Re: Tweaking notehead direction in chords

[Thomas Morley]

2012/12/23 Paul Morris <address@hidden>:
> On Dec 20, 2012, at 7:51 PM, Thomas Morley <address@hidden> wrote:
>
>> I think there is no way to align moved noteheads left and right from
>> the stem _and_ to keep a correct 'stem-attachment in x-axis-direction
>> in all thinkable cases.
>> The y-value of 'stem-attachment has to be modified in several situations 
>> anyway.
>
> Hi Harm,
>
> I had some more time to look at this, and I think I may be catching up with 
> you now.  :-)
>
> I now see that using (/ stem-x-width 2) nicely handles all four possibilities 
> correctly in terms of positioning note heads relative to the stem on the 
> X-axis (upwards or downwards stem, moving a note head to the default or to 
> the opposite-of-default side of the stem).  So this is all that is needed to 
> correctly align notes vertically on either side of the stem.
>
> But I also see how this means the stem may not attach properly in some cases. 
>  The main (or only?) instance of this seems to be when a note head that is at 
> the end of a stem has been offset to the non-default side of the stem.  It 
> overlaps only half of the stem width, and this does not look right.  (I can't 
> think of another case where this would be a problem.)
>
> It might be possible to handle this case automatically in the code (at least 
> for the X-axis of 'stem-attachment), but I'm not sure it would be worth it 
> since it can be tweaked manually using your adjustStem function.  (But just 
> for example...)
>
>     if note head is the lowest one on an upwards stem or
>     if note head is the highest one on a downwards stem
>     and it has been moved to the non-default side of the stem
>     then adjust the 'stem-attachment accordingly
>
>
> Also, it seems that changing the 'stem-attachment property moves the stem and 
> not the note.  This preserves the vertical alignment of the notes which is a 
> good thing, but it basically reverses the usual pattern of how note heads 
> overlap the stem.  (Notes on the non-default side of the stem will now 
> overlap the full width of the stem, and notes on the default side will now 
> overlap half the width of the stem -- the opposite of the usual pattern.)  
> There is no way around this, since offsetting a note at the end of the stem 
> means you either get the stem attachment right, or keep the usual pattern of 
> how note heads overlap the stem.  And clearly it's better to get the stem 
> attachment right.

Hi Paul,

that's all true and _much_ better explained than I could have done it.
I agree to all of it.

> So I don't have any further suggestions for the code.  I will try to find 
> some time to come up with a good concise example for the LSR, and put the 
> default notes on a separate staff above the offset notes.
>
> Best,
> -Paul
>

Thanks.
And I promise to approve it asap.


Regards,
  Harm