multiple rasters && mapview

[Bernhard Reiter]

On Sat, Jan 08, 2005 at 02:10:35AM -0500, Russell Nelson wrote:
> I'm still tracking down the problem with multiple rasters.  The
> intrinsic problem is that ProjectRasterFile (called from
> baserenderer.py and implemented in gdalwarp.cpp) always creates a
> bitmap that fills the viewport.  Doesn't matter how big the raster
> image actually is.  Doesn't matter if the actual data in the raster
> covers only a portion of the image.
> 
> You can see this for yourself.  Load a raster, and a layer that covers
> more than just the raster.  Then zoom to the full extents.  The white
> background of the viewport is entirely overlaid by the raster.
> 
> The fix is going to have to be in the way ProjectRasterFile gets
> called.  Instead of creating a BMP image, it needs to return a
> wxImage, clipping mask, and offset.  

Wouldn't this make it depend on wxWidgets a GUI library?
(I really don't know.) If possible we probably want to keep that independent.

> I don't know enough about GDAL to
> be able to do that yet.  

Could be a workaround to define one color that gets transformed
to a clipping mask after projecting out of the BMP?

> Mapview is now nicely editing line files.  I really like the UI, and
> I'll be putting it into Thuban, once Thuban gets as good as Mapview at
> displaying rasters.  The trouble I'm now running into is that I'm
> basically re-creating shapfiles.  Rather than going that, I need to
> add line editing to Thuban.  That way, everyone benefits.
> 
> I'm going to have to create an Extension for Terraserver tiles.

Cool.
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