title: How do I have Emacs load a font from a file?
body: <p>In the interest of making my emacs setup more portable, I'd like to be able to set the current font by specifying a file rather than a font name, i.e. "Load ~/config/myfont.ttf and use size 12". Is there a way to do that in my .emacs? All the instructions I've found assume the font is already installed on the system. I'm using the XFT support on Linux, so a linux specific hack would be OK but I'd prefer something that would work on all targets. </p>
  
  <p>Update: To be clear, I'm using a font that isn't standard on Windows / OS X / Linux. I'm not just looking to set a different font based on platform, but to specify a specific font file that I have (TTFs work on Windows and Linux, if not on Mac I'll get another version of the file but I still want to specify the font via file rather than name).</p>