Using SVG for icons (and scaling)

[Benjamin Summerton <def pri pub gmail com>]

I'm currently developing an application (using the Gtk 3.x series).  I've
got some icons I'd like to use (for buttons n' stuff) and they are in SVG
format.

It's pretty trivial to turn these into a PNG, and then into my .glade
file.  But I'm a bit concerned about how much smaller bitmap images will
look on high DPI displays.

I've been trying to search for the information on how to achieve this, but
I haven't found much of anything.  So to summerize:

How do I use an SVG as an Icon where I can scale it based on the DPI?

And if I can't do this in Glade, how would I do this in code?

Thanks,
~Ben