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

[Nikolay Sivov]

On 4/24/22 08:47, Jin-oh Kang wrote:
> On Sun, Apr 24, 2022, 2:18 PM Jinoh Kang <jinoh.kang.kr at gmail.com> 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 <jinoh.kang.kr at gmail.com>
>>>> ---
>>>>
>>>> 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.
>>
>> 1. 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.
>> 3. 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.

Ok, I didn't realize we already do.

>
>
>> --
>> Sincerely,
>> Jinoh Kang
>>