[OSM-talk] Parking symbols: YUCK!

[Robert (Jamie) Munro]

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Dave Stubbs wrote:
| On Mon, Feb 25, 2008 at 2:24 PM, Robert (Jamie) Munro
<rjmunro at arjam.net> wrote:
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|> Dave Stubbs wrote:
|>  | On Sun, Feb 24, 2008 at 11:14 PM, Robert (Jamie) Munro
|>  | <rjmunro at arjam.net> wrote:
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|>  |>
|>  |>  Tom Hughes wrote:
|>  |>  | In message <47C0892E.10708 at frankieandshadow.com>
|>  |>  |           David Earl <david at frankieandshadow.com> wrote:
|>  |>  |
|>  |>  |> Unfortunately removing the related node isn't going to work,
because
|>  |>  |> Mapnik won't then render parking symbols. And it is a lot of work
|>  to do
|>  |>  |> that.
|>  |>  |
|>  |>  | I believe it will - as far as I know mapnik has rendered those
|>  |>  | symbols for parking areas for some time.
|>  |>  |
|>  |>  |> Since we have contradictory behaviour in the two renderers we
can't
|>  |>  |> resolve this automatically unless osmarender can look and see on
|>  the fly
|>  |>  |> if there is a P node inside the area it is trying to do one for
|>  |>  |> automatically.
|>  |>  |
|>  |>  | I believe it is fundamentally wrong to add nodes which duplicate
|>  |>  | areas, although I know it is quite common.
|>  |>
|>  |>  I agree with this wholeheartedly. 1 item on the ground should be
1 item
|>  |>  in the database. What no one else has suggested is that if you
really
|>  |>  need to put something in the DB twice, then at least use a
relationship
|>  |>  to link the DB objects together.
|>  |>
|>  |>  I expect that someone with PostGIS knowledge can construct a
query to
|>  |>  quickly identify all the parking nodes inside parking areas and
produce
|>  |>  a list. I'm sure that many of us could write a perl or python
script to
|>  |>  take this list and delete or relate the nodes.
|>  |>
|>  |
|>  | As of the last planet there are 5881 such nodes. Interestingly there
|>  | are one or two car parks with two or three nodes in them.
|>  | My hugely overcomplicated postgis query could delete these for mapnik
|>  | in about 30 seconds if it was important to do so.
|>
|>  Can we have a vote on what to do next?
|>
|>  Options:
|>  1. Delete the nodes inside areas, make sure the areas are set
|>  access=public and any tagging (e.g. car park name) is copied across.
|>  2. Add a relationship between car park nodes and the area they are in
|>  and do nothing else.
|>  3. Add a relationship between car park nodes and the area they are in
|>  and change the tagging of the node somehow.
|>
|>  On that list, my vote would be, in order of preference, 1,3,2
|>
|
| You missed option 4:
|   - do nothing to the data and get the renderers etc to sort it out

You can add option 4 to the wiki if you want, as long as you can propose
how the renderers are going to sort it out. :-)

Relationships are designed for grouping things together. Doing nothing
is really option 2 - Dave Stubbs has proved it's possible to extract the
data easily, I'm prepared to write the code to add the relationships if
no one else will.

I can't see how option 4 could ever be preferable. If a renderer doesn't
want to use the relationship, they don't have to. If they need it and it
isn't there, we're going to be stuck with double symbols.

Robert (Jamie) Munro
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