Mercurial > parpg-source
view bGrease/world.py @ 182:f131a1b01254
Updated .hgsubstate
author | Beliar <KarstenBock@gmx.net> |
---|---|
date | Thu, 15 Mar 2012 14:30:37 +0100 |
parents | e856b604b650 |
children |
line wrap: on
line source
############################################################################# # # Copyright (c) 2010 by Casey Duncan and contributors # All Rights Reserved. # # This software is subject to the provisions of the MIT License # A copy of the license should accompany this distribution. # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. # ############################################################################# """Worlds are environments described by a configuration of components, systems and renderers. These parts describe the data, behavioral and presentation aspects of the world respectively. The world environment is the context within which entities exist. A typical application consists of one or more worlds containing entities that evolve over time and react to internal and external interaction. See :ref:`an example of world configuration in the tutorial <tut-world-example>`. """ __version__ = '$Id$' import itertools from parpg.bGrease import mode from parpg.bGrease.component import ComponentError from parpg.bGrease.entity import Entity, ComponentEntitySet class BaseWorld(object): """A coordinated collection of components, systems and entities A world is also a mode that may be pushed onto a :class:`grease.mode.Manager` """ components = None """:class:`ComponentParts` object containing all world components. :class:`grease.component.Component` objects define and contain all entity data """ systems = None """:class:`Parts` object containing all world systems. :class:`grease.System` objects define world and entity behavior """ renderers = None """:class:`Parts` object containing all world renderers. :class:`grease.Renderer` objects define world presentation """ entities = None """Set of all entities that exist in the world""" def __init__(self): self.components = ComponentParts(self) self.systems = Parts(self) self.renderers = Parts(self) self.new_entity_id = itertools.count().next self.new_entity_id() # skip id 0 self.entities = WorldEntitySet(self) self._full_extent = EntityExtent(self, self.entities) self._extents = {} self.configure() def configure(self): """Hook to configure the world after construction. This method is called immediately after the world is initialized. Override in a subclass to configure the world's components, systems, and renderers. The default implementation does nothing. """ def __getitem__(self, entity_class): """Return an :class:`EntityExtent` for the given entity class. This extent can be used to access the set of entities of that class in the world or to query these entities via their components. Examples:: world[MyEntity] world[...] :param entity_class: The entity class for the extent. May also be a tuple of entity classes, in which case the extent returned contains union of all entities of the classes in the world. May also be the special value ellipsis (``...``), which returns an extent containing all entities in the world. This allows you to conveniently query all entities using ``world[...]``. """ if isinstance(entity_class, tuple): entities = set() for cls in entity_class: if cls in self._extents: entities |= self._extents[cls].entities return EntityExtent(self, entities) elif entity_class is Ellipsis: return self._full_extent try: return self._extents[entity_class] except KeyError: extent = self._extents[entity_class] = EntityExtent(self, set()) return extent def draw_renderers(self): """Draw all renderers""" for renderer in self.renderers: renderer.draw() class WorldEntitySet(set): """Entity set for a :class:`World`""" def __init__(self, world): self.world = world def add(self, entity): """Add the entity to the set and all necessary class sets Return the unique entity id for the entity, creating one as needed. """ super(WorldEntitySet, self).add(entity) for cls in entity.__class__.__mro__: if issubclass(cls, Entity): self.world[cls].entities.add(entity) def remove(self, entity): """Remove the entity from the set and, world components, and all necessary class sets """ super(WorldEntitySet, self).remove(entity) for component in self.world.components: try: del component[entity] except KeyError: pass for cls in entity.__class__.__mro__: if issubclass(cls, Entity): self.world[cls].entities.discard(entity) def discard(self, entity): """Remove the entity from the set if it exists, if not, do nothing """ try: self.remove(entity) except KeyError: pass class EntityExtent(object): """Encapsulates a set of entities queriable by component. Extents are accessed by using an entity class as a key on the :class:`World`:: extent = world[MyEntity] """ entities = None """The full set of entities in the extent""" def __init__(self, world, entities): self.__world = world self.entities = entities def __getattr__(self, name): """Return a queriable :class:`ComponentEntitySet` for the named component Example:: world[MyEntity].movement.velocity > (0, 0) Returns a set of entities where the value of the :attr:`velocity` field of the :attr:`movement` component is greater than ``(0, 0)``. """ component = getattr(self.__world.components, name) return ComponentEntitySet(component, self.entities & component.entities) class Parts(object): """Maps world parts to attributes. The parts are kept in the order they are set. Parts may also be inserted out of order. Used for: - :attr:`World.systems` - :attr:`World.renderers` """ _world = None _parts = None _reserved_names = ('entities', 'entity_id', 'world') def __init__(self, world): self._world = world self._parts = [] def _validate_name(self, name): if (name in self._reserved_names or name.startswith('_') or hasattr(self.__class__, name)): raise ComponentError('illegal part name: %s' % name) return name def __setattr__(self, name, part): if not hasattr(self.__class__, name): self._validate_name(name) if not hasattr(self, name): self._parts.append(part) else: old_part = getattr(self, name) self._parts[self._parts.index(old_part)] = part super(Parts, self).__setattr__(name, part) if hasattr(part, 'set_world'): part.set_world(self._world) elif name.startswith("_"): super(Parts, self).__setattr__(name, part) else: raise AttributeError("%s attribute is read only" % name) def __delattr__(self, name): self._validate_name(name) part = getattr(self, name) self._parts.remove(part) super(Parts, self).__delattr__(name) def insert(self, name, part, before=None, index=None): """Add a part with a particular name at a particular index. If a part by that name already exists, it is replaced. :arg name: The name of the part. :type name: str :arg part: The component, system, or renderer part to insert :arg before: A part object or name. If specified, the part is inserted before the specified part in order. :arg index: If specified, the part is inserted in the position specified. You cannot specify both before and index. :type index: int """ assert before is not None or index is not None, ( "Must specify a value for 'before' or 'index'") assert before is None or index is None, ( "Cannot specify both 'before' and 'index' arguments when inserting") self._validate_name(name) if before is not None: if isinstance(before, str): before = getattr(self, before) index = self._parts.index(before) if hasattr(self, name): old_part = getattr(self, name) self._parts.remove(old_part) self._parts.insert(index, part) super(Parts, self).__setattr__(name, part) if hasattr(part, 'set_world'): part.set_world(self._world) def __iter__(self): """Iterate the parts in order""" return iter(tuple(self._parts)) def __len__(self): return len(self._parts) class ComponentParts(Parts): """Maps world components to attributes. The components are kept in the order they are set. Components may also be inserted out of order. Used for: :attr:`World.components` """ def join(self, *component_names): """Join and iterate entity data from multiple components together. For each entity in all of the components named, yield a tuple containing the entity data from each component specified. This is useful in systems that pull data from multiple components. Typical Usage:: for position, movement in world.components.join("position", "movement"): # Do something with each entity's position and movement data """ if component_names: components = [getattr(self, self._validate_name(name)) for name in component_names] if len(components) > 1: entities = components[0].entities & components[1].entities for comp in components[2:]: entities &= comp.entities else: entities = components[0].entities for entity in entities: yield tuple(comp[entity] for comp in components)