= Command line =
You start Mark IV with the '''context''' command, and Mark II with '''texexec'''. The two programs are not the same, and even though they have mostly the same command line, there are some differences. Mostly, this is because '''context''' is still lacking a number of options of texexec like for example --passon (those will probably be implemented at some point in the future), but it also parses the command line
different. You must remember to always give the full name of the options, and then the effects should be almost unnoticeable.
= Parameter processing =
= Paragraph formatting =
Mark IV extends the
<cmd >definefontfeature </cmd> to make full use of the lua opentype engine by adding
'''mode=node''', and various opentype tags features that you want on or off. In the distribution, there is only one case of this:
\definefontfeature [arabic] [mode=node,language=dflt,script=arab,ccmp=yes, init=yes,medi=yes,fina=yes,isol=yes, liga=yes,dlig=yes,rlig=yes,clig=yes,calt=yes, mark=yes,mkmk=yes,kern=yes,curs=yes]
It should come as no surprise that such a '''mode=node''' generates different effects, but even with a traditional font setup there are incompatibilies unless you use tfm-only fonts, because the metric information of fonts used in Mark IV
Linebreaks can be different because full-blown UTF-8 hyphenation patterns are used.
HH: regimes still work so unless something is broken other encodings also should work but going utf8 is definitely wise
= Fonts and Typescripts =
Typescripts in Mark IV never specify any encoding at all (Unicode is mandatory)
= Metapost =
This means there are two things you have to watch out for:
# You should load the MP packages you need in
<cmd >startMPinclusions </cmd>.. <cmd >stopMPinclusions </cmd>; not inside a graphic.
# You have to make sure that you do not re-state equations that were already solved in a previous graphic.
These are in fact the exact same rules that you have to adhere to in
mkii if <cmd >runMPgraphicsfalse </cmd> is active.
Another difference is the way text is handled in
mkiv. In particular, color (<code>withcolor</code>)
is not applied to metapost text. For example,
currently does <b>not</b> work in
does work. This second solution works both in
mkiv and in mkii.
(Note that <code>\color[red]</code> can be abbreviated <code>\red</code>.)
= Images =
The official way of placing image in in
mkii way was
= Logos =
The logo commands (
<cmd >definelogo </cmd> c.s.) do not exist in mkiv; use layers instead.
= Itemizations =
<cmd >item </cmd> paragraphs (without enclosing list) are not allowed.
= Nomarking/Select =
<cmd >nomarking </cmd> is currently broken and will likely be removed from mkiv; use <cmd >select </cmd> instead: