[GD-Windows] In memory bitmap to HBITMAP

[Brian H. <bri...@py...>]

I'm struggling with something fairly basic -- I want to load a BMP out
of a compressed file, convert to an HBITMAP, then blit it into a DDraw
surface.  I know how to do the first and last part, but the middle is
causing problems.  Even worse, I'm not getting any errors.

Loading the bitmap doesn't seem to be a problem.  I load it up and parse
and find the BITMAPFILEHEADER and BITMAPINFOHEADER no probs.  I also
locate the raw bits no problem (and inspect with the debugger to make
sure I'm getting what I think I'm getting -- in this case, solid
magenta).  Looks fine.

The next step is to create a DC compatible with the desktop:

HDC hDC = CreateCompatibleDC( NULL );

I then create a HBITMAP compatible with DC, and using the bits I pulled:

HBITMAP hbm;

hbm = CreateDIBitmap( hDC, lpBMIH, CBM_INIT, lpBits, lpBMIH,
DIB_RGB_COLORS );

lpBMIH are simply pointers to the appropriate BITMAPINFOHEADER.  They
have correct values in them.  The bitmap is returned successfully.

To verify things, I grab the bits out of the Bitmap to make sure
everything is cool:

GetDIBits( hDC, hbm, 0, iHeight, tempbuffer, &bmi, DIB_RGB_COLORS );

It returns the correct number of scan lines, but tempbuffer is filled
with black.  This means either the CreateDIBitmap() filled in the bitmap
with black, or the GetDIBits() failed somehow.  I can't figure out which
is the real culprit, but the bitmap is pretty much a black square.

Any suggestions on how to hunt this down?