On Friday 31 July 2009 17:15:12 80n wrote:
On Fri, Jul 31, 2009 at 3:42 PM, Tels nospam-abuse@bloodgate.com
wrote:
On Thursday 30 July 2009 09:13:37 Daniel Kinzler wrote:
Hi all
I'm wondering if any thought has been given to rendering maps to SVG. I'm asking that especially in the light of http://techblog.wikimedia.org/2009/07/svg-for-all-with-flash/ which might give use in-browser display of SVG, and perhaps even interactive SVG. Using that with OSM would be really cool!
Now, afaik Mapnik supports SVG rendering. But I suspect that interactive vector maps would work differently from interactive pixel-based maps: you could scale smoothly, could use much bigger tiles, and would use level-of-detail layers instead of pre-scaled tiles...
Does somethign like that exist yet?
I toyed around with the idea, but I think SVG would not be able to handle a few hundred thousand objects that you get on zooming to level 11 and lower. Someone prove me wrong please :)
The trick, surely, is to filter the data at that zoom level so that you don't try to render too much.
Erm, eys, but when you render the inner parts of a big city like Bonn, or Berlin, you end up with a couple of ten thousands streets alone, not minding the POIs, etc.
Outputting that purely all in SVG and giving it a browser to render in real-time sounds tricky to me.
That is why I choose a canvas solution, not SVG. For instance, if you want to pan the map with pre-rendered canvas elements (caption-less), you need only to move the few canvas tiles, then maybe rerender the labels. With everything in SVG, each pan from the user would need the browser to rerender the whole SVG (probably).
Of course, I haven't tried it, just wish I had more time for these things :(
All the best,
Tels