[mkgmap-dev] r3784 produces large img files than r3773

Sat Feb 4 12:28:39 GMT 2017

Hi Gerd

One of the reasons I went along the PredictPoints route is that MapArea
was calculating the subDivision usage (number of items, amount of data)
based on totally unfiltered lines/polygons, regardless of the
resolution, so this was forcing splits where no need whatsoever.

I didn't want to add additional complexity to it (ie DouglasPeuker).
Even without that it makes a big improvement, mainly at lower
resolution levels. It must never underestimate the number of points,
but slight overestimation is still masses better than previous
behavior. Generally subdivisions are much fuller, hence there should be
more scope for ShapeMergeFilter.

Having backtracking to do the points-limit splitting will be better
than doing it earlier based on PredictPoints

I don't think this the full reason for the change in images size
behaviour that you see; I need to think a bit more about grouping items
during splitting.

I can't do anything for a couple of days but I'd like to combine the
methods.

Ticker