[Devel] Re: FreeType and Type 1C fonts

[David Turner]

Hi Ken,

Ken Carpenter a écrit :
> 
> Hello, I came across the FreeType project recently, and
> had a couple of quick questions which I couldn't find
> answers for on the web site.
> 
> I have a Java-based PDF renderer that currently works
> quite nicely for TrueType fonts, but cannot handle
> Type 1 or Type 1C fonts under Java.
> 
> 1. Does FreeType support Adobe Type 1C fonts?  These seem
>    to be the preferred format within PDF files.
>
FreeType supports the format known as "CFF", which probably
is the thing that you call Type 1C. Several people are already
using it to manage fonts in PDF files actually..
 
> 2. Do you know if anyone else has used FreeType from Java?
>    I was planning on writing a Java Native Interface (JNI)
>    wrapper for FreeType if it supports Type 1C fonts, but
>    I don't want to reinvent the wheel if someone else
>    has already done it.
>
I believe that someone started a re-implementation (not a binding)
in Java for FreeType 1.x, but it was a long time ago and I don't
know what it became..

Regarding FreeType 2, no-one has been working on a Java binding
yet, or at least announced it ! Please feel free to start
this interesting challenge :-)

> 3. Are there any performance metrics for FreeType with
>    particular caching scenarios?  I would most likely be
>    caching only outlines, and not rendered characters
>    since I want true sub-pixel rendering (i.e., in the
>    sequence 'ee', each letter 'e' could have a different
>    set of coverage values).  Right now the Java code is
>    just too slow (over a second for a full page of 8-pt
>    text).  FYI, it seems to be the compositing that is
>    taking most of the time, not the rasterizing.
>
Well, you can still try the demo program called "fttimer", 
which will report rasterization speeds both in monochrome
and anti-aliased modes. The rasterizer is very fast in
my opinion, but you could also cache pixmaps in certain
cases (typically for small pixel sizes, use a small bitmap
cache).

FreeType 2 comes with a caching sub-system. It's just that
it's not fully documented yet, given that I could not find
the time to improve it as I intend to. I don't know if it'd
be a good idea to use it in a Java binding though..

I'd rather try to provide something that is as close as
possible to what FT2 provides, i.e. a font service..
Java2D seems a very interesting graphics library, and I'm
pretty certain you'd better use it (as well as the usual
Java high-speed containers) to perform your
caching/blitting.

Of course, if the compositing is the problem, there is
nothing you can really do to solve that within FT2 :-)

Regards,

- David