Re: LatLon to XY space

Hi Pieter,

I just want to baseline my use of terms before answering. We think of
data as being in lat/lon space, world X/Y space (projected data), and
user X/Y screen space (the view).

Currenty, OpenMap takes lat/lon, and does the conversion all the way to
user X/Y screen space. There isn't a path to get to the world X/Y
space, yet. We're planning on addressing this sometime this year.

That said, the com.bbn.openmap.proj package projection objects, although
they are used to work with lat/lon <-> screen X/Y data, if you set the
screen map parameters to your world X/Y values, you will end up with the
world X/Y coordinates.

Once you have those coordinates, management of the map becomes something
you have to manage, with an AffineTransform, or some other mechanism.
The MapBean projection methods, and working with other standard OpenMap
layers, might become a problem unless you handle them the same way
(projecting the data, and then reusing/scaling the results). You should
expect to have to do some work to manage the world X/Y to screen X/Y
conversions for your layers.

Hope this helps,

Don

Pieter Beyens wrote:
>
> Hello,
>
> in the documentation, I found that, for performance reasons, one can
> work strictly in XY space.
> I now have data in Latlon and my question is: how do I convert these
> data into XY? Are there any examples of this operation (transformation)?
> An example layer that only works with XY maybe?
>
> thx,
> Pieter
>
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