bulletml/impl.py

   1 """BulletML implementation.
   2
   3 http://www.asahi-net.or.jp/~cs8k-cyu/bulletml/index_e.html
   4 """
   5
   6 from __future__ import division
   7
   8 import math
   9
  10 from bulletml import parser
  11
  12 # TODO(jfw): This is very non-Pythonic, it's pretty much just the
  13 # BulletML reference ActionImpl translated to Python.
  14
  15 PI_2 = math.pi * 2
  16
  17 class Action(object):
  18     """Running action implementation."""
  19
  20     def __init__(self, owner, parent, actions, params, rank):
  21         self.actions = actions
  22         self.parent = parent
  23         self.repeat = 1
  24         self.wait_frames = 0
  25         self.speed = 0
  26         self.speed_frames = 0
  27         self.aim_direction = 0
  28         self.direction = 0
  29         self.direction_frames = 0
  30         self.aiming = False
  31         self.aim_mx = 0
  32         self.aim_my = 0
  33         self.mx = 0
  34         self.my = 0
  35         self.owner = owner
  36         self.accel_frames = 0
  37         self.previous_fire_direction = 0
  38         self.previous_fire_speed = 0
  39         self.params = params
  40         self.rank = rank
  41         self.pc = -1
  42         self.finished = False
  43         if parent:
  44             self.copy_state(parent)
  45
  46     def __repr__(self):
  47         return "%s(pc=%r, actions=%r)" % (
  48             type(self).__name__, self.pc, self.actions)
  49
  50     def vanish(self):
  51         """End this action and its parents."""
  52         if self.parent:
  53             self.parent.vanish()
  54         self.pc = None
  55         self.finished = True
  56
  57     def copy_state(self, other):
  58         """Copy fire/movement state from other to self."""
  59         self.direction_frames = other.direction_frames
  60         self.direction = other.direction
  61         self.aiming = other.aiming
  62         self.speed_frames = other.speed_frames
  63         self.speed = other.speed
  64         self.accel_frames = other.accel_frames
  65         self.mx = other.mx
  66         self.my = other.my
  67         self.previous_fire_direction = other.previous_fire_direction
  68         self.previous_fire_speed = other.previous_fire_speed
  69
  70     def step(self):
  71         """Advance by one frame."""
  72         created = []
  73
  74         if self.speed_frames > 0:
  75             self.speed_frames -= 1
  76             self.owner.speed += self.speed
  77
  78         if self.direction_frames > 0:
  79             self.direction_frames -= 1
  80             if self.direction_frames <= 0:
  81                 if self.aiming:
  82                     self.owner.direction += self.owner.aim
  83             else:
  84                 self.owner.direction += self.direction
  85
  86         if self.accel_frames > 0:
  87             self.accel_frames -= 1
  88             self.owner.mx += self.mx
  89             self.owner.my += self.my
  90
  91         if self.pc is None:
  92             return created
  93
  94         if self.wait_frames > 0:
  95             self.wait_frames -= 1
  96             return created
  97
  98         while True:
  99             self.pc += 1
 100
 101             if self.pc >= len(self.actions):
 102                 self.repeat -= 1
 103                 if self.repeat <= 0:
 104                     self.pc = None
 105                     self.finished = True
 106                     if self.parent is not None:
 107                         self.parent.copy_state(self)
 108                         self.owner.replace(self, self.parent)
 109                     break
 110                 else:
 111                     self.pc = 0
 112
 113             action = self.actions[self.pc]
 114
 115             if isinstance(action, parser.Repeat):
 116                 repeat, (actions, params) = action(self.params, self.rank)
 117                 child = Action(self.owner, self, actions, params, self.rank)
 118                 child.repeat = repeat
 119                 self.owner.replace(self, child)
 120                 created.extend(child.step())
 121                 break
 122
 123             elif isinstance(action, (parser.ActionDef, parser.ActionRef)):
 124                 actions, params = action(self.params, self.rank)
 125                 child = Action(self.owner, self, actions, params, self.rank)
 126                 self.owner.replace(self, child)
 127                 created.extend(child.step())
 128                 break
 129
 130             elif isinstance(action, (parser.FireDef, parser.FireRef)):
 131                 direction, speed, actions = action(self.params, self.rank)
 132                 if direction:
 133                     direction, type = direction
 134                     if type == "aim" or type is None:
 135                         direction += self.owner.aim
 136                     elif type == "sequence":
 137                         direction += self.previous_fire_direction
 138                     elif type == "relative":
 139                         direction += self.owner.direction
 140                 else:
 141                     direction = self.owner.aim
 142                 self.previous_fire_direction = direction
 143
 144
 145                 if speed:
 146                     speed, type = speed
 147                     if type == "sequence":
 148                         speed += self.previous_fire_speed
 149                     elif type == "relative":
 150                         # FIXME(jfw): Reference impl uses prvFireSpeed
 151                         # here?  That doesn't seem right at all.
 152                         speed += self.owner.speed
 153                 else:
 154                     speed = 1
 155                 self.previous_fire_speed = speed
 156
 157                 bullet = Bullet(self.owner.x, self.owner.y, direction, speed,
 158                                 self.owner.target, actions, self)
 159                 created.append(bullet)
 160
 161             elif isinstance(action, parser.ChangeSpeed):
 162                 frames, (speed, type) = action(self.params, self.rank)
 163                 self.speed_frames = frames
 164                 if type == "sequence":
 165                     self.speed = speed
 166                 elif type == "relative":
 167                     self.speed = speed / frames
 168                 else:
 169                     self.speed = (speed - self.owner.speed) / frames
 170
 171             elif isinstance(action, parser.ChangeDirection):
 172                 frames, (direction, type) = action(self.params, self.rank)
 173                 self.direction_frames = frames
 174                 self.aiming = False
 175                 if type == "sequence":
 176                     self.aiming = False
 177                     self.direction = direction
 178                 else:
 179                     if type == "absolute":
 180                         self.aiming = False
 181                         self.direction = (
 182                             direction - self.owner.direction) % PI_2
 183                     elif type == "relative":
 184                         self.aiming = False
 185                         self.direction = direction
 186                     else:
 187                         self.aiming = True
 188                         self.direction = (
 189                             direction
 190                             + self.owner.aim
 191                             - self.owner.direction) % PI_2
 192
 193                     while self.direction > math.pi:
 194                         self.direction -= PI_2
 195                     while self.direction < -math.pi:
 196                         self.direction += PI_2
 197                     self.direction /= self.direction_frames
 198
 199             elif isinstance(action, parser.Accel):
 200                 frames, horizontal, vertical = action(self.params, self.rank)
 201                 self.accel_frames = frames
 202                 if horizontal:
 203                     mx, type = horizontal
 204                     if type == "sequence":
 205                         self.mx = mx
 206                     elif type == "absolute":
 207                         self.mx = (mx - self.owner.mx) / frames
 208                     elif type == "relative":
 209                         self.mx = mx / frames
 210                 if vertical:
 211                     my, type = vertical
 212                     if type == "sequence":
 213                         self.my = my
 214                     elif type == "absolute":
 215                         self.my = (my - self.owner.my) / frames
 216                     elif type == "relative":
 217                         self.my = my / frames
 218
 219             elif isinstance(action, parser.Wait):
 220                 self.wait_frames = action(self.params, self.rank)
 221                 break
 222
 223             elif isinstance(action, parser.Vanish):
 224                 self.owner.vanish()
 225                 break
 226
 227         return created
 228
 229 class Bullet(object):
 230     """Simple bullet implementation."""
 231
 232     def __init__(self, x=0, y=0, direction=0, speed=0, target=None,
 233                  actions=(), parent=None, rank=None):
 234         self.x = self.px = x
 235         self.y = self.py = y
 236         self.mx = 0
 237         self.my = 0
 238         self.direction = direction
 239         self.speed = speed
 240         self.vanished = False
 241         self.target = target
 242         self.actions = []
 243         if rank is None:
 244             rank = parent.rank if parent else 0.5
 245         # New bullets reset the parent hierarchy.
 246         self.actions = [Action(self, None, action, params, rank)
 247                         for action, params in actions]
 248
 249     def __repr__(self):
 250         return ("%s(%r, %r, accel=%r, direction=%r, speed=%r, "
 251                 "actions=%r, target=%r, vanished=%r)") % (
 252             type(self).__name__, self.x, self.y, (self.mx, self.my),
 253             self.direction, self.speed, self.actions, self.target,
 254             self.vanished)
 255
 256     @property
 257     def aim(self):
 258         """Angle to the target."""
 259         if self.target is None:
 260             return self.direction
 261         else:
 262             return math.atan2(self.target.x - self.x, self.y - self.target.y)
 263
 264     @property
 265     def finished(self):
 266         """Check if this bullet is finished running."""
 267         for action in self.actions:
 268             if not action.finished:
 269                 return False
 270         return self.vanished
 271
 272     def vanish(self):
 273         """Vanish this bullet and stop all actions."""
 274         self.vanished = True
 275         for action in self.actions:
 276             action.vanish()
 277         self.actions = []
 278
 279     def replace(self, old, new):
 280         """Replace an active action with another."""
 281         try:
 282             idx = self.actions.index(old)
 283         except ValueError:
 284             pass
 285         else:
 286             self.actions[idx] = new
 287
 288     def step(self):
 289         """Advance by one frame."""
 290         created = []
 291
 292         for action in self.actions:
 293             created.extend(action.step())
 294
 295         self.px = self.x
 296         self.py = self.y
 297         self.x += self.mx + math.sin(self.direction) * self.speed
 298         self.y += self.my - math.cos(self.direction) * self.speed
 299
 300         return created
 301
 302     @classmethod
 303     def FromDoc(cls, doc, params=(), x=0, y=0, speed=0, direction=0,
 304                 target=None, rank=0.5):
 305         """Construct a bullet from top-level actions in a document."""
 306         actions = [act(params, rank) for act in doc.top]
 307         return cls(x, y, direction, speed, target, actions, rank=rank)
 308