Using .map file as a raster layer source

[Tamas Szekeres]

Frank,

Certainly this solution should also work in the conventional way, when the
DATA field contains the name of the mapfile. However that modification
would also address the case when we have an overall map (like a Country)
and a high number of detailed maps for a lower scale (cityes and
villages), and if the user is zooming in an area the corresponding high
detailed map should be drawn over the overall map. Tileindex is an option
to prefilter the maps falling into the zooming area.
Up to present I haven't found a built in alternative to achieve this
issue, because for WMS, all of the hundreds of maps should be
predownloaded and written into the filesystem though only one or two maps
should be really drawn. Suppose that the detailed maps are with completely
different layer structure, so layer level tileindexing does not work.

However anyone could write a script to realize this, but I think that it
is not practical to duplicate many of the functions already exist in the
system.

Using mapfile as a data source (like inline WMS) is a different approach
which requires to realize many other features like selection of the
layers, with much of work. In this case the "CONNECTIONTYPE MAPFILE"
pseudo configuration would be syntactically more convenient.


Tamas Szekeres



On Thu, 25 Aug 2005 11:07:31 -0400, Frank Warmerdam <fwarmerdam at GMAIL.COM>
wrote:

>On 8/25/05, Sean Gillies <sgillies at frii.com> wrote:
>> Neither of you say it, but to me this seems to be sorta like an inline
>> WMS. I like the idea, and we should see about fitting it into the
>> proposed new layer architecture.
>
>Sean,
>
>It is indeed a bit like an inlined WMS, though it also, potentially,
>is benefiting from the tile index.
>
>However, I see it as orthagonal to the layer plugin proposal which
>is really about making the layer *feature* access plugable.   It does
>not address other aspects of layers, such as the Draw interface
>which is still based on the layer TYPE.   In this case this is a
>special case in the TYPE RASTER tileindex processing.
>
>Actually, Tamas, does the mapfile name have to come from a
>tileindex?  I don't see why it shouldn't be possible to have a single
>mapfile listed in the DATA argument instead of having to use the
>tileindex.  This would be in keeping with how other files work.
>
>Best regards,
>--
>---------------------------------------+----------------------------------
----
>I set the clouds in motion - turn up   | Frank Warmerdam,
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>light and sound - activate the windows | http://pobox.com/~warmerdam
>and watch the world go round - Rush    | Geospatial Programmer for Rent