Hi

I want to add physx to my engine but I'm getting a very strange errors:

1>------ Build started: Project: Game, Configuration: Debug Win32 ------
1>PhysX3CommonCHECKED_x86.lib(PhysX3CommonCHECKED_x86.dll) : error LNK2005: "public: class physx::PxFlags<enum physx::PxSerialFlag::Enum,unsigned short> __thiscall physx::PxFlags<enum physx::PxSerialFlag::Enum,unsigned short>::operator~(void)const " (??S?$PxFlags@W4Enum@PxSerialFlag@physx@@G@physx@@QBE?AV01@XZ) already defined in FreeCamera.obj
1>PhysX3CommonCHECKED_x86.lib(PhysX3CommonCHECKED_x86.dll) : error LNK2005: "public: __thiscall physx::PxFlags<enum physx::PxSerialFlag::Enum,unsigned short>::PxFlags<enum physx::PxSerialFlag::Enum,unsigned short>(enum physx::PxSerialFlag::Enum)" (??0?$PxFlags@W4Enum@PxSerialFlag@physx@@G@physx@@QAE@W4Enum@PxSerialFlag@1@@Z) already defined in FreeCamera.obj
1>PhysX3CommonCHECKED_x86.lib(PhysX3CommonCHECKED_x86.dll) : error LNK2005: "public: class physx::PxFlags<enum physx::PxSerialFlag::Enum,unsigned short> & __thiscall physx::PxFlags<enum physx::PxSerialFlag::Enum,unsigned short>::operator&=(class physx::PxFlags<enum physx::PxSerialFlag::Enum,unsigned short> const &)" (??_4?$PxFlags@W4Enum@PxSerialFlag@physx@@G@physx@@QAEAAV01@ABV01@@Z) already defined in FreeCamera.obj
1>PhysX3CommonCHECKED_x86.lib(PhysX3CommonCHECKED_x86.dll) : error LNK2005: "public: __thiscall physx::PxFlags<enum physx::PxSerialFlag::Enum,unsigned short>::PxFlags<enum physx::PxSerialFlag::Enum,unsigned short>(void)" (??0?$PxFlags@W4Enum@PxSerialFlag@physx@@G@physx@@QAE@XZ) already defined in FreeCamera.obj
1>PhysX3CommonCHECKED_x86.lib(PhysX3CommonCHECKED_x86.dll) : error LNK2005: "public: __thiscall physx::PxFlags<enum physx::PxSerialFlag::Enum,unsigned short>::PxFlags<enum physx::PxSerialFlag::Enum,unsigned short>(class physx::PxFlags<enum physx::PxSerialFlag::Enum,unsigned short> const &)" (??0?$PxFlags@W4Enum@PxSerialFlag@physx@@G@physx@@QAE@ABV01@@Z) already defined in FreeCamera.obj
1>PhysX3CommonCHECKED_x86.lib(PhysX3CommonCHECKED_x86.dll) : error LNK2005: "public: __thiscall physx::PxFlags<enum physx::PxSerialFlag::Enum,unsigned short>::operator bool(void)const " (??B?$PxFlags@W4Enum@PxSerialFlag@physx@@G@physx@@QBE_NXZ) already defined in FreeCamera.obj
1>PhysX3CommonCHECKED_x86.lib(PhysX3CommonCHECKED_x86.dll) : error LNK2005: "public: class physx::PxFlags<enum physx::PxSerialFlag::Enum,unsigned short> __thiscall physx::PxFlags<enum physx::PxSerialFlag::Enum,unsigned short>::operator&(enum physx::PxSerialFlag::Enum)const " (??I?$PxFlags@W4Enum@PxSerialFlag@physx@@G@physx@@QBE?AV01@W4Enum@PxSerialFlag@1@@Z) already defined in FreeCamera.obj
1>E:\Tools\game_engine\MyEngine\Engine\Debug\Game.exe : fatal error LNK1169: one or more multiply defined symbols found

I found a single line in my code that cause these errors but the code is true here my code for starting physx:

CPhysxPhysic::CPhysxPhysic(void)
{
	m_Physics=NULL;
	m_Foundation=NULL;

   //static PxDefaultErrorCallback gDefaultErrorCallback;
   //static PxDefaultAllocator gDefaultAllocatorCallback;

   printf("initializing PhysX\n");
 
   printf("creating Foundation\n");
 // create foundation object with default error and allocator callbacks.
   m_Foundation = PxCreateFoundation(PX_PHYSICS_VERSION,gDefaultAllocatorCallback,gDefaultErrorCallback);
 
   printf("creating Physics\n");
   // create Physics object with the created foundation and with a 'default' scale tolerance.
   m_Physics = PxCreatePhysics(PX_PHYSICS_VERSION,*m_Foundation,PxTolerancesScale());

   m_Cooking = PxCreateCooking(PX_PHYSICS_VERSION, *m_Foundation, PxCookingParams());
   if (!m_Cooking)
    printf("PxCreateCooking failed!\n");

   if (!PxInitExtensions(*m_Physics))//This line is the problem!!!
    printf("PxInitExtensions failed!\n");

   m_ProfileZoneManager = &PxProfileZoneManager::createProfileZoneManager(m_Foundation);
	if(!m_ProfileZoneManager)
		printf("PxProfileZoneManager::createProfileZoneManager failed!\n");

	#ifdef PX_WINDOWS
		pxtask::CudaContextManagerDesc cudaContextManagerDesc;
		m_CudaContextManager = pxtask::createCudaContextManager(*m_Foundation, cudaContextManagerDesc, m_ProfileZoneManager);
		if( m_CudaContextManager )
		{
			if( !m_CudaContextManager->contextIsValid() )
			{
				m_CudaContextManager->release();
				m_CudaContextManager = NULL;
			}
		}
#endif



   PxInitVehicleSDK(*m_Physics);
   PxVehicleSetBasisVectors(PxVec3(0,1,0),PxVec3(0,0,1));

  // static PxDefaultSimulationFilterShader gDefaultFilterShader;

   PxSceneDesc sceneDesc(m_Physics->getTolerancesScale());
   sceneDesc.gravity = PxVec3(0.0f, -9.81f, 0.0f);
   // customizeSceneDesc(sceneDesc);

    if(!sceneDesc.cpuDispatcher)
    {
      m_CpuDispatcher = PxDefaultCpuDispatcherCreate(2);
       if(!m_CpuDispatcher)
          printf("PxDefaultCpuDispatcherCreate failed!\n");
       sceneDesc.cpuDispatcher    = m_CpuDispatcher;
    }
    if(!sceneDesc.filterShader)
        sceneDesc.filterShader    = PxDefaultSimulationFilterShader;

    #ifdef PX_WINDOWS
    if(!sceneDesc.gpuDispatcher && m_CudaContextManager)
    {
        sceneDesc.gpuDispatcher = m_CudaContextManager->getGpuDispatcher();
    }
    #endif

    m_Scene = m_Physics->createScene(sceneDesc);
    if (!m_Scene)
        printf("createScene failed!\n");


 
   printf("PhysX initialized\n");
}

If I remove this line I an compile the code:

 if (!PxInitExtensions(*m_Physics))//This line is the problem!!!
    printf("PxInitExtensions failed!\n");

Why I got multiply defined symbols?and how should I solve it?

EDIT:I solve it my self(after 3 days of testing I finally found the answer 5 minutes after asking here :D).I included <PxPhysicsAPI.h> before any other header file and it solved my problem.

I'm glad you solved your problem! Thank you for the follow up. It could be useful for other people, in the future.

Graham