X-Git-Url: https://git.yukkurigames.com/?p=python-bulletml.git;a=blobdiff_plain;f=bulletml%2Fimpl.py;h=f0e8964d806351cd9a2e876db194730da44bc4f9;hp=4dde9fb4b608115ad2dec45a6426a89255282faf;hb=bf5ff1d116840e1330c80894132919ec515596e4;hpb=006fb3dcabc9600997f5c3c8fcc5e80baa7fc1e0

diff --git a/bulletml/impl.py b/bulletml/impl.py
index 4dde9fb..f0e8964 100644
--- a/bulletml/impl.py
+++ b/bulletml/impl.py
@@ -1,42 +1,46 @@
-"""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, errors
+from bulletml import parser
 
-# TODO(jfw): This is very non-Pythonic, it's pretty much just the
-# BulletML reference ActionImpl translated to Python.
+__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:
             self.copy_state(parent)
 
@@ -44,16 +48,18 @@ class Action(object):
         return "%s(pc=%r, actions=%r)" % (
             type(self).__name__, self.pc, self.actions)
 
-    @property
-    def finished(self):
-        return self.pc is None
+    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.parent.vanish()
         self.pc = None
+        self.finished = True
 
     def copy_state(self, other):
+        """Copy fire/movement state from other to self."""
         self.direction_frames = other.direction_frames
         self.direction = other.direction
         self.aiming = other.aiming
@@ -65,168 +71,89 @@ class Action(object):
         self.previous_fire_direction = other.previous_fire_direction
         self.previous_fire_speed = other.previous_fire_speed
 
-    def step(self):
-        created = []
+    def step(self, owner, created):
+        """Advance by one frame."""
+        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())
+            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.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())
+            elif action(owner, self, s_params, rank, created):
                 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":
-                        # FIXME(jfw): Reference impl uses prvFireSpeed
-                        # here?  That doesn't seem right at all.
-                        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) % 360
-                    elif type == "relative":
-                        self.aiming = False
-                        self.direction = direction
-                    else:
-                        self.aiming = True
-                        self.direction = (
-                            direction
-                            + self.owner.aim
-                            - self.owner.direction) % 360
-
-                    while self.direction > 180:
-                        self.direction -= 360
-                    while self.direction < -180:
-                        self.direction += 360
-                    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)
-                break
-
-            elif isinstance(action, parser.Vanish):
-                self.owner.vanish()
-                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
@@ -235,35 +162,59 @@ class Bullet(object):
         self.speed = speed
         self.vanished = False
         self.target = target
-        self.actions = []
-        if rank is None:
-            rank = parent.rank if parent else 0.5
-        for action, params in actions:
-            # New bullets reset the parent hierarchy.
-            self.actions.append(Action(self, None, action, params, rank))
+        self.rank = rank
+        self.tags = set(tags)
+        self.appearance = appearance
+        # New bullets reset the parent hierarchy.
+        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.degrees(
-                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.
+
+        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."""
@@ -273,6 +224,10 @@ class Bullet(object):
         self.actions = []
 
     def replace(self, old, new):
+        """Replace an active action with another.
+
+        This is mostly used by actions internally to queue children.
+        """
         try:
             idx = self.actions.index(old)
         except ValueError:
@@ -281,22 +236,21 @@ class Bullet(object):
             self.actions[idx] = new
 
     def step(self):
+        """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)
 
-        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 + 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):
-        actions = [act(params, rank) for act in doc.top]
-        return cls(x, y, direction, speed, target, actions, rank=rank)
-