[OSM-dev] SVG maps and web browsers (was: Re: "Retina" tiles - best way to support them?)

Robert Joop 5313501608656osm at rainbow.in-berlin.de
Sun Jul 1 22:16:04 BST 2012


On 12-06-28 19:09:42 CEST, Stefan de Konink wrote:
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> On 27-06-12 23:12, Robert Joop wrote:
> > Why unreadable? What viewport setting do you use?
> 
> A mapquest widget is used within a native app.

Ok, I had web browsers in mind, out of personal experience.

> > How good is the SVG support on mobile devices?
> 
> <http://en.wikipedia.org/wiki/Scalable_Vector_Graphics#Mobile_profiles>

Well, this doesn’t tell me anything about the quantity and quality of
the support on the devices out in the field.
But this doesn’t concern you, I suppose, as with an app you’ll cover
only a small part of the market (expressed in percentage of devices,
not in percentage of market share, of course), and you can know those
devices fairly well, or bring along the libraries as needed...?

Me, thinking along mobile web browser support, am much more reluctant
when it comes to using SVG heavily on them.

Actually, thinking about it, I wonder whether desktop browsers are up for
it. Following the hint on http://wiki.openstreetmap.org/wiki/SVG
I tried the OSM SVG export, central Cologne at zoom level 15, and loaded
the result in Firefox 3.6 on my netbook: it takes ages to render, some
45 seconds.
The Maperitive example offered there for the center of Dublin takes some
30 seconds to render.

The remainder of the tests is with the OSM Cologne export.
My desktop PC is even slower, 100 seconds with Firefox 3.6.
A more current desktop PC at work:
- 31 seconds with Firefox 3.6
- 6 seconds with Firefox 10
- 2 seconds with Chrome 20

But how about mobile devices? In case anybody's as curious as myself:

Acer A100 (Android 4): some 14 s
  Opera Mobile on it seems slightly faster
Samsung Galaxy Tab 10.1: also some 14 s; panning and zooming almost fast
  enough to use.
Windows Phone 7: no SVG support
HTC Desire, HTC Sensation: I get a blank page!
Apple iPhone: more than 2 minutes till it has finished rendering, and
  then panning and zooming feels glacial as well.
Apple iPhone 4: some 33 s where nothing seems to happen, then the finished
  result appears. Panning and zooming is too slow to use.

(On most devices, one can watch the map getting rendered.)

To sum it up, I believe it is safe to say that heavy use of SVG like those
from OSM exports should only be used on targets you know very well. ;-)

YMMV,
have fun,
rj



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