Performance issues with SVG-rendering

[fab1an]

Here is a long discussion about SVG-rendering, which tends to be slow in leaflet, compared to other libraries: https://groups.google.com/forum/#!topic/leaflet-js/_WJquNpdmH0

Norbert Renner did some improvements, some of which change leaflet's functionality, but is there anything endusers can do to improve performance?

non-optimized: https://gist.github.com/nrenner/7535077
optimized: https://gist.github.com/nrenner/5635334

[mourner]

Thanks for the report, I've joined the discussion there.

Regarding easy workarounds, one thing to try is switching to Canvas for rendering http://leafletjs.com/reference.html#global. There can be a problem with hovering performance, but rendering lots of features should be much faster.

[fab1an]

I have tried L_PREFER_CANVAS = true; with 0.7 now, strangely enough it makes my map unusable because there are constantly "moveend" events fired on initialization.

Reproducible in Mac/Firefox and Chrome

[mourner]

This should be improved significantly as of #2290 and some other recent perf improvements like better FeatureGroup events propagation (both SVG & Canvas). @fab1an try the new Canvas code (see changelog and debug/vector/vector2.html for example)

The only optimization left to do is event delegation for SVG, but lets keep this in a separate issue #2315

[mourner]

OK, event delegation implemented, along with some other optimizations, so now SVG should perform much better (in my tests, 3 times faster init/adding of GeoJSON compared to 0.7.1).