I need directions on how to get started with a virtual math font... I'd like to take an existing math font, say Latin Modern, and replace certain glyphs by their corresponding ones from an OpenType font, say Minion Pro. (Proper math kerning won't be an issue at the moment since I'm having in mind a proof-of-principle type of thing.) How would I do that?
It depends on your goal. For instance if you want to support minion math, and it's not an otf font, then you need tfm with the right metrics. Given that they are in default tex encoding, you then just need to set up a virtual font definition (you can look into px-math.lfg to see how that is done for palatino). If your fonts have lots of exceptions you might need to create additional vectors.
This sounds complicated... almost as I expected ;-) I'm not quite sure what these vectors are good for... so for the sake of a simple scenario: I'd like to start with the standard Latin Modern math fonts but grab the lower case italic \alpha from the OpenType font MinionPro-It.otf. Would I need to write such an additional vector? Oliver