Hi, i have problems initializing my Directdraw object. I want to have an object which has only one primary surface and no backbuffers. Here''s my code: // Create the primary surface with 1 back buffer memset(&ddsd, 0, sizeof(ddsd)); ddsd.dwSize=sizeof(ddsd); ddsd.dwFlags=DDSD_CAPS | DDSD_BACKBUFFERCOUNT; ddsd.ddsCaps.dwCaps=DDSCAPS_PRIMARYSURFACE | DDSCAPS_FLIP | DDSCAPS_COMPLEX; ddsd.dwBackBufferCount=1; hRet=g_pDD->CreateSurface(&ddsd, &g_pDDSPrimary, NULL); if (hRet!=DD_OK) { TRACE("Could not create primary surface - error code %d\n", hRet); return false; } I have tried to set dwBackBufferCount to 0 but this didn''t work. When i try to lock the primary surface, i get an DERR_INVALIDPARAMS, and i guess it''s due to this initialization. Can anyone help me please? Thanks, Chris

Try doing like this instead...

memset(&ddsd, 0, sizeof(ddsd));
ddsd.dwSize=sizeof(ddsd);

// enable valid fields
ddsd.dwFlags = DDSD_CAPS;

// request primary surface
ddsd.ddsCaps.dwCaps = DDSCAPS_PRIMARYSURFACE;

// create the primary surface
hRet = g_pDD->CreateSurface(&ddsd, &g_pDDSPrimary, NULL);
if (hRet!=DD_OK)
{
TRACE("Could not create primary surface - error code %d\n", hRet);
return false;
}

Thanks, this works. My problem is that i always tried to lock() the primary surface and i needed some time to figure out that the primary surface can''t be locked...

Therefore another question: Why can''t the primary surface be locked? Sure, this is a decision of the guys at microsoft, but i don''t see the advantage of this...

Chris

Everybody can lock but me

OK, i create my primary surface as written above, and then try to lock it:

HRESULT hRes;
DDSURFACEDESC2 DDSurfaceDesc;
hRes=g_pDDSPrimary->Lock(NULL, &DDSurfaceDesc,
DDLOCK_SURFACEMEMORYPTR | DDLOCK_WAIT, NULL);
if (hRes!=DD_OK) {
TRACE("Could not lock - return code %d\n", hRes);
return false;
}

The error value is INVALID_PARAMETER. What am i doing wrong?

Chris

You might want to try...

//==========================================
DDSURFACEDESC2 surfaceDesc;
memset (&surfaceDesc,0,(sizeof(surfaceDesc)));
surfaceDesc.dwSize = sizeof (surfaceDesc);
//========================================

before passing the DDSURFACEDESC to Lock.

/ Tooon