Re: Issue 1955 in lilypond: Patch: improving spacing over and below bar lines

[lilypond]

Comment #9 on issue 1955 by address@hidden: Patch: improving spacing over and  
below bar lines
http://code.google.com/p/lilypond/issues/detail?id=1955

This is all about visual balance.  Accidentals usually are not a  
significant part of the optical structure, so letting them overhang other  
structures is totally natural.  Things become different when the structures  
they overhang are close enough that they interact more visually with the  
accidental than with the supporting structure.  In that case, you need to  
establish a distance that is about equally annoying as the increased  
distance between the base structures.

So you have a balance between near-field interaction (like  
accidental/barline) and far-field interaction (like stem/barline).  The  
near-field interaction gets weak with additional vertical distance (you  
don't want to let an accidental overhang right over a barline, but if it is  
far away, it does not matter that much).  How much vertical distance?   
Depends on the "verticality" of the overhanging structure.  Things like  
text and accidentals are not all that vertical.  Stems are.

So as a rough measure, take the "spine" of the overhanging structure.  Take  
the vertical distance of its lower end to the aligning structure (like the  
barline).  Divide by the height of spine.  Multiply by the width of the  
spine.  Multiply by a fudge factor to be determined by drinking lots of  
beer and staring at various overhanging pictures.  That's the basic amount  
of overhang you can administer.