Video work (#2356)

* Only use -no-pdf for xelatex rendering

* Instead of tracking du and dv points on surface, track points off the surface in the normal direction

This means that surface shading will not necessarily work well for arbitrary transformations of the surface. But the existing solution was flimsy anyway, and caused annoying issues with singularity points.

* Have density of anchor points on arcs depend on arc length

* Allow for specifying true normals and orientation of Sphere

* Change miter threshold on stroke shader

* Add get_start_and_end to DashedLine

* Add min_total_width option to DecimalNumber

* Have BackgroundRectangle.set_style absorb (and ignore) added configuration

Note, this feels suboptimal

* Add LineBrace

* Update font_size adjustment in Tex

* Add scale_factor parameter to BulletedList.fade_all_but

* Minor import tweaks

* Add play_sound

* Small if -> elif update

* Always use Group for FadeTransform

* Use time_spanned_alpha in ChangingDecimal

* Change priority of number_config vs. self.decimal_number_config in NumberLine init

* Fix clock animation

* Allow sample_coords to be passed into VectorField

manimlib/animation/composition.py

@@ -43,7 +43,7 @@ class AnimationGroup(Animation):
         mobs = remove_list_redundancies([a.mobject for a in self.animations])
         if group is not None:
             self.group = group
-        if group_type is not None:
+        elif group_type is not None:
             self.group = group_type(*mobs)
         elif all(isinstance(anim.mobject, VMobject) for anim in animations):
             self.group = VGroup(*mobs)

manimlib/animation/fading.py

@@ -6,6 +6,7 @@ from manimlib.animation.animation import Animation
 from manimlib.animation.transform import Transform
 from manimlib.constants import ORIGIN
 from manimlib.mobject.types.vectorized_mobject import VMobject
+from manimlib.mobject.mobject import Group
 from manimlib.utils.bezier import interpolate
 from manimlib.utils.rate_functions import there_and_back
 
@@ -101,7 +102,7 @@ class FadeTransform(Transform):
         self.dim_to_match = dim_to_match
 
         mobject.save_state()
-        super().__init__(mobject.get_group_class()(mobject, target_mobject.copy()), **kwargs)
+        super().__init__(Group(mobject, target_mobject.copy()), **kwargs)
 
     def begin(self) -> None:
         self.ending_mobject = self.mobject.copy()

manimlib/animation/numbers.py

@@ -29,9 +29,9 @@ class ChangingDecimal(Animation):
         self.mobject = decimal_mob
 
     def interpolate_mobject(self, alpha: float) -> None:
-        self.mobject.set_value(
-            self.number_update_func(alpha)
-        )
+        true_alpha = self.time_spanned_alpha(alpha)
+        new_value = self.number_update_func(true_alpha)
+        self.mobject.set_value(new_value)
 
 
 class ChangeDecimalToValue(ChangingDecimal):

manimlib/mobject/number_line.py

@@ -164,7 +164,7 @@ class NumberLine(Line):
         **number_config
     ) -> DecimalNumber:
         number_config = merge_dicts_recursively(
-            number_config, self.decimal_number_config,
+            self.decimal_number_config, number_config,
         )
         if direction is None:
             direction = self.line_to_number_direction

manimlib/mobject/svg/drawings.py

@@ -344,6 +344,8 @@ class ClockPassesTime(AnimationGroup):
                 angle=12 * hour_radians,
                 **rot_kwargs
             ),
+            group=clock,
+            run_time=run_time,
             **kwargs
         )
 

manimlib/mobject/vector_field.py

@@ -145,6 +145,7 @@ class VectorField(VMobject):
         func: Callable[[VectArray], VectArray],
         # Typically a set of Axes or NumberPlane
         coordinate_system: CoordinateSystem,
+        sample_coords: Optional[VectArray] = None,
         density: float = 2.0,
         magnitude_range: Optional[Tuple[float, float]] = None,
         color: Optional[ManimColor] = None,
@@ -168,6 +169,9 @@ class VectorField(VMobject):
         self.norm_to_opacity_func = norm_to_opacity_func
 
         # Search for sample_points
+        if sample_coords is not None:
+            self.sample_coords = sample_coords
+        else:
             self.sample_coords = get_sample_coords(coordinate_system, density)
         self.update_sample_points()
 
@@ -175,7 +179,7 @@ class VectorField(VMobject):
             step_size = get_norm(self.sample_points[1] - self.sample_points[0])
             self.max_displayed_vect_len = max_vect_len_to_step_size * step_size
         else:
-            self.max_displayed_vect_len = max_vect_len * coordinate_system.get_x_unit_size()
+            self.max_displayed_vect_len = max_vect_len * coordinate_system.x_axis.get_unit_size()
 
         # Prepare the color map
         if magnitude_range is None:
@@ -406,7 +410,7 @@ class StreamLines(VGroup):
 
         noise_factor = self.noise_factor
         if noise_factor is None:
-            noise_factor = (cs.get_x_unit_size() / self.density) * 0.5
+            noise_factor = (cs.x_axis.get_unit_size() / self.density) * 0.5
 
         return np.array([
             coords + noise_factor * np.random.random(coords.shape)