Remove joints whose bodies no longer exist

src/play_clj/core.clj

@@ -19,7 +19,7 @@
             IsometricStaggeredTiledMapRenderer
             IsometricTiledMapRenderer
             OrthogonalTiledMapRenderer]
-           [com.badlogic.gdx.physics.box2d World]
+           [com.badlogic.gdx.physics.box2d Joint World]
            [com.badlogic.gdx.scenes.scene2d Actor Stage]))
 
 (load "core_global")

src/play_clj/core_graphics.clj

@@ -15,11 +15,18 @@
 (defn ^:private update-box-2d!
   [{:keys [^World world]} entities]
   (when-not (.isLocked world)
-    (let [bodies (u/gdx-array [])]
-      (.getBodies world bodies)
-      (doseq [body bodies]
+    (let [arr (u/gdx-array [])]
+      ; remove bodies that no longer exist
+      (.getBodies world arr)
+      (doseq [body arr]
         (when-not (some #(= body (:body %)) entities)
-          (.destroyBody world body))))))
+          (.destroyBody world body)))
+      ; remove joints whose bodies no longer exist
+      (.getJoints world arr)
+      (doseq [^Joint joint arr]
+        (when (and (not (some #(= (.getBodyA joint) (:body %)) entities))
+                   (not (some #(= (.getBodyB joint) (:body %)) entities)))
+          (.destroyJoint world joint))))))
 
 (defn ^:private update-screen!
   ([{:keys [world g2dp-listener]}]

src/play_clj/utils.clj

@@ -88,7 +88,7 @@
 (defn create-field-setters
   [obj {:keys [] :as args}]
   (map (fn [[k v]]
-         `(set! (. ~obj ~(symbol (key->camel k))) (eval ~v)))
+         `(set! (. ~obj ~(symbol (key->camel k))) ~v))
        args))
 
 (defmacro fields!