Refactored ShowCreation submobject management to Mobject class

animation/simple_animations.py

@@ -4,6 +4,8 @@ import itertools as it
 from helpers import *
 
 from mobject import Mobject
+from mobject.vectorized_mobject import VMobject
+from mobject.tex_mobject import DecimalNumber
 from animation import Animation
 
 
@@ -36,24 +38,11 @@ class ShowPartial(Animation):
         "submobject_mode" : None
     }
     def update_mobject(self, alpha):
-        pairs = zip(
-            self.starting_mobject.submobject_family(),
-            self.mobject.submobject_family()
+        self.mobject.become_partial(
+            self.starting_mobject, 
+            *self.get_bounds(alpha),
+            submobject_partial_creation_mode = self.submobject_mode
         )
-        for i, (start, mob) in enumerate(pairs):
-            if self.submobject_mode == "lagged_start":
-                sub_alpha = 2*alpha - float(i)/len(pairs)
-                sub_alpha = max(0, sub_alpha)
-                sub_alpha = min(1, sub_alpha)
-            elif self.submobject_mode == "one_at_a_time":
-                lower = float(i)/len(pairs)
-                upper = float(i+1)/len(pairs)
-                sub_alpha = (alpha-lower)/(upper-lower)
-                sub_alpha = max(0, sub_alpha)
-                sub_alpha = min(1, sub_alpha)
-            else:
-                sub_alpha = alpha
-            mob.become_partial(start, *self.get_bounds(sub_alpha))
 
     def get_bounds(self, alpha):
         raise Exception("Not Implemented")
@@ -175,6 +164,55 @@ class MoveAlongPath(Animation):
         point = self.path.points[int(alpha*n)]
         self.mobject.shift(point-self.mobject.get_center())
 
+class RangingValues(Animation):
+    CONFIG = {
+        "num_decimal_points" : 2,
+        "rate_func" : None,
+        "tracking_function" : None,
+        "tracked_mobject" : None,
+        "tracked_mobject_next_to_kwargs" : {},
+    }
+    def __init__(self, start_val, end_val, **kwargs):
+        digest_config(self, kwargs, locals())
+        Animation.__init__(self, self.get_mobject_at_alpha(0), **kwargs)
+
+    def update_mobject(self, alpha):
+        pairs = zip(
+            self.mobject.family_members_with_points(),
+            self.get_mobject_at_alpha(alpha).family_members_with_points()
+        )
+        for old, new in pairs:
+            ##TODO, figure out a better way
+            old.__dict__.update(new.__dict__)
+
+    def get_number(self, alpha):
+        return interpolate(self.start_val, self.end_val, alpha)
+
+    def get_mobject_at_alpha(self, alpha):
+        mob = DecimalNumber(
+            self.get_number(alpha), 
+            num_decimal_points=self.num_decimal_points
+        )
+        if self.tracking_function:
+            self.tracking_function(alpha, mob)
+        elif self.tracked_mobject:
+            mob.next_to(
+                self.tracked_mobject,
+                **self.tracked_mobject_next_to_kwargs
+            )
+        return mob
+
+    def set_tracking_function(self, func):
+        """
+        func shoudl be of the form func(alpha, mobject), and
+        should dictate where to place running number during an 
+        animation
+        """
+        self.tracking_function = func
+
+
+
+
 ### Animation modifiers ###
 
 class ApplyToCenters(Animation):

mobject/mobject.py

@@ -21,7 +21,9 @@ class Mobject(object):
         "stroke_width" : DEFAULT_POINT_THICKNESS,
         "name"         : None,
         "dim"          : 3,
-        "target"       : None
+        "target"       : None,
+        #Options are lagged_start, one_at_a_time, all_at_once
+        "submobject_partial_creation_mode" : "lagged_start",
     }
     def __init__(self, *submobjects, **kwargs):
         digest_config(self, kwargs)
@@ -219,6 +221,13 @@ class Mobject(object):
         self.shift(target_point - anchor_point + buff*direction)
         return self
 
+    def shift_onto_screen(self):
+        space_lengths = [SPACE_WIDTH, SPACE_HEIGHT]
+        for vect in UP, DOWN, LEFT, RIGHT:
+            dim = np.argmax(np.abs(vect))
+            if abs(self.get_edge_center(vect)[dim]) > space_lengths[dim]:
+                self.to_edge(vect)
+
     def stretch_to_fit(self, length, dim, stretch = True):
         old_length = self.length_over_dim(dim)
         if old_length == 0:
@@ -423,12 +432,9 @@ class Mobject(object):
             self.submobject_family()
         )
 
-    def arrange_submobjects(self, 
-                            direction = RIGHT, 
-                            buff = DEFAULT_MOBJECT_TO_MOBJECT_BUFFER, 
-                            center = True):
+    def arrange_submobjects(self, direction = RIGHT, center = True, **kwargs):
         for m1, m2 in zip(self.submobjects, self.submobjects[1:]):
-            m2.next_to(m1, direction, buff = buff)
+            m2.next_to(m1, direction, **kwargs)
         if center:
             self.center()
         return self
@@ -533,13 +539,37 @@ class Mobject(object):
     def interpolate_color(self, mobject1, mobject2, alpha):
         raise Exception("Not implemented")
 
-    def become_partial(self, mobject, a, b):
+    def become_partial(self, mobject, a, b, submobject_partial_creation_mode = None):
         """
         Set points in such a way as to become only
         part of mobject.  
         Inputs 0 <= a < b <= 1 determine what portion
         of mobject to become.
         """
+        self.pointwise_become_partial(mobject, a, b)
+        #TODO, color        
+        # self.interpolate_color(self, mobject, b)
+
+        spcm = submobject_partial_creation_mode or self.submobject_partial_creation_mode
+        pairs = zip(self.submobjects, mobject.submobjects)
+        for i, (self_sub, mob_sub) in enumerate(pairs):
+            if spcm == "lagged_start":
+                prop = float(i)/len(pairs)
+                sub_a = np.clip(2*a - prop, 0, 1)
+                sub_b = np.clip(2*b - prop, 0, 1)
+            elif spcm == "one_at_a_time":
+                lower = float(i)/len(pairs)
+                upper = float(i+1)/len(pairs)
+                sub_a = np.clip((a-lower)/(upper-lower), 0, 1)
+                sub_b = np.clip((b-lower)/(upper-lower), 0, 1)
+            elif spcm == "all_at_once":
+                sub_a, sub_b = a, b
+            else:
+                raise Exception("Invalid submobject partial creation mode")
+            self_sub.become_partial(mob_sub, sub_a, sub_b)
+        return self
+
+    def pointwise_become_partial(self, mobject, a, b):
         raise Exception("Not implemented")
 
 
@@ -557,3 +587,4 @@ class Mobject(object):
 
 
 
+

mobject/point_cloud_mobject.py

@@ -129,7 +129,7 @@ class PMobject(Mobject):
             mobject1.rgbs, mobject2.rgbs, alpha
         )
 
-    def become_partial(self, mobject, a, b):
+    def pointwise_become_partial(self, mobject, a, b):
         lower_index, upper_index = [
             int(x * mobject.get_num_points())
             for x in a, b

mobject/tex_mobject.py

@@ -7,7 +7,7 @@ TEXT_MOB_SCALE_VAL = 0.05
 
 
 class TexSymbol(VMobjectFromSVGPathstring):
-    def become_partial(self, mobject, a, b):
+    def pointwise_become_partial(self, mobject, a, b):
         #TODO, this assumes a = 0
         if b < 0.5:
             b = 2*b 
@@ -17,7 +17,7 @@ class TexSymbol(VMobjectFromSVGPathstring):
             width = 2 - 2*b
             opacity = 2*b - 1
             b = 1
-        VMobjectFromSVGPathstring.become_partial(
+        VMobjectFromSVGPathstring.pointwise_become_partial(
             self, mobject, 0, b
         )
         self.set_stroke(width = width)
@@ -64,10 +64,7 @@ class TexMobject(SVGMobject):
     def handle_list_expression(self):
         #TODO, next_to not sufficient?
         subs = [
-            # TexMobject(expr)
-            self.__class__(
-                expr
-            )
+            TexMobject(expr)
             for expr in self.expression
         ]
         self.initial_scale_val = 1
@@ -110,6 +107,27 @@ class Brace(TexMobject):
         for mob in mobject, self:
             mob.rotate(angle)
 
+class DecimalNumber(TexMobject):
+    CONFIG = {
+        "num_decimal_points" : 2,
+        "digit_to_digit_buff" : 0.05
+    }
+    def __init__(self, float_num, **kwargs):
+        digest_config(self, kwargs)
+        num_string = '%.*f' % (self.num_decimal_points, float_num)
+        TexMobject.__init__(self, list(num_string))
+        self.arrange_submobjects(
+            buff = self.digit_to_digit_buff,
+            aligned_edge = DOWN
+        )
+        if float_num < 0:
+            minus = self.submobjects[0]
+            minus.next_to(
+                self.submobjects[1], LEFT,
+                buff = self.digit_to_digit_buff
+            )
+
+    
 def tex_hash(expression, template_tex_file):
     return str(hash(expression + template_tex_file))
 

mobject/vectorized_mobject.py

@@ -300,7 +300,7 @@ class VMobject(Mobject):
                 # print getattr(mobject2, attr)
                 setattr(self, attr, getattr(mobject2, attr))
 
-    def become_partial(self, mobject, a, b):
+    def pointwise_become_partial(self, mobject, a, b):
         assert(isinstance(mobject, VMobject))
         #Partial curve includes three portions:
         #-A middle section, which matches the curve exactly

topics/geometry.py

@@ -133,6 +133,7 @@ class Arrow(Line):
         "buff"       : 0.3,
         "propogate_style_to_family" : False,
         "preserve_tip_size_when_scaling" : True,
+        "submobject_partial_creation_mode" : "one_at_a_time",
     }
     def __init__(self, *args, **kwargs):
         if len(args) == 1: