HeatMapFeatureLayer

[patrickarlt]

We should leveage heatmap js to build dynamic headmaps based on FeatureLayers

http://www.patrick-wied.at/static/heatmapjs/example-heatmap-leaflet.html

[patrickarlt]

Since this is a very specific use case and would need external dependancies it wont be part of the Esri Leaflet core, but instead would live under something like dist/plugins or dist/extras and throw an error if h337 is not found. Yes h337 is the proper namespace for heatmap.js.

[patrickarlt]

After asking around at PDX JS it looks like there are several other heatmap implementations we could try.

https://github.com/pyalot/webgl-heatmap uses WebGL so its fast but has rather limited browser support.

http://www.labs.ecotrust.org/eknuth/hexbin/ Organizes content in hexbins which has the same purpose in showing density as heatmaps but would be very performant and easy to draw.

http://zat.com/apps/heatmap.html Uses L.DivIcon and radial gradients which could be promising but might not perform well under a heavy load of points.

[patrickarlt]

Leaflet.heat seems like it could be a likely candidate for this.

[patrickarlt]

Basic version of this is done but should eventually broken out into its own repository.

[ghost]

API docs also need updating. Should we wait with this until you extract this plugin into its own repo?

[patrickarlt]

Closing in favor of #369.