[Xastir] Difficulty loading Geotif

[Curt, WE7U]

On Fri, 26 Mar 2004, Brian D Heaton wrote:

> 	Yep, I looked at the the DOI10s against a couple of DRGs late last
> night.  The biggest difference on first inspection is that the DRGs are
> projected and the DOI10s are GCS.

First thing I noticed as well, but I haven't had time to check
whether anything else was drastically different.


> 	I've got it locked down to the line in map_tif.c where we first fail
> part of the process. Its line 1234 and I've pasted it below.  I'm still
> poking around to see exactly what is failing.  I'm leaning towards
> proper handling of the GCS_WGS84 projection definition.
>
> 	Is there a different function call to convert GCS (non-projected)
> rasters to the internal coordinate systems?
>
> ------------------------------------------------------
> if ( GTIFProj4FromLatLong( &defn, 1, &xxx, &yyy ) )
> ------------------------------------------------------

I recall putting those in there, but I don't recall much more about
it.  Those calls are often what fail if you don't install
libproj/libgeotiff in the correct manner.

Don't get too carried away in fixing this stuff up, as the GDAL
library also handles geoTIFF, and we'll most likely be switching to
that library eventually.  Same for Shapelib versus OGR, we'll be
going to OGR eventually.  Both GDAL and OGR handle multiple formats
with the same API calls, so getting those integrated in will give us
more map support, and will also allow automatic datum conversion and
probably projection conversion as we draw the maps.

--
Curt, WE7U			    archer at eskimo dot com
Arlington, WA, USA		http://www.eskimo.com/~archer
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