The fonts are looked up relative to the filesystem by this piece of code that's called from here when the font is resolved. So, it doesn't look like there's a way to read the font directly from the jar unfortunately.

Hmm... I tracked it down to this if statement breaking the chain:

It gets an url in an absolute format: file:/Users/username/project-name/target/uberjar/project-name-0.1.0-SNAPSHOT-standalone.jar!/public/fonts/

Is there something we could maybe change in this code or am I totally off? I'm not familiar with Java.

I manually inspected the .jar file and the fonts folder is at the specified path

Yeah it should be possible to add support for reading from an input stream, however that part of the code only deals with reading the filenames. Also need to track down places where the content gets read when the font is used. I'll try take a look when I get a chance, but if you're feeling brave in the meantime I can help with a PR as well.

Sure, if you've got patience for it then I'm happy to give it a try. I'll dig deeper tomorrow. Thanks

edit: I've been busy today, I might get to it closer to the weekend.

sounds like a plan

I think I may have misdiagnosed the problem from the beginning.
Here's what I was trying to do originally:

(g2d/g2d-register-fonts [[(-> "fonts/" io/resource .getPath) false]])

;; later when generating the pdf
[:graphics {:under true :translate [0 200]}
       (fn [g2d]
         (doto g2d
           (.setFont (java.awt.Font. "Strato" java.awt.Font/PLAIN 20))
           (.drawString "Testing Graphics" 20 160)))]

And it worked with lein run but not with java -jar ....
What I missed is the fact that I had the "Strato" font installed in the system, which is why the java.awt.Font. was able to pick it up.
I presume this is not the right way to use custom fonts with [:graphics] element?

As for other elements, ie: [:paragraph {:ttf-name "...."}], it appears to be working even from a jar.
I created an example project here https://github.com/smogg/custom-font-test
The output/ folder contains a PDF created with lein run and with java -jar ... (from outside of the project dir to make sure resources/fonts folder is not available).

When you run the test project I also print (g2d/get-font-maps), which correctly displays fonts when lein run (even tho my [:graphics] still looks like a default font) and prints empty map I run the jar.

Ah so that's mostly good news then if it's a problem specific to the graphics element. The java.awt.Font construction looks right, but perhaps the fonts for awt have to be registered differently. You could try using:

(java.awt.Font/createFont java.awt.Font/TRUETYPE_FONT font-input-stream)

Yeah, I've came up with similar code:

    (defn graphics-env []
      (.. java.awt.GraphicsEnvironment
          getLocalGraphicsEnvironment))

    (let [font (java.awt.Font/createFont java.awt.Font/TRUETYPE_FONT (io/input-stream (io/resource "fonts/Strato-linked.ttf")))]
      (.registerFont (graphics-env) font)
      (println (.getAvailableFontFamilyNames (graphics-env )))) ;; font is available

But using it by name, later on, doesn't seem to be working. But I think we are getting closer. It's late in my timezone so I'll continue investigating tomorrow.

Ok, I feel like this is above me. I've tried a lot of things, I see fonts registered but have no idea how to use them without calling the DefaultFontMapper/insertDirectory method, which doesn't work when running from a jar. I tried creating new java.awt.Font's like above, but they don't work if not registered. I tried using FontFactory/getFont but .setFont expects java.awt.font type. I give up for now and will probably use a temp directory with g2d-register-fonts unless you have some pointers?

I can't really think of much else that you could do here unfortunately.