working with Processing in clojure (assumes Processing jars have been imported / specified on project.clj)

app.clj

(ns processing-test.core
    (:gen-class)
  (:require
    [processing-test.sketch :as sk])
    (:import
      [processing.core PApplet]))

(defn -main
  "I don't do a whole lot ... yet."
  [& args]
  (PApplet/runSketch (into-array String ["--present" "sketch"]) sk/sketch))

sketch.clj

(ns processing-test.sketch
  (:import
    [processing.core PApplet]))


(def sketch
  (proxy [PApplet] []

    (settings []
     (proxy-super size 300 300)
      )

    (setup []     
      )


    (draw [])

    ))