1 """BulletML implementation."""
3 from __future__
import division
5 from math
import atan2
, sin
, cos
7 __all__
= ["Action", "Bullet"]
10 """Running action implementation.
12 To implement new actions, add a new element/class pair to
13 parser.ActionDef.CONSTRUCTORS. It should support FromXML,
14 __getstate__, and __setstate__, and 5-ary __call__:
16 def __call__(self, owner, action, params, rank, created)
18 Which will be called to execute it. This function should modify
19 owner, action, and created in-place, and return true if action
20 execution should stop for this bullet this frame.
24 def __init__(self
, parent
, actions
, params
, rank
, repeat
=1):
25 self
.actions
= actions
32 self
.direction_frames
= 0
37 self
.previous_fire_direction
= 0
38 self
.previous_fire_speed
= 0
43 self
.copy_state(parent
)
46 return "%s(pc=%r, actions=%r)" % (
47 type(self
).__name
__, self
.pc
, self
.actions
)
50 """End this action and its parents."""
56 def copy_state(self
, other
):
57 """Copy fire/movement state from other to self."""
58 self
.direction_frames
= other
.direction_frames
59 self
.direction
= other
.direction
60 self
.aiming
= other
.aiming
61 self
.speed_frames
= other
.speed_frames
62 self
.speed
= other
.speed
63 self
.accel_frames
= other
.accel_frames
66 self
.previous_fire_direction
= other
.previous_fire_direction
67 self
.previous_fire_speed
= other
.previous_fire_speed
69 def step(self
, owner
, created
):
70 """Advance by one frame."""
72 if self
.speed_frames
> 0:
73 self
.speed_frames
-= 1
74 owner
.speed
+= self
.speed
76 if self
.direction_frames
> 0:
77 self
.direction_frames
-= 1
78 # I'm still not sure what the aim check is supposed to do.
79 if self
.aiming
and self
.direction_frames
<= 0:
80 owner
.direction
+= owner
.aim
82 owner
.direction
+= self
.direction
84 if self
.accel_frames
> 0:
85 self
.accel_frames
-= 1
92 if self
.wait_frames
> 0:
96 s_params
= self
.params
103 action
= self
.actions
[self
.pc
]
109 if self
.parent
is not None:
110 self
.parent
.copy_state(self
)
111 owner
.replace(self
, self
.parent
)
115 action
= self
.actions
[self
.pc
]
117 if action(owner
, self
, s_params
, rank
, created
):
120 class Bullet(object):
121 """Simple bullet implementation.
124 x, y - current X/Y position
125 px, py - X/Y position prior to the last step
126 mx, my - X/Y axis-oriented speed modifier ("acceleration")
127 direction - direction of movement, in radians
128 speed - speed of movement, in units per frame
129 target - object with .x and .y fields for "aim" directions
130 vanished - set to true by a <vanish> action
131 rank - game difficulty, 0 to 1, default 0.5
132 tags - string tags set by the running actions
133 appearance - string used to set bullet appearance
134 radius - radius for collision
135 finished - true if all actions are finished and the bullet vanished
137 Contructor Arguments:
138 x, y, direction, speed, target, rank, tags, appearance, radius
139 - same as the above attributes
140 actions - internal action list
141 Action - custom Action constructor
145 def __init__(self
, x
=0, y
=0, direction
=0, speed
=0, target
=None,
146 actions
=(), rank
=0.5, tags
=(), appearance
=None,
153 self
.direction
= direction
155 self
.vanished
= False
156 self
.finished
= False
159 self
.tags
= set(tags
)
160 self
.appearance
= appearance
161 self
.actions
= list(actions
)
164 def FromDocument(cls
, doc
, x
=0, y
=0, direction
=0, speed
=0, target
=None,
165 params
=(), rank
=0.5, Action
=Action
):
166 """Construct a new Bullet from a loaded BulletML document."""
167 actions
= [action(None, Action
, params
, rank
)
168 for action
in doc
.actions
]
169 return cls(x
=x
, y
=y
, direction
=direction
, speed
=speed
,
170 target
=target
, actions
=actions
, rank
=rank
)
173 return ("%s(%r, %r, accel=%r, direction=%r, speed=%r, "
174 "actions=%r, target=%r, appearance=%r, vanished=%r)") % (
175 type(self
).__name
__, self
.x
, self
.y
, (self
.mx
, self
.my
),
176 self
.direction
, self
.speed
, self
.actions
, self
.target
,
177 self
.appearance
, self
.vanished
)
181 """Angle to the target, in radians.
183 If the target does not exist or cannot be found, return 0.
186 target_x
= self
.target
.x
187 target_y
= self
.target
.y
188 except AttributeError:
191 return atan2(target_x
- self
.x
, target_y
- self
.y
)
194 """Vanish this bullet and stop all actions."""
196 for action
in self
.actions
:
200 def replace(self
, old
, new
):
201 """Replace an active action with another.
203 This is mostly used by actions internally to queue children.
206 idx
= self
.actions
.index(old
)
210 self
.actions
[idx
] = new
213 """Advance by one frame.
215 This updates the position and velocity, and may also set the
218 It returns any new bullets this bullet spawned during this step.
222 finished
= self
.vanished
223 for action
in self
.actions
:
224 action
.step(self
, created
)
225 finished
= finished
and action
.finished
226 self
.finished
= finished
229 direction
= self
.direction
232 self
.x
+= self
.mx
+ sin(direction
) * speed
233 self
.y
+= -self
.my
+ cos(direction
) * speed