[Mapserver-users] Rotating symbols

[Brent Fraser]

Thorsten,

  We had a similar requirement recently.  Unfortunately currently there is
no simple way to rotate symbols (that I know of).  It would require the
creation of a CLASSANGLEITEM keyword into the LAYER object (plus source code
changes to internal MapServer structures and function calls).

  The timeline of our particular project was too tight for a source code
enhancement of that magnitude, so we simply used eight classes in  a single
layer.  Each class represented a range of angles of 45 degrees (e.g., N, NE,
E, SE, etc) and the expression in the class filtered the record based on a
heading attribute:

 CLASS
   EXPRESSION ([HEADING]<23 or [HEADING]>337)
   SYMBOL 'arrowup'
   SIZE 10
   COLOR 255 0 255
   OUTLINECOLOR 0 0 0
 END # CLASS


Obviously this method does not render the symbol with the exact direction,
but for our purposes it was close enough.

For the long term, we too would like to see symbol rotation from an
attribute implemented.

On a related note, we did add OUTLINECOLOR support for truetype symbols.  I
see that it is now checked into CVS and available via nightly builds.


Brent Fraser
GeoAnalytic Inc


----- Original Message -----
From: "Thorsten Fischer" <thfischer at mapmedia.de>
To: <mapserver-users at lists.gis.umn.edu>
Sent: Monday, March 24, 2003 3:09 AM
Subject: [Mapserver-users] Rotating symbols


> Dear list,
>
> I was asked a question about symbols recently. A lady (who already makes
> heavy use of mapserver in her institute) involved into mapping
> seismographic events asked about the possibility of rotating labels. She
> has some ellipsoids (easy to create with a ELLIPSE symbol) but they need
> to be rotated, thus showing errors of measurement errors in the
> direction of the larger radius of the ellipse. I know of ANGLE and
> LABELANGLEITEM for labels; but that only covers annotations. Is there a
> way to rotate 'ordinary' symbols? Should I file a feature request? :)
>
>
> tia,
>
> thorsten
>
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