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

دار الآثار للنشر والتوزيع-صنعاء Dar Alathar-Yemen hubaishan at outlook.com
Sat Nov 10 11:11:08 UTC 2018

I think I did not understand you, because in https://overpass-turbo.eu/

outputs nearly all countries
and query

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<mailto: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<mailto: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<mailto: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.

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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