[mkgmap-dev] Commit r4645: LinePrepOpt.patch by Ticker Berkin

Fri Apr 9 08:36:24 BST 2021

Version mkgmap-r4645 was committed by gerd on Fri, 09 Apr 2021

LinePrepOpt.patch by Ticker Berkin
- improve efficency of bitstream optimization in LinePreparer

"If starting with unsigned deltas in polyline encoding, and attempting
to reduce the length by testing reduced x/yBase values, there isn't any
point in testing Base-1, as the normal number of bits will be the same
(added sign bit) and there will be some overflows.

Patch attached to change this - it gives me a very slight reduction in
RGN size and might give a performance improvement (I didn't detect
any).

I've also fixed a couple of log. logic errors and changed minDx/y
initial to 0, which is much less confusing because they are symmetric
with maxDx/y which do use 0."

http://www.mkgmap.org.uk/websvn/revision.php?repname=mkgmap&rev=4645