[MSW] Masks mirrored in RTL

[xeee]

When I run the contrib editlbox sample in RTL mode, the button images don't look right, after some investigation I found out that masks are mirrored horizontally, unfortunately I'm not experienced with GDI, I really spent a lot of time trying to fix this bug but I couldn't.
I don't know whether the bug happens with anything else, but I assume it does, at least with other XPM images, I'm not sure that it's MSW-only, but I assume so.

If someone guides me in the right direction, I'm ready to put more effort trying to solve this bug.

you can find images of the sample in both RTL and LTR mode.

[xeee]

RTL to the left, LTR to the right.

[catalin]

This one (using "contrib editlbox sample") is most probably not about wxW sources.

[vadz]

It is, this contrib was moved into wx itself, see source:wxWidgets/trunk/include/wx/editlbox.h​.

The problem here is that I thought bitmaps were supposed to be mirrored in RTL, so I'm not sure if the problem is that the masks are mirrored or that bitmaps themselves are not...

[catalin]

AFAICS in wxW the bitmaps are not rotated for RTL layout. Nor are they in Firefox, Opera, LibreOffice.
The problem here looks like it is with the mask. If the drawing is done without using the mask (in wxAnyButton::MSWOnDraw), the results are identical.
Test patch attached.

[vadz]

Thanks for debugging, I've fixed this locally (the bug is at wxDC level, we don't use the same layout for the temporary memory HDC we create as for the main one) but while doing it I found #15031 so it's not like RTL is usable in wxMSW currently :-(

[VZ]

(In [73484]) Fix drawing of bitmaps with masks in mirrored wxDC.

The mask must be mirrored in the same way as the main bitmap itself (currently
it's not mirrored at all but this could change in the future), so create the
temporary memory HDC with the same layout as is used by the main HDC.

Closes #3995.

[VZ]

(In [73488]) Don't call ::GetLayout() in wxMSW code directly.

Use wxMSW::GetLayout() wrapper to avoid directly binding to a function not
present in old Windows versions and also to fix linking errors with MinGW
after the changes of r73484.

See #3995.