oo-circles-toxic-03.clj

(ns oo-circles.core
  (:use quil.core)
  (:import [toxi.geom Vec2D]))


(def WIDTH 800)
(def HEIGHT 600)

(def num-circles 30)

(def center-vec (Vec2D. (/ WIDTH 2) (/ HEIGHT 2)))


(defn mk-circle []
  "Circle object constructor"
  (let [position (new Vec2D 0 0)]
    {:position position
     :velocity (atom (random TWO-PI))
     :center-radius (atom 80)
     :noise-inc (atom (random 10000))
     :radius   (+ 5 (random 5))
     :fill-col (color (random 55) (random 155) (random 180 255))
     :alph     (+ 55 (random 200))}))


(defn make-circles [n]
  "Return a lazyseq of n circles created with mk-circle"
  (repeatedly n mk-circle))


(defn update-circle [{:keys [position velocity center-radius noise-inc radius] :as circle}]
  "Creates a new position variable from the result of adding current position and velocity"
  (let [new-position-x (+ (.x center-vec) (* (cos @velocity) @center-radius))
        new-position-y (+ (.y center-vec) (* (sin @velocity) @center-radius))]
    (swap! noise-inc + 0.1)
    (swap! center-radius + (* (noise @noise-inc) 3))
    (swap! velocity + 0.01)
    (assoc circle :noise-inc @noise-inc)
    (assoc circle :center-radius @center-radius)
    (assoc circle :velocity @velocity)
    (assoc circle :position (new Vec2D new-position-x new-position-y))))


(defn update-circles [circles]
  (map update-circle circles))


(defn draw-circle [{:keys [position radius fill-col alph]}]
  (no-stroke)
  (fill fill-col alph)
  (ellipse (.x position) (.y position) radius radius))


(defn setup []
  (background 0)
  (smooth)
  (set-state! :circles (atom (make-circles num-circles))))


(defn draw []
  (no-stroke)
  (fill 0 8)
  (rect 0 0 WIDTH HEIGHT)
  
  (let [circles (state :circles)]
    (swap! circles update-circles)
    (doseq [c @circles]
      (draw-circle c))))


(defn mouse-released []
  "Simply concat a new set of circles to the existing pool."
  (swap! (state :circles) concat (make-circles num-circles)))


(defsketch oo-circles
  :title "OO Circles Toxic"
  :setup setup
  :draw draw
  :mouse-released mouse-released
  :size [WIDTH HEIGHT])

project.clj

(defproject oo-circles "0.1.0-SNAPSHOT"
  :description "FIXME: write description"
  :url "http://example.com/FIXME"
  :license {:name "Eclipse Public License"
            :url "http://www.eclipse.org/legal/epl-v10.html"}
  :dependencies [[org.clojure/clojure "1.4.0"]
                 [quil "1.6.0"]])

Open to suggestions for optimisation