Re: Generating a score for screen display

[Han-Wen Nienhuys]

Pete Yandell wrote:
> I'm writing a music tuition type app for Mac OS X, and Lilypond is  top 
> of my list of potential tools for generating scores for display  on the 
> screen. Lilypond seems a good choice because it can spit out  nice 
> looking scores in PDF, and can also spit out some basic MIDI.
>
> Now the questions. I have several, in order of importance:
>
>
> 1. Can I work out which notes in the MIDI file correspond to which  
> notes in the PDF of the score?
>
> I want to highlight notes on the screen as they're played, so I need  to 
> map between the MIDI data and locations of notes in the PDF.
>
> Currently, as a quick-and-dirty solution, I'm scanning the PDF for  the 
> hyperlinks that connect the notes back to the original source  file, 
> sorting these, and assuming that one note in the score equals  one note 
> in the MIDI file. This is (obviously) not what you'd call a  robust 
> solution. Any of the Lilypond gurus/developers suggest a  better way?

I could implement origin information in the MIDI, by sending out extra 
MIDI text events. This would be a sponsored feature. Contact me at 
address@hidden if you're interested.

> 2. Can I generate a score as a single horizontal line rather than as  
> multiple lines and pages?
>
> I may want to have the music scroll horizontally as it is played,  
> rather than vertically. To do this, I'd need to make Lilypond spit  out 
> one long line of music.

Yes. Try the EPS backend, with raggedright and a really long linewidth.
You can then use ps2pdf and pdfcrop to get PDF file.


> 3. Can I make Lilypond put all the staff lines, bar lines, note  stems, 
> etc. on integer pixel boundaries such that horizontal and  vertical 
> lines aren't anti-aliased?
>
> Obviously this would make the screen display a bit nicer.

I could try to cook up something for you, but this is rather fragile. 
For example, if the stem and note head X-position are both rounded, it 
might be that an upstem note gets disconnected with the stem.

You can tune the vertical size by doing #(set-global-staff-size 19.985)
to make the coordinates observe some nice ratio.

--
 Han-Wen Nienhuys - address@hidden - http://www.xs4all.nl/~hanwen