bug#54564: 29.0.50; [PATCH] Use gsettings font rendering entries for pgtk builds

[Pieter van Prooijen]

Hi All, 

It took a fair bit of digging, but sub-pixel anti-aliasing on pgtk now
seems to work correctly.

The problem lies with the "source" operator set by pgtk when drawing a
font, this will take a particular execution path in the cairo glyph
compositor (using a mask image) which converts the colors created by
freetype for the sub pixel effect to greys-cale. Using the default
"over" operator takes a different path which preserves the colors. Note
that on small screens the difference between sub-pixel and grey-scale
rendering is hard to see, it's more pronounced on larger displays)

I've amended my gsettings patch with this change, only replacing the
operator for anti-aliased fonts in ftcrfont_draw, because I'm not sure
about its impact for non-anti-aliased fonts.    

I've also fixed the indent error, but couldn't find the non-breaking
space in the patch, it's perhaps caused by the mail program.

Regarding the copyright assignment, I've had no response after sending
in the questionnaire at
https://git.savannah.gnu.org/cgit/gnulib.git/plain/doc/Copyright/request-assign.future
to assign@gnu.org

Do you get sent a paper form of some kind which has to be filled in?
(I'm not at my home address atm so I will have missed that)

Kind Regards,

Pieter


On Fri, 2022-04-01 at 10:00 +0800, Po Lu wrote:
> Pieter van Prooijen <pieter.van.prooijen@teloden.nl> writes:
> 
> > Hi All,
> > 
> > Thanks for the review, I've updated the commit message and other
> > changes you mentioned in the attached patch (against
> > c5af19cba5924de89a38e7a177c07f42fd3cd543)
> > 
> > I've requested the form for the copyright assignment, but have not
> > received it yet, will send it in as soon as it arrives.
> > 
> > No progress yet on the problem with subpixel antialiasing, but it
> > doesn't look like a fontconfig issue, as a non-pgtk build from the
> > same
> > source works correctly, will have to dig deeper to find out what is
> > happening. 
> 
> Thanks.
> 
> > > > +   on the result.  */
> 
> Hmm... Is there an actual non-breaking space character here, or is your
> MUA munging the messages?
> 
> > +  if (dpyinfo_valid (first_dpyinfo))
> > +      store_config_changed_event (Qfont_render,
> > +                                  XCAR (first_dpyinfo-
> > >name_list_element));
> 
> You got the indentation wrong here.  The "s" in
> "store_config_changed_event" should be two spaces behind where it is
> now.
> 
> Otherwise, LGTM.  Hopefully the copyright paperwork can be finished
> soon.

0001-Use-gsettings-font-rendering-entries-for-pgtk-builds.patch
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