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Diffstat (limited to 'systems/doc/luatex/luatex-fonts.tex')
-rw-r--r-- | systems/doc/luatex/luatex-fonts.tex | 47 |
1 files changed, 46 insertions, 1 deletions
diff --git a/systems/doc/luatex/luatex-fonts.tex b/systems/doc/luatex/luatex-fonts.tex index 400550a96d..136d20dd3b 100644 --- a/systems/doc/luatex/luatex-fonts.tex +++ b/systems/doc/luatex/luatex-fonts.tex @@ -1,4 +1,4 @@ -% language=uk +% language=uk engine=luatex \environment luatex-style @@ -861,6 +861,51 @@ value is the index in \type {font.fonts}, the second the font itself, as a \LUA\ table. The indices are listed incrementally, but they do not always form an array of consecutive numbers: in some cases there can be holes in the sequence. +\startsubsection[title={\type{\glyphdimensionsmode}}] + +Already in the early days of \LUATEX\ the decision was made to calculate the +effective height and depth of glyphs in a way that reflected the applied vertical +offset. The height got that offset added, the depth only when the offset was +larger than zero. We can now control this in more detail with this mode +parameter. An offset is added to the height and|/|or subtracted from the depth. +The effective values are never negative. The zero mode is the default. + +\starttabulate[|l|pl|] +\DB value \BC effect \NC\NR +\TB +\NC \type {0} \NC the old behavior: add the offset to the height and only subtract + the offset only from the depth when it is positive \NC \NR +\NC \type {1} \NC add the offset to the height and subtract it from the depth \NC \NR +\NC \type {2} \NC add the offset to the height and subtract it from the depth but + keep the maxima of the current and previous results \NC \NR +\NC \type {3} \NC use the height and depth of the glyph, so no offset is applied \NC \NR +\LL +\stoptabulate + +\stopsubsection + +\startsubsection[title={\type {\discretionaryligaturemode}}] + +This parameter controls how complex ligatures interact with discretionaries (as +injected by the hyphenator). The non||zero values prevent the construction of +so called init and select discretionaries. + +\definefontfeature[ligmodetest][default][mode=base] +\definefont [ligmodefont][Serif*ligmodetest] + +\hyphenation{xx-f-f-i-xx} + +\starttabulate[|p|p|p|] + \DB 0 \BC 1 \BC 2 \NC \NR + \TB + \NC \ligmodefont \discretionaryligaturemode0 \hsize1pt xxffixx + \NC \ligmodefont \discretionaryligaturemode1 \hsize1pt xxffixx + \NC \ligmodefont \discretionaryligaturemode2 \hsize1pt xxffixx \NC \NR + \LL +\stoptabulate + +\stopsubsection + \stopsection \stopchapter |