X-Git-Url: https://git.ctpug.org.za/?a=blobdiff_plain;f=koperkapel%2Fscenes%2Fbase.py;h=14998034ce7557a883bb14ee478f5c6e67bab647;hb=0a4ee2b80d2af7627366380919dbe6d5204e2999;hp=6bb7f5584347e7c6f39e20e509c37fe3c5789286;hpb=e14b3fe596763b16ad52b0504e93012063c49f07;p=koperkapel.git

diff --git a/koperkapel/scenes/base.py b/koperkapel/scenes/base.py
index 6bb7f55..1499803 100644
--- a/koperkapel/scenes/base.py
+++ b/koperkapel/scenes/base.py
@@ -1,11 +1,234 @@
 """ 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 & scene management.
+        """
+
+    def __init__(self, app, scene, world):
+        self._app = app
+        self._scene = scene
+        self._world = world
+        self._update_vehicle = False
+
+    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._scene.move_screen(offset)
+
+    def add_roach(self):
+        self._world.add_new_roach()
+
+    @apply_events
+    def update(self, dt):
+        return self._scene.update(self._world.proxy(), self, dt)
+
+    def draw(self):
+        self._scene.draw(self._app.screen)
+
+    @apply_events
+    def on_mouse_down(self, pos, button):
+        return self._scene.on_mouse_down(pos, button)
+
+    @apply_events
+    def on_mouse_up(self, pos, button):
+        return self._scene.on_mouse_up(pos, button)
+
+    @apply_events
+    def on_key_down(self, key, mod, unicode):
+        return self._scene.on_key_down(key, mod, unicode)
+
+    @apply_events
+    def on_key_up(self, key, mod):
+        return self._scene.on_key_up(key, mod)
+
+    @apply_events
+    def on_music_end(self):
+        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 AddRoachEvent(Event):
+    """ Change to a new scene. """
+
+    ENGINE_METHOD = "add_roach"
+
+
+class Layer:
+    """ A single layer of actors. """
+
+    def __init__(self, name):
+        self.name = name
+        self.actors = []
+
+    def __iter__(self):
+        return iter(self.actors)
+
+    def __getitem__(self, i):
+        return self.actors[i]
+
+    def __len__(self):
+        return len(self.actors)
+
+    def add(self, actor):
+        self.actors.append(actor)
+        return actor
+
+    def clear(self):
+        self.actors.clear()
+
+    def remove(self, actor):
+        self.actors.remove(actor)
+        return actor
+
+
+class Actors:
+    """ Layers 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._ordered_layers = []
+        self._layers = {}
+        self.add_layer("default", 0)
+
+    def __getattr__(self, name):
+        return self._layers[name]
+
+    def add_layer(self, name, level):
+        layer = self._layers[name] = Layer(name)
+        self._ordered_layers.append((level, name))
+        self._ordered_layers.sort()
+        return layer
+
+    def add(self, actor, layer="default"):
+        return self._layers[layer].add(actor)
+
+    def remove(self, actor, layer="default"):
+        return self._layers[layer].remove(actor)
+
+    def draw(self, screen):
+        for lvl, name in self._ordered_layers:
+            for actor in self._layers[name]:
+                # actor.draw doesn't allow blitting to anything other than
+                # the game scene
+                screen.blit(actor._surf, actor.topleft)
+
+
+def defer_to_update(f):
+    """ Defers a function until the next update run. """
+    @functools.wraps(f)
+    def wrapper(self, *args, **kw):
+        self._deferred_updates.append((f, args, kw))
+    return wrapper
+
 
 class Scene:
     """ Base class for scenes. """
 
-    def update(self, dt):
+    def __init__(self):
+        self.actors = Actors()
+        self.viewport = (0, 0)
+        self._deferred_updates = []
+
+    def move_screen(self, offset):
+        self.viewport = (self.viewport[0] + offset[0],
+                         self.viewport[1] + offset[1])
+
+    def calc_offset(self, x, y):
+        """ Return a position offset by the viewport. """
+        return x - self.viewport[0], y - self.viewport[1]
+
+    def enter(self, world):
         pass
 
+    def exit(self, world):
+        pass
+
+    def update(self, world, engine, dt):
+        deferred_updates, self._deferred_updates = self._deferred_updates, []
+        for f, args, kw in deferred_updates:
+            f(self, world, *args, **kw)
+
     def draw(self, screen):
+        screen.clear()
+        self.actors.draw(screen)
+
+    def on_mouse_down(self, pos, button):
+        pass
+
+    def on_mouse_up(self, pos, button):
+        pass
+
+    def on_key_down(self, key, mod, unicode):
+        pass
+
+    def on_key_up(self, key, mod):
+        pass
+
+    def on_music_end(self):
         pass