Aphorism two

src/aphorisms/two.clj

@@ -0,0 +1,50 @@
+(ns aphorisms.two
+  (:require [quil.core :as q]
+            [quil.middleware :as m]))
+
+(def radius 75)
+(def color-progress 1.7)
+
+(defn settings []
+  (q/pixel-density (q/display-density)))
+
+(defn setup []
+  ; Set frame rate to 30 frames per second.
+  (q/frame-rate 30)
+  ; Set color mode to HSB (HSV) instead of default RGB.
+  (q/color-mode :hsb)
+  ; setup function returns initial state. It contains
+  ; circle color and position.
+  {:color 0})
+
+(defn update-state [state]
+  ; Update sketch state by changing circle color and position.
+  (assoc state :color (mod (+ (:color state) color-progress) 255)))
+
+(defn draw-state [state]
+  (q/background 240)
+  (q/no-fill)
+  (q/with-translation [(/ (q/width) 2)
+                       (/ (q/height) 2)]
+    (dotimes [i 18]
+      (let [color (- (:color state) (* i color-progress))
+            angle (- (/ (* q/TWO-PI (q/frame-count)) 60) (* i (/ q/PI 6)))
+            x (* radius (q/sin angle))
+            y (* radius (q/cos angle))]
+        (q/stroke color 255 255)
+        (q/line (* 0.6 x) (* 0.6 y) x y)))))
+
+(q/defsketch aphorism-two
+  :title "Two"
+  :size [500 500]
+  :settings settings
+  ; setup function called only once, during sketch initialization.
+  :setup setup
+  ; update-state is called on each iteration before draw-state.
+  :update update-state
+  :draw draw-state
+  :features [:keep-on-top]
+  ; This sketch uses functional-mode middleware.
+  ; Check quil wiki for more info about middlewares and particularly
+  ; fun-mode.
+  :middleware [m/fun-mode m/pause-on-error])