Thread: linker errors

I've never had any experience with linker problems before. Looks like it might be the way I call some D3D and WINAPI methods, but I checked their usage, and it looks ok. After a long debugging session I finally got my project to compile, but now I have multiple linker errors (four).

Here's the error text:

error LNK2019: unresolved external symbol "public: void __thiscall CApplication::CheckDeviceCaps(void)" (?CheckDeviceCaps@CApplication@@QAEXXZ) referenced in function "public: void __thiscall CApplication::InitDirect3D(void)" (?InitDirect3D@CApplication@@QAEXXZ)

error LNK2019: unresolved external symbol _Direct3DCreate9@4 referenced in function "public: void __thiscall CApplication::InitDirect3D(void)" (?InitDirect3D@CApplication@@QAEXXZ)

error LNK2019: unresolved external symbol __imp__InitCommonControls@0 referenced in function "public: void __thiscall CApplication::InitWindow(void)" (?InitWindow@CApplication@@QAEXXZ)

error LNK2019: unresolved external symbol _D3DXMatrixPerspectiveFovLH@20 referenced in function "public: void __thiscall CApplication::InitScene(void)" (?InitScene@CApplication@@QAEXXZ)

How do I resolve problems like these?

I realize this might be a game programming question, but because the errors were reported by my c++ compiler I thought this would be the appropriate place to post my problem.

Do you have the code written for those functions, and is it included in the project?

Also make sure all the correct libs are included in your project...

Ok, this is what I have found out so far:

Doug, this will explain your confusion over the word "void". I had prototyped void CheckDeviceCaps(); (I'm sure you know () is just like (void)) in my header file and had called it in InitDirect3D(); , but it doesn't need to be implemented yet so just stubbing it out solved the problem.

Code:

void CApplication::CheckDeviceCaps()
{
}

InitCommonControls() is supposed to do something with winXP styles; for other operating systems nothing happens. Obviously it's not needed and causing my a big freaking headache, so now the call reads /*InitCommonControls();*/

The other two I cannot figure out. They're supposed to be helpful Direct3D functions, but don't seem to exist. I downloaded the project from the people that wrote the tutorials and still got the same errors when building.

Anyway, just thought ya'll would want to know what the "unresolved external symbol" linker error means. It means "You called this function, and I have an address for it (prototype), but I can't find it's implementation."