X-Git-Url: https://git.yukkurigames.com/?p=python-bulletml.git;a=blobdiff_plain;f=bulletml%2Fimpl.py;h=f0e8964d806351cd9a2e876db194730da44bc4f9;hp=358aae1a1c192a60d8c4567aa5ddf63b6821a321;hb=bf5ff1d116840e1330c80894132919ec515596e4;hpb=62bfd556a69becf6b23715a150accac703af9058

diff --git a/bulletml/impl.py b/bulletml/impl.py
index 358aae1..f0e8964 100644
--- a/bulletml/impl.py
+++ b/bulletml/impl.py
@@ -2,21 +2,28 @@
 
 from __future__ import division
 
-import math
+from math import atan2, sin, cos
 
 from bulletml import parser
 
-# 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."""
+    """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, repeat=1):
+    def __init__(self, parent, actions, params, rank, repeat=1):
         self.actions = actions
         self.parent = parent
         self.repeat = repeat
@@ -41,6 +48,9 @@ class Action(object):
         return "%s(pc=%r, actions=%r)" % (
             type(self).__name__, self.pc, self.actions)
 
+    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:
@@ -61,19 +71,17 @@ class Action(object):
         self.previous_fire_direction = other.previous_fire_direction
         self.previous_fire_speed = other.previous_fire_speed
 
-    def step(self, owner, rank):
+    def step(self, owner, created):
         """Advance by one frame."""
-        created = []
+        s_params = self.params
+        rank = owner.rank
 
         if self.speed_frames > 0:
             self.speed_frames -= 1
             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.
+            # I'm still not sure what the aim check is supposed to do.
             self.direction_frames -= 1
             if self.aiming and self.direction_frames <= 0:
                 owner.direction += owner.aim
@@ -86,11 +94,11 @@ class Action(object):
             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
@@ -110,130 +118,16 @@ class Action(object):
                     self.pc = 0
                     action = self.actions[self.pc]
 
-            if isinstance(action, parser.Repeat):
-                repeat, (actions, params) = action(self.params, rank)
-                child = Action(owner, self, actions, params, rank, repeat)
+            if isinstance(action, (parser.ActionDef, parser.ActionRef)):
+                actions, params = action(s_params, rank)
+                child = self.__class__(self, actions, params, rank)
                 owner.replace(self, child)
-                created.extend(child.step(owner, rank))
+                child.step(owner, created)
                 break
 
-            elif isinstance(action, (parser.ActionDef, parser.ActionRef)):
-                actions, params = action(self.params, rank)
-                child = Action(owner, self, actions, params, rank)
-                owner.replace(self, child)
-                created.extend(child.step(owner, rank))
+            elif action(owner, self, s_params, rank, created):
                 break
 
-            elif isinstance(action, (parser.FireDef, parser.FireRef)):
-                direction, speed, actions, offset = action(self.params, rank)
-                if direction:
-                    direction, type = direction
-                    if type == "aim" or type is None:
-                        direction += owner.aim
-                    elif type == "sequence":
-                        direction += self.previous_fire_direction
-                    elif type == "relative":
-                        direction += owner.direction
-                else:
-                    direction = owner.aim
-                self.previous_fire_direction = direction
-
-                if speed:
-                    speed, type = speed
-                    if type == "sequence":
-                        speed += self.previous_fire_speed
-                    elif type == "relative":
-                        # The reference Noiz implementation uses
-                        # prvFireSpeed here, but the standard is
-                        # pretty clear -- "In case of the type is
-                        # "relative", ... the speed is relative to the
-                        # speed of this bullet."
-                        speed += owner.speed
-                else:
-                    speed = 1
-                self.previous_fire_speed = speed
-
-                x, y = owner.x, owner.y
-                if offset:
-                    off_x, off_y = offset(self.params, rank)
-                    if offset.type == "relative":
-                        sin = math.sin(direction)
-                        cos = math.cos(direction)
-                        x += cos * off_x + sin * off_y
-                        y += sin * off_x - cos * off_y
-                    else:
-                        x += off_x
-                        y += off_y
-
-                bullet = Bullet(
-                    x, y, direction, speed, owner.target, actions, self, rank)
-                created.append(bullet)
-
-            elif isinstance(action, parser.ChangeSpeed):
-                frames, (speed, type) = action(self.params, rank)
-                self.speed_frames = frames
-                if type == "sequence":
-                    self.speed = speed
-                elif type == "relative":
-                    self.speed = speed / frames
-                else:
-                    self.speed = (speed - owner.speed) / frames
-
-            elif isinstance(action, parser.ChangeDirection):
-                frames, (direction, type) = action(self.params, rank)
-                self.direction_frames = frames
-                self.aiming = False
-                if type == "sequence":
-                    self.direction = direction
-                else:
-                    if type == "absolute":
-                        self.direction = (
-                            direction - owner.direction) % PI_2
-                    elif type == "relative":
-                        self.direction = direction
-                    else:
-                        self.aiming = True
-                        self.direction = (
-                            direction
-                            + owner.aim
-                            - owner.direction) % PI_2
-
-                    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):
-                frames, horizontal, vertical = action(self.params, rank)
-                self.accel_frames = frames
-                if horizontal:
-                    mx, type = horizontal
-                    if type == "sequence":
-                        self.mx = mx
-                    elif type == "absolute":
-                        self.mx = (mx - 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 - owner.my) / frames
-                    elif type == "relative":
-                        self.my = my / frames
-
-            elif isinstance(action, parser.Wait):
-                self.wait_frames = action(self.params, rank)
-                break
-
-            elif isinstance(action, parser.Vanish):
-                owner.vanish()
-                break
-
-        return created
-
 class Bullet(object):
     """Simple bullet implementation.
 
@@ -246,17 +140,20 @@ class Bullet(object):
     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 - same as the attributes
+    x, y, direction, speed, target, rank, tags, appearance
+        - same as the above attributes
     actions - internal action list
-    parent - parent of actions, None for manually-created bullets
-
+    Action - custom Action constructor
 
     """
 
     def __init__(self, x=0, y=0, direction=0, speed=0, target=None,
-                 actions=(), parent=None, rank=0.5):
+                 actions=(), rank=0.5, tags=(), appearance=None,
+                 Action=Action):
         self.x = self.px = x
         self.y = self.py = y
         self.mx = 0
@@ -266,24 +163,40 @@ class Bullet(object):
         self.vanished = False
         self.target = target
         self.rank = rank
+        self.tags = set(tags)
+        self.appearance = appearance
         # New bullets reset the parent hierarchy.
-        self._actions = [Action(self, None, action, params, rank)
+        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.direction, self.speed, self.actions, self.target,
+            self.appearance, self.vanished)
 
     @property
     def aim(self):
-        """Angle to the target, in radians."""
-        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.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):
@@ -298,7 +211,7 @@ class Bullet(object):
         """
         if not self.vanished:
             return False
-        for action in self._actions:
+        for action in self.actions:
             if not action.finished:
                 return False
         return True
@@ -306,9 +219,9 @@ class Bullet(object):
     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.
@@ -316,11 +229,11 @@ class Bullet(object):
         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.
@@ -332,12 +245,12 @@ class Bullet(object):
         """
         created = []
 
-        for action in self._actions:
-            created.extend(action.step(self, self.rank))
+        for action in self.actions:
+            action.step(self, created)
 
         self.px = self.x
         self.py = self.y
-        self.x += self.mx + math.sin(self.direction) * self.speed
-        self.y += self.my - math.cos(self.direction) * self.speed
+        self.x += self.mx + sin(self.direction) * self.speed
+        self.y += -self.my + cos(self.direction) * self.speed
 
         return created