The following might be off topic, not sure... Ian's comment about compilers made me recall working on the interpolate function (SE 1.1 thing). It works perfectly well but is horribly slow because, like all the other filter functions, it starts from square 1 each time. In this case that means working out what type of interpolation the user has requested, then checking the sequence of values provided and falling back to some other interp method if necessary, then (finally) processing the input value. If you actually used this implementation in a raster colormap (the original intention) you could get through a long novel while waiting for it to slog through all of the redundant repetition.
The problem is that it is an interpreter with no caching of symbols, values or the abstract syntax tree. It's crying out for a scripting language approach. A little while before I had been working on the jiffle scripting language (http://code.google.com/p/jai-tools/wiki/Jiffle) which works with images as inputs. It was relatively easy to implement (thanks to the ANTLR parser) and would zip through the above interpolation task. I'd love to try to ANTLR-ize the filter functions and the SLD parser at some stage (GeoTools 3.0 perhaps :) Michael ------------------------------------------------------------------------------ This SF Dev2Dev email is sponsored by: WikiLeaks The End of the Free Internet http://p.sf.net/sfu/therealnews-com _______________________________________________ Geotools-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/geotools-devel
