from __future__ import division
-import math
+from math import atan2, sin, cos, pi as PI
from bulletml import parser
-# TODO(jfw): This is very non-Pythonic, it's pretty much just the
-# BulletML reference ActionImpl translated to Python.
-
-PI_2 = math.pi * 2
+PI_2 = PI * 2
__all__ = ["Action", "Bullet"]
class Action(object):
- """Running action implementation."""
+ """Running action implementation.
+
+ To implement new actions,
+
+ - Add a new element/class pair to parser.ActionDef.CONSTRUCTORS.
+ It should support FromXML, __getstate__, and __setstate__.
+ - Subclass impl.Action and override the 'handle' method to handle
+ your custom action type.
+ - Pass the impl.Bullet constructor your Action subclass when
+ creating your root Bullet.
+ """
def __init__(self, owner, parent, actions, params, rank, repeat=1):
self.actions = actions
self.previous_fire_direction = other.previous_fire_direction
self.previous_fire_speed = other.previous_fire_speed
- def step(self, owner, rank, created, sin=math.sin, cos=math.cos):
+ def step(self, owner, created):
"""Advance by one frame."""
s_params = self.params
+ rank = owner.rank
if self.speed_frames > 0:
self.speed_frames -= 1
if isinstance(action, parser.Repeat):
repeat, (actions, params) = action(s_params, rank)
- child = Action(owner, self, actions, params, rank, repeat)
+ child = self.__class__(
+ owner, self, actions, params, rank, repeat)
owner.replace(self, child)
- child.step(owner, rank, created, sin, cos)
+ child.step(owner, created)
break
elif isinstance(action, (parser.ActionDef, parser.ActionRef)):
actions, params = action(s_params, rank)
- child = Action(owner, self, actions, params, rank)
+ child = self.__class__(owner, self, actions, params, rank)
owner.replace(self, child)
- child.step(owner, rank, created, sin, cos)
+ child.step(owner, created)
break
elif isinstance(action, (parser.FireDef, parser.FireRef)):
- direction, speed, actions, offset = action(s_params, rank)
+ direction, speed, offset, tags, appearance, actions = action(
+ s_params, rank)
if direction:
direction, type = direction
if type == "aim" or type is None:
x += off_x
y += off_y
- bullet = Bullet(
- x, y, direction, speed, owner.target, actions, self, rank)
+ if appearance is None:
+ appearance = owner.appearance
+ bullet = owner.__class__(
+ x=x, y=y, direction=direction, speed=speed,
+ target=owner.target, actions=actions, rank=rank,
+ appearance=appearance, tags=tags, Action=self.__class__)
created.append(bullet)
elif isinstance(action, parser.ChangeSpeed):
direction += owner.aim - owner.direction
# Normalize to [-pi, pi).
- direction = (direction + math.pi) % PI_2 - math.pi
+ direction = (direction + PI) % PI_2 - PI
if frames <= 0:
owner.direction += direction
else:
elif isinstance(action, parser.Wait):
self.wait_frames = action(s_params, rank)
- if self.wait_frames:
- break
+ break
elif isinstance(action, parser.Vanish):
owner.vanish()
break
+ elif isinstance(action, parser.Appearance):
+ owner.appearance = action.appearance
+
+ else:
+ self.handle(action, owner, created)
+
+ def handle(self, action, owner, created):
+ """Override in subclasses for new action types."""
+ raise NotImplementedError(action.__class__.__name__)
+
class Bullet(object):
"""Simple bullet implementation.
Contructor Arguments:
x, y, direction, speed, target, rank - same as the attributes
actions - internal action list
- parent - parent of actions, None for manually-created bullets
+ Action - custom Action constructor
"""
def __init__(self, x=0, y=0, direction=0, speed=0, target=None,
- actions=(), parent=None, rank=0.5):
+ actions=(), rank=0.5, tags=(), appearance=None,
+ Action=Action):
self.x = self.px = x
self.y = self.py = y
self.mx = 0
self.vanished = False
self.target = target
self.rank = rank
- self.tags = set()
+ self.tags = set(tags)
+ self.appearance = appearance
# New bullets reset the parent hierarchy.
self._actions = [Action(self, None, action, params, rank)
for action, params in actions]
+ @classmethod
+ def FromDocument(cls, doc, x=0, y=0, direction=0, speed=0, target=None,
+ params=(), rank=0.5, Action=Action):
+ """Construct a new Bullet from a loaded BulletML document."""
+ actions = [a(params, rank) for a in doc.actions]
+ return cls(x=x, y=y, direction=direction, speed=speed,
+ target=target, actions=actions, rank=rank, Action=Action)
+
def __repr__(self):
return ("%s(%r, %r, accel=%r, direction=%r, speed=%r, "
- "actions=%r, target=%r, vanished=%r)") % (
+ "actions=%r, target=%r, appearance=vanished=%r)") % (
type(self).__name__, self.x, self.y, (self.mx, self.my),
self.direction, self.speed, self._actions, self.target,
- self.vanished)
+ self.appearance, self.vanished)
@property
def aim(self):
- """Angle to the target, in radians."""
- if self.target is None:
- return self.direction
+ """Angle to the target, in radians.
+
+ If the target does not exist or cannot be found, return 0.
+ """
+ try:
+ target_x = self.target.x
+ target_y = self.target.y
+ except AttributeError:
+ return 0
else:
- return math.atan2(self.target.x - self.x, self.y - self.target.y)
+ return atan2(target_x - self.x, target_y - self.y)
@property
def finished(self):
else:
self._actions[idx] = new
- def step(self, sin=math.sin, cos=math.cos):
+ def step(self):
"""Advance by one frame.
This updates the position and velocity, and may also set the
created = []
for action in self._actions:
- action.step(self, self.rank, created, sin, cos)
+ action.step(self, created)
self.px = self.x
self.py = self.y
self.x += self.mx + sin(self.direction) * self.speed
- self.y += self.my - cos(self.direction) * self.speed
+ self.y += -self.my + cos(self.direction) * self.speed
return created
projects / python-bulletml.git / blobdiff