Hagen - Pragma ADE

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\font \MyFontG = lmr12 sa 1.2
This method is not part of T E X but is provided by ConT E Xt, MkII as well as MkIV. It means
as much as “scale this font to 1.2 times the bodyfontsize”. As this involves parsing the
specification, it does not work as advertised here, but the next definition works okay:
\definefont[MyFontG][lmr12 sa 1.2]
This indicates that we already had a parser for font specifications on board which in
turn made it relatively easy to do even more parsing, for instance for font features as
introduced in X Ǝ T E X and LuaT E X.
3.2 Specifications
In LuaT E X we intercept the font loader. We do so for several reasons.
• We want to make decisions on what file to load, this is needed when for instance there
are files with the same name but different properties.
• We want to be able to lookup by file, by name, and by more abstract specification. In
doing so, we want to be as tolerant as possible.
• We want to support several scaling methods, as discussed in the previous section.
• We want to implement several strategies for passing features and defining non standard
approaches.
The formal specification of a font is as follows:
\definefont[PublicReference][filename]
\definefont[PublicReference][filename at dimension]
\definefont[PublicReference][filename scaled number]
We already had that extended to:
\definefont[PublicReference][filename]
\definefont[PublicReference][filename at dimension]
\definefont[PublicReference][filename scaled number]
\definefont[PublicReference][filename sa number]
So let’s generalize that to:
\definefont[PublicReference][filename scaling]
And in MkIV we now have:
\definefont[PublicReference][filename*featurenames scaling]
\definefont[PublicReference][filename:featurespecication scaling]
\definefont[PublicReference][filename@virtualconstructor scaling]