MapInfo .MAP files contain metadata that actually keeps a counts of lines
(2 point, polyline and arc), regions (regions, rects, ellipses), points
(and multipoints) and text. This metadata does not exist for server tables
unfortunately. This metadata in addition to the overall MBR of the data is
used to determine default layer order. It is also used to enable the style
override buttons for a layer in the layer control, for example and is of
some help in doing cartographic legends.
It is not of use in doing a spatial search, however. So, as nifty as
Martin's suggestion would be, it would have to be done by internally
querying records and their object types. This would essentially be no
different than a generic option to draw order by criteria, as I mentioned.
The criteria would be object type.
Eric Blasenheim
Software Architect
MapInfo Corporation
Mats Elfstr�m
<[EMAIL PROTECTED]>
To
09/01/2004 05:12 <[EMAIL PROTECTED]>
AM cc
[EMAIL PROTECTED],
"MapInfo-L"
<[EMAIL PROTECTED]>
Subject
Ang. MI-L Drawing Order
Hi Martin!
A splendid idea, and probably quite feasible to implement within the
current architecture.
My suggestion for draw order would be (top down)
Text > Points > Lines > Regions
But it would of course not solve Christines original question, where she
wanted to control the draw order of individual lines in a line layer.
Another interesting research project is to find out how MapInfo determines
the kind of table when deciding the layer order.
As you all know, opening a mix of tables and simply load them into a
mapper most often produces a reasonable order of points on top of regions
and so on.
There is no time to scan each table to find the predominant feature type,
so I guess this in some way is an attribute of the table known beforehand.
H�lsning/ Best regards Mats.E
________________________
FB Engineering AB
S�dra F�rstadsgatan 26
211 43 Malm�
Observera att vi byter telefonnummer 1 september!
Tel: 040-665 64 80 fr�n 1/9 040-660 2550
Mobil: 0705-27 60 27 �ndras inte
Fax: 040-665 69 90 fr�n 1/9 040-660 2599
e-post: [EMAIL PROTECTED]
http://www.fbe.se
"Martin Higham" <[EMAIL PROTECTED]>
2004-09-01 10:39
S�nd svar till
<[EMAIL PROTECTED]>
Till
"MapInfo-L" <[EMAIL PROTECTED]>,
<[EMAIL PROTECTED]>
Kopia
�rende
MI-L Drawing Order
What does intrigue me is the issue of layers containing 2 or more types of
object.
If you're going to allow points, lines and regions to be stored together
(sometimes useful though its a no-no from a database point of view), why
wouldn't you force points to draw on top of lines on top of regions ?
If this "redraw order by object type" functionality was implemented, then
it
would make multi-object-type layers useful for map annotations.
Best Regards,
Martin Higham
Avantra Geosystems
ph (61 3) 8504 0428 0425-730-428
fx (61 3) 9596 7997
www.avantra.com.au
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> Sent: Wednesday, 1 September 2004 03:38
>
> <...cut...>
>
> As to why we do not have this feature, I would start a different thread
on
> that. The short answer is that we could but it is unclear how one would
> decide what was drawn when. If the criteria was based on data, the
> implementation would best do queries just as you can now. If the
criteria
> was arbitrary, then you have some draw order list, which is only
> manageable
> for small amounts of data and will be slow because the draw code can't
use
> the spatial index.
---------------------------------------------------------------------
List hosting provided by Directions Magazine | www.directionsmag.com |
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Message number: 13160
---------------------------------------------------------------------
List hosting provided by Directions Magazine | www.directionsmag.com |
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
Message number: 13167
