How to stop Emacs by returning to rasterized Unicode characters?

Question

I'm trying to create a good Agda environment, but the big stumbling block is Unicode character readability in my Emacs setup.

I am on Mac OS X 10.7 with Emacs (.app) 23.3.1 and have set my default font in Monaco using Set Default Font... in the Options menu. However, for Unicode characters like ≤, ≠, and →, it goes back to some ugly low-resolution bitmap glyphs that don't seem to be Monaco or any other monospaced font that I checked. This is a huge readability problem for frequently reading the Unicode-rich Agda data source.

How can I get Emacs to use cute TTF characters instead?

Here is a screenshot with an enlarged view of some characters in the Emacs buffer (right) and the same characters inserted in the Font Book and displayed in Monaco (left):

Answer 1

Adding the following to my .emacs solved the problem based on this superuser response :

 (if (string-equal system-type "darwin") (set-fontset-font "fontset-default" 'unicode '("Monaco" . "iso10646-1"))) 

Apparently, using the ⌘-T font selection menu is not enough to change the font for all characters, but this configuration bit seems to affect the way all Unicode characters are displayed. Much better!

NB: For Agda's purposes, it turns out that Menlo may be a better choice than Monaco, since Monaco seems to lack useful characters like ∀.