[Fontconfig] Re: [Cairo] Text API proposal
keithp at keithp.com
Tue Aug 12 10:04:54 EST 2003
Around 18 o'clock on Aug 11, Owen Taylor wrote:
> I don't think even linking to FreeType on, say, Windows is right; for
> various reasons:
Hmm. I'm thinking of applications that want to generate identical results
on every system; using different font mechanisms makes that very difficult.
One obvious such application is a cairo test suite...
> - Having cairo_font_t be polymorphic on a single system is going
> to be confusing and lead to problems where people assume that
> a font *must* be a cairo_font_win32_t.
Hmm. Perhaps we don't need a 'cairo_font_win32_t'; all we really need is
the ability to convert from an FcPattern to a windows font handle (HFONT?)
> It isn't a bad idea to allow people to plug in a new font
> system on the fly if they are doing something really custom, but
> having two font systems always there is rather peculiar.
Hmm. That means that cairo applications will only be portable if they use
the trivial interface; those using lower level interfaces will need system
specific code. I think this means we should build an intermediate
interface that provides enough flexibility for "reasonable" applications
to succeed without needing operating-system specific code. I think it
should be possible to have an application like Mozilla run on top of the
> This is an appealing choice, as long as the goals mentioned in my last
> mail are possible: consistent list of fonts with the system, and minimal
> overhead when not used.
I believe we can map fontconfig patterns to windows font selection
structures. Some functionality may be lost; I don't believe Windows has
any notion of language support in the font infrastructure.
> Does this intermediate state of caring make sense? You shouldn't get one
> rasterization if you "don't care" or "really care", and a different
> rasterization if you "kind of care".
Instead of 'kinda care'/'really care', I should have said 'prefer portability'/
'prefer native fonts' -- it's a question of whether applications should be
forced to support win32 fonts when freetype could just as easily be
> What do you mean by an "abstract interface"? Do you mean a generic
> interface that goes beyond being useful for don't-care applications?
Yes. I don't want to provide a complete interface that masks the
differences between FreeType and Win32. That seems like a bad plan...
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