Difference between revisions of "Mark IV"

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== Introducing Mark IV ==
 
== Introducing Mark IV ==
  
Mark IV is the name of the [[LuaTeX]]-aware part of ConTeXt; that is, when you use ConTeXt over the LuaTeX engine instead of PDFTeX or XeTeX. You run it with <code>texexec --lua</code>.
+
Mark IV is the name of the [[LuaTeX]]-aware part of ConTeXt; that is, when you use ConTeXt over the LuaTeX engine instead of PDFTeX or XeTeX. You run it with
  
The first public beta has been released on the 6th of August, 2007 and is readily available on [http://live.contextgarden.net/ ConTeXt Live]. It takes advantage of the amazing capabilities of LuaTeX and opens up a whole new world of possibilities, in particular with fonts.
+
context filename
  
How to [[install Mark IV]] is documented on a separate page.
+
There are fundamental differences between Mark IV and Mark II that you should be aware of. Many parts of ConTeXt have been redesigned from scratch making extensive use of the Lua programming language. And that is besides the heavy use of LuaTeX-only features in MkIV. As a result, there are a few intentional incompatibilities between the two ConTeXt versions. See [[MkIV Differences]] for these details.
  
== Sample code ==
+
The first public beta has been released on the 6th of August, 2007. Currently the easiest way to try it out is to install [[ConTeXt Standalone]].
  
Here are some examples of cool stuff you can do with Mark IV ([http://live.contextgarden.net/ test it!]).
+
It takes advantage of the amazing capabilities of LuaTeX and opens up a whole new world of possibilities, in particular with fonts.
  
=== Lua core ===
+
In the distribution the MkIV files have suffix 'mkiv'. There are also files with suffix 'mkvi' and more will follow. The most significant difference is that these files use a different (and still somewhat experimental) syntax.
  
The first thing you will want to test are the lua functions. Try
+
=== Mark VI ===
  
<texcode>
+
Mark VI is ''identical to Mark IV'' in every respect, except that when you define a new macro you can give parameters names instead of numbers. This make programming a great deal more pleasant. For example, instead of
\ctxlua{a = 1.5 ; b = 1.8 ; c = a*b ; tex.print(c) ;}
 
</texcode>
 
 
 
or the equivalent:
 
  
 
<texcode>
 
<texcode>
\startlua
+
\def\colortext[#1]#2%
a = 1.5
+
  {\color[#1]{#2}}
b = 1.8
 
c = a*b
 
tex.print(c)
 
\stoplua
 
 
</texcode>
 
</texcode>
  
You can also do more elaborate calculations with the lua <code>math</code> library:
+
you can write
  
 
<texcode>
 
<texcode>
\ctxlua{tex.print("$\string\\sqrt{2} = " .. math.sqrt(2) .. "$")}
+
\def\colortext[#color]#text%
 +
  {\color[#color]{#text}}
 
</texcode>
 
</texcode>
  
Note that the above works with any flavour of LuaTeX; nothing is actually ConTeXt-specific (except for <cmd>ctxlua</cmd> and <cmd>startlua</cmd>/<cmd>stoplua</cmd>).
+
To use Mark VI, add the comment {{code|1=% macros=mkvi}} as the first line of your file, or save the file with a {{code|.mkvi}} extension.
  
=== Fonts and typescripts ===
+
== Installation and maintenance ==
  
==== Good ol' typescripts ====
+
The Mark IV code needs to be configured before it is usable. [[Running Mark IV|This page]] explains how to do that.
  
Of course, Mark IV allows you to use typescripts as you've always done; for example:
+
== Troubleshooting ==
  
<texcode>
+
The environment variable TEXINPUTS has to be empty or unset. If not, you can get errors about "file/module/whatever not found".
\usetypescript[palatino]
 
\setupbodyfont[palatino,12pt]
 
effe fietsen 2: \input tufte $\sqrt{2}$ \eogonek
 
  
\sc effe fietsen 2: \input tufte $\sqrt{2}$ \eogonek
+
TEXINPUTS can *always* be a problem and really should not be used at all any more. It is a historical environment variable from the nineties, and it overrules just about every path in a modern texmf tree.
</texcode>
 
  
That's as simple as using a traditional ConTeXt typescript!
+
If you need something special, use TEXMFLOCAL or TEXMFPROJECT instead.
  
But ... how is it any different, then? Well, the difference is that in Mark IV, we can use an Opentype font directly, so that what is done here: when we want to use Palatino, the [[TeX Gyre]] equivalent (“Pagella”) is called and we can use its Opentype “features”; read on.
+
== Sample code ==
  
==== Opentype features ====
+
Here are some examples of cool stuff you can do with Mark IV.
 +
=== Lua core ===
  
A “feature”, in the Opentype jargon, is a set of rules describing changes in the appearance of the text. Hmm, that's not very precise. Let's show some examples. First of all, you have to know that features are referred to by 4-letter tags, and you will see this a lot. One of them is ‘smcp‘, for “small caps“. Let's consider the following Mark IV-only code:
+
The first thing you will want to test are the lua functions. Try
  
 
<texcode>
 
<texcode>
\definefontfeature[smallcaps][language=DFLT,script=latn,smcp=yes]
+
\ctxlua{a = 1.5 ; b = 1.8 ; c = a*b ; tex.print(c) ;}
\font\palasmallcaps=texgyrepagella-regular*smallcaps
 
\palasmallcaps This is a text in small capitals.
 
 
</texcode>
 
</texcode>
  
Here you basically define a (Mark IV) feature with the name ”smallcaps”, and associate it with the (Opentype) feature “smcp”. You have to specify which script you want to use it with; scripts in Opentype are also tagged with four letters, and “latn” is of course Latin.
+
or the equivalent:
 
 
Then you define a TeX font with that feature.
 
 
 
You can see what features are defined in a particular font with the following bit of code
 
  
 
<texcode>
 
<texcode>
\ctxlua
+
\startlua
{
+
a = 1.5
  fontname = 'texgyrepagella-regular.otf'
+
b = 1.8
 
+
c = a*b
  --[[ First read the font data.
+
tex.print(c)
    This makes heavy use of some of the Mark IV code]]
+
\stoplua
  tfmdata = fonts.tfm.read_and_define("file:" .. fontname, 655360)
 
  font = tfmdata.shared.otfdata
 
  if font
 
  then
 
    gsubfeatures = fonts.otf.analyze_features(font.gsub)
 
    gposfeatures = fonts.otf.analyze_features(font.gpos)
 
  end
 
 
 
  if gsubfeatures then
 
    table.sort(gsubfeatures) % We want our list sorted alphabetically!
 
    tex.sprint("\\rm GSUB features: \\tt ") % Beware: you don't want \rm to be interpreted by lua (\rm would yield carriage return + letter m)!
 
    for _, feat in ipairs(gsubfeatures)
 
    do tex.sprint(feat) tex.sprint(' ')
 
    end
 
  else tex.sprint("\\rm No GSUB features")
 
  end
 
  tex.sprint("\\par")
 
 
 
  if gposfeatures then
 
    tex.sprint("\\rm GPOS features: \\tt ")
 
    table.sort(gposfeatures)
 
    for _, feat in ipairs(gposfeatures)
 
    do tex.sprint(feat) tex.sprint(' ')
 
    end
 
  else tex.sprint("\\rm No GPOS features")
 
  end
 
}
 
 
</texcode>
 
</texcode>
  
It prints the list on the page. You'll notice there are two sets of features, each one of them defined in a different table of the Opentype font: the <code>GSUB</code> table (for Glyph SUBstitution) gives rules for replacing glyphs in certains circumstances (think of ligatures: f + i -> fi); the <code>GPOS</code> table (Glyph POSititioning) gives rules for moving glyphs (think of kerning: A + V -> A <kerning> V).
+
You can also do more elaborate calculations with the lua <code>math</code> library:
 
 
Incidentally, the above code gives some basic examples of LuaTeX programming, a mixture of both Lua and TeX programming with some special features (features in the general sense, not the Opentype one :-).
 
 
 
==== A (Complete) Typescript Example ====
 
  
 
<texcode>
 
<texcode>
\starttypescript [sans] [franklin]
+
\ctxlua{tex.print("$\string\\sqrt{2} = " .. math.sqrt(2) .. "$")}
 
 
    \definefontsynonym [FranklinBookRegular]  [name:FranklinGothicBookITC-Regular]  [features=default]
 
    \definefontsynonym [FranklinMediumRegular] [name:FranklinGothicMediumITC-Regular] [features=default]
 
    \definefontsynonym [FranklinDemiRegular]  [name:FranklinGothicDemiITC-Regular]  [features=default]
 
    \definefontsynonym [FranklinHeavyRegular]  [name:FranklinGothicHeavyITC-Regular]  [features=default]
 
 
    \definefontsynonym [FranklinBookItalic]  [name:FranklinGothicBookITC-Italic]    [features=default]
 
    \definefontsynonym [FranklinDemiItalic]  [name:FranklinGothicMediumITC-Italic]  [features=default]
 
    \definefontsynonym [FranklinHeavyItalic]  [name:FranklinGothicDemiITC-Italic]    [features=default]
 
    \definefontsynonym [FranklinMediumItalic] [name:FranklinGothicHeavyITC-Italic]  [features=default]
 
 
 
\stoptypescript
 
 
 
\starttypescript [sans] [franklin]
 
 
 
    \definefontsynonym [Sans]            [FranklinBookRegular] [features=default]
 
    \definefontsynonym [SansItalic]      [FranklinBookItalic]  [features=default]
 
    \definefontsynonym [SansBold]        [FranklinDemiRegular] [features=default]
 
    \definefontsynonym [SansBoldItalic]  [FranklinDemiItalic]  [features=default]
 
    \definefontsynonym [SansSlanted]    [SansItalic]          [features=default]
 
    \definefontsynonym [SansBoldSlanted] [SansBoldItalic]      [features=default]
 
    \definefontsynonym [SansCaps]        [Sans]                [features=smallcaps]
 
 
 
\stoptypescript
 
 
 
\definetypeface[franklin][rm][sans][franklin][default]
 
\definetypeface[franklin][ss][sans][franklin][default]
 
\definetypeface[franklin][tt][mono][modern]  [default][rscale=1.12]
 
\definetypeface[franklin][mm][math][iwona]  [default][rscale=1.02]
 
 
 
\setupbodyfont[franklin,ss,10pt]
 
 
</texcode>
 
</texcode>
  
==== Using System Fonts ====
+
Note that the above works with any flavour of LuaTeX; nothing is actually ConTeXt-specific (except for <cmd>ctxlua</cmd> and <cmd>startlua</cmd>/<cmd>stoplua</cmd>).
  
LuaTeX can see system fonts if you set the <code>OSFONTDIR</code> variable, for instance
+
=== Fonts and typescripts ===
  set OSFONTDIR=c:/windows/fonts//
 
 
 
[[Category:Fonts]]
 
[[Category:International]]
 
  
 +
This is detailed in [[Fonts in LuaTeX]].
  
 
=== More sample code ===
 
=== More sample code ===
  
 
Other examples of Lua(TeX) code are to be found on [[User:Luigi.scarso#Luatex_examples|Luigi's user page]] as well as [http://luatex.bluwiki.com/ http://luatex.bluwiki.com/]
 
Other examples of Lua(TeX) code are to be found on [[User:Luigi.scarso#Luatex_examples|Luigi's user page]] as well as [http://luatex.bluwiki.com/ http://luatex.bluwiki.com/]
 +
 +
[[Category:LuaTeX]]

Latest revision as of 08:24, 16 February 2020

Introducing Mark IV

Mark IV is the name of the LuaTeX-aware part of ConTeXt; that is, when you use ConTeXt over the LuaTeX engine instead of PDFTeX or XeTeX. You run it with

context filename

There are fundamental differences between Mark IV and Mark II that you should be aware of. Many parts of ConTeXt have been redesigned from scratch making extensive use of the Lua programming language. And that is besides the heavy use of LuaTeX-only features in MkIV. As a result, there are a few intentional incompatibilities between the two ConTeXt versions. See MkIV Differences for these details.

The first public beta has been released on the 6th of August, 2007. Currently the easiest way to try it out is to install ConTeXt Standalone.

It takes advantage of the amazing capabilities of LuaTeX and opens up a whole new world of possibilities, in particular with fonts.

In the distribution the MkIV files have suffix 'mkiv'. There are also files with suffix 'mkvi' and more will follow. The most significant difference is that these files use a different (and still somewhat experimental) syntax.

Mark VI

Mark VI is identical to Mark IV in every respect, except that when you define a new macro you can give parameters names instead of numbers. This make programming a great deal more pleasant. For example, instead of

\def\colortext[#1]#2%
   {\color[#1]{#2}}

you can write

\def\colortext[#color]#text%
   {\color[#color]{#text}}

To use Mark VI, add the comment % macros=mkvi as the first line of your file, or save the file with a .mkvi extension.

Installation and maintenance

The Mark IV code needs to be configured before it is usable. This page explains how to do that.

Troubleshooting

The environment variable TEXINPUTS has to be empty or unset. If not, you can get errors about "file/module/whatever not found".

TEXINPUTS can *always* be a problem and really should not be used at all any more. It is a historical environment variable from the nineties, and it overrules just about every path in a modern texmf tree.

If you need something special, use TEXMFLOCAL or TEXMFPROJECT instead.

Sample code

Here are some examples of cool stuff you can do with Mark IV.

Lua core

The first thing you will want to test are the lua functions. Try

\ctxlua{a = 1.5 ; b = 1.8 ; c = a*b ; tex.print(c) ;}

or the equivalent:

\startlua
a = 1.5
b = 1.8
c = a*b
tex.print(c)
\stoplua

You can also do more elaborate calculations with the lua math library:

\ctxlua{tex.print("$\string\\sqrt{2} = " .. math.sqrt(2) .. "$")}

Note that the above works with any flavour of LuaTeX; nothing is actually ConTeXt-specific (except for \ctxlua and \startlua/\stoplua).

Fonts and typescripts

This is detailed in Fonts in LuaTeX.

More sample code

Other examples of Lua(TeX) code are to be found on Luigi's user page as well as http://luatex.bluwiki.com/