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RE: Are centimeters second class units?

From: Adam Van Den Hoven <Adam.Hoven@bluezone.net>
Date: Tue, 12 Dec 2000 12:38:10 -0800
Message-ID: <00BB1956AE40D411B5B60050DA27311F121BEB@mail1.bluezone.net>
To: "SVG Mailing List (E-mail)" <www-svg@w3.org>
Actually, the solution is very simple:
(I had sent something directly to Elliotte by acciden tbut this is a better
thought)

Since we're looking at a map, start with the following (lets assume we are
mapping a region 100km X 100 km)

<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 20001102//EN"
"http://www.w3.org/TR/2000/CR-SVG-20001102/DTD/svg-20001102.dtd">
<svg width="10000000cm" height="10000000cm">
		<!-- you'll probably also want to set the viewbox so that
the top left accurately points to 0,0 in the projection -->
  <desc>A map</desc>
  <!-- Map vectors here -->
</svg>

You now have a very happy map. Then the consumer of that map needs to know
the dimesions of what he's working with and simply scale it appropriately
with something like:

	<g transform="scale(0.000001)"> <!-- That should give you 1cm:10km
resolution -->

<!-- It might be worth while extending the available units to include some
real world scale (say metres, km, miles and feet) so that we don't run into
this problem. -->

The nice thing about this way of doing things is it lets you separate your
data from the presentation (which is part of the point). 

Adam van den Hoven

> -----Original Message-----
> From: Wilson AJ [mailto:Wilson_AJ@prc.com]
> Sent: Tuesday, December 12, 2000 12:14 PM
> To: 'Arnold, Curt'; 'Elliotte Rusty Harold'
> Cc: 'www-svg@w3.org'
> Subject: RE: Are centimeters second class units?
> 
> 
> Isn't the point here though that you cannot develop a reusable
> objects that can be placed to different drawings?  Doesn't
> using arbitrary measurement units requires one to know the
> viewbox "dimensions" that are going to be used in advance?
> 
> > -----Original Message-----
> > From: Arnold, Curt [mailto:Curt.Arnold@hyprotech.com]
> > Sent: Tuesday, December 12, 2000 11:26 AM
> > To: 'Elliotte Rusty Harold'
> > Cc: 'www-svg@w3.org'
> > Subject: RE: Are centimeters second class units?
> > 
> > 
> > You could always use foreign attributes or elements to 
> > contain the actual physical dimensions.  These wouldn't be 
> > used by SVG, but they would keep the information handy for 
> > your scripts so that if you
> > do something like stretch a room, you wouldn't stretch all 
> > the furniture also.
> > 
> 
Received on Tuesday, 12 December 2000 15:46:09 GMT

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