feature : log file with positions of notes

[Franck Revolle]

Suggestion of (new ? ) feature :
When a lilypond score-image is created ( e.g. a png file ), a log file can be 
used by an external software. This log file contains information about 
graphical position of the notes, within the score-image ( e.g. beat, stave,  # 
of page, x-y-width-heigh ). The external software can use the score-image, and 
make graphical « interaction » with the picture ( highlight the items, ... ).

Usage :
I would like to develop a new version of my Expresseur freeware ( 
www.expresseur.com ). I would like to use lilypond to build the score-image, 
according to the user’s options ( staves to play/display ). 
For this, I can use Lilypond to build easily the score-image, building 
automatically the lilypond source-code. 
But I also need to interact with the score-image, to highlight position 
dynamically. So, I need to know where to find graphically the notes, within the 
image. The log file can be a solution …

My contribution :
I can update source-code ( C++, .. ). But some help can be useful to know where 
to « touch » this (large) project….

Alternative :
Filter tha available logs.
May be(?), this information is already available in a « verbose » log. In this 
case, I just need some indications to know how to generate this information, 
and where to find it in the log. With this information, it will be easy for me 
to parse the text logs…

For consideration
Franck Revolle