When you save a drawing to disk, jPicEdt writes the drawing content twice,
Since both the XML code and the LaTeX code reside in the same file, the whole block of XML code is commented out by a percent symbol so that the file can be properly compiled by LaTeX. The XML code allows jPicEdt to reload the drawing without losing even the tiniest piece of information, a feature which the PSTricks format alone (not to speak about the eepic format) would not guarantee.
Therefore, when parsing input files, jPicEdt first tries to look for a JPIC-XML preamble. If it's there, then the drawing is rebuilt solely by parsing the XML code (this means that any changes made to other parts of the file have no effect). Otherwise (which is the case if you're loading a picture written by hand or by another LaTeX-capable software like GnuPlot, or if you deleted the XML code), jPicEdt delegates to an embedded LaTeX parser which currently supports three LaTeX formats, namely the standard picture environment, the eepic package, and the PSTricks package (all three can be combined into a single file, for that matter, except that only the first begin{(ps)picture}...end{(ps)picture} declaration is considered). The LaTeX parser can handle a variety of, say, syntax deviations, and you needn't worry too much about whether your syntax is perfectly LaTeX-, eepic- or PSTricks- compliant or not, since the parser will issue a pretty informative message as soon as it finds a syntax error, an incorrect format number, etc... However, we strongly encourage you to follow these rules :
\unitlength
or a \psset{unit=xxx}
(or xunit, yunit, runit)
command at the very beginning of your file, or at least before the
first command you want to be processed ; it not, default unitlength will be
assumed, e.g. 1cm for PSTricks until one of these commands are found.
\multiput
(and its PSTricks equivalent) are not handled yet. I know there's
been steady pressure toward supporting add-ons, but it's tricky, i tell you...
\psset
commands) won't interfere
with LaTeX or eepic ones (e.g. linethickness
).
\end{picture}
(or its equivalent for PSTricks) is found.