Re: [Devel] freetype layout -- Where?

[David Turner]

Hi Tobias,

Tobias Hunger a écrit :
> 
> Hi!
> 
> Any pointers to any docs/wishlists/featurelists/anything about ftlayout?
> I need that library:-) What can I do to help?
>

Don't expect any real code before _lots_ of months :-)

However, I've come to the following ideas during my research
on FT Layout:

  - heavily Unicode-biased.

  - only supports UCS4 (i.e. 32-bit Unicode charcodes), for the
    sake of simplicity, performance and reliability. It's much
    better to ask the client developer to perform decompression
    and, most importantly, validation, itself..

  - provides "styles" (i.e. grouped attributes) that can be
    applied to text runs. Attributes should be modeled around
    CSS2 whenever possible. The idea is to make "rich text"
    particularly easy to implement with FT Layout.

    (For a better idea, have a look at ATSUI, i.e. Apple Text
     Layout Engine)

  - we'll most probably start using UCI as the back-end for
    most layout operations, since this code is very good..
    I imagine we're going to re-use some parts of Pango too
    [1].

  - the text layout library will depend on external providers
    for things like font installation lists, font metadata
    (e.g. which languages are really supported, advanced layout
     tables, etc..).

    This is currently a major detail of the implementation,
    actually..


  - no rendering support (though some routines will probably
    be implemented to support underlining, strike-through and
    a few other similar effects..)

Any comments ??

- David

[1] We can't use Pango, since it relies on GLib which happens
    to automatically abort programs when a memory exhaustion
    occurs.. !! but since FT Layout will be released under the
    LGPL, we'll be able to share code with it..

PS: I suggest you to look at UCI for Berlin, since it's written
    in C++ and works pretty well right now..