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<body class='hmmessage'><div dir='ltr'>Hi Felix,<br><br>see <br>http://gis.19327.n5.nabble.com/Patch-v1-detect-cases-where-Herons-formula-is-failing-in-3D-tp5812773.html<br><br>please let me know if the patched verrsion causes any problems.<br><br>The only expected effect of the patch is that fewer points are removed<br>from the original data. On normal OSM data, the effect is minimal.<br><br>I tried it with normal OSM data and some contourlines. For data<br>in Australia I see small changes at low resolutions (<=15) for shorelines,<br>but I can't say which result is worse, as both versions are a mess.<br><br>Gerd<br><br><div>> Date: Fri, 25 Jul 2014 11:24:44 +0200<br>> From: extremecarver@gmail.com<br>> To: mkgmap-dev@lists.mkgmap.org.uk<br>> Subject: Re: [mkgmap-dev] Incorrect compilation of grid lines<br>> <br>> Hi Gerd,<br>> <br>> the only thing I am afraid about is broken contourlines data (due to <br>> errors or missing data). There you quite often end up with long straight <br>> lines. So the patch shouldn't make such errors even worse - I long even <br>> hoped that mkgmap could have a function/filter to delete all long lines <br>> - say straight over 5km without intersection, because I don't think that <br>> such long straight lines exist in OSM data (except ferry lines, power <br>> lines, railways and highway=motorway/trunk)<br>> <br>> <br>> So maybe better not detect such a problem automatically, but add a <br>> filter for the style-file where you could switch off douglas peucker <br>> especially<br>> e.g.: gridlines=yes [0x* nodouglaspeucker]<br>> On 25.07.2014 11:15, Gerd Petermann wrote:<br>> > a simple patch that tries to detect that the formula doesn't work.<br>> > I just have to decide what to do in that case, typically it is better <br>> > to keep the point, so<br>> > img size might increase.<br>> <br>> -- <br>> keep on biking and discovering new trails<br>> <br>> Felix<br>> openmtbmap.org & www.velomap.org<br>> <br>> _______________________________________________<br>> mkgmap-dev mailing list<br>> mkgmap-dev@lists.mkgmap.org.uk<br>> http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev<br></div> </div></body>
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