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[mkgmap-dev] Include the following patches into trunk -- Patch4 - decrease douglas peucker error

From Johann Gail johann.gail at gmx.de on Wed Mar 2 19:54:36 GMT 2011

Okay I've done some comparisons between the two approximations.
> For polygons the old version is much better because the patched version
> creates bad artifacts. For streets at resolution 23 (if used) to 21 I
> prefer it too. At resolution 20 I am indifferent and cannot really
> decide what is better. However from 19 to x the  approach as given by
> the patch is far superior (drawing speed on GPS much higher, actually
> using the normal DP filter maps become more or less unusable for
> resolution 16,18 or 19 on etrex).
> Can someone see how this behaviour could be implemented for lines only
> from resolution 20 or 19 downwards, while keeping the current approach
> of the DP filter for the rest?
Thanks for intensively testing my old patches and the propose for them 
being checked in.
Glad to see them work fine and beeing useful. :-)

I have looked at this patch again. I think your proposal of switching 
between them at a given resolution is a good one. This should preserve 
the accuracy at higher zooms and compress the data at lower zooms. 
Should be worth a try.

I'm sorry, but at the moment I have no toolchain ready for compiling 
mkgmap and preparing patches. If I find the time, I will look into it 
the next days.


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