RFC 5 - Horizon clipping during reprojection

[Bruce Raup]

Hi Frank,

RFC-5 was just today called to my attention.  I think it's great that this
is being (has been) addressed.  Two closely related issues (I think) are these:

A.  How are polygon vertices joined?  1) By straight lines in the
projection, or 2) as great-circle arcs?  Can this be specified in the
mapfile?  If not, it would be great to have a LAYER-level parameter,
something like JOINVERTICES=greatcircle or JOINVERTICES=straightline. 
The GMT program "psxy" offers such a choice (the -A option).

B.  When making a selection in the mapserver viewport (via jbox, for
example), only the corner coordinates of that box get converted back
to the coordinate system of the data, which means that what is
selected can be very different from what you see.  I wrote about this
before.  See http://spot.colorado.edu/~braup/MapServer/ for an example
of polar weirdness.  Has this issue made it to the bug list?  I can do
that if you guide me on how.

Best regards,
Bruce


2005/10/21, Frank Warmerdam <warmerdam at pobox.com>:
> Folks,
>
> I have committed the changes in MapServer CVS for the
> RFC 5 reprojection changes for over the horizon features.
> I have also prepared a short web page demonstrating what
> was done that might be of some interest.
>
>   http://home.gdal.org/~warmerda/reproject/
>
> I would also like to thank TMC Technologies for their financial
> support of this effort.
>
> Best regards,
> --
> ---------------------------------------+--------------------------------------
> I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
> light and sound - activate the windows | http://pobox.com/~warmerdam
> and watch the world go round - Rush    | Geospatial Programmer for Rent
>


--
Bruce Raup
http://cires.colorado.edu/~braup/