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<body class='hmmessage'><div dir='ltr'>Hi Andrzej,<br><br><div>> > attached patch forwards the "guessed" drive-on-left value in a thread<br>> > safe way to the NOD header by using a ThreadLocal variable. This is a<br>> > small code change.<br>> > Anyhow this makes only sense if you think that the guess algorithm is <br>> > ok.<br>> <br>> Shouldn't it be a TRE header? Or TRE header too?<br>If we use guessing, yes, TRE header too.<br><br>> <br>> According to help for options, guessing is connected with <br>> "check-roundabouts", which revers directions of roundabouts. This option <br>> is wrong for tiles, that contain multiple countries with different <br>> drive-on rules. In that case "check-roundabouts" would damage some good <br>> roundabouts.<br>well, "check-roundabouts" also enables some checks in RouteNode<br>regarding overlapping and forking of roundabouts. I do not yet understand<br>the meaning of them.<br><br>> <br>> If you make a map for a single country, you don't need guessing. And you <br>> can't invoke guessing for a map with multiple countries. So this <br>> guessing feature looks rather redundant.<br>+1<br><br>> <br>> In my opinion there should be no guessing but a simple count. If a tile <br>> has more than 50% of roundabouts as drive-on-left, then this tile should <br>> be marked as drive-on-left. That way most of roundabouts would look <br>> correctly when navigating.<br>+1, esp. if you take care to have reasonable tile borders. In my eyes, a value near 50%<br>should produce a warning. <br><br>> <br>> Perfect solution would be to make tile splitting along country border. <br>> But if we can't do that, then maybe we could get statistically best <br>> settings for drive-on flags?<br>That's a very interesting point. If I got that right, the IMG format doesn't<br>require a rectangular tile border, so we would need some changes:<br>1) tile splitter should allow to create such tiles. The bounding polygon <br>option was a first step into this direction. <br>2) tile splitter has to pass the information about the used polygon <br>within each tile. I don't know an "official" way, so maybe this means<br>to add a way with a tag like splitter:tile-border which has to be filtered<br>by mkgmap?<br><br>Gerd<br> <br></div> </div></body>
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