Inspired by this Twitter post: https://twitter.com/LorenBednar/status/398200950969483264/

builder-issues.clj

(ns builder-issues
  (:use quil.applet)
  (:use quil.core))

(def screen-w 800)
(def screen-h 800)

(defn- rand-color []
  (repeatedly 3 (fn [] (rand-int 255))))

(defn- setup []
  (background 0)
  (smooth)
  (no-stroke)
  (no-loop)
  (ellipse-mode :center)
  )

(defn draw []
  (let [rows 20
        columns 8
        outer-radius 150
        ring-width 30
        inner-radius (- outer-radius ring-width)
        delta-x 50
        delta-y 40]
    (translate (/ outer-radius 2) (/ outer-radius 2))
    (doseq [r (range rows)]
      (push-matrix)
      (doseq [c (range columns)]
        (apply fill (rand-color))
        (ellipse 0 0 outer-radius outer-radius)
        (apply fill (rand-color))
        (ellipse 0 0 inner-radius inner-radius)
        (translate (- outer-radius delta-x) 0)
        )
      (pop-matrix)
      (translate 0 delta-y)
      )
    )
    (save "builder-issues.png")
  )

(sketch
  :title "builder-issues"
  :setup setup
  :draw draw
  :size [screen-w screen-h]
  :renderer :java2d   ; :p2d is awful here and using it results in strange lines in fills.
  )