[Qgis-developer] Proposal: Lift feature freeze for labelling

[Tim Sutton]

Hi All

My apologies for the delay in providing feedback on this topic - I was
away for a week post conference trip with Marco Hugentobler, Horst
Deuster and Till Adams. On the code sprint day we had a long detailed
discussion with the PAL folks so let me bullet out the synopsis:

- Max, one of the PAL developers is finalising some API cleanups and
generally getting it ready for us / folks like us to use. Because of
this, introducing PAL into QGIS now is probably not a good idea and we
are proposing to do it in QGIS 1.1 rather.
- PAL does not do curve fitting of labels, it is a label placement
library only and does no rendering.
- PAL is currently using GEOS C++ api, since they had issues with some
equavalet parts of the C api in GEOS not being implemented yet. On IRC
Jeurgen Fischer suggested this could be addressed with patches to
GEOS.
- There is probably scope for Martin to do a Masters project on
labelling still because although PAL will offer  a huge leap forward
to QGIS labelling, there are still a number of things it doesnt do:

  * intelligent dropping of 'unimportant' labels when conflicts occur
  * incremental drawing of labels (it needs to search for the entire
solution first)
  * curve fitting etc of labels
  * prevention of labelling when adjacent features (e.g. road
segments) have the same attributes
  * we would probably want a way to force some labels to specific
locations (e.g. grass label points) and then make others flow around
those.

In short we came away feeling that we should wait for QGIS 1.1.0 for
labelling. On an aside, the PAL guys are really great - very helpful
and friendly so they should be receptive to the enevitable queries etc
the will come up along the way....

Best regards

Tim

2008/10/10 John C. Tull <john.tull at wildnevada.org>:
> On Oct 10, 2008, at 1:25 AM, Paolo Cavallini wrote:
>
>> Tim Sutton ha scritto:
>>
>>> Marco and I will look at the feasibility of incorporating the PAL
>>> library into QGIS, and what kind of effect it would have on the API
>>> during the FOSS4G code sprint on saturday.
>>
>> Hi Tim + others.
>> Any news about the integration of PAL? Does it look feasible within a
>> reasonable time frame?
>> Looking forward to it.
>> All the best, and thanks.
>> pc
>
> Others can chime in on this, but I "overheard" on irc that PAL does not have
> a mature enough API to include in 1.0, so the plan is to hopefully have it
> in 1.1. So it will not be in 1.0 from my understanding.
>
> Regards,
> John
>
>



-- 
Tim Sutton - QGIS Project Steering Committee Member (Release  Manager)
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