Refactor many definitions out of topics and into folders within mobject

animation/specialized.py

@@ -0,0 +1,67 @@
+from __future__ import absolute_import
+
+import numpy as np
+
+from constants import *
+
+from animation.transform import ApplyMethod
+from animation.composition import LaggedStart
+from mobject.svg.drawings import Car
+from mobject.types.vectorized_mobject import VGroup
+from mobject.geometry import Circle
+from utils.config_ops import digest_config
+
+class MoveCar(ApplyMethod):
+    CONFIG = {
+        "moving_forward" : True,
+    }
+    def __init__(self, car, target_point, **kwargs):
+        assert isinstance(car, Car)
+        ApplyMethod.__init__(self, car.move_to, target_point, **kwargs)
+        displacement = self.target_mobject.get_right()-self.starting_mobject.get_right()
+        distance = np.linalg.norm(displacement)
+        if not self.moving_forward:
+            distance *= -1
+        tire_radius = car.get_tires()[0].get_width()/2
+        self.total_tire_radians = -distance/tire_radius
+
+    def update_mobject(self, alpha):
+        ApplyMethod.update_mobject(self, alpha)
+        if alpha == 0:
+            return
+        radians = alpha*self.total_tire_radians
+        for tire in self.mobject.get_tires():
+            tire.rotate_in_place(radians)
+
+class Broadcast(LaggedStart):
+    CONFIG = {
+        "small_radius" : 0.0,
+        "big_radius" : 5,
+        "n_circles" : 5,
+        "start_stroke_width" : 8,
+        "color" : WHITE,
+        "remover" : True,
+        "lag_ratio" : 0.7,
+        "run_time" : 3,
+        "remover" : True,
+    }
+    def __init__(self, focal_point, **kwargs):
+        digest_config(self, kwargs)
+        circles = VGroup()
+        for x in range(self.n_circles):
+            circle = Circle(
+                radius = self.big_radius, 
+                stroke_color = BLACK,
+                stroke_width = 0,
+            )
+            circle.move_to(focal_point)
+            circle.save_state()
+            circle.scale_to_fit_width(self.small_radius*2)
+            circle.set_stroke(self.color, self.start_stroke_width)
+            circles.add(circle)
+        LaggedStart.__init__(
+            self, ApplyMethod, circles,
+            lambda c : (c.restore,),
+            **kwargs
+        )
+