-"""BulletML implementation.
-
-http://www.asahi-net.or.jp/~cs8k-cyu/bulletml/index_e.html
-"""
+"""BulletML implementation."""
from __future__ import division
-import math
+from math import atan2, sin, cos
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
+__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__, and 5-ary __call__:
+
+ def __call__(self, owner, action, params, rank, created)
+
+ 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):
+ """
+
+ def __init__(self, parent, actions, params, rank, repeat=1):
self.actions = actions
self.parent = parent
- self.repeat = 1
+ self.repeat = repeat
self.wait_frames = 0
self.speed = 0
self.speed_frames = 0
- self.aim_direction = 0
self.direction = 0
self.direction_frames = 0
self.aiming = False
- self.aim_mx = 0
- self.aim_my = 0
self.mx = 0
self.my = 0
- self.owner = owner
self.accel_frames = 0
self.previous_fire_direction = 0
self.previous_fire_speed = 0
self.params = params
- self.rank = rank
self.pc = -1
self.finished = False
if parent:
return "%s(pc=%r, actions=%r)" % (
type(self).__name__, self.pc, self.actions)
+ def Child(self, actions, params, rank, repeat=1):
+ return type(self)(self, actions, params, rank, repeat)
+
def vanish(self):
"""End this action and its parents."""
if self.parent:
self.previous_fire_direction = other.previous_fire_direction
self.previous_fire_speed = other.previous_fire_speed
- def step(self):
+ def step(self, owner, created):
"""Advance by one frame."""
- created = []
+ s_params = self.params
+ rank = owner.rank
if self.speed_frames > 0:
self.speed_frames -= 1
- self.owner.speed += self.speed
+ owner.speed += self.speed
if self.direction_frames > 0:
+ # I'm still not sure what the aim check is supposed to do.
self.direction_frames -= 1
- if self.direction_frames <= 0:
- if self.aiming:
- self.owner.direction += self.owner.aim
+ if self.aiming and self.direction_frames <= 0:
+ owner.direction += owner.aim
else:
- self.owner.direction += self.direction
+ owner.direction += self.direction
if self.accel_frames > 0:
self.accel_frames -= 1
- self.owner.mx += self.mx
- self.owner.my += self.my
+ owner.mx += self.mx
+ owner.my += self.my
if self.pc is None:
- return created
+ return
if self.wait_frames > 0:
self.wait_frames -= 1
- return created
+ return
while True:
self.pc += 1
- if self.pc >= len(self.actions):
+ try:
+ action = self.actions[self.pc]
+ except IndexError:
self.repeat -= 1
if self.repeat <= 0:
self.pc = None
self.finished = True
if self.parent is not None:
self.parent.copy_state(self)
- self.owner.replace(self, self.parent)
+ owner.replace(self, self.parent)
break
else:
self.pc = 0
+ action = self.actions[self.pc]
- action = self.actions[self.pc]
-
- if isinstance(action, parser.Repeat):
- repeat, (actions, params) = action(self.params, self.rank)
- child = Action(self.owner, self, actions, params, self.rank)
- child.repeat = repeat
- self.owner.replace(self, child)
- created.extend(child.step())
- break
-
- elif isinstance(action, (parser.ActionDef, parser.ActionRef)):
- actions, params = action(self.params, self.rank)
- child = Action(self.owner, self, actions, params, self.rank)
- self.owner.replace(self, child)
- created.extend(child.step())
- break
-
- elif isinstance(action, (parser.FireDef, parser.FireRef)):
- direction, speed, actions = action(self.params, self.rank)
- if direction:
- direction, type = direction
- if type == "aim" or type is None:
- direction += self.owner.aim
- elif type == "sequence":
- direction += self.previous_fire_direction
- elif type == "relative":
- direction += self.owner.direction
- else:
- direction = self.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 -- "0 means that the direction
- # of this fire and the direction of the bullet
- # are the same".
- speed += self.owner.speed
- else:
- speed = 1
- self.previous_fire_speed = speed
-
- bullet = Bullet(self.owner.x, self.owner.y, direction, speed,
- self.owner.target, actions, self)
- created.append(bullet)
-
- elif isinstance(action, parser.ChangeSpeed):
- frames, (speed, type) = action(self.params, self.rank)
- self.speed_frames = frames
- if type == "sequence":
- self.speed = speed
- elif type == "relative":
- self.speed = speed / frames
- else:
- self.speed = (speed - self.owner.speed) / frames
-
- elif isinstance(action, parser.ChangeDirection):
- frames, (direction, type) = action(self.params, self.rank)
- self.direction_frames = frames
- self.aiming = False
- if type == "sequence":
- self.aiming = False
- self.direction = direction
- else:
- if type == "absolute":
- self.aiming = False
- self.direction = (
- direction - self.owner.direction) % PI_2
- elif type == "relative":
- self.aiming = False
- self.direction = direction
- else:
- self.aiming = True
- self.direction = (
- direction
- + self.owner.aim
- - self.owner.direction) % PI_2
-
- while self.direction > math.pi:
- self.direction -= PI_2
- while self.direction < -math.pi:
- self.direction += PI_2
- self.direction /= self.direction_frames
-
- elif isinstance(action, parser.Accel):
- frames, horizontal, vertical = action(self.params, self.rank)
- self.accel_frames = frames
- if horizontal:
- mx, type = horizontal
- if type == "sequence":
- self.mx = mx
- elif type == "absolute":
- self.mx = (mx - self.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 - self.owner.my) / frames
- elif type == "relative":
- self.my = my / frames
-
- elif isinstance(action, parser.Wait):
- self.wait_frames = action(self.params, self.rank)
+ if isinstance(action, (parser.ActionDef, parser.ActionRef)):
+ actions, params = action(s_params, rank)
+ child = self.__class__(self, actions, params, rank)
+ owner.replace(self, child)
+ child.step(owner, created)
break
- elif isinstance(action, parser.Vanish):
- self.owner.vanish()
+ elif action(owner, self, s_params, rank, created):
break
- return created
-
class Bullet(object):
- """Simple bullet implementation."""
+ """Simple bullet implementation.
+
+ Attributes:
+ x, y - current X/Y position
+ px, py - X/Y position prior to the last step
+ mx, my - X/Y axis-oriented speed modifier ("acceleration")
+ direction - direction of movement, in radians
+ speed - speed of movement, in units per frame
+ 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
+
+ Contructor Arguments:
+ x, y, direction, speed, target, rank, tags, appearance
+ - same as the above attributes
+ actions - internal action list
+ Action - custom Action constructor
+
+ """
def __init__(self, x=0, y=0, direction=0, speed=0, target=None,
- actions=(), parent=None, rank=None):
+ actions=(), rank=0.5, tags=(), appearance=None,
+ Action=Action):
self.x = self.px = x
self.y = self.py = y
self.mx = 0
self.speed = speed
self.vanished = False
self.target = target
- self.actions = []
- if rank is None:
- rank = parent.rank if parent else 0.5
+ self.rank = rank
+ 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]
+ self.actions = [Action(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."""
- 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):
- """Check if this bullet is finished running."""
+ """Check if this bullet is finished running.
+
+ A bullet is finished when it has vanished, and all its
+ actions have finished.
+
+ 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 not self.vanished:
return False
for action in self.actions:
self.actions = []
def replace(self, old, new):
- """Replace an active action with another."""
+ """Replace an active action with another.
+
+ This is mostly used by actions internally to queue children.
+ """
try:
idx = self.actions.index(old)
except ValueError:
self.actions[idx] = new
def step(self):
- """Advance by one frame."""
+ """Advance by one frame.
+
+ This updates the position and velocity, and may also set the
+ vanished flag.
+
+ It returns any new bullets this bullet spawned during this step.
+ """
created = []
for action in self.actions:
- created.extend(action.step())
+ action.step(self, created)
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(self.direction) * self.speed
+ self.y += -self.my + cos(self.direction) * self.speed
return created
-
- @classmethod
- def FromDoc(cls, doc, params=(), x=0, y=0, speed=0, direction=0,
- target=None, rank=0.5):
- """Construct a bullet from top-level actions in a document."""
- actions = [act(params, rank) for act in doc.top]
- return cls(x, y, direction, speed, target, actions, rank=rank)
-
projects / python-bulletml.git / blobdiff