Redoing the animation example

desktop/sources/lisp/prelude.lisp

@@ -17,4 +17,18 @@
     (if 
       (gt v 1) 
       (times 
-        (sub v 1) f))))
+        (sub v 1) f))))
+; convert deg to radians
+(defn deg-rad 
+  (deg) 
+  (mul deg 
+    (div PI 180)))
+; position on a circle from angle
+(defn circle-pos 
+  (cx cy r a) {:x 
+  (add cx 
+    (mul r 
+      (cos a))) :y 
+  (add cy 
+    (mul r 
+      (sin a)))})