[mkgmap-dev] Work on is_in branch

Fri Mar 6 09:32:44 GMT 2020

Hi Gerd

Nothing else I want to change. I keep thinking there must be other ways
to do the lineInShape logic, but I think it has taken enough time
already.

Ticker

On Fri, 2020-03-06 at 08:16 +0000, Gerd Petermann wrote:
> Hi Ticker,
> 
> My concerns regarding a merge to trunk are resolved. Anything else
> you want to change?
> 
> Gerd
> 
> 
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> von Gerd Petermann <gpetermann_muenchen at hotmail.com>
> Gesendet: Dienstag, 3. März 2020 15:22
> An: Ticker Berkin; Development list for mkgmap
> Betreff: Re: [mkgmap-dev] Work on is_in branch
> 
> Hi Ticker,
> 
> nice :)
> Committed with r4461, with small changes.
> 
> This even allows to change the test case for lamp4 from expected="?"
> to expected="2" (ON).
> 
> reg. the distance calculations: I don't remember the details and
> maybe all is wrong.
> 
> See svn log for r3333 : 
> http://www.mkgmap.org.uk/websvn/revision.php?repname=mkgmap&rev=3333
> and search the archives for "Great Britain National Grid".
> 
> The math behind projections and distance formulas is too complex for
> me.
> 
> Gerd
> 
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> von Ticker Berkin <rwb-mkgmap at jagit.co.uk>
> Gesendet: Dienstag, 3. März 2020 14:24
> An: Development list for mkgmap
> Betreff: Re: [mkgmap-dev] Work on is_in branch
> 
> Hi Gerd
> 
> Patch attached:
> 
> - inherits your is_in-function_v14.patch
> 
> - adds Math.round to Coord.makeBetweenPoint(); Is this how you
> indented?
> 
> - removes IsInUtil.insidePolygon() and changes callers to use
> isPointInShape()
> 
> - adds ON tolerance to isPointInShape() - I couldn't work out how to
> do
> this with the winding algo, so changed it to crossing-point, which is
> fine for mkgmap polygons.
> 
> - add some more tolerances to isLineInShape
> 
> - isLineInShape had comment:
> 
> // it is unlikely but not impossible that pTest is on boundary :(
> 
> and it returned the wrong result if it was. This contributed to the
> difficulties with b14 (and b19). I've fixed it and, I think, improved
> and simplified the running status setting
> 
> - fix spelling of rhumLine to rhumbLine
> 
> There are still a couple of places that have complicated distance
> calculation and point insertion using, bearings, rhumbline, meter
> conversion but I don't think it is worth re-implementing them for
> this.
> 
> I'm slightly surprised how much use there is of
> bearing/rhumbLine/Mercator projection calculations. I think real
> distance/metre calcs should be "great circle" and internal poly/line
> chopping, testing etc should be high-precision polar coords.
> 
> Ticker
> 
> On Thu, 2020-02-27 at 19:36 +0000, Gerd Petermann wrote:
> > Hi Ticker,
> > 
> > if you see a way to change the algo just do it.
> > I've just noticed that I forgot to commit a change  in
> > Coord.makeBetweenPoint().
> > This routine should use Math.round. Will reduce the error by 50%,
> > right?
> > 
> > Gerd
> > 
> > ________________________________________
> > Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> > von Ticker Berkin <rwb-mkgmap at jagit.co.uk>
> > Gesendet: Donnerstag, 27. Februar 2020 20:24
> > An: Development list for mkgmap
> > Betreff: Re: [mkgmap-dev] Work on is_in branch
> > 
> > Hi Gerd
> > 
> > Looking at the distance calculations to compare with EPS (ie very
> > small), wouldn't it be much simpler and clearer just to calculate
> > it
> > as
> > highPrecisionSquared units, not bothering with degrees/radians,
> > rhumb
> > -line, metre conversion etc. Then EPS would be 4.
> > 
> > Then, considering IsInUtil.insidePolgon and can it be changed to
> > have
> > some tolerance and maybe changing the interface to return
> > IN/ON/OUT,
> > it
> > looks like it will stop, returning onBoundary, if there is a
> > polygon
> > segment that 'aims at' the point.
> > 
> > Ticker
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