The Geomerative library includes TrueType support.

Processing contains all of the functionality you'd need to implement support for any sort of file format. If you would like to import BMP files (or write them), you merely need to implement the format parser yourself.

wotsit.org is a good site for finding the documentation for file formats. There are 4 listings for the BMP file format under the Graphics Files category.

It is probably easier, though, to convert the files using a different program and use something else. BMPs are bloated and archaic... I can't imagine any advantage they'd have over anything else. PNGs are natively supported and are a much more favorable format, with lossless compression, full colors, and 8-bit transparency.

The language strives to provide many useful functions, but it is not possible for them to implement every file format that people may want, and patents may restrict them from doing so. The same goes for other features too, e.g. I want to make a chess game, where is the chess() function

also read the reference:
http://processing.org/reference/loadFont_.html
http://processing.org/reference/createFont_.html

it explains how loadFont works, and how to use createFont to load a ttf.