Separate element constructors from regular constructors.

[python-bulletml.git] / bulletml / impl.py

diff --git a/bulletml/impl.py b/bulletml/impl.py
index a0ef92c..92982db 100644 (file)
--- a/bulletml/impl.py
+++ b/bulletml/impl.py
@@ -7,7 +7,7 @@ from __future__ import division
 
 import math
 
-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.
@@ -18,7 +18,7 @@ class Action(object):
     def __init__(self, owner, parent, actions, params, rank):
         self.actions = actions
         self.parent = parent
-        self.repeat = 0
+        self.repeat = 1
         self.wait_frames = 0
         self.speed = 0
         self.speed_frames = 0
@@ -40,10 +40,17 @@ class Action(object):
         if parent:
             self.copy_state(parent)
 
+    def __repr__(self):
+        return "%s(pc=%r, actions=%r)" % (
+            type(self).__name__, self.pc, self.actions)
+
+    @property
+    def finished(self):
+        return self.pc is None
+
     def vanish(self):
         if self.parent:
             self.parent.vanish()
-        self.repeat = 0
         self.pc = None
 
     def copy_state(self, other):
@@ -64,6 +71,7 @@ class Action(object):
         if self.speed_frames > 0:
             self.speed_frames -= 1
             self.owner.speed += self.speed
+
         if self.direction_frames > 0:
             self.direction_frames -= 1
             if self.direction_frames <= 0:
@@ -71,6 +79,7 @@ class Action(object):
                     self.owner.direction += self.owner.aim
             else:
                 self.owner.direction += self.direction
+
         if self.accel_frames > 0:
             self.accel_frames -= 1
             self.owner.mx += self.mx
@@ -85,13 +94,14 @@ class Action(object):
 
         while True:
             self.pc += 1
+
             if self.pc >= len(self.actions):
                 self.repeat -= 1
                 if self.repeat <= 0:
                     self.pc = None
                     if self.parent is not None:
                         self.parent.copy_state(self)
-                    self.owner.replace(self, self.parent)
+                        self.owner.replace(self, self.parent)
                     break
                 else:
                     self.pc = 0
@@ -228,9 +238,9 @@ class Bullet(object):
         self.actions = []
         if rank is None:
             rank = parent.rank if parent else 0.5
-        for action, params in actions:
-            self.actions.append(
-                Action(self, parent, action, params, rank))
+        # New bullets reset the parent hierarchy.
+        self.actions = [Action(self, None, action, params, rank)
+                        for action, params in actions]
 
     def __repr__(self):
         return ("%s(%r, %r, accel=%r, direction=%r, speed=%r, "
@@ -246,11 +256,14 @@ class Bullet(object):
             return self.direction
         else:
             return math.degrees(
-                math.atan2(self.target.x - self.x, self.target.y - self.y))
+                math.atan2(self.target.x - self.x, self.y - self.target.y))
 
     @property
     def finished(self):
-        return self.vanished and not self.actions
+        for action in self.actions:
+            if not action.finished:
+                return False
+        return self.vanished
 
     def vanish(self):
         """Vanish this bullet and stop all actions."""
@@ -270,20 +283,21 @@ class Bullet(object):
     def step(self):
         created = []
 
-        self.actions = filter(None, self.actions)
-
         for action in self.actions:
             created.extend(action.step())
 
         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.y += self.my - math.cos(direction) * self.speed
 
         return created
 
     @classmethod
     def FromDoc(cls, doc, params=(), x=0, y=0, speed=0, direction=0,
                 target=None, rank=0.5):
+        """Construct a bullet from top-level actions in a document."""
         actions = [act(params, rank) for act in doc.top]
         return cls(x, y, direction, speed, target, actions, rank=rank)