--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flax/Timeline.py	Wed Jul 03 09:37:57 2002 +0000
@@ -0,0 +1,437 @@
+from TLUtility import make_attributes_from_args, dict_scale, dict_max, \
+    DummyClass, last_less_than, first_greater_than
+from time import time
+from __future__ import division # "I'm sending you back to future!"
+
+"""
+Quote of the Build (from Ghostbusters II)
+Dana:  Okay, but after dinner, I don't want you putting any of your old cheap 
+       moves on me. 
+Peter: Ohhhh no! I've got all NEW cheap moves.
+"""
+
+class MissingBlender(Exception):
+    """Raised when a TimedEvent is missing a blender."""
+    def __init__(self, timedevent):
+        make_attributes_from_args('timedevent')
+        Exception.__init__(self, "%r is missing a blender." % \
+            self.timedevent)
+
+# these are chosen so we can multiply by -1 to reverse the direction,
+# and multiply direction by the time difference to determine new times.
+FORWARD = 1
+BACKWARD = -1
+
+MISSING = 'missing'
+
+class TimedEvent:
+    """Container for a Frame which includes a time that it occurs at,
+    and which blender occurs after it."""
+    def __init__(self, time, frame=MISSING, blender=None, level=1.0):
+        make_attributes_from_args('time', 'frame')
+        self.next_blender = blender
+        self.level = level
+    def __float__(self):
+        return self.time
+    def __cmp__(self, other):
+        if other is None:
+            raise "I can't compare with a None.  I am '%s'" % str(self)
+        if type(other) in (float, int):
+            return cmp(self.time, other)
+        else:
+            return cmp(self.time, other.time)
+    def __repr__(self):
+        return "<TimedEvent %s at %.2f, time=%.2f, next blender=%s>" % \
+            (self.frame, self.level, self.time, self.next_blender)
+    def get_level(self):
+        return self.level
+    def __hash__(self):
+        return id(self.time) ^ id(self.frame) ^ id(self.next_blender)
+
+class Blender:
+    """Blenders are functions that merge the effects of two LevelFrames."""
+    def __init__(self):
+        pass
+    def __call__(self, startframe, endframe, blendtime,  time_since_startframe):
+        """Return a LevelFrame combining two LevelFrames (startframe and 
+        endframe).  blendtime is how much of the blend should be performed
+        and will be expressed as a percentage divided by 100, i.e. a float
+        between 0.0 and 1.0.  time_since_startframe is the time since the
+        startframe was on screen in seconds (float).
+        
+        Very important note: Blenders will *not* be asked for values
+        at end points (i.e. blendtime=0.0 and blendtime=1.0).
+        The LevelFrames will be allowed to specify the values at
+        those times.  This is unfortunately for implemementation and
+        simplicity purposes.  In other words, if we didn't do this,
+        we could have two blenders covering the same point in time and
+        not know which one to ask for the value.  Thus, this saves us
+        a lot of messiness with minimal or no sacrifice."""
+        pass
+    def __str__(self):
+        """As a default, we'll just return the name of the class.  Subclasses
+        can add parameters on if they want."""
+        return str(self.__class__)
+    def linear_blend(self, startframe, endframe, blendtime):
+        """Utility function to help you produce linear combinations of two
+        blends.  blendtime is the percent/100 that the blend should 
+        completed.  In other words, 0.25 means it should be 0.75 * startframe +
+        0.25 * endframe.  This function is included since many blenders are
+        just functions on the percentage and still combine start and end frames
+        in this way."""
+        if startframe.frame == endframe.frame:
+            level = startframe.level + (blendtime * \
+                (endframe.level - startframe.level))
+            levels = {startframe.frame : level}
+        else:
+            levels = {startframe.frame : (1.0 - blendtime) * startframe.level,
+                endframe.frame : blendtime * endframe.level}
+        return levels
+
+class InstantEnd(Blender):
+    """Instant change from startframe to endframe at the end.  In other words,
+    the value returned will be the startframe all the way until the very end
+    of the blend."""
+    def __call__(self, startframe, endframe, blendtime, time_since_startframe):
+        # "What!?" you say, "Why don't you care about blendtime?"
+        # This is because Blenders never be asked for blenders at the endpoints
+        # (after all, they wouldn't be blenders if they were). Please see
+        # 'Very important note' in Blender.__doc__
+        return {startframe.frame : startframe.level}
+
+class InstantStart(Blender):
+    """Instant change from startframe to endframe at the beginning.  In other
+    words, the value returned will be the startframe at the very beginning
+    and then be endframe at all times afterwards."""
+    def __call__(self, startframe, endframe, blendtime, time_since_startframe):
+        # "What!?" you say, "Why don't you care about blendtime?"
+        # This is because Blenders never be asked for blenders at the endpoints
+        # (after all, they wouldn't be blenders if they were). Please see
+        # 'Very important note' in Blender.__doc__
+        return {endframe.frame : endframe.level}
+
+class LinearBlender(Blender):
+    """Linear fade from one frame to another"""
+    def __call__(self, startframe, endframe, blendtime, time_since_startframe):
+        return self.linear_blend(startframe, endframe, blendtime)
+
+class ExponentialBlender(Blender):
+    """Exponential fade fron one frame to another.  You get to specify
+    the exponent.  If my math is correct, exponent=1 means the same thing
+    as LinearBlender."""
+    def __init__(self, exponent):
+        self.exponent = exponent
+    def __call__(self, startframe, endframe, blendtime, time_since_startframe):
+        blendtime = blendtime ** self.exponent
+        return self.linear_blend(startframe, endframe, blendtime)
+
+# 17:02:53 drewp: this makes a big difference for the SmoothBlender 
+#                 (-x*x*(x-1.5)*2) function
+class SmoothBlender(Blender):
+    """Drew's "Smoove" Blender function.  Hopefully he'll document and
+    parametrize it."""
+    def __call__(self, startframe, endframe, blendtime, time_since_startframe):
+        blendtime = (-1 * blendtime) * blendtime * (blendtime - 1.5) * 2
+        return self.linear_blend(startframe, endframe, blendtime)
+
+class Strobe(Blender):
+    "Strobes the frame on the right side between offlevel and onlevel."
+    def __init__(self, ontime, offtime, onlevel=1, offlevel=0):
+        "times are in seconds (floats)"
+        make_attributes_from_args('ontime', 'offtime', 'onlevel', 'offlevel')
+        self.cycletime = ontime + offtime
+    def __call__(self, startframe, endframe, blendtime, time_since_startframe):
+        # time into the current period
+        period_time = time_since_startframe % self.cycletime
+        if period_time <= self.ontime:
+            return {endframe.frame : self.onlevel}
+        else:
+            return {endframe.frame : self.offlevel}
+
+class TimelineTrack:
+    """TimelineTrack is a single track in a Timeline.  It consists of a
+    list of TimedEvents and a name.  Length is automatically the location
+    of the last TimedEvent.  To extend the Timeline past that, add an
+    EmptyTimedEvent (which doesn't exist :-/)."""
+    def __init__(self, name, *timedevents, **kw):
+        if kw.get('default_frame'):
+            self.default_frame = kw['default_frame']
+        else:
+            self.default_frame = None
+        self.name = name
+        self.set_events(list(timedevents))
+    def set_events(self, events):
+        """This is given a list of TimedEvents.  They need not be sorted."""
+        self.events = events
+        self._cleaup_events()
+    def _cleaup_events(self):
+        """This makes sure all events are in the right order and have defaults
+        filled in if they have missing frames."""
+        self.events.sort()
+        self.fill_in_missing_frames()
+    def add_event(self, event):
+        """Add a TimedEvent object to this TimelineTrack"""
+        self.events.append(event)
+        self._cleaup_events(self.events)
+    def delete_event(self, event):
+        """Delete event by TimedEvent object"""
+        self.events.remove(event)
+        self._cleaup_events(self.events)
+    def delete_event_by_name(self, name):
+        """Deletes all events matching a certain name"""
+        self.events = [e for e in self.events if e.name is not name]
+        self._cleaup_events(self.events)
+    def delete_event_by_time(self, starttime, endtime=None):
+        """Deletes all events within a certain time range, inclusive.  endtime
+        is optional."""
+        endtime = endtime or starttime
+        self.events = [e for e in self.events
+            if e.time >= starttime and e.time <= endtime]
+        self._cleaup_events(self.events)
+    def fill_in_missing_frames(self):
+        """Runs through all events and sets TimedEvent with missing frames to
+        the default frame."""
+        for event in self.events:
+            if event.frame == MISSING:
+                event.frame = self.default_frame
+    def __str__(self):
+        return "<TimelineTrack with events: %r>" % self.events
+    def has_events(self):
+        """Whether the TimelineTrack has anything in it.  In general,
+        empty level Tracks should be avoided.  However, empty function tracks
+        might be common."""
+        return len(self.events)
+    def length(self):
+        """Returns the length of this track in pseudosecond time units.
+        This is done by finding the position of the last TimedEvent."""
+        return float(self.events[-1])
+    def get(self, key, direction=FORWARD):
+        """Returns the event at a specific time key.  If there is no event
+        at that time, a search will be performed in direction.  Also note
+        that if there are multiple events at one time, only the first will
+        be returned.  (Probably first in order of adding.)  This is not
+        a problem at the present since this method is intended for LevelFrames,
+        which must exist at unique times."""
+        if direction == BACKWARD:
+            func = last_less_than
+        else:
+            func = first_greater_than
+
+        return func(self.events, key)
+    def get_range(self, i, j, direction=FORWARD):
+        """Returns all events between i and j, exclusively.  If direction
+        is FORWARD, j will be included.  If direction is BACKWARD, i will
+        be included.  This is because this is used to find FunctionFrames
+        and we assume that any function frames at the start point (which
+        could be i or j) have been processed."""
+        return [e for e in self.events if e >= i and e <= j]
+
+        if direction == FORWARD:
+            return [e for e in self.events if e > i and e <= j]
+        else:
+            return [e for e in self.events if e >= i and e < j]
+    def __getitem__(self, key):
+        """Returns the event at or after a specific time key.
+        For example: timeline[3] will get the first event at time 3.
+
+        If you want to get all events at time 3, you are in trouble, but
+        you could achieve it with something like: 
+        timeline.get_range(2.99, 3.01, FORWARD) 
+        This is hopefully a bogus problem, since you can't have multiple
+        LevelFrames at the same time."""
+        return self.get(key, direction=FORWARD)
+    def get_surrounding_frames(self, time):
+        """Returns frames before and after a specific time.  This returns
+        a 2-tuple: (previousframe, nextframe).  If you have chosen the exact 
+        time of a frame, it will be both previousframe and nextframe."""
+        return self.get(time, direction=BACKWARD), \
+               self.get(time, direction=FORWARD)
+    def get_levels_at_time(self, time):
+        """Returns a LevelFrame with the levels of this track at that time."""
+        before, after = self.get_surrounding_frames(time)
+        
+        if not after or before == after:
+            return {before.frame : before.level}
+        else: # we have a blended value
+            diff = after.time - before.time
+            elapsed = time - before.time
+            percent = elapsed / diff
+            if not before.next_blender:
+                raise MissingBlender, before
+            return before.next_blender(before, after, percent, elapsed)
+
+class Timeline:
+    def __init__(self, name, tracks, rate=1, direction=FORWARD):
+        """
+        Most/all of this is old:
+
+        You can have multiple FunctionFrames at the same time.  Their
+        order is important though, since FunctionFrames will be applied
+        in the order seen in this list.  blenders is a list of Blenders.
+        rate is the rate of playback.  If set to 1, 1 unit inside the
+        Timeline will be 1 second.  direction is the initial direction.
+        If you want to do have looping, place a LoopFunction at the end of
+        the Timeline.  Timelines don't have a set length.  Their length
+        is bounded by their last frame.  You can put an EmptyFrame at
+        some time if you want to extend a Timeline."""
+        
+        make_attributes_from_args('name', 'tracks', 'rate', 'direction')
+        self.current_time = 0
+        self.last_clock_time = None
+        self.stopped = 1
+    def length(self):
+        """Length of the timeline in pseudoseconds.  This is determined by
+        finding the length of the longest track."""
+        track_lengths = [track.length() for track in self.tracks]
+        return max(track_lengths)
+    def play(self):
+        """Activates the timeline.  Future calls to tick() will advance the 
+        timeline in the appropriate direction."""
+        self.stopped = 0
+    def stop(self):
+        """The timeline will no longer continue in either direction, no
+        FunctionFrames will be activated."""
+        self.stopped = 1
+        self.last_clock_time = None
+    def reset(self):
+        """Resets the timeline to 0.  Does not change the stoppedness of the 
+        timeline."""
+        self.current_time = 0
+    def tick(self):
+        """Updates the current_time and runs any FunctionFrames that the cursor
+        passed over.  This call is ignored if the timeline is stopped."""
+        if self.stopped:
+            return
+        
+        last_time = self.current_time
+        last_clock = self.last_clock_time
+        
+        # first, determine new time
+        clock_time = time()
+        if last_clock is None:
+            last_clock = clock_time
+        diff = clock_time - last_clock
+        new_time = (self.direction * self.rate * diff) + last_time
+        
+        # update the time
+        self.last_clock_time = clock_time
+        self.current_time = new_time
+        
+        # now we make sure we're in bounds (we don't do this before, since it
+        # can cause us to skip events that are at boundaries.
+        self.current_time = max(self.current_time, 0)
+        self.current_time = min(self.current_time, self.length())
+    def reverse_direction(self):
+        """Reverses the direction of play for this node"""
+        self.direction = self.direction * -1
+    def set_direction(self, direction):
+        """Sets the direction of playback."""
+        self.direction = direction
+    def set_rate(self, new_rate):
+        """Sets the rate of playback"""
+        self.rate = new_rate
+    def set_time(self, new_time):
+        """Set the time to a new time."""
+        self.current_time = new_time
+    def get_levels(self):
+        """Return the current levels from this timeline.  This is done by
+        adding all the non-functional tracks together."""
+        levels = [t.get_levels_at_time(self.current_time)
+                    for t in self.tracks]
+        return dict_max(*levels)
+
+if __name__ == '__main__':
+    def T(*args, **kw):
+        """This used to be a synonym for TimedEvent:
+
+        T = TimedEvent
+
+        It now acts the same way, except that it will fill in a default 
+        blender if you don't.  The default blender is a LinearBlender."""
+        linear = LinearBlender()
+        if 'blender' not in kw:
+            kw['blender'] = linear
+
+        return TimedEvent(*args, **kw)
+
+    quad = ExponentialBlender(2)
+    invquad = ExponentialBlender(0.5)
+    smoove = SmoothBlender()
+
+    track1 = TimelineTrack('red track',
+        T(0, 'red', level=0),
+        T(4, 'red', blender=quad, level=0.5),
+        T(12, 'red', blender=smoove, level=0.7),
+        T(15, 'red', level=0.0)) # last TimedEvent doesn't need a blender
+    track2 = TimelineTrack('green track',
+        T(0, 'green', blender=invquad, level=0.2),
+        T(5, 'green', blender=smoove, level=1),
+        T(10, 'green', level=0.8),
+        T(15, 'green', level=0.6),
+        T(20, 'green', level=0.0)) # last TimedEvent doesn't need a blender
+    track3 = TimelineTrack('tableau demo',
+        T(0, 'blue', level=0.0),
+        T(2, 'blue', level=1.0, blender=InstantEnd()),
+        T(18, 'blue', level=1.0),
+        T(20, 'blue', level=0.0))
+
+    tl = Timeline('test', [track1, track2, track3])
+
+    tl.play()
+
+    import Tix
+    root = Tix.Tk()
+    colorscalesframe = Tix.Frame(root)
+    scalevars = {}
+    # wow, this works out so well, it's almost like I planned it!
+    # (actually, it's probably just Tk being as cool as it usually is)
+    # ps. if this code ever turns into mainstream code for flax, I'll be
+    # pissed (reason: we need to use classes, not this hacked crap!)
+    colors = 'red', 'blue', 'green', 'yellow', 'purple'
+    for color in colors:
+        sv = Tix.DoubleVar()
+        scalevars[color] = sv
+        scale = Tix.Scale(colorscalesframe, from_=1, to_=0, res=0.01, bg=color,
+            variable=sv)
+        scale.pack(side=Tix.LEFT)
+
+    def set_timeline_time(time):
+        tl.set_time(float(time))
+        # print 'set_timeline_time', time
+
+    def update_scales():
+        levels = tl.get_levels()
+        for color in colors:
+            scalevars[color].set(levels.get(color, 0))
+    
+    colorscalesframe.pack()
+    time_scale = Tix.Scale(root, from_=0, to_=tl.length(), 
+        orient=Tix.HORIZONTAL, res=0.01, command=set_timeline_time)
+    time_scale.pack(side=Tix.BOTTOM, fill=Tix.X, expand=1)
+
+    def play_tl():
+        tl.tick()
+        update_scales()
+        time_scale.set(tl.current_time)
+        # print 'time_scale.set', tl.current_time
+        root.after(10, play_tl)
+    
+    controlwindow = Tix.Toplevel()
+    Tix.Button(controlwindow, text='Stop', 
+        command=lambda: tl.stop()).pack(side=Tix.LEFT)
+    Tix.Button(controlwindow, text='Play', 
+        command=lambda: tl.play()).pack(side=Tix.LEFT)
+    Tix.Button(controlwindow, text='Reset', 
+        command=lambda: time_scale.set(0)).pack(side=Tix.LEFT)
+    Tix.Button(controlwindow, text='Flip directions', 
+        command=lambda: tl.reverse_direction()).pack(side=Tix.LEFT)
+    Tix.Button(controlwindow, text='1/2x', 
+        command=lambda: tl.set_rate(0.5 * tl.rate)).pack(side=Tix.LEFT)
+    Tix.Button(controlwindow, text='2x', 
+        command=lambda: tl.set_rate(2 * tl.rate)).pack(side=Tix.LEFT)
+    
+    root.after(100, play_tl)
+
+    # Timeline.set_time = trace(Timeline.set_time)
+        
+    Tix.mainloop()