Question regarding LNK2005

[kaltz]

So I have this main.cpp and another header and cpp file called system.h and system.cpp

I declared the LPDIRECT3D9 and LPDIRECT3DDEVICE9 type variables like:

extern LPDIRECT3D9 g_pD3D;
extern LPDIRECT3DDEVICE9 g_pd3dDevice;

on my system.h and initialized them inside my system.cpp file

at my main.cpp, I included the system.h file like :

#include "system.h"

when I tried to compile it, it said that something along the lines of:

error LNK2005: "struct IDirect3D9 * g_pD3D" (?g_pD3D@@3PAUIDirect3D9@@A) already defined in main.obj

and the same error for the second variable.

I haven't defined or declared the two variables on the main.cpp, I haven't even called the two variables at all.

I temporarily solved the problem by using extern on the two variables on system.h
But I have a feeling that this might not be a 100% solution.

I was wondering what was causing the problem and how can I fix it..

Thank you in advance.

[LuX]

Dunno. Maybe the header is viewed multiple times. Do you have a header guard in it?
A header guard will make sure the file is only read once.

[chili]

Can't say without seeing your code. It's some sort of redefinition.