Hi WanMil,
Date: Thu, 23 Feb 2012 21:38:47 +0100 From: wmgcnfg@web.de To: mkgmap-dev@lists.mkgmap.org.uk Subject: [mkgmap-dev] Idea for minor speed improvement for boundary preprocessing
Hi Gerd,
boundary preprocessing takes quite a lot of time. That's not a big problem because it's performed only by some people who publish their results.
But I think some speed improvements would not be bad anyhow?!
Well, at least for me it is ;-)
While preprocessing asia and america I go an idea. The area of a boundary is splitted into the raster. But each time the complete area is intersected to the raster. In case an area is big and/or complex (boundary of russia, USA, canada etc.) this takes a long time. It would be possible first to cut the area into smaller pieces (columns or rows of the raster) and then do the final cut to the raster. Maybe this saves time because the column or row areas should be less complex.
What do you think?
I think you are right and it should be easy to do. We just have to replace BoundarySaver.splitArea() by a another quadtree with a big bbox. I'll try it. Gerd