Re: Rendering SingletonSet as Ellipse/Circle (was Rivers)

Hi James,

> Back in August last year (28th), a query was posted about
> representing river confluence points as a circle:
> One of Bill Hibbard's suggestions (excerpt below) was to extend SingletonSet
> and override makePointGeometry to render the singleton as a circle.

I'm afraid that my earlier advice was wrong.  This is clearly
something that should be done using ScalarMaps to Display.Shape
and Display.ShapeScale.  RealTypes mapped to Shape are quantized
according to a 1-D Set in the ShapeControl and the resulting
integers are used as indices into an array of VisADGeometryArrays.
RealTypes mapped to ShapeScale are used to linearly scale these

The makePointGeometry() method of Set seems to have no purpose
and somehow I got it confused with the method of the same name
of ShadowType.  I'll look into this a bit more when I return from
my travels.  Sorry for the confusion.

Note the visad/rabin/ program provides a very simple
example of Shape, as do Test46 and Test47 in visad/examples.

Bill Hibbard, SSEC, 1225 W. Dayton St., Madison, WI  53706
hibbard@xxxxxxxxxxxxxxxxx  608-263-4427  fax: 608-263-6738