Merge pull request #45 from clojerl/15-rotate-functions

[#15] Add rotate and with-rotation functions

src/doodler/core.clje

@@ -350,6 +350,20 @@
   ([tx ty] (p/translate *canvas* tx ty))
   ([tx ty tz] (throw "Unsupported")))
 
+(defmacro with-rotation
+  [rotation & body]
+  `(let [tr# ~rotation]
+     (doodler.core/push-matrix)
+     (try
+       (apply doodler.core/rotate tr#)
+       ~@body
+       (finally
+         (doodler.core/pop-matrix)))))
+
+(defn rotate
+  [angle]
+  (p/rotate *canvas* angle))
+
 ;; Drawing
 
 (defn arc

src/doodler/examples/tailspin.clje

@@ -28,6 +28,7 @@
 
 (defn draw-state [state]
   (d/background 255)
+  (d/stroke 0)
   (d/fill 0)
   (let [dots (:dots state)]
     (loop [curr (first dots)

src/doodler/examples/transformations.clje

@@ -0,0 +1,22 @@
+(ns doodler.examples.transformations
+  (:require [doodler.core :as d]))
+
+(defn setup
+  []
+  (d/frame-rate 10))
+
+(defn draw []
+  (d/stroke (rand-int 256) (rand-int 256) (rand-int 256))
+  (d/fill (rand-int 256) (rand-int 256) (rand-int 256))
+  (d/with-translation [(float (rand-int 100)) (float (rand-int 100))]
+    (d/with-rotation [(float (rand-int 360))]
+      (d/rect 0.0 0.0 10.0 10.0))))
+
+(d/defsketch sketch
+  :title "Transformations"
+  :size [100 100]
+  :setup setup
+  :draw draw
+  :features [:resizable :keep-on-top]
+  :bgcolor [200]
+  :open-gl true)