[Tagging] رد: رد: New rag to draw node name with rotate angle

Marc Gemis marc.gemis at gmail.com
Sat Nov 10 12:39:48 UTC 2018


Because all countries are mapped with relations of type boundary...

Op za 10 nov. 2018 12:12 schreef دار الآثار للنشر والتوزيع-صنعاء Dar
Alathar-Yemen <hubaishan at outlook.com:

> I think I did not understand you, because in https://overpass-turbo.eu/
>
> Query:
>
> node
>
>   [place=country];
>
> out;
>
>
>
> outputs nearly all countries
>
> and query
>
> area
>
>   [place=country]
>
>   ;
>
> out;
>
>
>
> outputs only 3 countries
>
>
> ------------------------------
> *من:* Mateusz Konieczny <matkoniecz at tutanota.com>
> *‏‏تم الإرسال:* Saturday, November 10, 2018 12:59:29 PM
> *إلى:* Tag discussion, strategy and related tools
> *‏‏الموضوع:* Re: [Tagging] رد: New rag to draw node name with rotate angle
>
> Can you give example of a country not
>
> mapped as an area and incorrectly
>
> mapped as a node?
>
> 10. Nov 2018 07:01 by hubaishan at outlook.com:
>
> I am talking about nodes not areas or ways. Most of seas in OSM are tagged
> on node element. Also countries most of them are tagged on node element
>
>
> ------------------------------
> *من:* Kevin Kenny <kevin.b.kenny at gmail.com>
> *‏‏تم الإرسال:* 01/ربيع الأول/1440 09:09 م
> *إلى:* Tag discussion, strategy and related tools
> *‏‏الموضوع:* Re: [Tagging] New rag to draw node name with rotate angle
>
> ‪On Fri, Nov 9, 2018 at 12:06 PM ‫دار الآثار للنشر والتوزيع-صنعاء Dar
> Alathar-Yemen‬‎ <hubaishan at outlook.com> wrote:‬
>
> I suggest new tag to tell map render to draw the node name with a
> specified rotate angle not horizontal. We need this for some seas like Red
> Sea, and Suez Gulf in Egypt.
>
>
> I have serious doubts whether encoding the rendering in the map in such a
> way is a good idea.
>
> A renderer that wished to label an area with an angled label could readily
> determine the angle for itself, by computing the principal axes of the
> area, and if its eccentricity exceeds a specified value, rotating the label
> to align with the major axis.
>
> An even better rendering could be achieved by computing the morphological
> skeleton of the area, and placing the label along some smooth curve that
> approximates the medial axis.
>
> There are also algorithms that handle curved label placement in the
> presence of interfering labels, although they are somewhat less well
> developed. One such is described in Mathieu BARRAULT, "A methodology for
> placement and evaluation of area map labels." _Computers, Environment and
> Urban Systems_ 25 (2001), pp. 33-52.
>
> http://geoinformatics.ntua.gr/courses/admcarto/lecture_notes/name_placement/bibliography/barrault_2001.pdf
>
> Barrault describes the process of choosing a family of circular arcs that
> well approximate the general contour of an area feature. Figure 3 of the
> paper is informative about what criteria his heuristic takes into account
> for 'goodness' of placement. Figures 10 and 11 show what the algorithm
> achieves on sample elongated figures and Figures 13-14 show what it can do
> in the presence of interfering labels.
>
> To place this task on the mapper forecloses on the possibility that a
> renderer can do it better.
>
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>
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