry(hkBuiltinTypeRegistrySingleton);
        loadOptions->m_classNameReg =
            hkBuiltinTypeRegistrySingleton->vtbl->GetClassNameRegistry(hkBuiltinTypeRegistrySingleton);
        loadOptions->options = new hkEnum<hkSerializeUtil_LoadOptionBits, int>();
        loadOptions->options.Storage = (int) hkSerializeUtil_LoadOptionBits.LOAD_DEFAULT;

        var resource = this.hkSerializeUtil_Load((char*) path, null, loadOptions);
        return resource;
    }

    private FileStream? Write(
        hkResource* resource,
        uint optionBits
    ) {
        hkOStream* oStream = stackalloc hkOStream[1];
        var tempFile = this.CreateTempFile();
        var path = Marshal.StringToHGlobalAnsi(tempFile);
        hkOstream_Ctor(oStream, (byte*) path);

        hkResult* result = stackalloc hkResult[1];
        var options = new hkFlags<hkSerializeUtil_SaveOptionBits, uint>();
        options.Storage = optionBits;

        var name = @"hkRootLevelContainer"u8;
        var resourceVtbl = *(hkResourceVtbl**) resource;
        hkRootLevelContainer* resourcePtr;
        fixed (byte* n = name) {
            resourcePtr = (hkRootLevelContainer*) resourceVtbl->getContentsPointer(
                resource, n, hkBuiltinTypeRegistrySingleton->vtbl->GetTypeInfoRegistry(hkBuiltinTypeRegistrySingleton));
        }

        if (resourcePtr == null) {
            this.hkOstream_Dtor(oStream);
            return null;
        }

        hkSerializeUtil_Save(result, resourcePtr, hkRootLevelContainerClass, oStream->m_writer.ptr, options);
        this.hkOstream_Dtor(oStream);

        if (result->Result == hkResult.hkResultEnum.Failure) {
            return null;
        }

        return new FileStream(tempFile, FileMode.Open);
    }
}