Re: [Denemo-devel] \partial Upbeat not shown in Denemo

[Richard Shann]

On Tue, 2008-11-04 at 11:55 +0100, Nils Gey wrote:
> Hi,
> 
> the upbeat-example shows clearly how to create an upbeat. And in the example 
> it shows right in Denemo.
> I created my own upbeat now and its shown wrong in Denemo, if I render it I 
> get a warning because the measures are wrong but the output is totally right 
> in the end.
> 
> What have I or Denemo done wrong? I've attached the .denemo file
You have 4 beats (4 quarter notes worth) in the first measure. You
should have 3 because you have 
\partial 4
in that measure which counts for one beat. Denemo does not understand
the \partial 4 and so it will then think the measure is incomplete, but
it doesn't do anything about that. It lets you have three beats.

So, as a user, when you have inserted \partial, it is up to you to put
the correct number of beats in the measure, and then start a new measure
for the first note of the full measure that follows.

The background is as follows:

Denemo outputs the character "|" into the LilyPond text wherever it
thinks a measure ends, but this character does not change what LilyPond
prints, it is only a diagnostic character, allowing LilyPond to warn you
that you have put a barline at the wrong point - i.e. where the number
of beats you have put does not correspond with a full measure.


A few points about all this:

      * I have often wondered whether it is helpful for Denemo to output
        these "|" characters. Perhaps it would be good not to do this if
        there are LilyPond inserts, since Denemo cannot be sure that
        they are correct.
      * We should have a sign (an orange "!" for example) to indicate
        Denemo thinks it is an incomplete measure. Again, it could give
        up if it cannot be sure & not show the marker.
      * In the future the LilyPond directives can contain information so
        that Denemo can get the duration count and the measure number
        correct (the upbeat is not counted as measure 1 in most scores,
        and multi-measure rests leave Denemo's measure count wrong) etc.

Incidentally, I have got LilyPond displaying some text now to indicate
what is happening, the next step will be to output some graphical
indicator (e.g. a double barline) instead of the green bar.

Richard