[AD] bug? blit_[to/from]_hdc()

[aj <aj@xxxxxxxxxx>]

using Wip 4.1.0 [20020713], MSVC 6, win2k sp2, 16bit desktop, gfxcard = 
GeForce2MX.


Here's what i do...

  // create a 16bit map.
  BITMAP* map16 = CreateBitmapEx(16,100,100);

  // grab a 100x100 from hdc, onto map.
  blit_from_hdc( hdc, map16, 0, 0, 0, 0, 100, 100 );

  // blit the map back to the same spot.
  blit_to_hdc( map16, hdc, 0, 0, 0, 0, 100, 100 );



What happens:

  the screen colours change, the green channel is out by 4.
  say i have some desktop colours [r,g,b]  45,181,23
  i run this code (above), and i get [r,g,b]  45,177,23

  i tried running  set_gdi_color_format()  late into
  my program, and it did not help, i also tried calling it
  as the next statement after allegro_init()
  just as the documenation describing the
  set_gdi_color_format() says to, and still it did
  not help.


the only thing that i could find that did not seem right was 
in  /allegro4.1.0/src/win/gdi.c    in method func named

BYTE get_dib(BITMAP * bitmap)

the code for 15bit packed pixel conversion,  and the code for 16bit packed 
pixel conversion looks very similar.
maybe the shifting is off by one or maybe 2 in this case,  coz isn't the 
green channel a different size for 15bit and 16bit code ?


aj.