chore: enable reading of big endian ipaks

src/ObjLoading/ObjContainer/IPak/IPakEntryReadStream.h

@@ -2,14 +2,17 @@
 
 #include "IPakStreamManager.h"
 #include "ObjContainer/IPak/IPakTypes.h"
+#include "Utils/Endianness.h"
 #include "Utils/ObjStream.h"
 
+#include <concepts>
 #include <istream>
 
 class IPakEntryReadStream final : public objbuf
 {
 public:
-    IPakEntryReadStream(std::istream& stream, IPakStreamManagerActions* streamManagerActions, uint8_t* chunkBuffer, int64_t startOffset, size_t entrySize);
+    IPakEntryReadStream(
+        std::istream& stream, bool isLittleEndian, IPakStreamManagerActions* streamManagerActions, uint8_t* chunkBuffer, int64_t startOffset, size_t entrySize);
     ~IPakEntryReadStream() override;
 
     [[nodiscard]] bool is_open() const override;
@@ -34,6 +37,14 @@ private:
         return num / alignTo * alignTo;
     }
 
+    template<std::integral T> void SwapBytesIfNecessary(T& value)
+    {
+        if (m_little_endian)
+            value = endianness::FromLittleEndian(value);
+        else
+            value = endianness::FromBigEndian(value);
+    }
+
     /**
      * \brief Reads the specified chunks from disk.
      * \param buffer The location to write the loaded data to. Must be able to hold the specified amount of data.
@@ -90,6 +101,8 @@ private:
 
     uint8_t* m_chunk_buffer;
 
+    bool m_little_endian;
+
     std::istream& m_stream;
     IPakStreamManagerActions* m_stream_manager_actions;