On 2/18/2012 11:32 AM, Michaël Michaud wrote: > Hi Martin, >> Does OJ use decimation to help improve rendering performance? I know >> this wasn't in JUMP, but perhaps it's been added? > Thanks to Larry Becker, we've had this kind of decimation for a few years. Oh, great. I'll have a look at the code. > > It has been a great improvement in the rendering system. > > I did a new addition last year to display efficiently huge geometries. > Displaying a linestring with several hundred thousand points was still > slow at scales were scale-based decimation was not active. > I removed segments which were not intersecting the window from > the rendering pipeline (even easier than the scale-base decimation). Yes, it's always easier to deal with LineStrings! > > But there is still no optimization for huge polygons display. I have no > other idea than a strict clipping of the polygon on the window (with > JTS intersection) which is a more heavy operation. I think it is not > worthwhile, but I may be wrong (it's already used for labelling display) I've thought about this as well. I did experiment a bit with developing a faster clipping algorithm using rectangles (since clipping against a rectangle should be able to produce a faster, simpler, robust algorithm). But I haven't had the chance to complete this work. I also wonder whether another approach is possible to drastically simplify the portion of the polygon outside the viewport in some way (obviously checking to ensure that the visible topology is not affected). > > Multi-geometries display could also be optimized based on the > envelop of their simple geometries, but I still did not do this > optimization. > > Thanks, your suggestion are always welcome, > > Michaël > >> If not, it's worth having a look at - it's fairly easy to implement, and >> it makes a big difference in rendering speed. I've just added >> decimation capability to the JTS ShapeWriter class - this can provide a >> model to follow (or maybe even be used directly). >> >> http://jts-topo-suite.svn.sourceforge.net/viewvc/jts-topo-suite/trunk/jts/java/src/com/vividsolutions/jts/awt/ShapeWriter.java?revision=545&view=markup >> >> Martin >> >> ------------------------------------------------------------------------------ >> Virtualization& Cloud Management Using Capacity Planning >> Cloud computing makes use of virtualization - but cloud computing >> also focuses on allowing computing to be delivered as a service. >> http://www.accelacomm.com/jaw/sfnl/114/51521223/ >> _______________________________________________ >> Jump-pilot-devel mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel >> >> > > ------------------------------------------------------------------------------ > Virtualization& Cloud Management Using Capacity Planning > Cloud computing makes use of virtualization - but cloud computing > also focuses on allowing computing to be delivered as a service. > http://www.accelacomm.com/jaw/sfnl/114/51521223/ > _______________________________________________ > Jump-pilot-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > > > ----- > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2012.0.1913 / Virus Database: 2112/4817 - Release Date: 02/18/12 > > >
------------------------------------------------------------------------------ Virtualization & Cloud Management Using Capacity Planning Cloud computing makes use of virtualization - but cloud computing also focuses on allowing computing to be delivered as a service. http://www.accelacomm.com/jaw/sfnl/114/51521223/ _______________________________________________ Jump-pilot-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
