Re: [PATCH v4 4/4] shell32: Partially implement IShellItemImageFactory (icon only, no thumbnail).

[Jin-oh Kang]

On Sun, Apr 24, 2022, 2:18 PM Jinoh Kang  wrote:
> On 4/24/22 06:27, Nikolay Sivov wrote:
> > On 4/23/22 20:53, Jinoh Kang wrote:
> > > Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=52673
> > > Signed-off-by: Jinoh Kang
> > >
> > > Notes:
> > >      v1 -> v2: no changes
> > >           v3 -> v4:
> > >      - Remove patch "shell32: Factor out ShellItem_get_uiobject."
> > >      - Use IShellItem2_BindToHandler instead of factoring out
> > >        ShellItem_get_uiobject
> > >      - Use CreateCompatibleDC(NULL) instead of GetDC(NULL)
> > >      - Remove new dependency on win32u, use GetIconInfo instead
> > >      - Remove new dependency on windowcodecs, use gdiplus instead
> >
> > I probably missed earlier iterations, but why do you need to use gdiplus
>
> at all?
>
> Because you have to convert potentially-transparent HICON to HBITMAP with
> alpha channel, which is quite a complicated feat.
> - HICON can take many pixel formats, ranging from 32-bit ARGB and
>
> monochrome with mask.

s/and/to/

2. hbmColor and hbmMask combinations aren't exactly simple to handle.
> - Windows always seems to output a 32-bit ARGB bitmap. GDI routines alone
>
> aren't particularly suited for the task (GdiAlphaBlend works with PARGB,
> not ARGB).
>
> Only WIC and GDI+ has functions to handle most of these.

have*

Also, shellole.c already imports GDI+ APIs.
> --
> Sincerely,
> Jinoh Kang