bug#10399: [PATCH] Document win32 font backends

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 31 Dec 2011 03:04:42 -0800
> From: Daniel Colascione <dancol@dancol.org>
> CC: lekktu@gmail.com, 10399@debbugs.gnu.org
> 
> The C compatibility issue arises from a problem with the header for
> the COM interface produced by the IDL compiler (probably, nobody tried
> to actually use DirectWrite from C before shipping.)  This problem
> doesn't prevent our using DirectWrite from C: as the MSDN comment
> indicates, the declarations just need to be extracted and rephrased as
> standard C.
> 
> > Also, I see no dwrite.h header in the MinGW runtime and w32api
> > distributions, and no lib*.a import libraries for dwrite.dll.  Am I
> > missing something?
> 
> No. Either these packages would need to be updated to include
> DirectWrite or we'd need to just include declarations for the
> appropriate functions and interfaces ourselves.

If a MinGW build of Emacs can use DirectWrite, and if there will be no
copyright issues with providing the missing headers and interface
libraries, then feel free to work on adding DirectWrite support to
Emacs.  Thanks in advance.