Re: [udig-devel] [Fwd: [Fwd: Re: [jump-devel] Creating a plugin]]

[Andrea Aime <andrea.aime@xxxxxxxxxxxxx>]

Alle 00:20, martedì 11 maggio 2004, Jody Garnett ha scritto:
> David Blasby wrote:
> > I've been sending messages to jody on stuff I've seen that might be
> > related to uDig.  I'll send them to this list.
> >
> > For example, here's a jump plugin that doesnt load all your shapes
> > (from shapefiles) into memory when it displays them.  It might be good
> > to look at the code or at least look at the performance so you can see
> > how it works...
>

In geotools, if you are using lite-renderer nothing is kept into memory and
only the geometries that are really needed are streamed (loaded) and 
processed. The only problem is that this renderer does the loading every 
time.
On the contrary, j2d.Renderer needs to load all of you area of interest before
starting to draw, and you can't change it afterwards... that's a design 
problem that can be overcomed, but it requires non trivial work (loading data 
and partitioning in a tiled fashion, and invert the relation between the 
renderedLayerFactory and the RenderedLayer so that the latter can ask 
the former to load and convert more geometries when needed)

As far as optimized shape loading is concerned, we also miss an optimization
in the shapefile data store, see 
http://jira.codehaus.org/secure/ViewIssue.jspa?key=GEOT-159

Best regards
Andrea Aime