the technique to do 90 degree rotations using only Blt is described in an
IEEE Computer Graphics and Applications, Oct 1987 or 1988 iirc.
> do the caps indicate this card/driver support rotation?
> if not, its not supported.
> these features were not well supported, its probably best to perform the
> rotation another way.
> hint: 90 degree rotations can be done using only Blt. 180 is just 2 90
> degree rotations.
> > Hello
> > I am using VC++6.0 and DirextX 8.1
> > When I blt the image without rotation all works well.
> > Want to blt an image with DDXF, and get the ERROR
> > DDERR_NOROTATION
> > Is there an error in my source?
> > Or can I simulate this behaviour?
> > Regards Remo
> > Source:
> > DDBLTFX ddx;
> > memset(&ddx,0,sizeof(DDBLTFX));
> > ddx.dwSize=sizeof(DDBLTFX);
> > ddx.dwDDFX=DDBLTFX_ROTATE180;
> > DWORD nFlag=DDBLT_DDFX;
> > ehr=m_pDDobject->m_primary.Blt(&m_rcControlPos, m_visibleMap,
> > &mySrc,nFlag,&ddx);