On 12/20/05, Ari Jolma <[EMAIL PROTECTED]> wrote: > The way it works now is a bit, well, maybe more than a bit, hackish. In > libral I have a C function to get a rectangle from GDAL (using > GDALRasterIO) into a libral data, and that's all. It's one way street > currently. In libral there's a function to write the data into a .bil file. > > Geo::Raster image (actually, an integer or real raster) is in the libral > C struct and has to be accessed from Perl through the Perl/C interface.
Ari, Python Numeric is similar in that the arrays are stored in memory arrays with meta information in a C struct. What I did to provide GDAL access was write a special driver that uses a "filename" with the pointer to the C struct encoded in the name. Then the in memory array can be treated as a GDAL dataset. > How is a raster (or for that matter a vector) dataset handled in (Perl) > mapscript? The Perl examples are a bit limited on mapserver website ;-) The name of the raster dataset needs to be assigned to the "DATA" item in the raster layer. This is turned into a file handle internally with a call to GDALOpen(). So to use a Geo::Raster image directly in MapServer you would pretty much have to build a GDAL driver around it. Alternatively, you could create a copy of the data as an "in memory" file using the GDAL MEM driver. The downside of this is that yet another copy of the image is made, but for common applications this might not be a problem. > I'm probably getting more involved with using mapserver with a project > we have -- or will have, the exact nature of it is still to be figured > out. That should give me an opportunity to learn mapserver more and work > out the link between it and libral. Let me know if you pursue this, and I will help as I can. Best regards, -- ---------------------------------------+-------------------------------------- I set the clouds in motion - turn up | Frank Warmerdam, [EMAIL PROTECTED] light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush | Geospatial Programmer for Rent
