Andrea Aime wrote: > Jody Garnett ha scritto: >> Hi Simboss; just a follow up to our question on how to separate out >> the Geometry -> Shape transition from the rendering code. Since we >> will be defining no new API we do not need a proposal for this one; >> you have my permission as module maintainer to package up the code in >> *main*; and I seem to recall that Jesse was okay with the change to >> renderer. > People, going thru a converter is a dangerous road performance wise. > As far as I can see, you want to do that to make the renderer > independent of the actual geometry type used, allowing it to render > JTS geometries, ISO geometries, or your random Point(x,y) beean. > Is this right? > > Well, in this case you don't only have to prepare stuff for decimation, > but also for reprojection. Reprojecting a shape is not as efficient > as doing it on a double[] or coordinates, not nearly as efficient. > > So, you either provide a reprojection hint too, or you ask for > something other that a Shape to be returned back, something like a JTS > geometry > using packed coordinate sequences, that can be efficiently reprojected > by transforming arrays of floats or doubles, otherwise we're going > to pay a high tax to this generality attempt. This is a good point Andrea; I have tried to explain the need for a "CoordinateSequence" abstraction when reviewing the ISO Geometry implementations (but so far I have not scene anything like that in the code base. I would really like to ensure that something of this nature is used by the GeometryFactory when constructing the various geometries ... we need to learn from our own experience with JTS & performance.
If you have any specific recomendations on what a "PackedCoordinateSequence" class would look like could you add it to the Geometry page please. Anything to do with Geometry and performance has way more opportunities to slow down then PropertyAccessor ever did. Jody ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier. Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Geotools-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-devel
