[OSM-talk] Tiles at Home client update
J.D. Schmidt
jdsmobile at gmail.com
Sun Mar 4 16:45:29 GMT 2007
Jochen Topf skrev:
> On Sun, Mar 04, 2007 at 02:45:02PM +0100, J.D. Schmidt wrote:
>> Jochen Topf skrev:
>>> every client can decide which rendering he wants.
>> Yes, although a client should not enable NoBezier, unless he has the
>> following problems :
>> A) Tiles generated with errors like the ones described in Kristians
>> post, and which has been identified as happening on AMD64 boxes running
>> Gentoo.
>> B) Persons who for some reason can't get Math::Vec installed, but still
>> want to participate in the T at H project.
>>
>>> So some clients will
>>> render their pieces of the map differently from others
>> Yes, just like today, where people are running a mixture of clients
>> version. If you look at the Log page, you can see both Agadir, Athens
>> and Bangkok revisions running.
>
> Which is also a problem. Everybody should use the same renderer. Of
> course there is some overlap until everybody has moved to the new
> version. Thats ok, because we are not re-rendering the whole world each
> time we change the code anyway. But old code and old tiles should eventually
> be worked out of the system by itself. Now, for the first time, you have
> created an incompatibility that will potentially last forever. Thats
> what I am objecting to.
>
>>> leading to
>>> problems at tiles boundaries
>> Those problems do NOT arise from the Beziercurve hinting used. Think it
>> over..
>
> Actually they do.
>
>> The beziercurve hinting does NOT change the position of the endpoint of
>> any ways. Therefore the endpoint at the edges of the tile will be at the
>> exact same point as if they were rendered without the Beziercurve
>> hinting. I'm putting up an example page on the wiki under the
>> tiles at home/problems page, which shows two neighbouring tiles rendered
>> with and without Beziercurvehinting.
>
> This might be true for a point sitting directly on the boundary. But in
> the general case the point is not directly on the boundary so this
> *will* lead to rendering problems.
>
>> It REALLY is a Non-Issue.
>> (Or as they say here in Copenhagen at the moment : Move along folks,
>> nothing to throw stones at.)
>>
>>
>>> and to strange "yesterday it looked
>>> different" problems.
>> That is again not due to the Beziercurve hinting. But due to the fact
>> there are different client versions running, using different stylesheets.
>
> See above.
>
>> The Beziercurve hinting is just that, a subtle hinting that smooth out
>> sharp bends into curves. On zoom level 12, it's hardly possible to see
>> it, on higher zoomlevels it gives the roads a more pleasing look. The
>> only way you can see a difference on the slippymap is when zoomed in to
>> zoom level 15 and beyond, and happen to look at a boundary where there
>> are a curve in a road. And then you still need to look closely, to see
>> the difference, which is only in the esthetics of the render, not in the
>> actual lineup of the tiles.
>
> Nobody said that is was in the lineup of the tiles.
>
> But I see that you see my point which is exactly what you say here.
> There is a difference which affects "the esthetics of the render". And
> thats the whole point. I want the map to look beautiful, I assume you do,
> too. So I don't like this little "difference" and you don't care about
> this difference, because it is too small for you. Well, I do care. And I
> assume other do, too. (If it was that small we didn't need Bezier curves
> in the first place.)
>
>> You didn't misunderstand me, nor what the option do. You just
>> misunderstod the ramifications of the Beziercurve hinting. Whether its
>> because you got some beef with it being implemented this way, or whether
>> its because you didn't understand how the Beziercurve hinting affects
>> the data in the tile, I really can't say.
>
> No need to get personal. Have you considered that I might know a thing
> about how all of this works and my reason for bringing up this topic is
> that I care about nice looking maps?
>
> Jochen
The proof is in the pudding... See the examples on
http://wiki.openstreetmap.org/index.php/Tiles%40home/Problems and then
tell me again it is a major issue ?
J.D. "Dutch" Schmidt
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