Screen stack support

- rename "game-state" to "screen" (like "title screen", "options screen", etc)
- rename :state to :id
- provide helpers to load a screen given a "spec", deserialize a screen back to a spec, manage a screen stack
- rework test repl helper to allow setting the screen directly, instead of tweaking game state
- have start-game take a spec by default

src/hottub/core.clj

@@ -2,17 +2,21 @@
   (:require [hottub.slick :as slick]
             [hottub.gs :as gs]
             [hottub.resource :as res]
-            [hottub.timeline :as tln]))
+            [hottub.timeline :as tln]
+            [hottub.screen :as scr]))
 
 (defn -main [& args]
   (res/start-resource-expiry-thread)
-  (slick/start-game "Test game" 
-                    {:state :game
-                     :gs (gs/update-gs gs/gs-empty
-                                     (gs/add-index :name)
-                                     (gs/add-index :type)
-                                     (gs/set-entity (gs/gen-id) {:type :sprite :x 50 :y 50 
-                                                                 :image "res/man.png" :name :man}))}))
+  (slick/start-game "Test game" {:id :game}))
+
+(defmethod scr/screen-from-spec :game [spec]
+  {:gs (gs/update-gs gs/gs-empty
+                     (gs/add-index :name)
+                     (gs/add-index :type)
+                     (gs/set-entity (gs/gen-id) {:type :sprite :x 50 :y 50 
+                                                 :image "res/man.png" :name :man}))})
+
+(defmethod scr/spec-from-screen :game [screen] {:id :game})
 
 (defmethod slick/update-game :game [state inputtln delta]
   (assoc state :gs (gs/update-gs (:gs state)
@@ -26,11 +30,14 @@
       (if-let [image (res/get-image (:image sprite))]
         (.draw image (:x sprite) (:y sprite))))))
 
+;;; repl helpers
 (def ^:dynamic g nil)
 (def ^:dynamic s nil)
+(def ^:dynamic *newscreen* nil)
+
+(defn reload [] (reset! *newscreen* (scr/reload-screen s)))
 
 (defmethod slick/eval-with-bindings :default [state game f]
-  (binding [g game s state] 
+  (binding [g game s state *newscreen* (atom nil)] 
     (let [gsnew (gs/update-gs (:gs state) (f))]
-      (slick/game-setstate! game (assoc state :gs gsnew)))))
-
+      (slick/game-setstate! game (or @*newscreen* (assoc state :gs gsnew))))))

src/hottub/screen.clj

@@ -0,0 +1,39 @@
+(ns hottub.screen)
+
+(defmulti screen-from-spec (fn [spec] (:id spec)))
+(defmulti spec-from-screen (fn [screen] (:id screen)))
+
+(defn- -screen-from-spec [spec] (assoc (screen-from-spec spec) :id (:id spec)))
+(defn- -spec-from-screen [screen] (assoc (spec-from-screen screen) :id (:id screen)))
+
+(defn push-screen [screenold spec]
+  (let [specold (-spec-from-screen screenold)
+        screen (-screen-from-spec spec)]
+    (update-in [::stack] conj specold)))
+
+(defn pop-screen [screenold]
+  (let [stackold (::stack screenold)
+        specnew (peek stackold)
+        stacknew (pop stackold)
+        screen (-screen-from-spec specnew)]
+    (assoc screen ::stack stacknew)))
+
+(defn push-modal-screen [screenold spec]
+  (let [screen (-screen-from-spec spec)]
+    (assoc screen ::modal screenold)))
+
+(defn pop-modal-screen [screenold]
+  (::modal screenold))
+
+(defn screen-behind-modal [screen]
+  (pop-modal-screen screen))
+
+(defn update-screen [screenold screennew] 
+  (assoc screennew ::stack (::stack screenold)))
+
+(defn goto-screen [screenold spec]
+  (let [screen (-screen-from-spec spec)]
+    (assoc screen ::stack (::stack screenold))))
+
+(defn reload-screen [screen]
+  (goto-screen screen (-spec-from-screen screen)))

src/hottub/slick.clj

@@ -8,11 +8,12 @@
         [hottub.util :as u]
         [hottub.repl :as repl]
         [hottub.resource :as res]
-        [hottub.timeline :as tln]))
+        [hottub.timeline :as tln]
+        [hottub.screen :as scr]))
 
-(defmulti update-game (fn [state input delta] (:state state)))
-(defmulti render-game (fn [state graphics] (:state state)))
-(defmulti eval-with-bindings (fn [state game f] (:state state)))
+(defmulti update-game (fn [screen input delta] (:id screen)))
+(defmulti render-game (fn [screen graphics] (:id screen)))
+(defmulti eval-with-bindings (fn [screen game f] (:id screen)))
 
 (def slick-key-to-key
   {Input/KEY_0 :0
@@ -119,14 +120,14 @@
  :state   state
  :extends org.newdawn.slick.BasicGame)
 
-(defn game-create [title state] 
+(defn game-create [title screen] 
   [[title] 
-     {:state (atom state)
+     {:screen (atom screen)
       :repl (repl/repl-create 9999)
       :container (atom nil)
       :input (input-create)}])
 
-(defn game-state-atom [this] (:state (.state this)))
+(defn game-screen-atom [this] (:screen (.state this)))
 (defn game-container [this] @(:container (.state this)))
 
 (defn game-install-input [this]
@@ -147,7 +148,7 @@
   (game-install-input this)
   (repl/repl-start
    (:repl (.state this))
-   (fn [f] (eval-with-bindings @(game-state-atom this) this f))))
+   (fn [f] (eval-with-bindings @(game-screen-atom this) this f))))
   
 (defn game-update [this container delta]
   (doseq [ns-sym (modified-namespaces)]
@@ -158,29 +159,29 @@
         (.printStackTrace e))))
   (repl/repl-update (:repl (.state this)))
   (try
-    (if-let [statenew (update-game @(game-state-atom this) (input-timeline-clear! (:input (.state this))) delta)]
-      (reset! (game-state-atom this) statenew))
+    (if-let [screennew (update-game @(game-screen-atom this) (input-timeline-clear! (:input (.state this))) delta)]
+      (reset! (game-screen-atom this) screennew))
     (catch Exception e
-      (println "Couldn't update" (:state @(game-state-atom this)))
+      (println "Couldn't update" (:id @(game-screen-atom this)))
       (.printStackTrace e))))
 
 (defn game-render [this container graphics]
   (try
     (res/gc-expired-resources)
-    (render-game @(game-state-atom this) graphics)
+    (render-game @(game-screen-atom this) graphics)
     (catch Exception e 
-      (println "Couldn't render" (:state @(game-state-atom this)))
+      (println "Couldn't render" (:id @(game-screen-atom this)))
       (.printStackTrace e))))
 
-(defn game-setstate! [this statenew]
-  (reset! (game-state-atom this) statenew))
+(defn game-setscreen! [this screennew]
+  (reset! (game-screen-atom this) screennew))
 
-(defmethod update-game :default [state input delta])
-(defmethod render-game :default [state graphics])
-(defmethod eval-with-bindings :default [state game f] (f))
+(defmethod update-game :default [screen input delta])
+(defmethod render-game :default [screen graphics])
+(defmethod eval-with-bindings :default [screen game f] (f))
 
-(defn start-game [title startstate]
-  (let [game (hottub.slick.Game. title startstate)
+(defn start-game [title spec]
+  (let [game (hottub.slick.Game. title (scr/goto-screen nil spec))
         container (AppGameContainer. game 640 480 false)]
     (.setAlwaysRender container true)
     (.start container)