Re: [Devel] [SF BUG#473296] No support for MS composit glyphs

[David Turner]

Hi Antoine,

Antoine Leca a écrit :
> 
> Hi guys,
> 
> I was reviewing SourceForge, and I noticed a looooooooong list of bugs
> there, most if not all without any commitment.
> I then decided to copy them here, to make them able to be handled.
> Expect several messages from me, but please don't ask me to solve any
> questions, nor flame me with bad description or bad assumptions, I made
> NO attempts to check or validate anything, or whatever you may ask for
> a proper bug report.
>
Thanks, I though that I _already_ closed the SF bug tracker since I
wasn't able to force it to send bug reports via e-mail to this list
(and I just checked it, the preferences are correctly set !$@&!!)

Anyway, as Werner already pointed out, SourceForge is not very convenient
to use if you don't have a permanent link to the Internet so for now, the
best way we can do is to maintain our own hand-crafter database, which
is the file "docs/BUGS" introduced recently in the CVS tree..

I'll try to update it with the SF bug reports and see what can be done
to fix them..
 
> Since this bug seems to be signed, I cc:ed what seems to be the author,
> "George Williams". To him, I should make clear that the SF bug tracker
> system is NOT the place to report bugs (BTW, David, probably we should
> close it).
>
Yep, I just closed it (well, _tried_ too, since it's SF !!)

 
> Antoine
> 
> Category: FT2 truetype driver
> 
> I notice that truetype/ttgload.c only supports Apple's
> definition of offsets for composit glyphs. Apple and
> Microsoft behave differently if there is a scale
> factor. OpenType defines some bits to disambiguate.
> 
> (a problem in both 2.0.4 and 2.0.5)
> 
> Apple says
> (http://fonts.apple.com/TTRefMan/RM06/Chap6glyf.html)
> that if flags&ARGS_ARE_XY is set then the offsets
> should be scaled by the scale factors (as you have
> done), but they also say something very cryptic about
> what happens when the component is rotated at 45°
> (which you do not support)-- See the "Important" note
> at the bottom.
> 
> The old truetype spec from Microsoft did not mention
> this. The OpenType spec
> (http://www.microsoft.com/typography/otspec/glyf.htm,
> http://partners.adobe.com/asn/developer/opentype/glyf.html)
> efines two new bits to disambiguate:
> SCALED_COMPONENT_OFFSET 11
> Composite designed to have the component offset scaled
> (designed for Apple rasterizer)
> UNSCALED_COMPONENT_OFFSET 12
> Composite designed not to have the component offset
> scaled (designed for the Microsoft TrueType rasterizer)
> 
> Perhaps you could add a load_flag to allow the user to
> define the default setting?
>

Wow, I was not even aware of this, it will probably take a little
time to implement since I don't have any font that implement these
"features", and also because I believe that we're running out of
bits for "load_flag", some other way to set preferences is probably
needed..

- David