Issue 1692 in lilypond: Spanner::calc_normalized_endpoints is broken for line-spanners

[lilypond]

Status: New
Owner: ----

New issue 1692 by address@hidden: Spanner::calc_normalized_endpoints  
is broken for line-spanners
http://code.google.com/p/lilypond/issues/detail?id=1692

Spanner::calc_normalized_endpoints will fail for all but the least complex  
line spanners.  Various aspects of the line spanner, such as its padding,  
arrows, and additional stencils are not taken into account when  
normalized-endpoints is calculated.

To fix this, I propose that a large chunk of logic in Line_spanner::print  
be moved to Line_spanner::calc_bound_info and that Spanner::spanner_length  
be modified to first search for bound info before calculating length.

My composition slate is pretty full these days, so if anyone has the  
will/desire to fix this, I'd very much appreciate it.  It'd be a great  
project for newbs to the C++ side, and I'd be happy to help them along the  
way.  I'm planning on adding stemmed glissandi to LilyPond (glissandi that  
have intermediary stems between the termini to show duration - comes up in  
a lot in Xenakis), and the only way to do this is to have squeaky-clean  
information about the slope and position of a glissando.