Thread: Various DirectX questions

This is what it says on MSDN, for changing display modes in DirectX 7:

ddrval = lpDD->SetDisplayMode(640, 480, 8);

I stuck that into my compiler, and it spat out an error, something along the lines of "SetDisplayMode() doesn't take 3 parameters". I looked it up on my MSVC help, and it said that it took 5 parameters, except that it was "IDirectDraw2::SetDisplayMode()". It fixed when I used 5 parameters, but the IDirectDraw2 looks bad. Is there anything wrong with what I'm doing?

This is another bit of code of mine:

Code:

DirectDrawCreateEx(NULL, (void**)&ddraw, IID_IDirectDraw7, NULL)

On MSDN, it says that if I put anything other than IID_IDirectDraw7, it will choke and die. But my linker choked and died anyways It says that "_IID_IDirectDraw7" is an "unresolved external symbol". Am I forgetting a header or something? I have ddraw.h included.

SetDisplayMode does in fact take 5 parameters in DirectX 7.0. Perhaps you were looking at an earlier SDK Help?

As far as the IID_IDirectDraw7, you are not linking to a necessary file. Try adding "dxguid.lib" to your link path. This will fix the problem. Explanation:

You must link to this library. It defines all of the Globally unique identifiers ( GUIDs ) for the DirectX Foundation COM interfaces. An alternative to linking to that file, you can put

Code:

#define INITGUID

prior to all of your other includes. Hope this helps!

Hmm, not sure how old the help was, but it was in MSDN's "archives", since DirectX8 already came out.

But what would #define INITGUID do? Wouldn't I still need the library for the GUID definitions?

If you use the INITGUID , it will use pre-defined choices. If you link to the library however, I think it will generate a new one

You mean you think it will:

a) use pre-defined GUID's if you use INITGUID
b) generate a totally new GUID if you include the library

Am I right?

Yes, that is what I think.

Again, everyone I know who writes DirectX games seems to just link to the library.

Alright, thanks a lot

P.S. Well, it is called "dxguid.lib"