X-Git-Url: https://git.ctpug.org.za/?a=blobdiff_plain;f=koperkapel%2Fscenes%2Fbase.py;h=d0b9a951ae16c57e20e279560f54fd9ab8a7b7a4;hb=1df183b924e272541198f34c1ebb3d33406192a6;hp=859f816e6359249e8dfbdc61e36f24b4699fcc44;hpb=8631d4fcb6dbc05c0f8f8283f1740ef6ca835ed1;p=koperkapel.git

diff --git a/koperkapel/scenes/base.py b/koperkapel/scenes/base.py
index 859f816..d0b9a95 100644
--- a/koperkapel/scenes/base.py
+++ b/koperkapel/scenes/base.py
@@ -1,44 +1,164 @@
 """ Scene utilities. """
 
+import functools
+
+
+def apply_events(f):
+    """ Decorator that applies events to an engine. """
+    @functools.wraps(f)
+    def wrap(self, *args, **kw):
+        events = f(self, *args, **kw)
+        self._apply_events(events)
+    return wrap
+
 
 class Engine:
-    """ A holder for game state. """
+    """ A holder for game state & scene management.
+        """
 
-    def __init__(self, app, scene):
+    def __init__(self, app, scene, world):
         self._app = app
         self._scene = scene
+        self._world = world
+        self._viewport = (0, 0)
+
+    def _apply_events(self, events):
+        if not events:
+            return
+        for ev in events:
+            ev.apply(self)
+
+    def change_scene(self, scene):
+        self._apply_events(self._scene.exit(self._world.proxy()))
+        self._scene = scene
+        self._apply_events(self._scene.enter(self._world.proxy()))
 
+    def change_world(self, *args, **kw):
+        self._world.apply_event(*args, **kw)
+
+    def quit_game(self):
+        from pgzero.game import exit
+        exit()
+
+    def move_screen(self, offset):
+        self._viewport = (self._viewport[0] + offset[0],
+                          self._viewport[1] + offset[1])
+
+    @apply_events
     def update(self, dt):
-        self._scene.update(dt)
+        return self._scene.update(self._world.proxy(), dt)
 
     def draw(self):
-        self._scene.draw(self._app.screen)
+        self._scene.draw(self._app.screen, self._viewport)
 
+    @apply_events
     def on_mouse_down(self, pos, button):
-        self._scene.on_mouse_down(pos, button)
+        return self._scene.on_mouse_down(pos, button)
 
+    @apply_events
     def on_mouse_up(self, pos, button):
-        self._scene.on_mouse_up(pos, button)
+        return self._scene.on_mouse_up(pos, button)
 
+    @apply_events
     def on_key_down(self, key, mod, unicode):
-        self._scene.on_key_down(key, mod, unicode)
+        return self._scene.on_key_down(key, mod, unicode)
 
+    @apply_events
     def on_key_up(self, key, mod):
-        self._scene.on_key_up(key, mod)
+        return self._scene.on_key_up(key, mod)
 
+    @apply_events
     def on_music_end(self):
-        self._scene.on_music_end()
+        return self._scene.on_music_end()
+
+
+class Event:
+    """ Base class for events. """
+
+    ENGINE_METHOD = "unknown_event"
+
+    def __init__(self, *args, **kw):
+        self._args = args
+        self._kw = kw
+
+    def apply(self, engine):
+        getattr(engine, self.ENGINE_METHOD)(*self._args, **self._kw)
+
+
+class ChangeSceneEvent(Event):
+    """ Change to a new scene. """
+
+    ENGINE_METHOD = "change_scene"
+
+
+class WorldEvent(Event):
+    """ Be a hero. Change the world. """
+
+    ENGINE_METHOD = "change_world"
+
+
+class QuitEvent(Event):
+    """ Quit the game. """
+
+    ENGINE_METHOD = "quit_game"
+
+
+class MoveViewportEvent(Event):
+    """ Change to a new scene. """
+
+    ENGINE_METHOD = "move_screen"
+
+
+class Actors:
+    """ A list of actors.
+
+    Actors may be rendered in different layers. Layers with lower levels
+    are rendered lower than layers with higher ones.
+    """
+
+    def __init__(self):
+        self._layer_order = []
+        self._layers = {}
+        self.add_layer("default", 0)
+
+    def add_layer(self, name, level):
+        self._layer_order.append((level, name))
+        self._layer_order.sort()
+        self._layers[name] = []
+
+    def add(self, actor, layer="default"):
+        self._layers[layer].append(actor)
+        return actor
+
+    def remove(self, actor, layer="default"):
+        self._layers[layer].remove(actor)
+        return actor
+
+    def draw(self, screen):
+        for lvl, layer in self._layer_order:
+            for actor in self._layers[layer]:
+                actor.draw()  # TODO: allow an option screen to be passed in
 
 
 class Scene:
     """ Base class for scenes. """
 
-    def update(self, dt):
+    def __init__(self):
+        self.actors = Actors()
+
+    def enter(self, world):
         pass
 
-    def draw(self, screen):
+    def exit(self, world):
         pass
 
+    def update(self, world, dt):
+        pass
+
+    def draw(self, screen, viewport):
+        screen.clear()
+        self.actors.draw(screen)
+
     def on_mouse_down(self, pos, button):
         pass