Re: Design flaw in Rest_collision

[address@hidden]

On 6 nov. 2012, at 04:51, Keith OHara <address@hidden> wrote:

> mike <at> mikesolomon.org <mike <at> mikesolomon.org> writes:
> 
>> On 5 nov. 2012, at 11:15, Werner LEMBERG <wl <at> gnu.org> wrote:
>>> 
>>> So the answer is yes: The height (resp. the depth) is larger for
>>> outside-staff glyphs.
>>> 
>> 
>> So we officially have a circular dependency: in order to know the height 
>> (for collision resolution) we need to know the extent, but in order to 
>> know the extent (because of the glyph) we need to know the height.
> 
> Just to be clear, rest-collision.cc breaks the circular dependency by setting
> positioning-done := true,  

I'm still not sure how this breaks the dependency.  If I look up the extent of 
a rest, this will set 'Y-extent to 'calculation-in-progress for the rest.  
Then, when 'Y-extent is read again in calc_positioning_done, it will still be 
'calculation-in-progress.  Setting 'positioning-done to #t only prevents 
calc_positioning_done by being called multiple times (say by other rests) - it 
doesn't fill in the 'calculation-in-progress for 'Y-extent.  Or am I missing 
something?

Cheers,
MS