Re: [ft-devel] FT_LOAD_FORCE_AUTOHINT and FT_LOAD_FORCE_AUTOHINT

[Derek Clegg]

Just to follow up a bit, it appears that part of my problem was my  
choice of flags to "FT_Load_Glyph" — since I wanted the glyph path in  
font units, I passed in "FT_LOAD_NO_SCALE |  
FT_LOAD_IGNORE_TRANSFORM".  It appears, however, that this ended up  
by-passing the hinter, and so my glyph paths were incorrect.  I'm not  
sure whether this is by design, however.

In any case, thanks again for your help.

Derek

On Jun 14, 2007, at 3:48 PM, Derek Clegg wrote:

> Thanks very much to you and Werner — this is excellent and very  
> helpful information.  I appreciate it a lot.
>
> Derek
>
> On Jun 10, 2007, at 4:47 PM, David Turner wrote:
>
> > Hello Derek,
> >
> > FreeType can return glyph paths for these fonts, but you need to
> > use either the patented or unpatented bytecode interpreter to get
> > correct results (auto-hinting or even no hinting will return
> > garbage). this means one of the following:
> >
> > - activate the patented bytecode interpreter (since you have an  
> > @apple.com
> >   e-mail address, I guess this shouldn't be a problem to you :o) )
> >
> > - the font face name is "recognized" by FreeType (which contains a  
> > hard-coded
> >   list in src/truetype/ttobjs.c). In this case, the font engine  
> > automatically
> >   uses the unpatented hinter when calling FT_Load_Glyph (unless  
> > you disable
> >   hinting, force auto-hinting, or use the "light" hinting mode)
> >
> > - you activate the unpatented hinter by using the appropriate  
> > parameter
> >   (FT_PARAM_TAG_UNPATENTED_HINTING) when calling FT_Open_Face. See  
> > Werner's
> >   last e-mail on the subject for the details.
> >
> > I've just added a new API called FT_Face_CheckTrueTypePatents that  
> > scans
> > *all* the glyph hints in a given TrueType fonts to see if they use  
> > any of
> > the patented opcodes. This should help you determine if you should  
> > use the
> > unpatented hinter or not.
> >
> > Note that this call is *slow* by design, since it parses the whole  
> > font file,
> > so caching its result is better.
> >
> > There is also now a program called "ftpatentcheck" in 'ft2demos'  
> > that can
> > be used to check wether a given font uses patented opcodes (still  
> > very rough,
> > but functional)
> >
> > I'll later try to add the ability to switch the unpatented hinter  
> > *after*
> > creating/opening a FT_Face; that should be more convenient to use.
> >
> > Hope this helps,
> >
> > - David Turner
> > - The FreeType Project  (www.freetype.org)
> >
> >
> > On Tue, 29 May 2007 10:04:26 -0700, "Derek Clegg"  
> > <address@hidden> said:
> > > On May 27, 2007, at 11:34 PM, Werner LEMBERG wrote:
> > >
> > > > Whatever font it is, the images do *not* show `PMingLiU' from
> > > > mingliu.ttc!  This font can't be displayed with the autohinter  
> > > > because
> > > > the glyph components need the bytecode interpreter to be positioned
> > > > correctly.  Please always use ftview, ftstring, or ftdiff to  
> > > > inspect
> > > > the font.  At the font size you are showing, mingliu.ttc contains
> > > > embedded bitmaps to improve the rendering, BTW.
> > >
> > > Can FreeType return glyph paths from mingliu and other fonts which
> > > need the bytecode interpreter for positioning?  In my experiments,
> > > I've failed to get correct results, but that may be my error  
> > > &#8212; I may
> > > not have supplied the correct combination of build parameters and
> > > flags.  In my case, I'm only interested in the path, not bitmaps.
> > > Thanks for any info!
> > >
> > > Derek
> > >
> > >
> > >
> > > _______________________________________________
> > > Freetype-devel mailing list
> > > address@hidden
> > > http://lists.nongnu.org/mailman/listinfo/freetype-devel
>
>
>
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