W3C home > Mailing lists > Public > www-svg@w3.org > November 2011

TPAC discussion on tiling and layering

From: Andreas Neumann <a.neumann@carto.net>
Date: Fri, 04 Nov 2011 14:44:58 +0100
To: www-svg <www-svg@w3.org>, Köbben Barend <kobben@itc.nl>
Message-ID: <387873a0a27f119424ee35933d98c399@carto.net>
 Hi,

 Before the tpac-discussion around tiling and layering I wanted to 
 submit my thoughts about tiling. Maybe you could consider them during 
 discussion:

 * Antialiasing issues at tile borders / artefacts that make tile 
 borders visible - any properties/settings to avoid this, esp. in the 
 light that the tile borders are always horizontal/vertical?

 * polygons with stroke will result in unwanted strokes at tile borders 
 (e.g. a lake with a fill and a stroke will be cut in two parts at the 
 tile border) - we don't want the strokes to appear at the tile border - 
 but we also do not want to specify the path two times for fill and 
 stroke. Well maybe this could be solved by an intelligent tiling tool 
 that generates open instead of closed paths?

 * make sure cache works fine for tiles - more an implementation issue

 * navigation issues (viewbox, zoom tools): Will there be any standard 
 navigation tools for zooming and panning for these multilevel/tiled 
 images? If not (most likely ther won't be standard navigation tools) - 
 how should the javascript zoom to trigger the various scale/zoom levels? 
 By setting a different viewBox or by setting the scale or both?

 * fixed tiling/naming scheme: do we propose a fixed tiling scheme, such 
 as used in TMS/OpenLayers/Google Maps/Quadtree - see 
 http://www.maptiler.org/google-maps-coordinates-tile-bounds-projection/ 
 or are users free to use whatever tiling scheme they want?

 Sorry - I haven't dived into the issue a lot - maybe it would be worth 
 contacting the OpenLayers people who seem to have quite some experience 
 with tiling.

 Thanks and looking forward to read the notes on the discussion!

 Andreas

 --
 Andreas Neumann
 Böschacherstrasse 10A
 8624 Grüt (Gossau ZH)
 Switzerland
Received on Friday, 4 November 2011 13:48:03 GMT

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