Start working on turtle graphics

src/ludus/turtle-graphics.clj

@@ -0,0 +1,77 @@
+(ns ludus.turtle-graphics
+ 	(:require [quil.core :as q]
+   	[quil.middleware :as m]))
+
+(defn setup []
+ 	(q/frame-rate 60)
+ 	(q/color-mode :rgb)
+ 	{:position [0 0]
+ 		:path []})
+
+(def path (atom []))
+
+(defn turns->degrees [turns] (mod (+ 90 (* -360 turns)) 360))
+
+(turns->degrees -0.25)
+
+(defn degrees->turns [degs] (mod (/ (- degs 90) -360) 1))
+
+(degrees->turns 360)
+
+(defn add [[x1 y1] [x2 y2]] [(+ x1 x2) (+ y1 y2)])
+
+(defn sub [[x1 y1 [x2 y2]]] [(- x1 x2) (- y1 y2)])
+
+(defn scale [[x y] m] [(* x m) (* y m)])
+
+(defn heading->vec [heading]
+ 	(let [degs (turns->degrees heading)]
+  		[(Math/cos degs) (Math/sin degs)]))
+
+(defn vec->heading [[x y]]
+ 	(degrees->turns (Math/atan2 x y)))
+
+(defn forward [steps]
+ 	(let [prev (peek @path)
+      		heading (:heading prev)
+      		unit (heading->vec heading)
+      		move (scale unit steps)
+      		curr (update prev :postion #(add % move))]
+  		(swap! path #(conj % curr))))
+
+(defn back [steps] (forward (* -1 steps)))
+
+(defn right [turns] 
+ 	(let [prev (peek @path)
+      		curr (update prev :heading #(- % turns))]
+  		(swap! path #(conj % curr))))
+
+(defn left [turns] (right (* -1 turns)))
+
+(comment
+ 	:path {:start [x y] :end [x y] :color [R G B]}
+ 	)
+
+(defn update-state [state]
+ 	{:color (mod (+ (:color state) 0.7) 255)
+ 	 :angle (+ (:angle state) 0.1)})
+
+(defn draw-state [state]
+ 	(q/background 240)
+ 	(q/fill (:color state) 255 255)
+ 	(let [angle (:angle state)
+      		x (* 150 (q/cos angle))
+      		y (* 150 (q/sin angle))]
+ 	  (q/with-translation [(/ (q/width) 2) (/ (q/height) 2)]
+    		(q/ellipse x y 100 100))))
+
+(defn ludus-draw []
+ 	(q/defsketch sketch
+   	:title "Hello Ludus"
+   	:size [500 500]
+   	:setup setup
+   	:update update-state
+   	:draw draw-state
+   	:features []
+   	:middleware [m/fun-mode])
+ 	:ok)