Re: Fonts (2) -> problems with GSFontAntiAlias 'YES'

[Pascal Bourguignon]

Fred Kiefer <FredKiefer@gmx.de> wrote:
> 
> Perhaps I should explain a bit more on how the current Anti-Alias font
> implementation works and which limitations are caused by this.
> 
> This code was a hack that I came up with kust to see if there is any
> demand for better fonts in the GNUstep community or if this is only a
> low priority addon.
> Currently the available fonts are determined by the font cacher using
> the standard X font enumeration. This knows nothing about anti-aliasing
> and which fonts would support it. Than when a font is selected and AA is
> switched on the normal X name of the font is handed on to the AA font
> module that tries to create a font for this X name, if it does not find
> a suitable AA font it falls back on a standard AA font (or even a simple
> X font). SO what would be needed here is a separate font manager for the
> AA fonts that would run its own cacher, looking only at AA fonts. This
> manager could than know more about the available fonts and select a
> better one if the requested is not available.

Ok. That behavior is now understandable.


I would  say that  the AA fonts  are some different  representation of
some "same" non AA font. Only  that when the user choose the better AA
representations  of the  fonts, and  for the  specific  font currently
selected there  exist a AA  representation, then it's used  instead of
the normal  font, otherwise  we keep the  normal font. Some  fonts may
have  only AA  representations and  not be  available when  AA  is not
enabled though. 

That is, the fall  back should not be IMHO to a  standard AA font, but
to a normal font in the same family and typeface.

 
> This should explain your 3. problem and a way to solve it. What it does
> not account for is the first problem you are having. For this I will
> need some more information. Does this only happen for specific text?
> (E.g. some encodings might not be available for the AA fonts) I could
> not reproduce this with the standard GNUstep applications.
> 
> Cheers
> Fred

Well, I  last updated from CVS  on January 22th, and  now this problem
does  not  happen anymore.  Anyway,  I suspect  it  was  a problem  of
graphics  flushing to  the screen,  that I  believe has  been somewhat
addressed by recent changes by Adam I think.


> > > > When  I open the  Font Panel,  I get  a list  with about  60 different
> > > > fonts.  However,  in  the Preview  they  all  look  the same  but  the
> > > > following:
> > >
> > > I reverted the xgps backend to find fonts by pixel size. Please let me
> > > know if anything improves.
> > 
> > Yes and  no. I updated from CVS  12 yours ago (after  your email), and
> > tested  it now.  Here are  the results.  (See attached  window content
> > dumps).
> > 
> > I've found what  produced the bad results I got :  I had the following
> > default set: NSGlobalDomain GSFontAntiAlias 'YES'
> > 
> > When removing it, everything works as expected, I can change the fonts
> > and size  with the  corresponding defaults and  I don't get  any black
> > rectangle.
> > 
> > When I have NSGlobalDomain GSFontAntiAlias 'YES' set, then:
> > 
> > 1/
> > 
> > It  seems  that  for most  windows,  the  display  of the  text  halts
> > halfway.
> > 
> > For  the  menu,  I've seen  once  when  updating  slowly that  it  had
> > transitorily  the  state  of  black  rectangles,  then  the  text  was
> > overwritten.
> > 
> > For the  other windows, when  resizing the window, sometimes  the text
> > would appear  and sometimes it  would disappear, but this  state stays
> > untile the window is resized again.
> > 
> > Notably, for the open panel,  whatever navigation is done don't change
> > the state black rectangle or  text. Moving the window off-screen, then
> > back on-scren does  not change anything. The same  occurs for the Font
> > panel. When  I don't get  the black rectangles, it  previews correctly
> > the fonts.
> > 
> > The text in pop-up menus appears correctly.
> > 
> > It's probably the same bug than  that that don't display pictures in a
> > window when not running with a runloop. Note that in that case, moving
> > the window off-screen then on-screen would at least show the picture.
> > 
> > 2/
> > 
> > The  sizes are  correct.  The  NSFontSize default  is  not taken  into
> > account, but the other NS*FontSize are.
> > 
> > 3/
> > 
> > The same font  is used everywhere (seems to be Times)  but in the menu
> > title.
> > 
> > Thanks for the font size correction.


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