Turns on 3D viewer when needed; implements tetrahedron command. Still
quite several commands remaining for first test construction
(from Rostamian's incenter.html) to work.
With this loaded in under the Firefox debugger, one can see linked WRL files and Java Geometry Applets on arbitrary web pages.
This represents significant progress on #28, but getting more controls and getting it to work in other browsers is still on deck.
Reviewed-on: #38
Co-authored-by: Glen Whitney <glen@studioinfinity.org>
Co-committed-by: Glen Whitney <glen@studioinfinity.org>
