[josm-dev] Clockwise coastline, anti-clockwise water

[Dirk Stöcker]

On Mon, 7 Jul 2008, Roy Rankin wrote:

> http://wiki.openstreetmap.org/index.php/Tag:natural%3Dwater clearly
> states water should be drawn with land on the left and water on the
> right side ie clockwise. And hence counter-clockwise for land. My
> understanding is that this is required for the case of large bodies of
> waters or large islands composed of more than one way. (Although the
> test is only applied for a single closed way)
>
> I just looked at the patch again, and although I corrected the if
> statements, the error messages are wrong for coastline and water. I
> think that errortype should be "Anti-clockwise coastline" and
> "Anti-clockwise water".

Actually that is not, what the code does.

It checks for

anti-clockwise coastline
anti-clockwise land
clockwise water.

The problem is probably in semantics:

http://wiki.openstreetmap.org/index.php/Tag:natural=coastline
States as anti-clockwise, but regarding the land surrounded by water

http://wiki.openstreetmap.org/index.php/Tag:natural=water
States clockwise, but regarding the water itself and not the land.

Thus it seems the code must be fixed to handle coastline equal to 
water. And I will change the text, so it uses right and left 
instead of clockwise.

Now the remaining questions is natural=land. When should land be in this 
case?
natural=water --> land left
natural=coastline --> land left
natural=land --> land left?

or

natural=water --> tagged element (water) right
natural=coastline --> tagged element (sea) right
natural=land --> tagged element (land) right ?

Other comments?

Ciao
-- 
http://www.dstoecker.eu/ (PGP key available)