CreateSuface failing

Will somebody please tell me what's wrong with this. CreateSurface is
returning DDERR_INVALIDPARAMS. I'm trying to create a single surface to
display a picture. I'm using the Cygnus GNU-Win32 compiler (beta 18) and
need the code to be in C. I've looked at all the sample code I can find
and can't figure out what's wrong.

LPDIRECTDRAWSURFACE lpDDSPrimary;  
LPDIRECTDRAW lpDD;
HRESULT ddrval;
DDSURFACEDESC ddsd;
DDSCAPS ddscaps;
.
.
ddrval = DirectDrawCreate(NULL,&lpDD,NULL);
ddrval = lpDD->lpVtbl->SetCooperativeLevel(lpDD,hWnd,DDSCL_EXCLUSIVE |
DDSCL_FULLSCREEN);
ddrval = lpDD->lpVtbl->SetDisplayMode(lpDD,640,480,8);

memset(&ddsd,0,sizeof(ddsd));
ddsd.dwSize = sizeof(ddsd);
ddsd.dwFlags = DDSD_CAPS;
ddsd.ddsCaps.dwCaps = DDSCAPS_PRIMARYSURFACE;
ddrval = lpDD->lpVtbl->CreateSurface(lpDD,&ddsd,&lpDDSPrimary,NULL);
if (ddrval != DD_OK)
 {
 lpDD->lpVtbl->Release(lpDD);
 return FALSE;
 }

Thanks in advance...

Nick Gallimore
guzzaAsked:
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byangCommented:
Your code is too minimalistic. You also need to specify DDSD_HEIGHT|DDSD_WIDTH for dwFlags, and set dwWidth and dwHeight:

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

memset(&ddsd,0,sizeof(ddsd));
ddsd.dwSize = sizeof(ddsd);
ddsd.dwFlags = DDSD_CAPS|DDSD_HEIGHT|DDSD_WIDTH;
ddsd.dwHeight=480; ddsd.dwWidth=640;
ddsd.ddsCaps.dwCaps = DDSC
0
guzzaAuthor Commented:
Doesn't make a difference.
0
byangCommented:
Just add more flags. Don't expect CreateSurface to automatically creates a surface matching the current screen mode.
0
guzzaAuthor Commented:
Any ideas/suggestions as to which ones to try? I tried adding DDSD_BACKBUFFERCOUNT,  DDSD_ALPHABITDEPTH and DDSD_PIXELFORMAT, but nothing changed.

0
YamSengCommented:
There are several possibilities:
1) Use the ddscaps editor provided with dx to check whether the resolution you want is supported. If it's not it will not return a dd_ok.

2) Are u using the directx headers compiled for the cygnus gnu compiler? if u're not u may run into problems

I'm using DX5, my createsurface function requires only 3 parameters.  
0

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