self._app = app
self._scene = scene
self._world = world
- self._viewport = (0, 0)
+ self._update_vehicle = False
def _apply_events(self, events):
if not events:
exit()
def move_screen(self, offset):
- self._viewport = (self._viewport[0] + offset[0],
- self._viewport[1] + offset[1])
+ self._scene.move_screen(offset)
@apply_events
def update(self, dt):
- return self._scene.update(self._world.proxy(), dt)
+ return self._scene.update(self._world.proxy(), self, dt)
def draw(self):
- self._scene.draw(self._app.screen, self._viewport)
+ self._scene.draw(self._app.screen)
@apply_events
def on_mouse_down(self, pos, button):
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:
- """ A list of 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._layer_order = []
+ self._ordered_layers = []
self._layers = {}
self.add_layer("default", 0)
+ def __getattr__(self, name):
+ return self._layers[name]
+
def add_layer(self, name, level):
- self._layer_order.append((level, name))
- self._layer_order.sort()
- self._layers[name] = []
+ layer = self._layers[name] = Layer(name)
+ self._ordered_layers.append((level, name))
+ self._ordered_layers.sort()
+ return layer
def add(self, actor, layer="default"):
- self._layers[layer].append(actor)
- return actor
+ return self._layers[layer].add(actor)
def remove(self, actor, layer="default"):
- self._layers[layer].remove(actor)
- return actor
+ return self._layers[layer].remove(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
+ 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:
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, dt):
- 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, viewport):
+ def draw(self, screen):
screen.clear()
self.actors.draw(screen)