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 class Action(object):
  16     """Running action implementation."""
  17
  18     def __init__(self, owner, parent, actions, params, rank):
  19         self.actions = actions
  20         self.parent = parent
  21         self.repeat = 1
  22         self.wait_frames = 0
  23         self.speed = 0
  24         self.speed_frames = 0
  25         self.aim_direction = 0
  26         self.direction = 0
  27         self.direction_frames = 0
  28         self.aiming = False
  29         self.aim_mx = 0
  30         self.aim_my = 0
  31         self.mx = 0
  32         self.my = 0
  33         self.owner = owner
  34         self.accel_frames = 0
  35         self.previous_fire_direction = 0
  36         self.previous_fire_speed = 0
  37         self.params = params
  38         self.rank = rank
  39         self.pc = -1
  40         self.finished = False
  41         if parent:
  42             self.copy_state(parent)
  43
  44     def __repr__(self):
  45         return "%s(pc=%r, actions=%r)" % (
  46             type(self).__name__, self.pc, self.actions)
  47
  48     def vanish(self):
  49         """End this action and its parents."""
  50         if self.parent:
  51             self.parent.vanish()
  52         self.pc = None
  53         self.finished = True
  54
  55     def copy_state(self, other):
  56         """Copy fire/movement state from other to self."""
  57         self.direction_frames = other.direction_frames
  58         self.direction = other.direction
  59         self.aiming = other.aiming
  60         self.speed_frames = other.speed_frames
  61         self.speed = other.speed
  62         self.accel_frames = other.accel_frames
  63         self.mx = other.mx
  64         self.my = other.my
  65         self.previous_fire_direction = other.previous_fire_direction
  66         self.previous_fire_speed = other.previous_fire_speed
  67
  68     def step(self):
  69         """Advance by one frame."""
  70         created = []
  71
  72         if self.speed_frames > 0:
  73             self.speed_frames -= 1
  74             self.owner.speed += self.speed
  75
  76         if self.direction_frames > 0:
  77             self.direction_frames -= 1
  78             if self.direction_frames <= 0:
  79                 if self.aiming:
  80                     self.owner.direction += self.owner.aim
  81             else:
  82                 self.owner.direction += self.direction
  83
  84         if self.accel_frames > 0:
  85             self.accel_frames -= 1
  86             self.owner.mx += self.mx
  87             self.owner.my += self.my
  88
  89         if self.pc is None:
  90             return created
  91
  92         if self.wait_frames > 0:
  93             self.wait_frames -= 1
  94             return created
  95
  96         while True:
  97             self.pc += 1
  98
  99             if self.pc >= len(self.actions):
 100                 self.repeat -= 1
 101                 if self.repeat <= 0:
 102                     self.pc = None
 103                     self.finished = True
 104                     if self.parent is not None:
 105                         self.parent.copy_state(self)
 106                         self.owner.replace(self, self.parent)
 107                     break
 108                 else:
 109                     self.pc = 0
 110
 111             action = self.actions[self.pc]
 112
 113             if isinstance(action, parser.Repeat):
 114                 repeat, (actions, params) = action(self.params, self.rank)
 115                 child = Action(self.owner, self, actions, params, self.rank)
 116                 child.repeat = repeat
 117                 self.owner.replace(self, child)
 118                 created.extend(child.step())
 119                 break
 120
 121             elif isinstance(action, (parser.ActionDef, parser.ActionRef)):
 122                 actions, params = action(self.params, self.rank)
 123                 child = Action(self.owner, self, actions, params, self.rank)
 124                 self.owner.replace(self, child)
 125                 created.extend(child.step())
 126                 break
 127
 128             elif isinstance(action, (parser.FireDef, parser.FireRef)):
 129                 direction, speed, actions = action(self.params, self.rank)
 130                 if direction:
 131                     direction, type = direction
 132                     if type == "aim" or type is None:
 133                         direction += self.owner.aim
 134                     elif type == "sequence":
 135                         direction += self.previous_fire_direction
 136                     elif type == "relative":
 137                         direction += self.owner.direction
 138                 else:
 139                     direction = self.owner.aim
 140                 self.previous_fire_direction = direction
 141
 142
 143                 if speed:
 144                     speed, type = speed
 145                     if type == "sequence":
 146                         speed += self.previous_fire_speed
 147                     elif type == "relative":
 148                         # FIXME(jfw): Reference impl uses prvFireSpeed
 149                         # here?  That doesn't seem right at all.
 150                         speed += self.owner.speed
 151                 else:
 152                     speed = 1
 153                 self.previous_fire_speed = speed
 154
 155                 bullet = Bullet(self.owner.x, self.owner.y, direction, speed,
 156                                 self.owner.target, actions, self)
 157                 created.append(bullet)
 158
 159             elif isinstance(action, parser.ChangeSpeed):
 160                 frames, (speed, type) = action(self.params, self.rank)
 161                 self.speed_frames = frames
 162                 if type == "sequence":
 163                     self.speed = speed
 164                 elif type == "relative":
 165                     self.speed = speed / frames
 166                 else:
 167                     self.speed = (speed - self.owner.speed) / frames
 168
 169             elif isinstance(action, parser.ChangeDirection):
 170                 frames, (direction, type) = action(self.params, self.rank)
 171                 self.direction_frames = frames
 172                 self.aiming = False
 173                 if type == "sequence":
 174                     self.aiming = False
 175                     self.direction = direction
 176                 else:
 177                     if type == "absolute":
 178                         self.aiming = False
 179                         self.direction = (
 180                             direction - self.owner.direction) % 360
 181                     elif type == "relative":
 182                         self.aiming = False
 183                         self.direction = direction
 184                     else:
 185                         self.aiming = True
 186                         self.direction = (
 187                             direction
 188                             + self.owner.aim
 189                             - self.owner.direction) % 360
 190
 191                     while self.direction > 180:
 192                         self.direction -= 360
 193                     while self.direction < -180:
 194                         self.direction += 360
 195                     self.direction /= self.direction_frames
 196
 197             elif isinstance(action, parser.Accel):
 198                 frames, horizontal, vertical = action(self.params, self.rank)
 199                 self.accel_frames = frames
 200                 if horizontal:
 201                     mx, type = horizontal
 202                     if type == "sequence":
 203                         self.mx = mx
 204                     elif type == "absolute":
 205                         self.mx = (mx - self.owner.mx) / frames
 206                     elif type == "relative":
 207                         self.mx = mx / frames
 208                 if vertical:
 209                     my, type = vertical
 210                     if type == "sequence":
 211                         self.my = my
 212                     elif type == "absolute":
 213                         self.my = (my - self.owner.my) / frames
 214                     elif type == "relative":
 215                         self.my = my / frames
 216
 217             elif isinstance(action, parser.Wait):
 218                 self.wait_frames = action(self.params, self.rank)
 219                 break
 220
 221             elif isinstance(action, parser.Vanish):
 222                 self.owner.vanish()
 223                 break
 224
 225         return created
 226
 227 class Bullet(object):
 228     """Simple bullet implementation."""
 229
 230     def __init__(self, x=0, y=0, direction=0, speed=0, target=None,
 231                  actions=(), parent=None, rank=None):
 232         self.x = self.px = x
 233         self.y = self.py = y
 234         self.mx = 0
 235         self.my = 0
 236         self.direction = direction
 237         self.speed = speed
 238         self.vanished = False
 239         self.target = target
 240         self.actions = []
 241         if rank is None:
 242             rank = parent.rank if parent else 0.5
 243         # New bullets reset the parent hierarchy.
 244         self.actions = [Action(self, None, action, params, rank)
 245                         for action, params in actions]
 246
 247     def __repr__(self):
 248         return ("%s(%r, %r, accel=%r, direction=%r, speed=%r, "
 249                 "actions=%r, target=%r, vanished=%r)") % (
 250             type(self).__name__, self.x, self.y, (self.mx, self.my),
 251             self.direction, self.speed, self.actions, self.target,
 252             self.vanished)
 253
 254     @property
 255     def aim(self):
 256         """Angle to the target."""
 257         if self.target is None:
 258             return self.direction
 259         else:
 260             return math.degrees(
 261                 math.atan2(self.target.x - self.x, self.y - self.target.y))
 262
 263     @property
 264     def finished(self):
 265         """Check if this bullet is finished running."""
 266         for action in self.actions:
 267             if not action.finished:
 268                 return False
 269         return self.vanished
 270
 271     def vanish(self):
 272         """Vanish this bullet and stop all actions."""
 273         self.vanished = True
 274         for action in self.actions:
 275             action.vanish()
 276         self.actions = []
 277
 278     def replace(self, old, new):
 279         """Replace an active action with another."""
 280         try:
 281             idx = self.actions.index(old)
 282         except ValueError:
 283             pass
 284         else:
 285             self.actions[idx] = new
 286
 287     def step(self):
 288         """Advance by one frame."""
 289         created = []
 290
 291         for action in self.actions:
 292             created.extend(action.step())
 293
 294         direction = math.radians(self.direction)
 295         self.px = self.x
 296         self.py = self.y
 297         self.x += self.mx + math.sin(direction) * self.speed
 298         self.y += self.my - math.cos(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