# 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."""
- def __init__(self, owner, parent, actions, params, rank):
+ def __init__(self, owner, 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.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
- if self.direction_frames <= 0:
- if self.aiming:
- self.owner.direction += self.owner.aim
+ if self.aiming and self.direction_frames <= 0:
+ self.owner.direction += self.owner.aim
else:
self.owner.direction += self.direction
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
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
+ child = Action(
+ self.owner, self, actions, params, self.rank, repeat)
self.owner.replace(self, child)
created.extend(child.step())
break
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":
- # FIXME(jfw): Reference impl uses prvFireSpeed
- # here? That doesn't seem right at all.
+ # 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.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) % 360
+ 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) % 360
+ - self.owner.direction) % PI_2
- while self.direction > 180:
- self.direction -= 360
- while self.direction < -180:
- self.direction += 360
+ 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):
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
+
+ Contructor Arguments:
+ x, y, direction, speed, target - same as the attributes
+ actions - internal action list
+ parent - parent of actions, None for manually-created bullets
+ rank - game difficulty, 0 to 1
+
+ """
def __init__(self, x=0, y=0, direction=0, speed=0, target=None,
actions=(), parent=None, rank=None):
self.speed = speed
self.vanished = False
self.target = target
- self.actions = []
if rank is None:
rank = parent.rank if parent else 0.5
# New bullets reset the parent hierarchy.
- self.actions = [Action(self, None, action, params, rank)
- for action, params in actions]
+ self._actions = [Action(self, None, action, params, rank)
+ for action, params in actions]
def __repr__(self):
return ("%s(%r, %r, accel=%r, direction=%r, speed=%r, "
"actions=%r, target=%r, vanished=%r)") % (
type(self).__name__, self.x, self.y, (self.mx, self.my),
- self.direction, self.speed, self.actions, self.target,
+ self.direction, self.speed, self._actions, self.target,
self.vanished)
@property
def aim(self):
- """Angle to the target."""
+ """Angle to the target, in radians."""
if self.target is None:
return self.direction
else:
- return math.degrees(
- math.atan2(self.target.x - self.x, self.y - self.target.y))
+ return math.atan2(self.target.x - self.x, self.y - self.target.y)
@property
def finished(self):
- """Check if this bullet is finished running."""
- for action in self.actions:
+ """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:
if not action.finished:
return False
- return self.vanished
+ return True
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."""
+ """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."""
+ """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:
+ for action in self._actions:
created.extend(action.step())
- direction = math.radians(self.direction)
self.px = self.x
self.py = self.y
- self.x += self.mx + math.sin(direction) * self.speed
- self.y += self.my - math.cos(direction) * self.speed
+ self.x += self.mx + math.sin(self.direction) * self.speed
+ self.y += self.my - math.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