[OSM-dev] Line segment with width primitive?

Morten Kjeldgaard mok at bioxray.dk
Sat Sep 11 10:06:56 BST 2010


I think it would be extremely useful to have a line segment with a  
width primitive.

As an example of where this could be of use, is a thin strip of trees  
lining a field (say, 15m wide, 500m long). Currently, the only way to  
map this is using a very long, thin polygon. However, it would be much  
simpler (and space-saving) to store this as a simple way tagged with  
"width=15m". The renderers would draw this as a rectangle, the length  
of the way and with the specified width. Another example is a long,  
thin stretch of grass, for example between buildings or between roads.

In principle, this primitive could be used to draw all kinds of  
rectangular and square areas. A way of 100m, with a width of 100m  
would be rendered as a 100x100m square.

The width=* could also be applied to the end nodes of a line segment.  
If the widths are different, the area rendered would be a trapeze.  
With several joining line-segments with varying widths, more  
complicated shapes could be reproduced.

I think this primitive could substitute many simple polygons  
(buildings?), and it would increase the data-density and processing  


PS: I realize that another keyword beside "width" is probably needed,  
as not to confuse with the width of a road (not used by the renderers,  
to my knowledge).

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