Prevent circular dependency by moving core game data structures to another module.

3 files changed, 145 insertions, 27 deletions

diff --git a/2d/game-loop.scm b/2d/game-loop.scm
index 8dcc65c..0df3a04 100644
--- a/2d/game-loop.scm
+++ b/2d/game-loop.scm
@@ -29,6 +29,7 @@
   #:use-module (figl gl)
   #:use-module (2d agenda)
   #:use-module (2d coroutine)
+  #:use-module (2d private game)
   #:use-module (2d repl server)
   #:use-module (2d repl repl)
   #:use-module (2d mvars)
diff --git a/2d/game.scm b/2d/game.scm
index cb043ec..4a1d88f 100644
--- a/2d/game.scm
+++ b/2d/game.scm
@@ -22,22 +22,59 @@
 ;;; Code:
 
 (define-module (2d game)
-  #:use-module (srfi srfi-9)
+  #:use-module (2d private game)
   #:use-module (2d game-loop)
-  #:use-module (2d window)
+  #:use-module (2d helpers)
+  #:use-module (2d observer)
   #:use-module (2d vector2))
 
 ;;;
-;;; Games
+;;; Scenes
 ;;;
 
-(define-record-type <game>
-  (%make-game title resolution fullscreen first-scene)
-  game?
-  (title game-title)
-  (resolution game-resolution)
-  (fullscreen game-fullscreen?)
-  (first-scene game-first-scene))
+;; When no event callbacks are specified for a scene, these
+;; (hopefully) convenient defaults will be used.
+(define default-scene-events
+  `((quit     . ,(lambda (state) (quit-game-loop!)))
+    (key-down . ,(lambda (state key mode unicode)
+                   (when (any-equal? key 'escape 'q)
+                     (quit-game-loop!))))))
+
+(define* (make-scene #:optional #:key
+                     (title "A Guile-2D Scene")
+                     (events default-scene-events)
+                     (update (lambda (s) #f))
+                     (draw (lambda (s) #f))
+                     (state #f))
+  "Return a new scene. TITLE is a human readable name for the
+scene. EVENTS is an alist of event handlers. UPDATE is a procedure
+that updates the scene. DRAW is a procedure that renders the
+scene. STATE is an object that encapsulates the scene state."
+  (%make-scene title (alist->observer events) update draw state))
+
+(define-syntax-rule (define-scene name kwargs ...)
+  "Syntactic sugar over define and make-scene. Return a procedure that
+creates a new scene."
+  (define (name) (make-scene kwargs ...)))
+
+(re-export <scene>
+           scene?
+           scene-title
+           scene-observer
+           scene-update-proc
+           scene-draw-proc
+           scene-state
+           scene-trigger
+           scene-update
+           scene-draw)
+
+(export make-scene
+        define-scene
+        default-scene-events)
+
+;;;
+;;; Games
+;;;
 
 (define* (make-game #:optional #:key
                     (title "A Guile-2D Game")
@@ -49,23 +86,16 @@ value."
   (%make-game title resolution fullscreen first-scene))
 
 (define-syntax-rule (define-game name kwargs ...)
-  "Syntactic sugar for define and make-game."
+  "Syntactic sugar over define and make-game."
   (define name (make-game kwargs ...)))
 
-(define (run-game game)
-  "Open a window and start playing GAME."
-  (open-window (game-title game)
-               (game-resolution game)
-               (game-fullscreen? game))
-  (run-game-loop)
-  (close-window))
+(re-export <game>
+           game?
+           game-title
+           game-resolution
+           game-fullscreen?
+           game-first-scene
+           run-game)
 
-(export <game>
-        make-game
-        define-game
-        game?
-        game-title
-        game-resolution
-        game-fullscreen?
-        game-first-scene
-        run-game)
+(export make-game
+        define-game)
diff --git a/2d/private/game.scm b/2d/private/game.scm
new file mode 100644
index 0000000..63f0bd1
--- /dev/null
+++ b/2d/private/game.scm
@@ -0,0 +1,87 @@
+;;; guile-2d
+;;; Copyright (C) 2013 David Thompson <dthompson2@worcester.edu>
+;;;
+;;; Guile-2d is free software: you can redistribute it and/or modify it
+;;; under the terms of the GNU Lesser General Public License as
+;;; published by the Free Software Foundation, either version 3 of the
+;;; License, or (at your option) any later version.
+;;;
+;;; Guile-2d is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;;; Lesser General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU Lesser General Public
+;;; License along with this program.  If not, see
+;;; <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+;;
+;; Game data structure.
+;;
+;;; Code:
+
+(define-module (2d private game)
+  #:use-module (srfi srfi-9)
+  #:use-module (2d observer))
+
+;;;
+;;; Scenes
+;;;
+
+(define-record-type <scene>
+  (%make-scene title observer update-proc draw-proc state)
+  scene?
+  (title scene-title)
+  (observer scene-observer)
+  (update-proc scene-update-proc)
+  (draw-proc scene-draw-proc)
+  (state scene-state))
+
+(define (scene-trigger scene event-type . args)
+  "Trigger an event on the scene observer."
+  (apply observer-trigger
+         (scene-observer scene)
+         event-type
+         (scene-state scene)
+         args))
+
+(define (scene-draw scene)
+  "Draw scene."
+  ((scene-draw-proc scene) (scene-state scene)))
+
+(define (scene-update scene)
+  "Update scene."
+  ((scene-update-proc scene) (scene-state scene)))
+
+(export <scene>
+        %make-scene
+        scene?
+        scene-title
+        scene-observer
+        scene-update-proc
+        scene-draw-proc
+        scene-state
+        scene-trigger
+        scene-update
+        scene-draw)
+
+;;;
+;;; Games
+;;;
+
+(define-record-type <game>
+  (%make-game title resolution fullscreen first-scene)
+  game?
+  (title game-title)
+  (resolution game-resolution)
+  (fullscreen game-fullscreen?)
+  (first-scene game-first-scene))
+
+(export <game>
+        %make-game
+        game?
+        game-title
+        game-resolution
+        game-fullscreen?
+        game-first-scene)