Re: [PING] ClearType Patch

[Eli Zaretskii <eliz@gnu.org>]

> From: David Abrahams <dave@boost-consulting.com>
> Cc: emacs-devel@gnu.org
> Date: Wed, 08 Jun 2005 11:46:58 -0400
> 
> Sorry, but I have a lot on my plate, so once I start waiting a few
> more days it's likely to drop off my radar screen.

We all need to cope with this.

> Agreed, but I think the use of -D_WIN32_WINNT=0x0400 on the compiler
> command-line may be similarly bad (and is the reason I transcribed
> those constants).

Jason, could you perhaps tell why this compiler switch is used?  If
that is because we don't want to use features that are unavailable in
older versions of Windows, we could replace that with run-time checks,
like the one I suggest below, can't we?

> SPI_GETFONTSMOOTHING
> 
>   This one is in fact available for _WIN32_WINNT == 0x400; I should
>   have used it directly.
> 
> SPI_GETFONTSMOOTHINGTYPE
> FE_FONTSMOOTHINGCLEARTYPE
> 
>   These two are only enabled for _WIN32_WINNT >= 0x0501
> 
> 
> > where they are defined,
> 
> WinUser.h, IIRC

The MinGW version of winuser.h doesn't have them; perhaps that's a
MinGW bug.  So I think we need to condition the code on
SPI_GETFONTSMOOTHINGTYPE being defined, or perhaps provide a fallback
definition in src/s/ms-w32.h for MinGW.

> > Finally, MSDN seems to indicate that SPI_GETFONTSMOOTHINGTYPE is
> > unsupported on Windows 9x, so it sounds like your code should be
> > disabled for those versions of Windows.
> 
> Right, I should use an #ifdef _WIN32_WINNT >= 0x0501 ... except of
> course that the build process subverts that by forcing _WIN32_WINNT to
> 0x400.

I meant a run-time check, not a compile-time check (because Emacs
built on XP could then be run on Windows 98, for example: think binary
releases).  We have a global variable os_subtype which can be used for
such a run-time test, I think.

> > A ChangeLog entry for the patches would also be nice, btw.
> 
> I will be happy to write one.  I assume the format to follow is used
> in the ChangeLog file at the top of emacs' CVS tree?

Yes.  And in addition, the GNU Coding Standards (standards.texi) which
you can find on the GNU Web site, has a section about writing
ChangeLog entries.

TIA