2009/5/2 Marc Hohl <address@hidden>:
I have made some observations concerning \glissando:
1) accidentals are not recognised properly; I know this is in the bug list
and there are workarounds,
see http://lists.gnu.org/archive/html/bug-lilypond/2005-08/msg00235.html
This isn't at all straightforward to fix (I had a stab at it a while
ago, and it's tricky to get the positioning correct on the right hand
side because the accidental changes the anchor point for the end of
the glissando.)
2) the glissando line between half steps should indicate the direction;
e.g. a glissando line between c and c# should raise a bit and not be
parallel to the staff lines;
3) in tablature, the glissando is always indicated upwards, but it should be
drawn in respect to the fret number;
e.g. 3/5\3, not 3/5/3;
Should (2) and (3) be considered as bugs? I have found a request from
9/2005:
Probably.
It should be quite easy to fix both problems with a callback for
'extra-dy (see below)
http://lists.gnu.org/archive/html/bug-lilypond/2005-09/msg00112.html
and it seems to me that this has been partly implemented
(the lines betweeen fret numbers are now sloped, so there _has_ been some
progress).
Are there any hints/workarounds to solve this problem?
>From the glissando you can get the left and right noteheads using
ly:spanner-bound, from which it's possible to retrieve the pitches. A
simple comparision of pitches should allow you to set the correct
return value for 'extra-dy.