""" 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)
+
+ @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 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
projects / koperkapel.git / blobdiff