Zooming and projection problems (was: Success (sort-of)!)

[Bernhard Reiter]

On Sun, Dec 19, 2004 at 01:23:27PM -0500, Russell Nelson wrote:
> Success!!  I got my dataset to display correctly!
> 
> That's good for me in that I can get my task done.  However, the
> trouble that I had indicates that Thuban is fragile.  It doesn't
> withstand native users very well.  It has, in essence, the same
> problem that GRASS has: intolerance of ignorance.

After playing a bit with Russel's testdata (089uni00s.zip test.zip)
I can only wholeheartedly agree!

CVS of today.

> Here's what I had to do:
>   1) start with a new session (by running Thuban)
>   2) set the projection of the session using Map/Projection...
>   3) load the raster map, and set its projection using Layer/Projection...
>   4) load the shapefile.

If you miss 2) then even 3) will not help much
and Thuban behaves oddly when zooming around even with 1).

Probably more tests and thinking are needed 
but from a user perspective this is not inuitive.

Zooming issues:
	I can zoom out to get a scalebar of 0..70 km, 
	but after that a zoom out makes the map jump around
	and does not zoom out further. And I can loose the mapcontent
	because it gets out of focus.

	Zooming out should never make a user loose the mapcontent!


	I can zoom in to a scalebar of 0..600m and not further,
	okay, this probably is limited to the scaling issuses,
	still the user is not really informed of this.

Probably both are limits of the UTM 18N map projection, 
but zooming still behaves badly.
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