Little documentation update

src/dawn/display/animation/Animation.hpp

@@ -17,21 +17,24 @@ namespace Dawn {
       float_t duration = 0;
       Event<> eventAnimationEnd;
       
+      /**
+       * Ticks the animation along. Delta is whatever you want to update the
+       * animation by (in seconds). Animations can overshoot if necessary and
+       * will not be clamped (by default). Subclasses may interpret ticks in
+       * different ways.
+       * 
+       * @param delta Time delta (in seconds) to tick the animaiton by.
+       */
       virtual void tick(float_t delta) = 0;
       
       /**
        * Restart a running animation.
        */
-      virtual void restart() {
-        this->time = 0;
-        this->finished = false;
-      }
+      virtual void restart();
 
       /**
        * Clears an animaton of all its animation items and keyframes.
        */
-      virtual void clear() {
-        this->duration = 0;
-      }
+      virtual void clear();
   };
 }