[mkgmap-dev] Polyline base optimisation

Thu Apr 8 12:58:21 BST 2021

Hi Gerd

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.

Ticker
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