[OpenLayers-Users] Combining WMTS of api.geo.admin.ch with G* Maps or OpenStreetMap

[Stefan Keller]

Dear all

I'd like to combine the WMTS of api.geo.admin.ch with other WMTS (like
G* Maps or OpenStreetMap) using OpenLayers.
These other WMTS are not in EPSG:21781 but typically EPSG:900913
(being an alias to EPSG:3857).
Here we have a raster re-projection problem.
According to [1] this seems feasible by using proj4js - but I doubt if
this works and how performant it is (OpenLayers loads up to 60 tiles
which all have to be reprojected.)
Does anyone have experience with this?

Yours, Stefan

P.S. I know MapProxy but I really want to do this reprojection in the client.

[1] http://wiki.openstreetmap.org/wiki/OpenLayers_Simple_Example#Use_Proj4js_for_other_transformations