[poppler] Fontconfig dependency for pdftops?

[Jonathan Kew]

On 19 Feb 2008, at 9:32 pm, Albert Astals Cid wrote:

> A Dimarts 19 Febrer 2008, Peter Åstrand va escriure:
>> On Sun, 10 Feb 2008, Peter Åstrand wrote:
>>> We are updating our "pdftops" from the one shipped with  
>>> xpdf-2.02pl1 to
>>> the latest poppler version. Is fontconfig a hard dependency  
>>> nowadays,
>>> even for tools like pdftops?
>>
>> I think I can answer this myself. Yes, it's a hard dependency, but  
>> it's
>> easy to get rid of. pdftops seems to work perfectly fine without
>> fontconfig, and the size of the resulting binary is greatly reduced.
>> Another great advantage is that the binary will be self contained  
>> and does
>> not require a fontconfig configuration.
>>
>> In GlobalParams.cc, there's a comment:
>>
>>  /* if you can't or don't want to use Fontconfig, you need to  
>> implement
>>     this function for your platform. For Windows, it's in
>> GlobalParamsWin.cc */
>>
>> However, the code in question is surrounded by "#ifndef _MSC_VER",  
>> which
>> is not very generic. The attached patch generalizes this and  
>> depends on
>> the define "DISABLE_FONTCONFIG" instead. Additionally, it provides  
>> a stub
>> implementation of getDisplayFont on UNIX, when fontconfig is not  
>> used.
>>
>> Any chance this patch can be accepted? In addition to making it  
>> possible
>> to build Poppler without fontconfig on UNIX, it also makes it  
>> possible to
>> build Poppler for Windows with MinGW, without Fontconfig.
>
> First a easy question:
>  * Do you really need that config.h includes in HtmlFonts.cc and
> PreScanOutputDev.cc?
>
> And now onto the core part of the mail. You are "wrong", pdftops uses
> PSOutputDev which does getDisplayFont calls in some situations, so  
> right,
> it's not a HARD dependency, but you most probably want it or those  
> situations
> won't work.
>
> So i'm actually not much keen of adding that patch, but if others  
> OK it, i
> think i could tolerate it if we add a big warning saying that  
> "FontConfig
> will not be used and PDF without embedded fonts will not work"

I've been using a similar -disable-fontconfig patch to (cross-) 
compile with MinGW for Windows. I also use it to build on Mac OS X  
without requiring fontconfig (which is not universally available --  
it depends whether the user has installed the optional X11 package),  
in a context where I don't need support for non-embedded fonts.

What I think should eventually be offered would be several choices  
for the font-finding system:

* fontconfig (available on all platforms, but not "native" on Win32  
or Mac OS X)
* GDI (only on Win32, but should be available for both MSVC and MinGW  
builds)
* Apple Type Services (only on Mac OS X, code still to be written)
* omit support for local fonts (issuing a warning at build time would  
be fine)

Which of these is used (on Windows and Mac) should be independent of  
which compiler is being used. So it is correct to distinguish the  
fontconfig vs GDI question from the _MSC_VER conditional, and expose  
this through configure, but I'd like to see further work in this  
area. If I can find the time, I'm hoping to write a Mac OS X version  
of the getDisplayFont one of these days.

JK