Re: Design flaw in Rest_collision

[David Kastrup]

"address@hidden" <address@hidden> writes:

> On 5 nov. 2012, at 06:51, address@hidden wrote:
>
>> 1) rest->extent (common, Y_AXIS)
>> 2) Rest::height
>> 3) Rest::generic_extent_callback
>> 4) Rest::brew_internal_stencil
>> 5) Rest::glyph_name
>> 6) Staff_symbol_referencer::get_position
>> 7) rest->relative_coordinate (common, Y_AXIS);
>> 8) Rest_collision::force_shift_callback_rest
>> 9) Rest_collision::calc_positioning_done
>> 10) rest->extent (common, Y_AXIS)
>
> A better way to describe it just to wrap heads around it, with the
> circular dependency underlined:
>
> Rest extents depend on their stencil.  This stencil depends on
> placement on/off the staff.  Placement may depend on the placement of
> other rests.  To calculate the placement of other rests, we need to
> shift all of them.  The amount of space one must shift depends on the
> extent of the rest.

The co-dependent shifts should likely be done by Note_column.  About the
rest dimensions used for that: I'd likely just pick the on-staff glyph,
as the off-staff glyphs just differ by ledger lines IIRC.

Keep in mind that this advice is not based on any actual knowledge about
the backend, so it is entirely possible that it is a bunch of nonsense.

-- 
David Kastrup