from __future__ import division
-import math
+from math import atan2, sin, cos
-from bulletml import parser
+__all__ = ["Action", "Bullet"]
-# TODO(jfw): This is very non-Pythonic, it's pretty much just the
-# BulletML reference ActionImpl translated to Python.
+class Action(object):
+ """Running action implementation.
-PI_2 = math.pi * 2
+ To implement new actions, add a new element/class pair to
+ parser.ActionDef.CONSTRUCTORS. It should support FromXML,
+ __getstate__, and __setstate__, and 5-ary __call__:
-__all__ = ["Action", "Bullet"]
+ def __call__(self, owner, action, params, rank, created)
-class Action(object):
- """Running action implementation."""
+ Which will be called to execute it. This function should modify
+ owner, action, and created in-place, and return true if action
+ execution should stop for this bullet this frame.
- def __init__(self, owner, parent, actions, params, rank, repeat=1):
+ """
+
+ def __init__(self, parent, actions, params, rank, repeat=1):
self.actions = actions
self.parent = parent
self.repeat = repeat
self.previous_fire_direction = other.previous_fire_direction
self.previous_fire_speed = other.previous_fire_speed
- def step(self, owner, rank):
+ def step(self, owner, created):
"""Advance by one frame."""
- created = []
if self.speed_frames > 0:
self.speed_frames -= 1
owner.speed += self.speed
if self.direction_frames > 0:
- # The Noiz implementation was a little weird here, I think
- # there was a bug in it that prevented it from working if
- # the frame count was 1. I'm still not sure what the aim
- # check is supposed to do, exactly.
self.direction_frames -= 1
+ # I'm still not sure what the aim check is supposed to do.
if self.aiming and self.direction_frames <= 0:
owner.direction += owner.aim
else:
owner.my += self.my
if self.pc is None:
- return created
+ return
if self.wait_frames > 0:
self.wait_frames -= 1
- return created
+ return
+
+ s_params = self.params
+ rank = owner.rank
while True:
self.pc += 1
self.pc = 0
action = self.actions[self.pc]
- if isinstance(action, parser.Repeat):
- repeat, (actions, params) = action(self.params, rank)
- child = Action(owner, self, actions, params, rank, repeat)
- owner.replace(self, child)
- created.extend(child.step(owner, rank))
+ if action(owner, self, s_params, rank, created):
break
- elif isinstance(action, (parser.ActionDef, parser.ActionRef)):
- actions, params = action(self.params, rank)
- child = Action(owner, self, actions, params, rank)
- owner.replace(self, child)
- created.extend(child.step(owner, rank))
- break
-
- elif isinstance(action, (parser.FireDef, parser.FireRef)):
- direction, speed, actions, offset = action(self.params, rank)
- if direction:
- direction, type = direction
- if type == "aim" or type is None:
- direction += owner.aim
- elif type == "sequence":
- direction += self.previous_fire_direction
- elif type == "relative":
- direction += owner.direction
- else:
- direction = owner.aim
- self.previous_fire_direction = direction
-
- if speed:
- speed, type = speed
- if type == "sequence":
- speed += self.previous_fire_speed
- elif type == "relative":
- # The reference Noiz implementation uses
- # prvFireSpeed here, but the standard is
- # pretty clear -- "In case of the type is
- # "relative", ... the speed is relative to the
- # speed of this bullet."
- speed += owner.speed
- else:
- speed = 1
- self.previous_fire_speed = speed
-
- x, y = owner.x, owner.y
- if offset:
- off_x, off_y = offset(self.params, rank)
- if offset.type == "relative":
- sin = math.sin(direction)
- cos = math.cos(direction)
- x += cos * off_x + sin * off_y
- y += sin * off_x - cos * off_y
- else:
- x += off_x
- y += off_y
-
- bullet = Bullet(
- x, y, direction, speed, owner.target, actions, self, rank)
- created.append(bullet)
-
- elif isinstance(action, parser.ChangeSpeed):
- frames, (speed, type) = action(self.params, rank)
- self.speed_frames = frames
- if type == "sequence":
- self.speed = speed
- elif type == "relative":
- self.speed = speed / frames
- else:
- self.speed = (speed - owner.speed) / frames
-
- elif isinstance(action, parser.ChangeDirection):
- frames, (direction, type) = action(self.params, rank)
- self.direction_frames = frames
- self.aiming = False
- if type == "sequence":
- self.direction = direction
- else:
- if type == "absolute":
- self.direction = (
- direction - owner.direction) % PI_2
- elif type == "relative":
- self.direction = direction
- else:
- self.aiming = True
- self.direction = (
- direction
- + owner.aim
- - owner.direction) % PI_2
-
- if self.direction > math.pi:
- self.direction -= PI_2
- if self.direction < -math.pi:
- self.direction += PI_2
- self.direction /= self.direction_frames
-
- elif isinstance(action, parser.Accel):
- frames, horizontal, vertical = action(self.params, rank)
- self.accel_frames = frames
- if horizontal:
- mx, type = horizontal
- if type == "sequence":
- self.mx = mx
- elif type == "absolute":
- self.mx = (mx - owner.mx) / frames
- elif type == "relative":
- self.mx = mx / frames
- if vertical:
- my, type = vertical
- if type == "sequence":
- self.my = my
- elif type == "absolute":
- self.my = (my - owner.my) / frames
- elif type == "relative":
- self.my = my / frames
-
- elif isinstance(action, parser.Wait):
- self.wait_frames = action(self.params, rank)
- break
-
- elif isinstance(action, parser.Vanish):
- owner.vanish()
- break
-
- return created
-
class Bullet(object):
"""Simple bullet implementation.
target - object with .x and .y fields for "aim" directions
vanished - set to true by a <vanish> action
rank - game difficulty, 0 to 1, default 0.5
+ tags - string tags set by the running actions
+ appearance - string used to set bullet appearance
+ radius - radius for collision
+ finished - true if all actions are finished and the bullet vanished
Contructor Arguments:
- x, y, direction, speed, target, rank - same as the attributes
+ x, y, direction, speed, target, rank, tags, appearance, radius
+ - same as the above 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,
+ radius=0.5):
self.x = self.px = x
self.y = self.py = y
+ self.radius = radius
self.mx = 0
self.my = 0
self.direction = direction
self.speed = speed
self.vanished = False
+ self.finished = False
self.target = target
self.rank = rank
- # New bullets reset the parent hierarchy.
- self._actions = [Action(self, None, action, params, rank)
- for action, params in actions]
+ self.tags = set(tags)
+ self.appearance = appearance
+ self.actions = list(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 = [action(None, Action, params, rank)
+ for action in doc.actions]
+ return cls(x=x, y=y, direction=direction, speed=speed,
+ target=target, actions=actions, rank=rank)
def __repr__(self):
return ("%s(%r, %r, accel=%r, direction=%r, speed=%r, "
- "actions=%r, target=%r, vanished=%r)") % (
+ "actions=%r, target=%r, appearance=%r, vanished=%r)") % (
type(self).__name__, self.x, self.y, (self.mx, self.my),
- self.direction, self.speed, self._actions, self.target,
- self.vanished)
+ self.direction, self.speed, self.actions, self.target,
+ self.appearance, self.vanished)
@property
def aim(self):
- """Angle to the target, in radians."""
- if self.target is None:
- return self.direction
- else:
- return math.atan2(self.target.x - self.x, self.y - self.target.y)
-
- @property
- def finished(self):
- """Check if this bullet is finished running.
-
- A bullet is finished when it has vanished, and all its
- actions have finished.
+ """Angle to the target, in radians.
- If this is true, the bullet should be removed from the screen.
- (You will probably want to cull it under other circumstances
- as well).
+ If the target does not exist or cannot be found, return 0.
"""
- if not self.vanished:
- return False
- for action in self._actions:
- if not action.finished:
- return False
- return True
+ try:
+ target_x = self.target.x
+ target_y = self.target.y
+ except AttributeError:
+ return 0
+ else:
+ return atan2(target_x - self.x, target_y - self.y)
def vanish(self):
"""Vanish this bullet and stop all actions."""
self.vanished = True
- for action in self._actions:
+ for action in self.actions:
action.vanish()
- self._actions = []
+ self.actions = []
def replace(self, old, new):
"""Replace an active action with another.
This is mostly used by actions internally to queue children.
"""
try:
- idx = self._actions.index(old)
+ idx = self.actions.index(old)
except ValueError:
pass
else:
- self._actions[idx] = new
+ self.actions[idx] = new
def step(self):
"""Advance by one frame.
"""
created = []
- for action in self._actions:
- created.extend(action.step(self, self.rank))
-
+ finished = self.vanished
+ for action in self.actions:
+ action.step(self, created)
+ finished = finished and action.finished
+ if finished:
+ for action in self.actions:
+ finished = finished and action.finished
+ self.finished = finished
+
+ speed = self.speed
+ direction = self.direction
self.px = self.x
self.py = self.y
- self.x += self.mx + math.sin(self.direction) * self.speed
- self.y += self.my - math.cos(self.direction) * self.speed
+ self.x += self.mx + sin(direction) * speed
+ self.y += -self.my + cos(direction) * speed
return created