I recently in learning, directdraw when using the following function to display a picture of a big reduced, image is a little distortion M_pddsFrontBuffer - & gt; Blt (& amp; RtDest m_pddsStoreBuffer, & amp; RtSrc DDBLT_WAIT, & amp; DDBLTFX);
And under the GDI, by setting for HALFTONE pattern after call StretchBlt to zoom in, the effect will be much better than the above use directdraw PDC - & gt; SetStretchBltMode (HALFTONE); PDC - & gt; StretchBlt (l, t, w, h, this, l, t, w, h, SRCCOPY);
So in directdraw is also what the same method, to control the quality of the image zooming