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Re: SVG 1.2 Comment: vector effects

From: Philippe Lhoste <PhiLho@GMX.net>
Date: Tue, 23 Nov 2004 14:55:44 +0100
Message-ID: <41A34160.8040604@GMX.net>
To: Ian Hickson <ian@hixie.ch>
CC: Peter Sorotokin <psorotok@adobe.com>, www-svg@w3.org

Ian Hickson wrote:
 > On Wed, 10 Nov 2004, Peter Sorotokin wrote:
 >> > > - there is a need to "set back" strokes around the markers while
 >> > >   preserving actual path data
 >> > > - there is a need to reuse edges in several shapes (esp. on maps)
 >> >
 >> > Not sure what you mean by these, could you give examples?
 >>
 >> Setback is a break in the line so that it does not overlap with the
 >> marker.
 >>
 >> Sharing edges is when you have a map where there are "countries" and
 >> "borders". You want to define each border between two countries in a
 >> separate path and then plug them together to get the outline of the
 >> country. This involves reversing some of the paths. Sharing information
 >> like that allows one to have smaller files and to manipulate border 
data
 >> more efficiently; it potentially allows renderer to produce
 >> higher-quality antialiasing (shared borders are hard to antialias
 >> properly without knowledge that they are shared).

Good, since I recently worked on optimizing map paths, I thought it 
would be nice to have such a feature to dramatically reduce the size of 
maps in SVG. Think about the USA frontiers...

 > Thanks for the explanations.
 >
 > While I now understand why you feel these new features are important, I
 > still think the current proposed way of doing them is hugely over-
 > engineered and overly complex. It allows shapes to have other paths
 > arbitrarily applied to them, for instance.
 >
 > I mean, come on. If you want a shared edge on a map, just use one path
 > element, with one stroke, instead of having the edge drawn by both
 > elements.

Perhaps because it is important to keep closed paths for countries, for 
filling, for selecting them by clicking inside, etc. Also usually 
countries are defined by one path, sometime with multiple moveto, so 
they are only one shape, for the mainland and the islands for example.

-- 
Philippe Lhoste
--  (near) Paris -- France
--  Professional programmer and amateur artist
--  http://Phi.Lho.free.fr
--  --  --  --  --  --  --  --  --  --  --  --  --  --
Received on Tuesday, 23 November 2004 13:58:30 UTC

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