[mapserver-dev] Development of new functions "combine symbols" and "displace symbols"

[Tamas Szekeres]

Hi Olaf,

The idea looks compelling to me, however I would have some further questions
before trying to propose a reasonable approach to this feature:

Combine Symbols:
1. What would be the position of the combined feature? Would this be one of
the features have been combined or some other location (like the centroid of
the features)?
2. What did you mean by 'not to lose the FeatureInfo'? Does it mean that the
invidual features should be retrieved from a 'query by point option' and not
the combined feature?
3. Would this option affect only the point layers (with marker symbols) or
some other types as well? (like annotations)

Displace Symbols:
1. How the position of the relocated symbols should be calculated? Would
this be a constant vector assigned to each layer/class?
2. What should be happened when a relocated symbols would overlap with some
other symbols because of the relocation?
3. Shouldn't the relocation be displayed somehow? (ie. by using a line or
arrow along with the symbol)
4. What type of layers would be affected? (points only?)

Assuming the distance threshold is specified in screen coordinates, what
would be the possible values of COMBINEUNITS and DISPLACEUNITS?


Best regards,

Tamas




2011/1/24 Olaf Knopp <olaf.knopp at wheregroup.com>

>  Hello everybody,
>
> for a project we need some software development to be done. We think these
> new features will become more important to provide modern and elegant maps
> and therefore would be a great add-on for MapServer. As working titles we
> call these functions "combine symbols" and "displace symbols".
> Here follows a rough concept for the functions.
>
> 1. Combine symbols
> This function combines symbols of the same layer (or class) to one symbol
> containing the number of combined symbols if viewed in a certain scale.
> For this you have to mark a layer/class e.g. by "COMBINESYMBOLS TRUE", give
> a distance between the symbols (COMBINEDISTANCE xy, COMBINEUNITS …), perhaps
> a MAXCOUNT etc. You will also have to define a symbol and the label for the
> combination. It would be best no to lose the FeatureInfo and get a list of
> templates after clicking on the combined symbol. You will find a nice
> example of combined symbols here: http://www.verbeterdebuurt.nl/ (zoom to
> the Netherlands).
> By configuring a zoom range (e.g. COMBINEMAXSCALEDENOM,
> COMBINEMINSCALEDENOM) you define in which scales the symbols should be
> combined.
>
> 2. Displace Symbols
> This function should relocate symbols of objects with same or similar
> coordinates so they don't conceal each other or overlap.
> For this you have to mark the mapfile e.g. by "DISPLACESYMBOLS YES" and
> give a distance between symbols that should be displaced (DISPLACEDISTANCE
> xy, DISPLACEUNITS …). Then you have to configure every layer similar to a
> label by giving a priority, a displace distance and an displace angle.
> You will also have to give a zoom range similar to the combine function
> described above. FeatureInfo should still work by clicking on the moved
> symbols.
>
> Who can develop this functions until the end of February? Is there anybody
> else interested in these functions?
> Please conctact us to discuss further details and to calculate a proposal.
>
> Greetings
> Olaf Knopp
>
> --
> ********************************************
> Die WhereGroup ist umgezogen ...
>
> Seit dem 01.01.2011 lautet unsere neue Adresse:
>
> WhereGroup GmbH&  Co. KG
> Eifelstraße 7
> 53119 Bonn
>
> Alle Telefonnummern und eMail-Adressen
> bleiben unverändert.
> ********************************************
> -----------------------------------
> WhereGroup GmbH&  Co. KG
> Eifelstraße 7
> 53119 Bonn
> Germany
>
> Olaf Knopp
> Geschäftsführer
>
> Fon: +49 (0)228 / 90 90 38 - 27
> Fax: +49 (0)228 / 90 90 38 - 11
>
> info at wheregroup.com
> www.wheregroup.com
> Amtsgericht Bonn, HRA 6788
> -----------------------------------
> Komplementärin:
> WhereGroup Verwaltungs GmbH
> vertreten durch:
> Olaf Knopp, Peter Stamm
> -----------------------------------
>
> _______________________________________________
> mapserver-dev mailing list
> mapserver-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapserver-dev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/mapserver-dev/attachments/20110124/a3bce787/attachment.html