From f66b8dd5976e4c161b919b493a7450b729b6d343 Mon Sep 17 00:00:00 2001
From: oakes <zsoakes@gmail.com>
Date: Tue, 31 Dec 2013 15:28:50 -0500
Subject: [PATCH] Make all mutations entities to allow pure functional games

---
 common/src/play_clj/core.clj        | 32 +++++++++++++++++++++--------
 common/src/play_clj/core_2d.clj     | 12 +++++------
 common/src/play_clj/core_global.clj | 11 +++++-----
 common/src/play_clj/core_render.clj | 26 +++++++++++++++++++----
 4 files changed, 56 insertions(+), 25 deletions(-)

diff --git a/common/src/play_clj/core.clj b/common/src/play_clj/core.clj
index 34211bf..999fd91 100644
--- a/common/src/play_clj/core.clj
+++ b/common/src/play_clj/core.clj
@@ -12,20 +12,36 @@
             IsometricTiledMapRenderer
             OrthogonalTiledMapRenderer]))
 
+(defmulti execute-entity :command :default :draw)
+
 (load "core_2d")
 (load "core_global")
 (load "core_render")
 
-(defn transform
-  [l]
-  (->> l list flatten (remove nil?)))
+(defn expand-entity
+  [entity]
+  (if (keyword? entity)
+    {:command entity}
+    entity))
+
+(defn transform-entities
+  [entities]
+  (->> entities list flatten (remove nil?) (map expand-entity)))
+
+(defn execute-entities
+  [screen entities]
+  (->> entities
+       (map #(assoc % :screen screen))
+       (map execute-entity)
+       (remove #(not (:persistent? %)))
+       doall))
 
 (defn defscreen*
   [{:keys [on-show on-render on-dispose on-hide on-pause on-resize on-resume
            state renderer camera]
     :as options}]
   (let [screen (atom {})
-        entities (atom [])
+        entities (atom '())
         on-show (or on-show (fn [s]))
         on-render (or on-render (fn [s d]))
         on-hide (or on-hide (fn [s]))
@@ -40,7 +56,7 @@
                     :total-time 0
                     :delta-time 0)
              on-show
-             transform
+             transform-entities
              (reset! entities)))
       (render [delta-time]
         (let [total-time (+ (:total-time @screen) delta-time)
@@ -48,9 +64,9 @@
                                 :total-time total-time
                                 :delta-time delta-time)]
           (->> (on-render screen-map @entities)
-               transform
-               (reset! entities)
-               (draw! screen-map))))
+               transform-entities
+               (execute-entities screen-map)
+               (reset! entities))))
       (hide [] (on-hide @screen))
       (pause [] (on-pause @screen))
       (resize [w h] (on-resize @screen w h))
diff --git a/common/src/play_clj/core_2d.clj b/common/src/play_clj/core_2d.clj
index 1b30248..467d730 100644
--- a/common/src/play_clj/core_2d.clj
+++ b/common/src/play_clj/core_2d.clj
@@ -10,15 +10,13 @@
 (defmethod sprite-batch BatchTiledMapRenderer [screen]
   (.getSpriteBatch (:renderer screen)))
 
-(defn draw!
-  [screen entities]
+(defmethod execute-entity :draw [{:keys [screen image x y width height] :as entity}]
   (let [batch (sprite-batch screen)]
     (.begin batch)
-    (doseq [{:keys [image x y width height]} entities]
-      (when (and image x y width height)
-        (.draw batch image (float x) (float y) (float width) (float height))))
-    (.end batch)
-    batch))
+    (when (and image x y width height)
+      (.draw batch image (float x) (float y) (float width) (float height)))
+    (.end batch))
+  entity)
 
 ; textures
 
diff --git a/common/src/play_clj/core_global.clj b/common/src/play_clj/core_global.clj
index c26e39f..4511d61 100644
--- a/common/src/play_clj/core_global.clj
+++ b/common/src/play_clj/core_global.clj
@@ -2,12 +2,11 @@
 
 ; graphics
 
-(defn clear!
-  ([] (clear! 0 0 0 0))
-  ([r g b a]
-    (doto (Gdx/gl)
-      (.glClearColor r g b a)
-      (.glClear GL20/GL_COLOR_BUFFER_BIT))))
+(defmethod execute-entity :clear [{:keys [r g b a] :as entity}]
+  (doto (Gdx/gl)
+    (.glClearColor (or r 0) (or g 0) (or b 0) (or a 0))
+    (.glClear GL20/GL_COLOR_BUFFER_BIT))
+  entity)
 
 (defn game*
   [key]
diff --git a/common/src/play_clj/core_render.clj b/common/src/play_clj/core_render.clj
index ee0c725..0bbac84 100644
--- a/common/src/play_clj/core_render.clj
+++ b/common/src/play_clj/core_render.clj
@@ -12,10 +12,22 @@
   (assert (number? tile-size))
   (float (/ 1 tile-size)))
 
-(defn render-tiled-map!
-  [{:keys [^BatchTiledMapRenderer renderer ^OrthographicCamera camera]}]
-  (.setView renderer camera)
-  (.render renderer))
+(defmethod execute-entity :render-tiled-map [{:keys [screen] :as entity}]
+  (doto (:renderer screen)
+    (.setView (:camera screen))
+    .render)
+  entity)
+
+(defn tiled-map-layer
+  [{:keys [^BatchTiledMapRenderer renderer]} layer]
+  (-> renderer .getMap .getLayers (.get layer)))
+
+(defn tiled-map-cell
+  [{:keys [^BatchTiledMapRenderer renderer] :as screen} layer x y]
+  (-> (if (or (string? layer) (number? layer))
+        (tiled-map-layer screen layer)
+        layer)
+      (.getCell x y)))
 
 (defmulti create-renderer :type :default :orthogonal-tiled-map)
 
@@ -44,3 +56,9 @@
 (defn resize-camera!
   [{:keys [^Camera camera]} width height]
   (.setToOrtho camera false width height))
+
+(defn move-camera!
+  [{:keys [^Camera camera]} x y]
+  (when x (set! (. camera x) x))
+  (when y (set! (. camera y) y))
+  (.update camera))