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.ke...@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 <hubais...@outlook.com<mailto:hubais...@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.
_______________________________________________
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging
  • ... دار الآثار للنشر والتوزيع-صنعاء Dar Alathar-Yemen
    • ... OSMDoudou
    • ... Kevin Kenny
      • ... دار الآثار للنشر والتوزيع-صنعاء Dar Alathar-Yemen
        • ... OSMDoudou
          • ... دار الآثار للنشر والتوزيع-صنعاء Dar Alathar-Yemen
            • ... Kevin Kenny
            • ... Mateusz Konieczny
              • ... Dave Swarthout
        • ... Mateusz Konieczny
          • ... دار الآثار للنشر والتوزيع-صنعاء Dar Alathar-Yemen
            • ... Marc Gemis
        • ... Martin Koppenhoefer

Reply via email to