cm3d2.dll API

Filesystem types

CM3D2.dll recognizes two filesystem types: Windows (0) and Archive (1).

Filesystem structures

Externally, a filesystem is a struct:

struct FileSystem {
    int* internals_ptr;    // Pointer to the internal structure
    int  fs_type;          // Type of the filesystem (0 = windows, 1 = archive)
};

Internal file system

An internal file system consists of the following interfaces: InterfaceFileShare, InterfaceFileSystemAnsi, InterfaceFileSystemWide, InterfaceFileSystemUtf8, InterfaceFileSystem.

Archive internals

Internally, the class of

The archives' internals contains the following values.

The location is in bytes and relative to structure's start address.

Type	Offset (QWORDS)	Notes
Address	0	Pointer to vtable of FileSystemArchive
Address	1	Pointer to something
Address	2	Pointer to vtable of InterfaceFileSystemWide
Address	3	Pointer to something
Address	4	Pointer to vtable of InterfaceFileSystemUtf8
Address	5	Pointer to something
std::wstring	6 - 10	Current base directory
std::list	11-12	List of loaded ARCs?
Value	13	0x0
Value	14	Junk?
Address	15	Pointer to vtable of InterfaceFileShare

Notes

• Only the 4 top bytes are used from 1, 3 and 5. Thus essentially they contain values 70, 60 and 50 respectively. They probably mean the size of the vtables.
• There is a global counter for all initialized archives

FileSystemArchive

Signature:

class FileSystemArchive: public InterfaceFileSystem;

class InterfaceFileSystem: public InterfaceFileSystemAnsi, public InterfaceFileSystemWide, public InterfaceFileSystemUtf8;

class InterfaceFileSystemAnsi: public InterfaceFileShare;
class InterfaceFileSystemWide: public InterfaceFileShare;
class InterfaceFileSystemUtf8: public InterfaceFileShare;

virtual class InterfaceFileShare;

FileSystemArchive has the following functions:

First VFTable

Index	Function signature
0
1
2
3
4	Internal function for SetBaseDirectory
5	void SetBaseDirectory(*this, char* path)
6	Internal function for AddArchive
7
8	Internal for AddArchive
9	void AddArchive(*this, char* path)
10	void AddAutoPathForAllFolder(*this)
11
12
13	void AddAutoPath(*this, char* path)
14
15
16
17
18
19
20
21	Pointer to _LocaleUpdate::GetLocaleT()

Second VFTable (implements InterfaceFileSystemWide)

Index	Function signature
0	GetFileW(this, wchar_t* path)
1
2	CreateFileListW(this, std::vector<std::wstring>* vec, wchar_t* path, ListType list_type)

Third VFTable

Index	Function signature
0	FileMemory* GetFile(*this, char* file_str)
1
2	std::vector<std::string*>* CreateList(*this, std::vector<std::string*>* vector, char* path, ListType list_type)
3	(NOTE: Is structure; likely a lambda)
4
5
6
7
8	BOOL IsExistentFile(*this, char* path)
9
10

Fourth VFTable (InterfaceFileShare)

Index	Function signature
0	bool IsValid(*this)
1

File lists

A file list is a struct

struct FileListData 
{
    std::vector<std::string*> *file_list;
    int size;
}

The pointer to the vector is a simple IntPtr in C#.

File

The API provides two main file types: Win32File (WINAPI), FileNormalWindows (C file API), FileMemory (memory).

Signature:

class FileMemory {
    virtual ~FileMemory() = 0;
    virtual bool close_file() = 0;
    virtual bool seek(uint64_t dist, bool absolute) = 0;
    virtual uint64_t read(void* buffer, uint64_t length) = 0;
    virtual uint64_t read_from(void* buffer, uint64_t pos, uint64_t length) = 0;
    virtual bool is_open() = 0;
    virtual void* get_data_ptr() = 0;
    virtual uint64_t tell() = 0;
    virtual uint64_t length() = 0;
    virtual bool set_file(void* data_ptr, uint64_t data_length, uint64_t file_offset) = 0;
    virtual bool change_file_ptr2(void* data_ptr, uint64_t data_length, uint64_t file_offset) = 0;
    virtual size_t move_memory(void* dest, void* src, size_t len) = 0;
}

VTable structure:

Index	Function name	Notes
0	dispose	Disposes of the object and file pointer
1	close_file	Closes and frees raw file handler/pointer. Returns true if failed (?)
2	seek	Moves the read header by the given number of bytes absolutely or relatively. Return true on success
3	read	Reads at most length bytes into the given buffer. Returns the number of bytes actually read
4	read_from	Reads at most length bytes into the given buffer from absolute position pos. Returns the number of bytes actually read
5	is_open	Checks whether the file is open
6	get_data_ptr	Returns pointer to the data this FileMemory handles. Pretty much like c_ptr().
7	tell	Current read position
8	length	Total size of the current file
9	set_file	Initializes this FileMemory to track the given data from the specified offset. file_offset allows to track only a slice of the file instead of the whole file
10	change_file_ptr2	Does pretty much the same thing as set_file. Don't know why there is a duplicate.
11	move_memory	Moves data from one place to another.