copying DD surfaces

[sunnyl]

After blitting to the primary surface using BltFx (and using some of the effects), the result in the screen has those results, but the original surface (blitting source) doesn't. That means when the picturebox comes to be repainted, it will just blit the picture with no added effects. So the effects are pretty much lost.

What I've been trying to do is to make a copy of the primary surface back to the image surface so when the picture box is reblitted the effects are 'still there'. According to the DX7 SDK a primary surface can't be duplicated with DuplicateSurface, so I'm trying to get this to work:

    Dim imgDC As Long
    Dim imgSurfDC As Long
        
    imgSurfDC = imgBuffer.GetDC   'imgBuffer - surface of image
    imgDC = CreateCompatibleDC(0)
    SelectObject frmMain.picMain.hdc, imgDC
    
    'copy using blit
    BitBlt imgSurfDC, 0, 0, imgDesc.lWidth, imgDesc.lHeight, imgDC, 0, 0, vbSrcCopy

    'clean up and delete DCs
    imgBuffer.ReleaseDC imgSurfDC
    DeleteDC imgDC

I can't seem to get it to work, when the picture is repainted, the old image comes out, meaning the above copy code didn't do its work (no errors though). Or if I've got it completely wrong, what should I be doing?

[HarryW]

Why don't you use Blt or Blt Fast to copy the primary surface to another surface instead of using GetDC and BitBlt?

[sunnyl]

Thanks for the idea! Works great! Well...kind of

Call DX7.GetWindowRect(frmMain.picMain.hWnd, PrimaryRect)
retval = imgBuffer.BltFast(0, 0, Primary, PrimaryRect, DDBLTFAST_WAIT)

Since its using the co-ordinates of the picturebox relative to the screen, if I say, put half the picturebox behind the taskbar, the taskbar is copied as well.....bogus!!