Use reflection to avoid static initializer in g2d-physics

src/play_clj/core_listeners.clj

@@ -173,7 +173,7 @@
    (focus-listener options execute-fn!)])
 
 (defmulti contact-listener
-  (fn [screen options execute-fn!] (-> screen :world class))
+  (fn [screen options execute-fn!] (some-> screen :world class .getName))
   :default nil)
 
 (defmethod contact-listener nil [_ _ _])
@@ -199,7 +199,7 @@
     (add-input! renderer)))
 
 (defmulti update-physics!
-  (fn [screen & [entities]] (-> screen :world class))
+  (fn [screen & [entities]] (some-> screen :world class .getName))
   :default nil)
 
 (defmethod update-physics! nil [_ & _])

src/play_clj/g2d.clj

@@ -1,5 +1,6 @@
 (ns play-clj.g2d
-  (:require [play-clj.utils :as u])
+  (:require [play-clj.entities]
+            [play-clj.utils :as u])
   (:import [com.badlogic.gdx.graphics Pixmap Texture]
            [com.badlogic.gdx.graphics.g2d Animation BitmapFont NinePatch
             ParticleEffect TextureAtlas TextureRegion]

src/play_clj/g2d_physics.clj

@@ -2,9 +2,10 @@
   (:require [play-clj.core :as c]
             [play-clj.math :as m]
             [play-clj.utils :as u])
-  (:import [com.badlogic.gdx.physics.box2d Body BodyDef ChainShape CircleShape
+  (:import [com.badlogic.gdx.math Vector2]
+           [com.badlogic.gdx.physics.box2d Body BodyDef ChainShape CircleShape
             Contact ContactListener EdgeShape Fixture FixtureDef Joint JointDef
-            PolygonShape Transform World]))
+            PolygonShape Transform]))
 
 ; world
 
@@ -14,20 +15,26 @@
   ([gravity-x gravity-y]
     (box-2d* gravity-x gravity-y true))
   ([gravity-x gravity-y sleep?]
-    (World. (m/vector-2 gravity-x gravity-y) sleep?)))
+    ; use reflection to instantiate in order to avoid the static initializer
+    (some-> (try (Class/forName "com.badlogic.gdx.physics.box2d.World")
+              (catch Exception _))
+            .getDeclaredConstructors
+            first
+            (.newInstance
+              (object-array [(m/vector-2 gravity-x gravity-y) sleep?])))))
 
 (defmacro box-2d
   "Returns a [World](http://libgdx.badlogicgames.com/nightlies/docs/api/com/badlogic/gdx/physics/box2d/World.html).
 
     (box-2d 0 0)"
   [gravity-x gravity-y & options]
-  `(let [^World object# (box-2d* ~gravity-x ~gravity-y)]
+  `(let [object# (box-2d* ~gravity-x ~gravity-y)]
      (u/calls! object# ~@options)))
 
 (defmacro box-2d!
   "Calls a single method on a `box-2d`."
   [screen k & options]
-  `(let [^World object# (u/get-obj ~screen :world)]
+  `(let [object# (u/get-obj ~screen :world)]
      (u/call! object# ~k ~@options)))
 
 ; bodies
@@ -213,7 +220,7 @@ such as :on-begin-contact."
 ; misc
 
 (defmethod c/contact-listener
-  World
+  "com.badlogic.gdx.physics.box2d.World"
   [screen
    {:keys [on-begin-contact on-end-contact on-post-solve on-pre-solve]}
    execute-fn!]
@@ -228,8 +235,8 @@ such as :on-begin-contact."
       (execute-fn! on-pre-solve :contact c :old-manifold m))))
 
 (defmethod c/update-physics!
-  World
-  [{:keys [^World world contact-listener]} & [entities]]
+  "com.badlogic.gdx.physics.box2d.World"
+  [{:keys [world contact-listener]} & [entities]]
   (.setContactListener world contact-listener)
   (when (and entities (not (.isLocked world)))
     (let [arr (u/gdx-array [])]
@@ -248,7 +255,7 @@ such as :on-begin-contact."
 (defn step!
   "Runs the physics simulations for a single frame and optionally returns the
 `entities` with their positions updated."
-  [{:keys [^World world time-step velocity-iterations position-iterations]
+  [{:keys [world time-step velocity-iterations position-iterations]
      :or {time-step (/ 1 60) velocity-iterations 10 position-iterations 10}
      :as screen}
    & [entities]]

src/play_clj/g3d.clj

@@ -1,5 +1,6 @@
 (ns play-clj.g3d
-  (:require [play-clj.utils :as u])
+  (:require [play-clj.entities]
+            [play-clj.utils :as u])
   (:import [com.badlogic.gdx.graphics.g3d Environment Material Model ModelBatch
             ModelInstance]
            [com.badlogic.gdx.graphics.g3d.attributes BlendingAttribute

src/play_clj/g3d_physics.clj

@@ -267,7 +267,7 @@ such as :on-begin-contact."
 ; misc
 
 (defmethod c/contact-listener
-  World3D
+  "play_clj.g3d_physics.World3D"
   [screen
    {:keys [on-begin-contact on-end-contact]}
    execute-fn!]
@@ -284,7 +284,7 @@ such as :on-begin-contact."
       (.at arr i))))
 
 (defmethod c/update-physics!
-  World3D
+  "play_clj.g3d_physics.World3D"
   [screen & [entities]]
   ; initialize bodies if necessary
   (doseq [e entities]

src/play_clj/physics.clj

@@ -1,125 +1,123 @@
 (ns play-clj.physics
   (:require [play-clj.g2d-physics :as p2d]
             [play-clj.g3d-physics :as p3d]
-            [play-clj.utils :as u])
-  (:import [com.badlogic.gdx.physics.box2d Body World]
-           [play_clj.g3d_physics Body3D World3D]))
+            [play-clj.utils :as u]))
 
 ; this namespace is for internal use only. you should use the g2d-physics and
 ; g3d-physics namespaces directly, instead.
 
 (defmulti add-body!
-  (fn [screen body] (-> screen (u/get-obj :world) class)))
+  (fn [screen body] (some-> screen (u/get-obj :world) class .getName)))
 
 (defmethod add-body!
-  World
+  "com.badlogic.gdx.physics.box2d.World"
   [screen b-def]
   (p2d/add-body! screen b-def))
 
 (defmethod add-body!
-  World3D
+  "play_clj.g3d_physics.World3D"
   [screen body]
   (p3d/add-body! screen body))
 
 (defmulti body-position!
-  (fn [entity a1 a2 a3] (-> entity (u/get-obj :body) class)))
+  (fn [entity a1 a2 a3] (some-> entity (u/get-obj :body) class .getName)))
 
 (defmethod body-position!
-  Body
+  "com.badlogic.gdx.physics.box2d.Body"
   [entity x y angle]
   (p2d/body-position! entity x y angle))
 
 (defmethod body-position!
-  Body3D
+  "play_clj.g3d_physics.Body3D"
   [entity x y z]
   (p3d/body-position! entity x y z))
 
 (defmulti body-x!
-  (fn [entity x] (-> entity (u/get-obj :body) class)))
+  (fn [entity x] (some-> entity (u/get-obj :body) class .getName)))
 
 (defmethod body-x!
-  Body
+  "com.badlogic.gdx.physics.box2d.Body"
   [entity x]
   (p2d/body-x! entity x))
 
 (defmethod body-x!
-  Body3D
+  "play_clj.g3d_physics.Body3D"
   [entity x]
   (p3d/body-x! entity x))
 
 (defmulti body-y!
-  (fn [entity y] (-> entity (u/get-obj :body) class)))
+  (fn [entity y] (some-> entity (u/get-obj :body) class .getName)))
 
 (defmethod body-y!
-  Body
+  "com.badlogic.gdx.physics.box2d.Body"
   [entity y]
   (p2d/body-y! entity y))
 
 (defmethod body-y!
-  Body3D
+  "play_clj.g3d_physics.Body3D"
   [entity y]
   (p3d/body-y! entity y))
 
 (defmulti body-z!
-  (fn [entity z] (-> entity (u/get-obj :body) class)))
+  (fn [entity z] (some-> entity (u/get-obj :body) class .getName)))
 
 (defmethod body-z!
-  Body3D
+  "play_clj.g3d_physics.Body3D"
   [entity z]
   (p3d/body-z! entity z))
 
 (defmulti body-angle!
-  (fn [entity angle] (-> entity (u/get-obj :body) class)))
+  (fn [entity angle] (some-> entity (u/get-obj :body) class .getName)))
 
 (defmethod body-angle!
-  Body
+  "com.badlogic.gdx.physics.box2d.Body"
   [entity angle]
   (p2d/body-angle! entity angle))
 
 (defmulti first-entity
-  (fn [screen entities] (-> screen (u/get-obj :world) class)))
+  (fn [screen entities] (some-> screen (u/get-obj :world) class .getName)))
 
 (defmethod first-entity
-  World
+  "com.badlogic.gdx.physics.box2d.World"
   [screen entities]
   (p2d/first-entity screen entities))
 
 (defmethod first-entity
-  World3D
+  "play_clj.g3d_physics.World3D"
   [screen entities]
   (p3d/first-entity screen entities))
 
 (defmulti second-entity
-  (fn [screen entities] (-> screen (u/get-obj :world) class)))
+  (fn [screen entities] (some-> screen (u/get-obj :world) class .getName)))
 
 (defmethod second-entity
-  World
+  "com.badlogic.gdx.physics.box2d.World"
   [screen entities]
   (p2d/second-entity screen entities))
 
 (defmethod second-entity
-  World3D
+  "play_clj.g3d_physics.World3D"
   [screen entities]
   (p3d/second-entity screen entities))
 
 (defmulti add-joint!
-  (fn [screen joint] (-> screen (u/get-obj :world) class)))
+  (fn [screen joint] (some-> screen (u/get-obj :world) class .getName)))
 
 (defmethod add-joint!
-  World
+  "com.badlogic.gdx.physics.box2d.World"
   [screen j-def]
   (p2d/add-joint! screen j-def))
 
 (defmulti step!
-  (fn [screen & [entities]] (-> screen (u/get-obj :world) class)))
+  (fn [screen & [entities]] (some-> screen (u/get-obj :world) class .getName)))
 
 (defmethod step!
-  World
+  "com.badlogic.gdx.physics.box2d.World"
   [screen & [entities]]
   (p2d/step! screen entities))
 
 (defmethod step!
-  World3D
+  "play_clj.g3d_physics.World3D"
   [screen & [entities]]
   (p3d/step! screen entities))
 

src/play_clj/ui.clj

@@ -1,5 +1,6 @@
 (ns play-clj.ui
-  (:require [play-clj.g2d :as g2d]
+  (:require [play-clj.entities]
+            [play-clj.g2d :as g2d]
             [play-clj.utils :as u])
   (:import [com.badlogic.gdx Files Gdx]
            [com.badlogic.gdx.graphics Color Texture]