out of bounds doesn't result in crappy zoom.

desktop/src-common/advent/actions.clj

@@ -89,7 +89,7 @@
 (defn pan-to [screen entities x y scale-fn & [ease duration]]
   (let [ease (or ease tween/ease-in-out-quadratic)
         duration (or duration 3.0)
-        target-zoom (min 0.95 (max 0.75 (scale-fn [x y])))
+        target-zoom (min 0.95 (max 0.75 (scale-fn [(max 0 (min 319 x)) (max 0 (min 240 y))])))
         current-zoom (get-in entities [:cam :zoom] 1.0)
 
         ;; don't zoom  if it's a subtle difference