23 Feb
2008
23 Feb
'08
10:42 p.m.
Le 21 févr. 08 à 05:07, Sergiu Dumitriu a écrit :
We're currently using FOP to generate PDFs. FOP
cannot use DVIs (at
least not currently, with the available external resource plugins). It
does support some EPS.
Therefore I asked if drawing on some Graphics2D was doable as part of
that (I suppose it could be piped along with Batik's Graphics object
for example). We do have a dvi2svg tool already here.
We'd still be minimal in terms of installation... the TeX fonts only
and still not the TeX system.
However, using the TeX system brings some problems:
- there is a dependency on an external tool, as we cannot bundle a TeX
system.
No. That is the idea of using MathTran as a service... it's a remote
service.... currently the macro just generates the appropriate <img>
tags. All the PNG generation and TeX running is MathTran's.
For MathTran to do proper alignment it should be served from the
server so caching is being considered.
- TeX is pretty slow.
Damm less than FOP ! (;-)) (some FOP instances used TeX btw)
If it is used only for generating the PDF export of a
wiki
document with few equations, then that is not a major issue, since
exporting PDF is not something frequently done. But imagine using
it for displaying a document with several equations (>20), and how
long
it would take to make 20 shell commands to start TeX, generate the eps
files, load those files from the disk, and send them to the client. No
way this would work without a proper cache.
That is why MathTran is a TeX daemon... it seems to be able to make
at least hundreds expressions a second. Note... the i2geo server does
no rendering... it's all at mathtran's server at the open-university-
of-the-uk.
Another way to generate nice graphics from LaTeX
equations is by
combining these tools: one that converts LaTeX to MathML, and one that
converts MathML to something else.
MathML is surely very good and the MathML tool-set is far richer (see
MathML software section of w3.org/Math). I can attest this many times!
What's not rich enough to the taste of many mathematicians (and
cannot be fully rich since this language is not specified) is LaTeX
to MathML... the differences always byte TeX-experts. This is my sole
reason to push a pure TeX approach such as MathTran (aside of the
high-layout-quality).
As I indicated at other places I wish math-input would be in three
flavours:
- TeX because there will always be folks asking it
- some syntax (but which? Blahtex, which is known to cover the whole
wikipedia? itex2mml? LaTeXMML?) which goes to MathML-presentation for
supporting browsers (and pictures for others)
- a content-oriented syntax that produces OpenMath or MathML-content
(searchable, tooltippable, better-copy-and-pastable, ...).
In all these situations the TeX fonts are very often needed to do a
good quality rendering.
Should I rather stop the TeX approach (MathTran has limitations e.g.
with the usage of self-defined macros) and push more the MathML one?
It's basically about assessing the "eternal need for real TeX".
thoughts most welcome!
paul
The first tool is needed as LaTeX is not quite an open
standard. There
is only one fully supported compiler, and it has limitations. On the
other hand, MathML is interesting even as a final equation format, as
some browsers have support for it, although with some problems. But
there are many tools that work with MathML, viewers, editors,
converters...
Two candidates I found during a small Google session:
http://math.etsu.edu/LaTeXMathML/LaTeXMathML.js -> LaTeX => MathML
converter in JavaScript. The code should be converted to Java, so that
the whole process can be done in the native language for XWiki.
http://jeuclid.sourceforge.net/ -> MathML multipurpose tool. among
others, it has a MathML => PNG converter, and a FOP plugin to directly
support MathML in the XML source, which are preserved in the generated
PDF. This means that we don't need to separately convert equations
into
something else and then include some images in the PDF, but we can use
one XML file that contains all the XHTML source and the MathML
equations.
These tools can be combined into a Radeox filter + macro. The filter
allows a fast syntax, like $$\sum(i)$$, while the macro allows some
customization, like
{latex:align=right|zoom=2|background=yellow}\sum(i){latex}
Another TeX=>MML converter I found is BlahTeXML, but it is written
in C.
And the code is not so comprehensible, so porting it to java will be
harder. However, by comparing the size of blah and the js converter
above, I'd say that probably blah does a better job at the conversion.