updated luatex manual

git-svn-id: svn://tug.org/texlive/trunk@57746 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 23 insertions, 0 deletions

diff --git a/Master/texmf-dist/doc/luatex/base/luatex-enhancements.tex b/Master/texmf-dist/doc/luatex/base/luatex-enhancements.tex
index b81e1dbdae5..537961661f5 100644
--- a/Master/texmf-dist/doc/luatex/base/luatex-enhancements.tex
+++ b/Master/texmf-dist/doc/luatex/base/luatex-enhancements.tex
@@ -1266,6 +1266,29 @@ related primitives.
 
 \stopsubsection
 
+\startsubsection[title={\prm {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 behaviour: 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
+
 \stopsection
 
 \startsection[title={Control and debugging}]