release: ready to release v1.3.0

Construct `MTex`

docs/example.py

@@ -1,4 +1,4 @@
-from manimlib.imports import *
+from manimlib import *
 
 class SquareToCircle(Scene):
     def construct(self):

docs/source/development/changelog.rst

@@ -1,10 +1,128 @@
 Changelog
 =========
 
-Unreleased
-----------
+v1.3.0
+------
+
+Fixed bugs 
+^^^^^^^^^^
+
+- `#1653 <https://github.com/3b1b/manim/pull/1653>`__: Fixed ``Mobject.stretch_to_fit_depth``
+- `#1655 <https://github.com/3b1b/manim/pull/1655>`__: Fixed the bug of rotating camera
+- `c73d507 <https://github.com/3b1b/manim/pull/1688/commits/c73d507c76af5c8602d4118bc7538ba04c03ebae>`__: Fixed ``SurfaceMesh`` to be evenly spaced
+- `82bd02d <https://github.com/3b1b/manim/pull/1688/commits/82bd02d21fbd89b71baa21e077e143f440df9014>`__: Fixed ``angle_between_vectors`` add ``rotation_between_vectors``
+- `a717314 <https://github.com/3b1b/manim/pull/1688/commits/a7173142bf93fd309def0cc10f3c56f5e6972332>`__: Fixed ``VMobject.fade``
+- `fbc329d <https://github.com/3b1b/manim/pull/1688/commits/fbc329d7ce3b11821d47adf6052d932f7eff724a>`__: Fixed ``angle_between_vectors``
+- `bcd0990 <https://github.com/3b1b/manim/pull/1688/commits/bcd09906bea5eaaa5352e7bee8f3153f434cf606>`__: Fixed bug in ``ShowSubmobjectsOneByOne``
+- `7023548 <https://github.com/3b1b/manim/pull/1691/commits/7023548ec62c4adb2f371aab6a8c7f62deb7c33c>`__: Fixed bug in ``TransformMatchingParts``
+
+New Features
+^^^^^^^^^^^^
+
+- `e10f850 <https://github.com/3b1b/manim/commit/e10f850d0d9f971931cc85d44befe67dc842af6d>`__: Added CLI flag ``--log-level`` to specify log level
+- `#1667 <https://github.com/3b1b/manim/pull/1667>`__: Added operations (``+`` and ``*``) for ``Mobject``
+- `#1675 <https://github.com/3b1b/manim/pull/1675>`__: Added 4 boolean operations for ``VMobject`` in ``manimlib/mobject/boolean_ops.py``
+
+  - ``Union(*vmobjects, **kwargs)``  
+  - ``Difference(subject, clip, **kwargs)`` 
+  - ``Intersection(*vmobjects, **kwargs)`` 
+  - ``Exclusion(*vmobjects, **kwargs)`` 
+- `81c3ae3 <https://github.com/3b1b/manim/pull/1688/commits/81c3ae30372e288dc772633dbd17def6e603753e>`__: Added reflectiveness
+- `2c7689e <https://github.com/3b1b/manim/pull/1688/commits/2c7689ed9e81229ce87c648f97f26267956c0bc9>`__: Enabled ``glow_factor`` on ``DotCloud``
+- `d065e19 <https://github.com/3b1b/manim/pull/1688/commits/d065e1973d1d6ebd2bece81ce4bdf0c2fff7c772>`__: Added option ``-e`` to insert embed line from the command line
+- `0e78027 <https://github.com/3b1b/manim/pull/1688/commits/0e78027186a976f7e5fa8d586f586bf6e6baab8d>`__: Improved ``point_from_proportion`` to account for arc length
+- `781a993 <https://github.com/3b1b/manim/pull/1688/commits/781a9934fda6ba11f22ba32e8ccddcb3ba78592e>`__: Added shortcut ``set_backstroke`` for setting black background stroke
+- `0b898a5 <https://github.com/3b1b/manim/pull/1688/commits/0b898a5594203668ed9cad38b490ab49ba233bd4>`__: Added ``Suface.always_sort_to_camera``
+- `e899604 <https://github.com/3b1b/manim/pull/1688/commits/e899604a2d05f78202fcb3b9824ec34647237eae>`__: Added getter methods for specific euler angles
+- `407c53f <https://github.com/3b1b/manim/pull/1688/commits/407c53f97c061bfd8a53beacd88af4c786f9e9ee>`__: Hade ``rotation_between_vectors`` handle identical/similar vectors
+- `49743da <https://github.com/3b1b/manim/pull/1688/commits/49743daf3244bfa11a427040bdde8e2bb79589e8>`__: Added ``Mobject.insert_submobject`` method
+- `9dd1f47 <https://github.com/3b1b/manim/pull/1688/commits/9dd1f47dabca1580d6102e34e44574b0cba556e7>`__: Created single progress display for full scene render
+- `264f7b1 <https://github.com/3b1b/manim/pull/1691/commits/264f7b11726e9e736f0fe472f66e38539f74e848>`__: Added ``Circle.get_radius``
+- `83841ae <https://github.com/3b1b/manim/pull/1691/commits/83841ae41568a9c9dff44cd163106c19a74ac281>`__: Added ``Dodecahedron``
+- `a1d5147 <https://github.com/3b1b/manim/pull/1691/commits/a1d51474ea1ce3b7aa3efbe4c5e221be70ee2f5b>`__: Added ``GlowDot``
+- `#1678 <https://github.com/3b1b/manim/pull/1678>`__: Added ``MTex`` , see `#1678 <https://github.com/3b1b/manim/pull/1678>`__ for details
+
+Refactor
+^^^^^^^^
+
+- `#1662 <https://github.com/3b1b/manim/pull/1662>`__: Refactored support for command ``A`` in path of SVG 
+- `#1662 <https://github.com/3b1b/manim/pull/1662>`__: Refactored ``SingleStringTex.balance_braces``
+- `8b454fb <https://github.com/3b1b/manim/pull/1688/commits/8b454fbe9335a7011e947093230b07a74ba9c653>`__: Slight tweaks to how saturation_factor works on newton-fractal
+- `317a5d6 <https://github.com/3b1b/manim/pull/1688/commits/317a5d6226475b6b54a78db7116c373ef84ea923>`__: Made it possible to set full screen preview as a default
+- `e764da3 <https://github.com/3b1b/manim/pull/1688/commits/e764da3c3adc5ae2a4ce877b340d2b6abcddc2fc>`__: Used ``quick_point_from_proportion`` for graph points
+- `d2182b9 <https://github.com/3b1b/manim/pull/1688/commits/d2182b9112300558b6c074cefd685f97c10b3898>`__: Made sure ``Line.set_length`` returns self
+- `eea3c6b <https://github.com/3b1b/manim/pull/1688/commits/eea3c6b29438f9e9325329c4355e76b9f635e97a>`__: Better align ``SurfaceMesh`` to the corresponding surface polygons
+- `ee1594a <https://github.com/3b1b/manim/pull/1688/commits/ee1594a3cb7a79b8fc361e4c4397a88c7d20c7e3>`__: Match ``fix_in_frame`` status for ``FlashAround`` mobject
+- `ba23fbe <https://github.com/3b1b/manim/pull/1688/commits/ba23fbe71e4a038201cd7df1d200514ed1c13bc2>`__: Made sure ``Mobject.is_fixed_in_frame`` stays updated with uniforms
+- `98b0d26 <https://github.com/3b1b/manim/pull/1691/commits/98b0d266d2475926a606331923cca3dc1dea97ad>`__: Made sure ``skip_animations`` and ``start_at_animation_number`` play well together
+- `f8e6e7d <https://github.com/3b1b/manim/pull/1691/commits/f8e6e7df3ceb6f3d845ced4b690a85b35e0b8d00>`__: Updated progress display for full scene render
+- `8f1dfab <https://github.com/3b1b/manim/pull/1691/commits/8f1dfabff04a8456f5c4df75b0f97d50b2755003>`__: ``VectorizedPoint`` should call ``__init__`` for both super classes
+- `758f329 <https://github.com/3b1b/manim/pull/1691/commits/758f329a06a0c198b27a48c577575d94554305bf>`__: Used array copy when checking need for refreshing triangulation
+
+
+Dependencies
+^^^^^^^^^^^^
+
+- `#1675 <https://github.com/3b1b/manim/pull/1675>`__: Added dependency on python packages `skia-pathops <https://github.com/fonttools/skia-pathops>`__
+
+v1.2.0
+------
+
+Fixed bugs
+^^^^^^^^^^
+
+- `#1592 <https://github.com/3b1b/manim/pull/1592>`__: Fixed ``put_start_and_end_on`` in 3D
+- `#1601 <https://github.com/3b1b/manim/pull/1601>`__: Fixed ``DecimalNumber``'s scaling issue
+- `56df154 <https://github.com/3b1b/manim/commit/56df15453f3e3837ed731581e52a1d76d5692077>`__: Fixed bug with common range array used for all coordinate systems
+- `8645894 <https://github.com/3b1b/manim/commit/86458942550c639a241267d04d57d0e909fcf252>`__: Fixed ``CoordinateSystem`` init bug
+- `0dc096b <https://github.com/3b1b/manim/commit/0dc096bf576ea900b351e6f4a80c13a77676f89b>`__: Fixed bug for single-valued ``ValueTracker``
+- `54ad355 <https://github.com/3b1b/manim/commit/54ad3550ef0c0e2fda46b26700a43fa8cde0973f>`__: Fixed bug with SVG rectangles
+- `d45ea28 <https://github.com/3b1b/manim/commit/d45ea28dc1d92ab9c639a047c00c151382eb0131>`__: Fixed ``DotCloud.set_radii``
+- `b543cc0 <https://github.com/3b1b/manim/commit/b543cc0e32d45399ee81638b6d4fb631437664cd>`__: Temporarily fixed bug for ``PMobject`` array resizing
+- `5f878a2 <https://github.com/3b1b/manim/commit/5f878a2c1aa531b7682bd048468c72d2835c7fe5>`__: Fixed ``match_style``
+- `719c81d <https://github.com/3b1b/manim/commit/719c81d72b00dcf49f148d7c146774b22e0fe348>`__: Fixed negative ``path_arc`` case
+- `c726eb7 <https://github.com/3b1b/manim/commit/c726eb7a180b669ee81a18555112de26a8aff6d6>`__: Fixed bug with ``CoordinateSystem.get_lines_parallel_to_axis``
+- `7732d2f <https://github.com/3b1b/manim/commit/7732d2f0ee10449c5731499396d4911c03e89648>`__: Fixed ``ComplexPlane`` -i display bug
+
+New Features 
+^^^^^^^^^^^^
+
+- `#1598 <https://github.com/3b1b/manim/pull/1598>`__: Supported the elliptical arc command ``A`` for ``SVGMobject``
+- `#1607 <https://github.com/3b1b/manim/pull/1607>`__: Added ``FlashyFadeIn``
+- `#1607 <https://github.com/3b1b/manim/pull/1607>`__: Save triangulation 
+- `#1625 <https://github.com/3b1b/manim/pull/1625>`__: Added new ``Code`` mobject
+- `#1637 <https://github.com/3b1b/manim/pull/1637>`__: Add warnings and use rich to display log
+- `bd356da <https://github.com/3b1b/manim/commit/bd356daa99bfe3134fcb192a5f72e0d76d853801>`__: Added ``VCube``
+- `6d72893 <https://github.com/3b1b/manim/commit/6d7289338234acc6658b9377c0f0084aa1fa7119>`__: Supported ``ValueTracker`` to track vectors
+- `3bb8f3f <https://github.com/3b1b/manim/commit/3bb8f3f0422a5dfba0da6ef122dc0c01f31aff03>`__: Added ``set_max_width``, ``set_max_height``, ``set_max_depth`` to ``Mobject``
+- `a35dd5a <https://github.com/3b1b/manim/commit/a35dd5a3cbdeffa3891d5aa5f80287c18dba2f7f>`__: Added ``TracgTail``
+- `acba13f <https://github.com/3b1b/manim/commit/acba13f4991b78d54c0bf93cce7ca3b351c25476>`__: Added ``Scene.point_to_mobject``
+- `f84b8a6 <https://github.com/3b1b/manim/commit/f84b8a66fe9e8b3872e5c716c5c240c14bb555ee>`__: Added poly_fractal shader
+- `b24ba19 <https://github.com/3b1b/manim/commit/b24ba19dec48ba4e38acbde8eec6d3a308b6ab83>`__: Added kwargs to ``TipableVMobject.set_length``
+- `17c2772 <https://github.com/3b1b/manim/commit/17c2772b84abf6392a4170030e36e981de4737d0>`__: Added ``Mobject.replicate``
+- `33fa76d <https://github.com/3b1b/manim/commit/33fa76dfac36e70bb5fad69dc6a336800c6dacce>`__: Added mandelbrot_fractal shader
+- `f22a341 <https://github.com/3b1b/manim/commit/f22a341e8411eae9331d4dd976b5e15bc6db08d9>`__: Saved state before each embed
+- `e10a752 <https://github.com/3b1b/manim/commit/e10a752c0001e8981038faa03be4de2603d3565f>`__: Allowed releasing of Textures
+- `14fbed7 <https://github.com/3b1b/manim/commit/14fbed76da4b493191136caebb8a955e2d41265b>`__: Consolidated and renamed newton_fractal shader
+- `6cdbe0d <https://github.com/3b1b/manim/commit/6cdbe0d67a11ab14a6d84840a114ae6d3af10168>`__: Hade ``ImageMoject`` remember the filepath to the Image
+
+Refactor
+^^^^^^^^
+
+- `#1601 <https://github.com/3b1b/manim/pull/1601>`__: Changed back to simpler ``Mobject.scale`` implementation
+- `b667db2 <https://github.com/3b1b/manim/commit/b667db2d311a11cbbca2a6ff511d2c3cf1675486>`__: Simplified ``Square``
+- `40290ad <https://github.com/3b1b/manim/commit/40290ada8343f10901fa9151cbdf84689667786d>`__: Removed unused parameter ``triangulation_locked``
+- `8647a64 <https://github.com/3b1b/manim/commit/8647a6429dd0c52cba14e971b8c09194a93cfd87>`__: Reimplemented ``Arrow``
+- `d8378d8 <https://github.com/3b1b/manim/commit/d8378d8157040cd797cc47ef9576beffd8607863>`__: Used ``make_approximately_smooth`` for ``set_points_smoothly`` by default
+- `7b4199c <https://github.com/3b1b/manim/commit/7b4199c674e291f1b84678828b63b6bd4fcc6b17>`__: Refactored to call ``_handle_scale_side_effects`` after scaling takes place
+- `7356a36 <https://github.com/3b1b/manim/commit/7356a36fa70a8279b43ae74e247cbd43b2bfd411>`__: Refactored to only call ``throw_error_if_no_points`` once for ``get_start_and_end``
+- `0787c4f <https://github.com/3b1b/manim/commit/0787c4f36270a6560b50ce3e07b30b0ec5f2ba3e>`__: Made sure framerate is 30 for previewed scenes
+- `c635f19 <https://github.com/3b1b/manim/commit/c635f19f2a33e916509e53ded46f55e2afa8f5f2>`__: Pushed ``pixel_coords_to_space_coords`` to ``Window``
+- `d5a88d0 <https://github.com/3b1b/manim/commit/d5a88d0fa457cfcf4cb9db417a098c37c95c7051>`__: Refactored to pass tuples and not arrays to uniforms
+- `9483f26 <https://github.com/3b1b/manim/commit/9483f26a3b056de0e34f27acabd1a946f1adbdf9>`__: Refactored to copy uniform arrays in ``Mobject.copy``
+- `ed1fc4d <https://github.com/3b1b/manim/commit/ed1fc4d5f94467d602a568466281ca2d0368b506>`__: Added ``bounding_box`` as exceptional key to point_cloud mobject
+- `329d2c6 <https://github.com/3b1b/manim/commit/329d2c6eaec3d88bfb754b555575a3ea7c97a7e0>`__: Made sure stroke width is always a float
 
-No changes
 
 v1.1.0
 -------

docs/source/getting_started/config.rst

@@ -83,22 +83,3 @@ Its value is a dictionary, passed in as ``kwargs`` when initializing the ``Camer
 to modify the value of the properties of the ``Camera`` class.
 
 So the nesting of the ``CONFIG`` dictionary **essentially** passes in the value as ``kwargs``.
-
-Common usage
-------------
-
-When writing a class by yourself, you can add attributes or modify the attributes 
-of the parent class through ``CONFIG``.
-
-The most commonly used is to modify the properties of the camera when writing a ``Scene``:
-
-.. code-block:: python
-
-    class YourScene(Scene):
-        CONFIG = {
-            "camera_config": {
-                "background_color": WHITE,
-            },
-        }
-
-For example, the above dictionary will change the background color to white, etc.

docs/source/getting_started/configuration.rst

@@ -52,7 +52,8 @@ flag                                                       abbr   function
 ``--finder``                                                      Show the output file in finder
 ``--config``                                                      Guide for automatic configuration
 ``--file_name FILE_NAME``                                         Name for the movie or image file
-``--start_at_animation_number START_AT_ANIMATION_NUMBER``  ``-n`` Start rendering not from the first animation, but from another, specified by its index. If you passin two comma separated values, e.g. "3,6", it will end the rendering at the second value.
+``--start_at_animation_number START_AT_ANIMATION_NUMBER``  ``-n`` Start rendering not from the first animation, but from another, specified by its index. If you passing two comma separated values, e.g. "3,6", it will end the rendering at the second value.
+``--embed LINENO``                                         ``-e`` Takes a line number as an argument, and results in the scene being called as if the line ``self.embed()`` was inserted into the scene code at that line number
 ``--resolution RESOLUTION``                                ``-r`` Resolution, passed as "WxH", e.g. "1920x1080"
 ``--frame_rate FRAME_RATE``                                       Frame rate, as an integer
 ``--color COLOR``                                          ``-c`` Background color

docs/source/getting_started/example_scenes.rst

@@ -187,7 +187,7 @@ TexTransformExample
                 # Passing in muliple arguments to Tex will result
                 # in the same expression as if those arguments had
                 # been joined together, except that the submobject
-                # heirarchy of the resulting mobject ensure that the
+                # hierarchy of the resulting mobject ensure that the
                 # Tex mobject has a subject corresponding to
                 # each of these strings.  For example, the Tex mobject
                 # below will have 5 subjects, corresponding to the
@@ -335,7 +335,7 @@ UpdatersExample
             # If the argument itself might change, you can use f_always,
             # for which the arguments following the initial Mobject method
             # should be functions returning arguments to that method.
-            # The following line ensures thst decimal.set_value(square.get_y())
+            # The following line ensures that decimal.set_value(square.get_y())
             # is called every frame
             f_always(number.set_value, square.get_width)
             # You could also write the following equivalent line

docs/source/index.rst

@@ -6,7 +6,7 @@ Manim's documentation
 Manim is an animation engine for explanatory math videos. It's used to create precise animations programmatically, as seen in the videos
 at `3Blue1Brown <https://www.3blue1brown.com/>`_.
 
-And here is a Chinese version of this documentation: https://docs.manim.org.cn/shaders
+And here is a Chinese version of this documentation: https://docs.manim.org.cn/
 
 .. toctree::
    :maxdepth: 2

example_scenes.py

@@ -2,7 +2,7 @@ from manimlib import *
 import numpy as np
 
 # To watch one of these scenes, run the following:
-# python -m manim example_scenes.py SquareToCircle
+# manimgl example_scenes.py OpeningManimExample
 # Use -s to skip to the end and just save the final frame
 # Use -w to write the animation to a file
 # Use -o to write it to a file and open it once done
@@ -164,7 +164,7 @@ class TexTransformExample(Scene):
             # Passing in muliple arguments to Tex will result
             # in the same expression as if those arguments had
             # been joined together, except that the submobject
-            # heirarchy of the resulting mobject ensure that the
+            # hierarchy of the resulting mobject ensure that the
             # Tex mobject has a subject corresponding to
             # each of these strings.  For example, the Tex mobject
             # below will have 5 subjects, corresponding to the

manimlib/__init__.py

@@ -1,3 +1,7 @@
+import pkg_resources
+
+__version__ = pkg_resources.get_distribution("manimgl").version
+
 from manimlib.constants import *
 
 from manimlib.animation.animation import *
@@ -18,6 +22,7 @@ from manimlib.camera.camera import *
 
 from manimlib.window import *
 
+from manimlib.mobject.boolean_ops import *
 from manimlib.mobject.coordinate_systems import *
 from manimlib.mobject.changing import *
 from manimlib.mobject.frame import *
@@ -32,6 +37,7 @@ from manimlib.mobject.probability import *
 from manimlib.mobject.shape_matchers import *
 from manimlib.mobject.svg.brace import *
 from manimlib.mobject.svg.drawings import *
+from manimlib.mobject.svg.mtex_mobject import *
 from manimlib.mobject.svg.svg_mobject import *
 from manimlib.mobject.svg.tex_mobject import *
 from manimlib.mobject.svg.text_mobject import *

manimlib/__main__.py

@@ -1,11 +1,19 @@
 #!/usr/bin/env python
 import manimlib.config
+import manimlib.logger
 import manimlib.extract_scene
 import manimlib.utils.init_config
+from manimlib import __version__
 
 
 def main():
+    print(f"ManimGL \033[32mv{__version__}\033[0m")
+
     args = manimlib.config.parse_cli()
+    if args.version and args.file is None:
+        return
+    if args.log_level:
+        manimlib.logger.log.setLevel(args.log_level)
 
     if args.config:
         manimlib.utils.init_config.init_customization()
@@ -16,5 +24,6 @@ def main():
         for scene in scenes:
             scene.run()
 
-if __name__ == '__main__':
+
+if __name__ == "__main__":
     main()

manimlib/animation/creation.py

@@ -174,16 +174,12 @@ class ShowSubmobjectsOneByOne(ShowIncreasingSubsets):
         "int_func": np.ceil,
     }
 
-    def __init__(self, group, **kwargs):
-        new_group = Group(*group)
-        super().__init__(new_group, **kwargs)
-
     def update_submobject_list(self, index):
         # N = len(self.all_submobs)
         if index == 0:
             self.mobject.set_submobjects([])
         else:
-            self.mobject.set_submobjects(self.all_submobs[index - 1])
+            self.mobject.set_submobjects([self.all_submobs[index - 1]])
 
 
 # TODO, this is broken...

manimlib/animation/indication.py

@@ -9,6 +9,7 @@ from manimlib.animation.composition import Succession
 from manimlib.animation.creation import ShowCreation
 from manimlib.animation.creation import ShowPartial
 from manimlib.animation.fading import FadeOut
+from manimlib.animation.fading import FadeIn
 from manimlib.animation.transform import Transform
 from manimlib.mobject.types.vectorized_mobject import VMobject
 from manimlib.mobject.geometry import Circle
@@ -21,6 +22,8 @@ from manimlib.utils.bezier import interpolate
 from manimlib.utils.config_ops import digest_config
 from manimlib.utils.rate_functions import there_and_back
 from manimlib.utils.rate_functions import wiggle
+from manimlib.utils.rate_functions import smooth
+from manimlib.utils.rate_functions import squish_rate_func
 
 
 class FocusOn(Transform):
@@ -221,6 +224,8 @@ class FlashAround(VShowPassingFlash):
     def __init__(self, mobject, **kwargs):
         digest_config(self, kwargs)
         path = self.get_path(mobject)
+        if mobject.is_fixed_in_frame:
+            path.fix_in_frame()
         path.insert_n_curves(self.n_inserted_curves)
         path.set_points(path.get_points_without_null_curves())
         path.set_stroke(self.color, self.stroke_width)
@@ -361,3 +366,22 @@ class TurnInsideOut(Transform):
 
     def create_target(self):
         return self.mobject.copy().reverse_points()
+
+
+class FlashyFadeIn(AnimationGroup):
+    CONFIG = {
+        "fade_lag": 0,
+    }
+
+    def __init__(self, vmobject, stroke_width=2, **kwargs):
+        digest_config(self, kwargs)
+        outline = vmobject.copy()
+        outline.set_fill(opacity=0)
+        outline.set_stroke(width=stroke_width, opacity=1)
+
+        rate_func = kwargs.get("rate_func", smooth)
+        super().__init__(
+            FadeIn(vmobject, rate_func=squish_rate_func(rate_func, self.fade_lag, 1)),
+            VShowPassingFlash(outline, time_width=1),
+            **kwargs
+        )

manimlib/animation/transform.py

@@ -44,7 +44,7 @@ class Transform(Animation):
         self.check_target_mobject_validity()
         # Use a copy of target_mobject for the align_data_and_family
         # call so that the actual target_mobject stays
-        # preserved, since calling allign_data will potentailly
+        # preserved, since calling allign_data will potentially
         # change the structure of both arguments
         self.target_copy = self.target_mobject.copy()
         self.mobject.align_data_and_family(self.target_copy)
@@ -161,7 +161,7 @@ class ApplyMethod(Transform):
         method is a method of Mobject, *args are arguments for
         that method.  Key word arguments should be passed in
         as the last arg, as a dict, since **kwargs is for
-        configuration of the transform itslef
+        configuration of the transform itself
 
         Relies on the fact that mobject methods return the mobject
         """

manimlib/animation/transform_matching_parts.py

@@ -68,10 +68,10 @@ class TransformMatchingParts(AnimationGroup):
             anims.append(FadeTransformPieces(fade_source, fade_target, **kwargs))
         else:
             anims.append(FadeOutToPoint(
-                fade_source, fade_target.get_center(), **kwargs
+                fade_source, target_mobject.get_center(), **kwargs
             ))
             anims.append(FadeInFromPoint(
-                fade_target.copy(), fade_source.get_center(), **kwargs
+                fade_target.copy(), mobject.get_center(), **kwargs
             ))
 
         super().__init__(*anims)

manimlib/camera/camera.py

@@ -1,4 +1,5 @@
 import moderngl
+import math
 from colour import Color
 import OpenGL.GL as gl
 
@@ -67,7 +68,7 @@ class CameraFrame(Mobject):
         added_rot_T = rotation_matrix_transpose(angle, axis)
         new_rot_T = np.dot(curr_rot_T, added_rot_T)
         Fz = new_rot_T[2]
-        phi = np.arccos(Fz[2])
+        phi = np.arccos(clip(Fz[2], -1, 1))
         theta = angle_of_vector(Fz[:2]) + PI / 2
         partial_rot_T = np.dot(
             rotation_matrix_transpose(phi, RIGHT),
@@ -121,6 +122,15 @@ class CameraFrame(Mobject):
         self.refresh_rotation_matrix()
         return self
 
+    def get_theta(self):
+        return self.data["euler_angles"][0]
+
+    def get_phi(self):
+        return self.data["euler_angles"][1]
+
+    def get_gamma(self):
+        return self.data["euler_angles"][2]
+
     def get_shape(self):
         return (self.get_width(), self.get_height())
 
@@ -139,6 +149,16 @@ class CameraFrame(Mobject):
     def get_focal_distance(self):
         return self.focal_distance * self.get_height()
 
+    def get_implied_camera_location(self):
+        theta, phi, gamma = self.get_euler_angles()
+        dist = self.get_focal_distance()
+        x, y, z = self.get_center()
+        return (
+            x + dist * math.sin(theta) * math.sin(phi),
+            y - dist * math.cos(theta) * math.sin(phi),
+            z + dist * math.cos(phi)
+        )
+
     def interpolate(self, *args, **kwargs):
         super().interpolate(*args, **kwargs)
         self.refresh_rotation_matrix()
@@ -194,20 +214,30 @@ class Camera(object):
             fbo = self.get_fbo(ctx, 0)
         else:
             fbo = ctx.detect_framebuffer()
+        self.ctx = ctx
+        self.fbo = fbo
+        self.set_ctx_blending()
 
         # For multisample antialiasing
         fbo_msaa = self.get_fbo(ctx, self.samples)
         fbo_msaa.use()
+        self.fbo_msaa = fbo_msaa
 
-        ctx.enable(moderngl.BLEND)
-        ctx.blend_func = (
+    def set_ctx_blending(self, enable=True):
+        if enable:
+            self.ctx.enable(moderngl.BLEND)
+        else:
+            self.ctx.disable(moderngl.BLEND)
+        self.ctx.blend_func = (
             moderngl.SRC_ALPHA, moderngl.ONE_MINUS_SRC_ALPHA,
-            moderngl.ONE, moderngl.ONE
+            # moderngl.ONE, moderngl.ONE
         )
 
-        self.ctx = ctx
-        self.fbo = fbo
-        self.fbo_msaa = fbo_msaa
+    def set_ctx_depth_test(self, enable=True):
+        if enable:
+            self.ctx.enable(moderngl.DEPTH_TEST)
+        else:
+            self.ctx.disable(moderngl.DEPTH_TEST)
 
     def init_light_source(self):
         self.light_source = Point(self.light_source_position)
@@ -297,6 +327,9 @@ class Camera(object):
     def get_frame_center(self):
         return self.frame.get_center()
 
+    def get_location(self):
+        return self.frame.get_implied_camera_location()
+
     def resize_frame_shape(self, fixed_dimension=0):
         """
         Changes frame_shape to match the aspect ratio
@@ -316,17 +349,6 @@ class Camera(object):
         self.frame.set_height(frame_height)
         self.frame.set_width(frame_width)
 
-    def pixel_coords_to_space_coords(self, px, py, relative=False):
-        pw, ph = self.fbo.size
-        fw, fh = self.get_frame_shape()
-        fc = self.get_frame_center()
-        if relative:
-            return 2 * np.array([px / pw, py / ph, 0])
-        else:
-            # Only scale wrt one axis
-            scale = fh / ph
-            return fc + scale * np.array([(px - pw / 2), (py - ph / 2), 0])
-
     # Rendering
     def capture(self, *mobjects, **kwargs):
         self.refresh_perspective_uniforms()
@@ -338,17 +360,11 @@ class Camera(object):
         shader_wrapper = render_group["shader_wrapper"]
         shader_program = render_group["prog"]
         self.set_shader_uniforms(shader_program, shader_wrapper)
-        self.update_depth_test(shader_wrapper)
+        self.set_ctx_depth_test(shader_wrapper.depth_test)
         render_group["vao"].render(int(shader_wrapper.render_primitive))
         if render_group["single_use"]:
             self.release_render_group(render_group)
 
-    def update_depth_test(self, shader_wrapper):
-        if shader_wrapper.depth_test:
-            self.ctx.enable(moderngl.DEPTH_TEST)
-        else:
-            self.ctx.disable(moderngl.DEPTH_TEST)
-
     def get_render_group_list(self, mobject):
         try:
             return self.static_mobject_to_render_group_list[id(mobject)]
@@ -421,8 +437,10 @@ class Camera(object):
         for name, path in shader_wrapper.texture_paths.items():
             tid = self.get_texture_id(path)
             shader[name].value = tid
-        for name, value in it.chain(shader_wrapper.uniforms.items(), self.perspective_uniforms.items()):
+        for name, value in it.chain(self.perspective_uniforms.items(), shader_wrapper.uniforms.items()):
             try:
+                if isinstance(value, np.ndarray):
+                    value = tuple(value)
                 shader[name].value = value
             except KeyError:
                 pass
@@ -436,25 +454,32 @@ class Camera(object):
         anti_alias_width = self.anti_alias_width / (ph / fh)
         # Orient light
         rotation = frame.get_inverse_camera_rotation_matrix()
-        light_pos = self.light_source.get_location()
-        light_pos = np.dot(rotation, light_pos)
+        offset = frame.get_center()
+        light_pos = np.dot(
+            rotation, self.light_source.get_location() + offset
+        )
+        cam_pos = self.frame.get_implied_camera_location()  # TODO
 
         self.perspective_uniforms = {
             "frame_shape": frame.get_shape(),
             "anti_alias_width": anti_alias_width,
-            "camera_center": tuple(frame.get_center()),
+            "camera_offset": tuple(offset),
             "camera_rotation": tuple(np.array(rotation).T.flatten()),
+            "camera_position": tuple(cam_pos),
             "light_source_position": tuple(light_pos),
             "focal_distance": frame.get_focal_distance(),
         }
 
     def init_textures(self):
-        self.path_to_texture_id = {}
+        self.n_textures = 0
+        self.path_to_texture = {}
 
     def get_texture_id(self, path):
-        if path not in self.path_to_texture_id:
-            # A way to increase tid's sequentially
-            tid = len(self.path_to_texture_id)
+        if path not in self.path_to_texture:
+            if self.n_textures == 15:  # I have no clue why this is needed
+                self.n_textures += 1
+            tid = self.n_textures
+            self.n_textures += 1
             im = Image.open(path).convert("RGBA")
             texture = self.ctx.texture(
                 size=im.size,
@@ -462,12 +487,19 @@ class Camera(object):
                 data=im.tobytes(),
             )
             texture.use(location=tid)
-            self.path_to_texture_id[path] = tid
-        return self.path_to_texture_id[path]
+            self.path_to_texture[path] = (tid, texture)
+        return self.path_to_texture[path][0]
+
+    def release_texture(self, path):
+        tid_and_texture = self.path_to_texture.pop(path, None)
+        if tid_and_texture:
+            tid_and_texture[1].release()
+        return self
 
 
 # Mostly just defined so old scenes don't break
 class ThreeDCamera(Camera):
     CONFIG = {
         "samples": 4,
+        "anti_alias_width": 0,
     }

manimlib/config.py

@@ -5,10 +5,15 @@ import importlib
 import os
 import sys
 import yaml
+from contextlib import contextmanager
 from screeninfo import get_monitors
 
 from manimlib.utils.config_ops import merge_dicts_recursively
 from manimlib.utils.init_config import init_customization
+from manimlib.logger import log
+
+
+__config_file__ = "custom_config.yml"
 
 
 def parse_cli():
@@ -111,6 +116,12 @@ def parse_cli():
                  "in two comma separated values, e.g. \"3,6\", it will end"
                  "the rendering at the second value",
         )
+        parser.add_argument(
+            "-e", "--embed", metavar="LINENO",
+            help="Takes a line number as an argument, and results"
+                 "in the scene being called as if the line `self.embed()`"
+                 "was inserted into the scene code at that line number."
+        )
         parser.add_argument(
             "-r", "--resolution",
             help="Resolution, passed as \"WxH\", e.g. \"1920x1080\"",
@@ -136,10 +147,19 @@ def parse_cli():
             "--config_file",
             help="Path to the custom configuration file",
         )
+        parser.add_argument(
+            "-v", "--version",
+            action="store_true",
+            help="Display the version of manimgl"
+        )
+        parser.add_argument(
+            "--log-level",
+            help="Level of messages to Display, can be DEBUG / INFO / WARNING / ERROR / CRITICAL"
+        )
         args = parser.parse_args()
         return args
     except argparse.ArgumentError as err:
-        print(str(err))
+        log.error(str(err))
         sys.exit(2)
 
 
@@ -152,14 +172,30 @@ def get_manim_dir():
 def get_module(file_name):
     if file_name is None:
         return None
-    else:
-        module_name = file_name.replace(os.sep, ".").replace(".py", "")
-        spec = importlib.util.spec_from_file_location(module_name, file_name)
-        module = importlib.util.module_from_spec(spec)
-        spec.loader.exec_module(module)
-        return module
+    module_name = file_name.replace(os.sep, ".").replace(".py", "")
+    spec = importlib.util.spec_from_file_location(module_name, file_name)
+    module = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(module)
+    return module
+
+
+@contextmanager
+def insert_embed_line(file_name, lineno):
+    with open(file_name, 'r') as fp:
+        lines = fp.readlines()
+    line = lines[lineno - 1]
+    n_spaces = len(line) - len(line.lstrip())
+    lines.insert(lineno, " " * n_spaces + "self.embed()\n")
+
+    alt_file = file_name.replace(".py", "_inserted_embed.py")
+    with open(alt_file, 'w') as fp:
+        fp.writelines(lines)
+
+    try:
+        yield alt_file
+    finally:
+        os.remove(alt_file)
 
-__config_file__ = "custom_config.yml"
 
 def get_custom_config():
     global __config_file__
@@ -185,36 +221,49 @@ def get_custom_config():
     return config
 
 
+def check_temporary_storage(config):
+    if config["directories"]["temporary_storage"] == "" and sys.platform == "win32":
+        log.warning(
+            "You may be using Windows platform and have not specified the path of"
+            " `temporary_storage`, which may cause OSError. So it is recommended"
+            " to specify the `temporary_storage` in the config file (.yml)"
+        )
+
+
 def get_configuration(args):
     global __config_file__
 
     # ensure __config_file__ always exists
     if args.config_file is not None:
         if not os.path.exists(args.config_file):
-            print(f"Can't find {args.config_file}.")
+            log.error(f"Can't find {args.config_file}.")
             if sys.platform == 'win32':
-                print(f"Copying default configuration file to {args.config_file}...")
+                log.info(f"Copying default configuration file to {args.config_file}...")
                 os.system(f"copy default_config.yml {args.config_file}")
             elif sys.platform in ["linux2", "darwin"]:
-                print(f"Copying default configuration file to {args.config_file}...")
+                log.info(f"Copying default configuration file to {args.config_file}...")
                 os.system(f"cp default_config.yml {args.config_file}")
             else:
-                print("Please create the configuration file manually.")
-            print("Read configuration from default_config.yml.")
+                log.info("Please create the configuration file manually.")
+            log.info("Read configuration from default_config.yml.")
         else:
             __config_file__ = args.config_file
 
     global_defaults_file = os.path.join(get_manim_dir(), "manimlib", "default_config.yml")
 
     if not (os.path.exists(global_defaults_file) or os.path.exists(__config_file__)):
-        print("There is no configuration file detected. Initial configuration:\n")
+        log.info("There is no configuration file detected. Switch to the config file initializer:")
         init_customization()
 
     elif not os.path.exists(__config_file__):
-        print(f"Warning: Using the default configuration file, which you can modify in {global_defaults_file}")
-        print(f"If you want to create a local configuration file, you can create a file named {__config_file__}, or run manimgl --config")
+        log.info(f"Using the default configuration file, which you can modify in `{global_defaults_file}`")
+        log.info(
+            "If you want to create a local configuration file, you can create a file named"
+            f" `{__config_file__}`, or run `manimgl --config`"
+        )
 
     custom_config = get_custom_config()
+    check_temporary_storage(custom_config)
 
     write_file = any([args.write_file, args.open, args.finder])
     if args.transparent:
@@ -241,16 +290,22 @@ def get_configuration(args):
         "quiet": args.quiet,
     }
 
-    module = get_module(args.file)
+    if args.embed is None:
+        module = get_module(args.file)
+    else:
+        with insert_embed_line(args.file, int(args.embed)) as alt_file:
+            module = get_module(alt_file)
+
     config = {
         "module": module,
         "scene_names": args.scene_names,
         "file_writer_config": file_writer_config,
         "quiet": args.quiet or args.write_all,
         "write_all": args.write_all,
+        "skip_animations": args.skip_animations,
         "start_at_animation_number": args.start_at_animation_number,
-        "preview": not write_file,
         "end_at_animation_number": None,
+        "preview": not write_file,
         "leave_progress_bars": args.leave_progress_bars,
     }
 
@@ -263,7 +318,7 @@ def get_configuration(args):
     mon_index = custom_config["window_monitor"]
     monitor = monitors[min(mon_index, len(monitors) - 1)]
     window_width = monitor.width
-    if not args.full_screen:
+    if not (args.full_screen or custom_config["full_screen"]):
         window_width //= 2
     window_height = window_width * 9 // 16
     config["window_config"] = {
@@ -280,10 +335,6 @@ def get_configuration(args):
         else:
             config["start_at_animation_number"] = int(stan)
 
-    config["skip_animations"] = any([
-        args.skip_animations,
-        args.start_at_animation_number,
-    ])
     return config
 
 
@@ -319,9 +370,9 @@ def get_camera_configuration(args, custom_config):
     try:
         bg_color = args.color or custom_config["style"]["background_color"]
         camera_config["background_color"] = colour.Color(bg_color)
-    except AttributeError as err:
-        print("Please use a valid color")
-        print(err)
+    except ValueError as err:
+        log.error("Please use a valid color")
+        log.error(err)
         sys.exit(2)
 
     # If rendering a transparent image/move, make sure the

manimlib/default_config.yml

@@ -34,6 +34,7 @@ style:
 # the window on the monitor, e.g. "960,540"
 window_position: UR
 window_monitor: 0
+full_screen: False
 # If break_into_partial_movies is set to True, then many small
 # files will be written corresponding to each Scene.play and
 # Scene.wait call, and these files will then be combined

manimlib/extract_scene.py

@@ -1,9 +1,10 @@
 import inspect
 import sys
-import logging
+import copy
 
 from manimlib.scene.scene import Scene
 from manimlib.config import get_custom_config
+from manimlib.logger import log
 
 
 class BlankScene(Scene):
@@ -38,11 +39,14 @@ def prompt_user_for_choice(scene_classes):
             "\nScene Name or Number: "
         )
         return [
-            name_to_class[split_str] if not split_str.isnumeric() else scene_classes[int(split_str)-1]
+            name_to_class[split_str] if not split_str.isnumeric() else scene_classes[int(split_str) - 1]
             for split_str in user_input.replace(" ", "").split(",")
         ]
+    except IndexError:
+        log.error("Invalid scene number")
+        sys.exit(2)
     except KeyError:
-        logging.log(logging.ERROR, "Invalid scene")
+        log.error("Invalid scene name")
         sys.exit(2)
     except EOFError:
         sys.exit(1)
@@ -64,6 +68,26 @@ def get_scene_config(config):
     ])
 
 
+def compute_total_frames(scene_class, scene_config):
+    """
+    When a scene is being written to file, a copy of the scene is run with
+    skip_animations set to true so as to count how many frames it will require.
+    This allows for a total progress bar on rendering, and also allows runtime
+    errors to be exposed preemptively for long running scenes. The final frame
+    is saved by default, so that one can more quickly check that the last frame
+    looks as expected.
+    """
+    pre_config = copy.deepcopy(scene_config)
+    pre_config["file_writer_config"]["write_to_movie"] = False
+    pre_config["file_writer_config"]["save_last_frame"] = True
+    pre_config["file_writer_config"]["quiet"] = True
+    pre_config["skip_animations"] = True
+    pre_scene = scene_class(**pre_config)
+    pre_scene.run()
+    total_time = pre_scene.time - pre_scene.skip_time
+    return int(total_time * scene_config["camera_config"]["frame_rate"])
+
+
 def get_scenes_to_render(scene_classes, scene_config, config):
     if config["write_all"]:
         return [sc(**scene_config) for sc in scene_classes]
@@ -73,15 +97,15 @@ def get_scenes_to_render(scene_classes, scene_config, config):
         found = False
         for scene_class in scene_classes:
             if scene_class.__name__ == scene_name:
+                fw_config = scene_config["file_writer_config"]
+                if fw_config["write_to_movie"]:
+                    fw_config["total_frames"] = compute_total_frames(scene_class, scene_config)
                 scene = scene_class(**scene_config)
                 result.append(scene)
                 found = True
                 break
         if not found and (scene_name != ""):
-            logging.log(
-                logging.ERROR,
-                f"No scene named {scene_name} found",
-            )
+            log.error(f"No scene named {scene_name} found")
     if result:
         return result
     if len(scene_classes) == 1:

manimlib/logger.py

@@ -0,0 +1,13 @@
+import logging
+from rich.logging import RichHandler
+
+__all__ = ["log"]
+
+
+FORMAT = "%(message)s"
+logging.basicConfig(
+    level=logging.WARNING, format=FORMAT, datefmt="[%X]", handlers=[RichHandler()]
+)
+
+log = logging.getLogger("manimgl")
+log.setLevel("DEBUG")

manimlib/mobject/boolean_ops.py

@@ -0,0 +1,116 @@
+import numpy as np
+import pathops
+
+from manimlib.mobject.types.vectorized_mobject import VMobject
+
+
+# Boolean operations between 2D mobjects
+# Borrowed from from https://github.com/ManimCommunity/manim/
+
+def _convert_vmobject_to_skia_path(vmobject):
+    path = pathops.Path()
+    subpaths = vmobject.get_subpaths_from_points(vmobject.get_all_points())
+    for subpath in subpaths:
+        quads = vmobject.get_bezier_tuples_from_points(subpath)
+        start = subpath[0]
+        path.moveTo(*start[:2])
+        for p0, p1, p2 in quads:
+            path.quadTo(*p1[:2], *p2[:2])
+        if vmobject.consider_points_equals(subpath[0], subpath[-1]):
+            path.close()
+    return path
+
+
+def _convert_skia_path_to_vmobject(path, vmobject):
+    PathVerb = pathops.PathVerb
+    current_path_start = np.array([0.0, 0.0, 0.0])
+    for path_verb, points in path:
+        if path_verb == PathVerb.CLOSE:
+            vmobject.add_line_to(current_path_start)
+        else:
+            points = np.hstack((np.array(points), np.zeros((len(points), 1))))
+            if path_verb == PathVerb.MOVE:
+                for point in points:
+                    current_path_start = point
+                    vmobject.start_new_path(point)
+            elif path_verb == PathVerb.CUBIC:
+                vmobject.add_cubic_bezier_curve_to(*points)
+            elif path_verb == PathVerb.LINE:
+                vmobject.add_line_to(points[0])
+            elif path_verb == PathVerb.QUAD:
+                vmobject.add_quadratic_bezier_curve_to(*points)
+            else:
+                raise Exception(f"Unsupported: {path_verb}")
+    return vmobject
+
+
+class Union(VMobject):
+    def __init__(self, *vmobjects, **kwargs):
+        if len(vmobjects) < 2:
+            raise ValueError("At least 2 mobjects needed for Union.")
+        super().__init__(**kwargs)
+        outpen = pathops.Path()
+        paths = [
+            _convert_vmobject_to_skia_path(vmobject)
+            for vmobject in vmobjects
+        ]
+        pathops.union(paths, outpen.getPen())
+        _convert_skia_path_to_vmobject(outpen, self)
+
+
+class Difference(VMobject):
+    def __init__(self, subject, clip, **kwargs):
+        super().__init__(**kwargs)
+        outpen = pathops.Path()
+        pathops.difference(
+            [_convert_vmobject_to_skia_path(subject)],
+            [_convert_vmobject_to_skia_path(clip)],
+            outpen.getPen(),
+        )
+        _convert_skia_path_to_vmobject(outpen, self)
+
+
+class Intersection(VMobject):
+    def __init__(self, *vmobjects, **kwargs):
+        if len(vmobjects) < 2:
+            raise ValueError("At least 2 mobjects needed for Intersection.")
+        super().__init__(**kwargs)
+        outpen = pathops.Path()
+        pathops.intersection(
+            [_convert_vmobject_to_skia_path(vmobjects[0])],
+            [_convert_vmobject_to_skia_path(vmobjects[1])],
+            outpen.getPen(),
+        )
+        new_outpen = outpen
+        for _i in range(2, len(vmobjects)):
+            new_outpen = pathops.Path()
+            pathops.intersection(
+                [outpen],
+                [_convert_vmobject_to_skia_path(vmobjects[_i])],
+                new_outpen.getPen(),
+            )
+            outpen = new_outpen
+        _convert_skia_path_to_vmobject(outpen, self)
+
+
+class Exclusion(VMobject):
+    def __init__(self, *vmobjects, **kwargs):
+        if len(vmobjects) < 2:
+            raise ValueError("At least 2 mobjects needed for Exclusion.")
+        super().__init__(**kwargs)
+        outpen = pathops.Path()
+        pathops.xor(
+            [_convert_vmobject_to_skia_path(vmobjects[0])],
+            [_convert_vmobject_to_skia_path(vmobjects[1])],
+            outpen.getPen(),
+        )
+        new_outpen = outpen
+        for _i in range(2, len(vmobjects)):
+            new_outpen = pathops.Path()
+            pathops.xor(
+                [outpen],
+                [_convert_vmobject_to_skia_path(vmobjects[_i])],
+                new_outpen.getPen(),
+            )
+            outpen = new_outpen
+        _convert_skia_path_to_vmobject(outpen, self)

manimlib/mobject/changing.py

@@ -1,8 +1,13 @@
-from manimlib.constants import *
+import numpy as np
+from manimlib.constants import BLUE_D
+from manimlib.constants import BLUE_B
+from manimlib.constants import BLUE_E
+from manimlib.constants import GREY_BROWN
+from manimlib.constants import WHITE
+from manimlib.mobject.mobject import Mobject
 from manimlib.mobject.types.vectorized_mobject import VMobject
 from manimlib.mobject.types.vectorized_mobject import VGroup
 from manimlib.utils.rate_functions import smooth
-from manimlib.utils.space_ops import get_norm
 
 
 class AnimatedBoundary(VGroup):
@@ -74,25 +79,63 @@ class TracedPath(VMobject):
     CONFIG = {
         "stroke_width": 2,
         "stroke_color": WHITE,
-        "min_distance_to_new_point": 0.1,
+        "time_traced": np.inf,
+        "fill_opacity": 0,
+        "time_per_anchor": 1 / 15,
     }
 
     def __init__(self, traced_point_func, **kwargs):
         super().__init__(**kwargs)
         self.traced_point_func = traced_point_func
-        self.add_updater(lambda m: m.update_path())
+        self.time = 0
+        self.traced_points = []
+        self.add_updater(lambda m, dt: m.update_path(dt))
 
-    def update_path(self):
-        new_point = self.traced_point_func()
-        if not self.has_points():
-            self.start_new_path(new_point)
-            self.add_line_to(new_point)
+    def update_path(self, dt):
+        if dt == 0:
+            return self
+        point = self.traced_point_func().copy()
+        self.traced_points.append(point)
+
+        if self.time_traced < np.inf:
+            n_relevant_points = int(self.time_traced / dt + 0.5)
+            # n_anchors = int(self.time_traced / self.time_per_anchor)
+            n_tps = len(self.traced_points)
+            if n_tps < n_relevant_points:
+                points = self.traced_points + [point] * (n_relevant_points - n_tps)
+            else:
+                points = self.traced_points[n_tps - n_relevant_points:]
+            # points = [
+            #     self.traced_points[max(n_tps - int(alpha * n_relevant_points) - 1, 0)]
+            #     for alpha in np.linspace(1, 0, n_anchors)
+            # ]
+            # Every now and then refresh the list
+            if n_tps > 10 * n_relevant_points:
+                self.traced_points = self.traced_points[-n_relevant_points:]
         else:
-            # Set the end to be the new point
-            self.get_points()[-1] = new_point
+            # sparseness = max(int(self.time_per_anchor / dt), 1)
+            # points = self.traced_points[::sparseness]
+            # points[-1] = self.traced_points[-1]
+            points = self.traced_points
 
-            # Second to last point
-            nppcc = self.n_points_per_curve
-            dist = get_norm(new_point - self.get_points()[-nppcc])
-            if dist >= self.min_distance_to_new_point:
-                self.add_line_to(new_point)
+        if points:
+            self.set_points_smoothly(points)
+
+        self.time += dt
+        return self
+
+
+class TracingTail(TracedPath):
+    CONFIG = {
+        "stroke_width": (0, 3),
+        "stroke_opacity": (0, 1),
+        "stroke_color": WHITE,
+        "time_traced": 1.0,
+    }
+
+    def __init__(self, mobject_or_func, **kwargs):
+        if isinstance(mobject_or_func, Mobject):
+            func = mobject_or_func.get_center
+        else:
+            func = mobject_or_func
+        super().__init__(func, **kwargs)

manimlib/mobject/coordinate_systems.py

@@ -10,6 +10,7 @@ from manimlib.mobject.geometry import Rectangle
 from manimlib.mobject.number_line import NumberLine
 from manimlib.mobject.svg.tex_mobject import Tex
 from manimlib.mobject.types.vectorized_mobject import VGroup
+from manimlib.utils.config_ops import digest_config
 from manimlib.utils.config_ops import merge_dicts_recursively
 from manimlib.utils.simple_functions import binary_search
 from manimlib.utils.space_ops import angle_of_vector
@@ -25,13 +26,18 @@ class CoordinateSystem():
     """
     CONFIG = {
         "dimension": 2,
-        "x_range": np.array([-8.0, 8.0, 1.0]),
-        "y_range": np.array([-4.0, 4.0, 1.0]),
-        "width": None,
-        "height": None,
+        "default_x_range": [-8.0, 8.0, 1.0],
+        "default_y_range": [-4.0, 4.0, 1.0],
+        "width": FRAME_WIDTH,
+        "height": FRAME_HEIGHT,
         "num_sampled_graph_points_per_tick": 20,
     }
 
+    def __init__(self, **kwargs):
+        digest_config(self, kwargs)
+        self.x_range = np.array(self.default_x_range)
+        self.y_range = np.array(self.default_y_range)
+
     def coords_to_point(self, *coords):
         raise Exception("Not implemented")
 
@@ -127,6 +133,7 @@ class CoordinateSystem():
             **kwargs
         )
         graph.underlying_function = function
+        graph.x_range = x_range
         return graph
 
     def get_parametric_curve(self, function, **kwargs):
@@ -144,14 +151,14 @@ class CoordinateSystem():
         else:
             alpha = binary_search(
                 function=lambda a: self.point_to_coords(
-                    graph.point_from_proportion(a)
+                    graph.quick_point_from_proportion(a)
                 )[0],
                 target=x,
                 lower_bound=self.x_range[0],
                 upper_bound=self.x_range[1],
             )
             if alpha is not None:
-                return graph.point_from_proportion(alpha)
+                return graph.quick_point_from_proportion(alpha)
             else:
                 return None
 
@@ -282,7 +289,9 @@ class Axes(VGroup, CoordinateSystem):
                  x_range=None,
                  y_range=None,
                  **kwargs):
-        super().__init__(**kwargs)
+        CoordinateSystem.__init__(self, **kwargs)
+        VGroup.__init__(self, **kwargs)
+
         if x_range is not None:
             self.x_range[:len(x_range)] = x_range
         if y_range is not None:
@@ -441,7 +450,7 @@ class NumberPlane(Axes):
         return lines1, lines2
 
     def get_lines_parallel_to_axis(self, axis1, axis2):
-        freq = axis1.x_step
+        freq = axis2.x_step
         ratio = self.faded_line_ratio
         line = Line(axis1.get_start(), axis1.get_end())
         dense_freq = (1 + ratio)
@@ -501,15 +510,15 @@ class ComplexPlane(NumberPlane):
     def p2n(self, point):
         return self.point_to_number(point)
 
-    def get_default_coordinate_values(self):
+    def get_default_coordinate_values(self, skip_first=True):
         x_numbers = self.get_x_axis().get_tick_range()[1:]
         y_numbers = self.get_y_axis().get_tick_range()[1:]
         y_numbers = [complex(0, y) for y in y_numbers if y != 0]
         return [*x_numbers, *y_numbers]
 
-    def add_coordinate_labels(self, numbers=None, **kwargs):
+    def add_coordinate_labels(self, numbers=None, skip_first=True, **kwargs):
         if numbers is None:
-            numbers = self.get_default_coordinate_values()
+            numbers = self.get_default_coordinate_values(skip_first)
 
         self.coordinate_labels = VGroup()
         for number in numbers:
@@ -522,6 +531,15 @@ class ComplexPlane(NumberPlane):
                 axis = self.get_x_axis()
                 value = z.real
             number_mob = axis.get_number_mobject(value, **kwargs)
+            # For i and -i, remove the "1"
+            if z.imag == 1:
+                number_mob.remove(number_mob[0])
+            if z.imag == -1:
+                number_mob.remove(number_mob[1])
+                number_mob[0].next_to(
+                    number_mob[1], LEFT,
+                    buff=number_mob[0].get_width() / 4
+                )
             self.coordinate_labels.add(number_mob)
         self.add(self.coordinate_labels)
         return self

manimlib/mobject/geometry.py

@@ -1,4 +1,6 @@
 import numpy as np
+import math
+import numbers
 
 from manimlib.constants import *
 from manimlib.mobject.mobject import Mobject
@@ -27,6 +29,7 @@ DEFAULT_ARROW_TIP_LENGTH = 0.35
 DEFAULT_ARROW_TIP_WIDTH = 0.35
 
 
+# Deprecate?
 class TipableVMobject(VMobject):
     """
     Meant for shared functionality between Arc and Line.
@@ -302,6 +305,9 @@ class Circle(Arc):
             (angle - start_angle) / TAU
         )
 
+    def get_radius(self):
+        return get_norm(self.get_start() - self.get_center())
+
 
 class Dot(Circle):
     CONFIG = {
@@ -404,32 +410,38 @@ class Line(TipableVMobject):
         self.set_points_by_ends(self.start, self.end, self.buff, self.path_arc)
 
     def set_points_by_ends(self, start, end, buff=0, path_arc=0):
-        if path_arc:
-            self.set_points(Arc.create_quadratic_bezier_points(path_arc))
-            self.put_start_and_end_on(start, end)
-        else:
+        vect = end - start
+        dist = get_norm(vect)
+        if np.isclose(dist, 0):
             self.set_points_as_corners([start, end])
-        self.account_for_buff(self.buff)
+            return self
+        if path_arc:
+            neg = path_arc < 0
+            if neg:
+                path_arc = -path_arc
+                start, end = end, start
+            radius = (dist / 2) / math.sin(path_arc / 2)
+            alpha = (PI - path_arc) / 2
+            center = start + radius * normalize(rotate_vector(end - start, alpha))
+
+            raw_arc_points = Arc.create_quadratic_bezier_points(
+                angle=path_arc - 2 * buff / radius,
+                start_angle=angle_of_vector(start - center) + buff / radius,
+            )
+            if neg:
+                raw_arc_points = raw_arc_points[::-1]
+            self.set_points(center + radius * raw_arc_points)
+        else:
+            if buff > 0 and dist > 0:
+                start = start + vect * (buff / dist)
+                end = end - vect * (buff / dist)
+            self.set_points_as_corners([start, end])
+        return self
 
     def set_path_arc(self, new_value):
         self.path_arc = new_value
         self.init_points()
 
-    def account_for_buff(self, buff):
-        if buff == 0:
-            return
-        #
-        if self.path_arc == 0:
-            length = self.get_length()
-        else:
-            length = self.get_arc_length()
-        #
-        if length < 2 * buff:
-            return
-        buff_prop = buff / length
-        self.pointwise_become_partial(self, buff_prop, 1 - buff_prop)
-        return self
-
     def set_start_and_end_attrs(self, start, end):
         # If either start or end are Mobjects, this
         # gives their centers
@@ -439,8 +451,8 @@ class Line(TipableVMobject):
         # Now that we know the direction between them,
         # we can find the appropriate boundary point from
         # start and end, if they're mobjects
-        self.start = self.pointify(start, vect) + self.buff * vect
-        self.end = self.pointify(end, -vect) - self.buff * vect
+        self.start = self.pointify(start, vect)
+        self.end = self.pointify(end, -vect)
 
     def pointify(self, mob_or_point, direction=None):
         """
@@ -461,8 +473,10 @@ class Line(TipableVMobject):
 
     def put_start_and_end_on(self, start, end):
         curr_start, curr_end = self.get_start_and_end()
-        if (curr_start == curr_end).all():
-            self.set_points_by_ends(start, end, self.path_arc)
+        if np.isclose(curr_start, curr_end).all():
+            # Handle null lines more gracefully
+            self.set_points_by_ends(start, end, buff=0, path_arc=self.path_arc)
+            return self
         return super().put_start_and_end_on(start, end)
 
     def get_vector(self):
@@ -494,8 +508,9 @@ class Line(TipableVMobject):
         )
         return self
 
-    def set_length(self, length):
-        self.scale(length / self.get_length())
+    def set_length(self, length, **kwargs):
+        self.scale(length / self.get_length(), **kwargs)
+        return self
 
 
 class DashedLine(Line):
@@ -578,6 +593,80 @@ class Elbow(VMobject):
 
 
 class Arrow(Line):
+    CONFIG = {
+        "stroke_color": GREY_A,
+        "stroke_width": 5,
+        "tip_width_ratio": 4,
+        "width_to_tip_len": 0.0075,
+        "max_tip_length_to_length_ratio": 0.3,
+        "max_width_to_length_ratio": 10,
+        "buff": 0.25,
+    }
+
+    def set_points_by_ends(self, start, end, buff=0, path_arc=0):
+        super().set_points_by_ends(start, end, buff, path_arc)
+        self.insert_tip_anchor()
+        return self
+
+    def init_colors(self):
+        super().init_colors()
+        self.create_tip_with_stroke_width()
+
+    def get_arc_length(self):
+        # Push up into Line?
+        arc_len = get_norm(self.get_vector())
+        if self.path_arc > 0:
+            arc_len *= self.path_arc / (2 * math.sin(self.path_arc / 2))
+        return arc_len
+
+    def insert_tip_anchor(self):
+        prev_end = self.get_end()
+        arc_len = self.get_arc_length()
+        tip_len = self.get_stroke_width() * self.width_to_tip_len * self.tip_width_ratio
+        if tip_len >= self.max_tip_length_to_length_ratio * arc_len:
+            alpha = self.max_tip_length_to_length_ratio
+        else:
+            alpha = tip_len / arc_len
+        self.pointwise_become_partial(self, 0, 1 - alpha)
+        self.add_line_to(prev_end)
+        return self
+
+    def create_tip_with_stroke_width(self):
+        width = min(
+            self.max_stroke_width,
+            self.max_width_to_length_ratio * self.get_length(),
+        )
+        widths_array = np.full(self.get_num_points(), width)
+        nppc = self.n_points_per_curve
+        if len(widths_array) > nppc:
+            widths_array[-nppc:] = [
+                a * self.tip_width_ratio * width
+                for a in np.linspace(1, 0, nppc)
+            ]
+            self.set_stroke(width=widths_array)
+        return self
+
+    def reset_tip(self):
+        self.set_points_by_ends(
+            self.get_start(),
+            self.get_end(),
+            path_arc=self.path_arc,
+        )
+        self.create_tip_with_stroke_width()
+        return self
+
+    def set_stroke(self, color=None, width=None, *args, **kwargs):
+        super().set_stroke(color=color, width=width, *args, **kwargs)
+        if isinstance(width, numbers.Number):
+            self.max_stroke_width = width
+            self.reset_tip()
+        return self
+
+    def _handle_scale_side_effects(self, scale_factor):
+        return self.reset_tip()
+
+
+class FillArrow(Line):
     CONFIG = {
         "fill_color": GREY_A,
         "fill_opacity": 1,
@@ -842,16 +931,8 @@ class Rectangle(Polygon):
 
 
 class Square(Rectangle):
-    CONFIG = {
-        "side_length": 2.0,
-    }
-
-    def __init__(self, side_length=None, **kwargs):
-        digest_config(self, kwargs)
-
-        if side_length is None:
-            side_length = self.side_length
-
+    def __init__(self, side_length=2.0, **kwargs):
+        self.side_length = side_length
         super().__init__(side_length, side_length, **kwargs)
 
 

manimlib/mobject/matrix.py

@@ -68,7 +68,7 @@ class Matrix(VMobject):
 
     def __init__(self, matrix, **kwargs):
         """
-        Matrix can either either include numbres, tex_strings,
+        Matrix can either include numbers, tex_strings,
         or mobjects
         """
         VMobject.__init__(self, **kwargs)

manimlib/mobject/mobject.py

@@ -43,10 +43,13 @@ class Mobject(object):
         "opacity": 1,
         "dim": 3,  # TODO, get rid of this
         # Lighting parameters
-        # Positive gloss up to 1 makes it reflect the light.
-        "gloss": 0.0,
-        # Positive shadow up to 1 makes a side opposite the light darker
+        # ...
+        # Larger reflectiveness makes things brighter when facing the light
+        "reflectiveness": 0.0,
+        # Larger shadow makes faces opposite the light darker
         "shadow": 0.0,
+        # Makes parts bright where light gets reflected toward the camera
+        "gloss": 0.0,
         # For shaders
         "shader_folder": "",
         "render_primitive": moderngl.TRIANGLE_STRIP,
@@ -82,6 +85,14 @@ class Mobject(object):
     def __str__(self):
         return self.__class__.__name__
 
+    def __add__(self, other: 'Mobject') -> 'Mobject':
+        assert(isinstance(other, Mobject))
+        return self.get_group_class()(self, other)
+
+    def __mul__(self, other: 'int') -> 'Mobject':
+        assert(isinstance(other, int))
+        return self.replicate(other)
+
     def init_data(self):
         self.data = {
             "points": np.zeros((0, 3)),
@@ -94,6 +105,7 @@ class Mobject(object):
             "is_fixed_in_frame": float(self.is_fixed_in_frame),
             "gloss": self.gloss,
             "shadow": self.shadow,
+            "reflectiveness": self.reflectiveness,
         }
 
     def init_colors(self):
@@ -145,6 +157,7 @@ class Mobject(object):
         for mob in self.get_family():
             for key in mob.data:
                 mob.data[key] = mob.data[key][::-1]
+        self.refresh_unit_normal()
         return self
 
     def apply_points_function(self, func, about_point=None, about_edge=ORIGIN, works_on_bounding_box=False):
@@ -300,6 +313,11 @@ class Mobject(object):
         self.assemble_family()
         return self
 
+    def insert_submobject(self, index, new_submob):
+        self.submobjects.insert(index, new_submob)
+        self.assemble_family()
+        return self
+
     def set_submobjects(self, submobject_list):
         self.remove(*self.submobjects)
         self.add(*submobject_list)
@@ -365,14 +383,17 @@ class Mobject(object):
         self.center()
         return self
 
+    def replicate(self, n):
+        return self.get_group_class()(
+            *(self.copy() for x in range(n))
+        )
+
     def get_grid(self, n_rows, n_cols, height=None, **kwargs):
         """
         Returns a new mobject containing multiple copies of this one
         arranged in a grid
         """
-        grid = self.get_group_class()(
-            *(self.copy() for n in range(n_rows * n_cols))
-        )
+        grid = self.replicate(n_rows * n_cols)
         grid.arrange_in_grid(n_rows, n_cols, **kwargs)
         if height is not None:
             grid.set_height(height)
@@ -383,6 +404,7 @@ class Mobject(object):
             self.submobjects.sort(key=submob_func)
         else:
             self.submobjects.sort(key=lambda m: point_to_num_func(m.get_center()))
+        self.assemble_family()
         return self
 
     def shuffle(self, recurse=False):
@@ -390,6 +412,7 @@ class Mobject(object):
             for submob in self.submobjects:
                 submob.shuffle(recurse=True)
         random.shuffle(self.submobjects)
+        self.assemble_family()
         return self
 
     # Copying
@@ -408,8 +431,10 @@ class Mobject(object):
         for key in self.data:
             copy_mobject.data[key] = self.data[key].copy()
 
-        # TODO, are uniforms ever numpy arrays?
         copy_mobject.uniforms = dict(self.uniforms)
+        for key in self.uniforms:
+            if isinstance(self.uniforms[key], np.ndarray):
+                copy_mobject.uniforms[key] = self.uniforms[key].copy()
 
         copy_mobject.submobjects = []
         copy_mobject.add(*[sm.copy() for sm in self.submobjects])
@@ -561,7 +586,7 @@ class Mobject(object):
         )
         return self
 
-    def scale(self, scale_factor, min_scale_factor=1e-8, **kwargs):
+    def scale(self, scale_factor, min_scale_factor=1e-8, about_point=None, about_edge=ORIGIN):
         """
         Default behavior is to scale about the center of the mobject.
         The argument about_edge can be a vector, indicating which side of
@@ -574,11 +599,19 @@ class Mobject(object):
         scale_factor = max(scale_factor, min_scale_factor)
         self.apply_points_function(
             lambda points: scale_factor * points,
+            about_point=about_point,
+            about_edge=about_edge,
             works_on_bounding_box=True,
-            **kwargs
         )
+        for mob in self.get_family():
+            mob._handle_scale_side_effects(scale_factor)
         return self
 
+    def _handle_scale_side_effects(self, scale_factor):
+        # In case subclasses, such as DecimalNumber, need to make
+        # any other changes when the size gets altered
+        pass
+
     def stretch(self, factor, dim, **kwargs):
         def func(points):
             points[:, dim] *= factor
@@ -754,7 +787,7 @@ class Mobject(object):
         return self.rescale_to_fit(height, 1, stretch=True, **kwargs)
 
     def stretch_to_fit_depth(self, depth, **kwargs):
-        return self.rescale_to_fit(depth, 1, stretch=True, **kwargs)
+        return self.rescale_to_fit(depth, 2, stretch=True, **kwargs)
 
     def set_width(self, width, stretch=False, **kwargs):
         return self.rescale_to_fit(width, 0, stretch=stretch, **kwargs)
@@ -765,6 +798,21 @@ class Mobject(object):
     def set_depth(self, depth, stretch=False, **kwargs):
         return self.rescale_to_fit(depth, 2, stretch=stretch, **kwargs)
 
+    def set_max_width(self, max_width, **kwargs):
+        if self.get_width() > max_width:
+            self.set_width(max_width, **kwargs)
+        return self
+
+    def set_max_height(self, max_height, **kwargs):
+        if self.get_height() > max_height:
+            self.set_height(max_height, **kwargs)
+        return self
+
+    def set_max_depth(self, max_depth, **kwargs):
+        if self.get_depth() > max_depth:
+            self.set_depth(max_depth, **kwargs)
+        return self
+
     def set_coord(self, value, dim, direction=ORIGIN):
         curr = self.get_coord(dim, direction)
         shift_vect = np.zeros(self.dim)
@@ -823,7 +871,6 @@ class Mobject(object):
         return self
 
     def put_start_and_end_on(self, start, end):
-        # TODO, this doesn't currently work in 3d
         curr_start, curr_end = self.get_start_and_end()
         curr_vect = curr_end - curr_start
         if np.all(curr_vect == 0):
@@ -835,9 +882,12 @@ class Mobject(object):
         )
         self.rotate(
             angle_of_vector(target_vect) - angle_of_vector(curr_vect),
-            about_point=curr_start
         )
-        self.shift(start - curr_start)
+        self.rotate(
+            np.arctan2(curr_vect[2], get_norm(curr_vect[:2])) - np.arctan2(target_vect[2], get_norm(target_vect[:2])),
+            axis=np.array([-target_vect[1], target_vect[0], 0]),
+        )
+        self.shift(start - self.get_start())
         return self
 
     # Color functions
@@ -936,12 +986,12 @@ class Mobject(object):
     def fade(self, darkness=0.5, recurse=True):
         self.set_opacity(1.0 - darkness, recurse=recurse)
 
-    def get_gloss(self):
-        return self.uniforms["gloss"]
+    def get_reflectiveness(self):
+        return self.uniforms["reflectiveness"]
 
-    def set_gloss(self, gloss, recurse=True):
+    def set_reflectiveness(self, reflectiveness, recurse=True):
         for mob in self.get_family(recurse):
-            mob.uniforms["gloss"] = gloss
+            mob.uniforms["reflectiveness"] = reflectiveness
         return self
 
     def get_shadow(self):
@@ -952,6 +1002,14 @@ class Mobject(object):
             mob.uniforms["shadow"] = shadow
         return self
 
+    def get_gloss(self):
+        return self.uniforms["gloss"]
+
+    def set_gloss(self, gloss, recurse=True):
+        for mob in self.get_family(recurse):
+            mob.uniforms["gloss"] = gloss
+        return self
+
     # Background rectangle
 
     def add_background_rectangle(self, color=None, opacity=0.75, **kwargs):
@@ -1063,14 +1121,16 @@ class Mobject(object):
 
     def get_start(self):
         self.throw_error_if_no_points()
-        return np.array(self.get_points()[0])
+        return self.get_points()[0].copy()
 
     def get_end(self):
         self.throw_error_if_no_points()
-        return np.array(self.get_points()[-1])
+        return self.get_points()[-1].copy()
 
     def get_start_and_end(self):
-        return self.get_start(), self.get_end()
+        self.throw_error_if_no_points()
+        points = self.get_points()
+        return (points[0].copy(), points[-1].copy())
 
     def point_from_proportion(self, alpha):
         points = self.get_points()
@@ -1331,11 +1391,13 @@ class Mobject(object):
     @affects_shader_info_id
     def fix_in_frame(self):
         self.uniforms["is_fixed_in_frame"] = 1.0
+        self.is_fixed_in_frame = True
         return self
 
     @affects_shader_info_id
     def unfix_from_frame(self):
         self.uniforms["is_fixed_in_frame"] = 0.0
+        self.is_fixed_in_frame = False
         return self
 
     @affects_shader_info_id
@@ -1436,7 +1498,7 @@ class Mobject(object):
         return result
 
     def check_data_alignment(self, array, data_key):
-        # Makes sure that self.data[key] can be brodcast into
+        # Makes sure that self.data[key] can be broadcast into
         # the given array, meaning its length has to be either 1
         # or the length of the array
         d_len = len(self.data[data_key])
@@ -1578,6 +1640,10 @@ class Group(Mobject):
         Mobject.__init__(self, **kwargs)
         self.add(*mobjects)
 
+    def __add__(self, other: 'Mobject' or 'Group'):
+        assert(isinstance(other, Mobject))
+        return self.add(other)
+
 
 class Point(Mobject):
     CONFIG = {

manimlib/mobject/mobject_update_utils.py

@@ -23,7 +23,7 @@ def always(method, *args, **kwargs):
 def f_always(method, *arg_generators, **kwargs):
     """
     More functional version of always, where instead
-    of taking in args, it takes in functions which ouput
+    of taking in args, it takes in functions which output
     the relevant arguments.
     """
     assert_is_mobject_method(method)

manimlib/mobject/number_line.py

@@ -6,7 +6,6 @@ from manimlib.utils.bezier import interpolate
 from manimlib.utils.config_ops import digest_config
 from manimlib.utils.config_ops import merge_dicts_recursively
 from manimlib.utils.simple_functions import fdiv
-from manimlib.utils.space_ops import normalize
 
 
 class NumberLine(Line):
@@ -83,7 +82,7 @@ class NumberLine(Line):
         ticks = VGroup()
         for x in self.get_tick_range():
             size = self.tick_size
-            if x in self.numbers_with_elongated_ticks:
+            if np.isclose(self.numbers_with_elongated_ticks, x).any():
                 size *= self.longer_tick_multiple
             ticks.add(self.get_tick(x, size))
         self.add(ticks)
@@ -106,11 +105,13 @@ class NumberLine(Line):
         return interpolate(self.get_start(), self.get_end(), alpha)
 
     def point_to_number(self, point):
-        start, end = self.get_start_and_end()
-        unit_vect = normalize(end - start)
+        points = self.get_points()
+        start = points[0]
+        end = points[-1]
+        vect = end - start
         proportion = fdiv(
-            np.dot(point - start, unit_vect),
-            np.dot(end - start, unit_vect),
+            np.dot(point - start, vect),
+            np.dot(end - start, vect),
         )
         return interpolate(self.x_min, self.x_max, proportion)
 

manimlib/mobject/numbers.py

@@ -36,7 +36,9 @@ class DecimalNumber(VMobject):
 
         # Add non-numerical bits
         if self.show_ellipsis:
-            self.add(self.string_to_mob("..."))
+            dots = self.string_to_mob("...")
+            dots.arrange(RIGHT, buff=2 * dots[0].get_width())
+            self.add(dots)
         if self.unit is not None:
             self.unit_sign = self.string_to_mob(self.unit, SingleStringTex)
             self.add(self.unit_sign)
@@ -128,17 +130,15 @@ class DecimalNumber(VMobject):
 
     def set_value(self, number):
         move_to_point = self.get_edge_center(self.edge_to_fix)
-        old_submobjects = self.submobjects
+        old_submobjects = list(self.submobjects)
         self.set_submobjects_from_number(number)
         self.move_to(move_to_point, self.edge_to_fix)
         for sm1, sm2 in zip(self.submobjects, old_submobjects):
             sm1.match_style(sm2)
         return self
 
-    def scale(self, scale_factor, **kwargs):
-        super().scale(scale_factor, **kwargs)
+    def _handle_scale_side_effects(self, scale_factor):
         self.data["font_size"] *= scale_factor
-        return self
 
     def get_value(self):
         return self.number

manimlib/mobject/shape_matchers.py

@@ -47,7 +47,7 @@ class BackgroundRectangle(SurroundingRectangle):
                        fill_opacity=None,
                        family=True
                        ):
-        # Unchangable style, except for fill_opacity
+        # Unchangeable style, except for fill_opacity
         VMobject.set_style_data(
             self,
             stroke_color=BLACK,

manimlib/mobject/svg/drawings.py

@@ -200,12 +200,11 @@ class Laptop(VGroup):
 
 class VideoIcon(SVGMobject):
     CONFIG = {
-        "file_name": "video_icon",
         "width": FRAME_WIDTH / 12.,
     }
 
     def __init__(self, **kwargs):
-        SVGMobject.__init__(self, **kwargs)
+        super().__init__(file_name="video_icon", **kwargs)
         self.center()
         self.set_width(self.width)
         self.set_stroke(color=WHITE, width=0)

manimlib/mobject/svg/mtex_mobject.py

@@ -0,0 +1,521 @@
+import itertools as it
+import re
+from types import MethodType
+
+from manimlib.mobject.svg.svg_mobject import SVGMobject
+from manimlib.mobject.types.vectorized_mobject import VMobject
+from manimlib.mobject.types.vectorized_mobject import VGroup
+from manimlib.utils.iterables import adjacent_pairs
+from manimlib.utils.iterables import remove_list_redundancies
+from manimlib.utils.tex_file_writing import tex_to_svg_file
+from manimlib.utils.tex_file_writing import get_tex_config
+from manimlib.utils.tex_file_writing import display_during_execution
+
+
+SCALE_FACTOR_PER_FONT_POINT = 0.001
+
+
+tex_hash_to_mob_map = {}
+
+
+def _get_neighbouring_pairs(iterable):
+    return list(adjacent_pairs(iterable))[:-1]
+
+
+class _LabelledTex(SVGMobject):
+    CONFIG = {
+        "height": None,
+        "path_string_config": {
+            "should_subdivide_sharp_curves": True,
+            "should_remove_null_curves": True,
+        },
+    }
+
+    @staticmethod
+    def color_str_to_label(color_str):
+        if len(color_str) == 4:
+            # "#RGB" => "#RRGGBB"
+            color_str = "#" + "".join([c * 2 for c in color_str[1:]])
+        return int(color_str[1:], 16) - 1
+
+    def get_mobjects_from(self, element):
+        result = super().get_mobjects_from(element)
+        for mob in result:
+            if not hasattr(mob, "glyph_label"):
+                mob.glyph_label = -1
+        try:
+            color_str = element.getAttribute("fill")
+            if color_str:
+                glyph_label = _LabelledTex.color_str_to_label(color_str)
+                for mob in result:
+                    mob.glyph_label = glyph_label
+        except:
+            pass
+        return result
+
+
+class _TexSpan(object):
+    def __init__(self, script_type, label):
+        # script_type: 0 for normal, 1 for subscript, 2 for superscript.
+        # Only those spans with `script_type == 0` will be colored.
+        self.script_type = script_type
+        self.label = label
+        self.containing_labels = []
+
+    def __repr__(self):
+        return "_TexSpan(" + ", ".join([
+            attrib_name + "=" + str(getattr(self, attrib_name))
+            for attrib_name in ["script_type", "label", "containing_labels"]
+        ]) + ")"
+
+
+class _TexParser(object):
+    def __init__(self, mtex):
+        self.tex_string = mtex.tex_string
+        strings_to_break_up = remove_list_redundancies([
+            *mtex.isolate, *mtex.tex_to_color_map.keys(), mtex.tex_string
+        ])
+        if "" in strings_to_break_up:
+            strings_to_break_up.remove("")
+        unbreakable_commands = mtex.unbreakable_commands
+
+        self.tex_spans_dict = {}
+        self.current_label = 0
+        self.break_up_by_braces()
+        self.break_up_by_scripts()
+        self.break_up_by_additional_strings(strings_to_break_up)
+        self.merge_unbreakable_commands(unbreakable_commands)
+        self.analyse_containing_labels()
+
+    @staticmethod
+    def label_to_color_tuple(n):
+        # Get a unique color different from black,
+        # or the svg file will not include the color information.
+        rgb = n + 1
+        rg, b = divmod(rgb, 256)
+        r, g = divmod(rg, 256)
+        return r, g, b
+
+    @staticmethod
+    def contains(span_0, span_1):
+        return span_0[0] <= span_1[0] and span_1[1] <= span_0[1]
+
+    def add_tex_span(self, span_tuple, script_type=0, label=-1):
+        if script_type == 0:
+            # Should be additionally labelled.
+            label = self.current_label
+            self.current_label += 1
+
+        tex_span = _TexSpan(script_type, label)
+        self.tex_spans_dict[span_tuple] = tex_span
+
+    def break_up_by_braces(self):
+        tex_string = self.tex_string
+        span_tuples = []
+        left_brace_indices = []
+        for match_obj in re.finditer(r"(\\*)(\{|\})", tex_string):
+            # Braces following even numbers of backslashes are counted.
+            if len(match_obj.group(1)) % 2 == 1:
+                continue
+            if match_obj.group(2) == "{":
+                left_brace_index = match_obj.span(2)[0]
+                left_brace_indices.append(left_brace_index)
+            else:
+                left_brace_index = left_brace_indices.pop()
+                right_brace_index = match_obj.span(2)[1]
+                span_tuples.append((left_brace_index, right_brace_index))
+        if left_brace_indices:
+            self.raise_tex_parsing_error()
+
+        self.paired_braces_tuples = span_tuples
+        for span_tuple in span_tuples:
+            self.add_tex_span(span_tuple)
+
+    def break_up_by_scripts(self):
+        tex_string = self.tex_string
+        brace_indices_dict = dict(self.tex_spans_dict.keys())
+        for match_obj in re.finditer(r"((?<!\\)(_|\^)\s*)|(\s+(_|\^)\s*)", tex_string):
+            script_type = 1 if "_" in match_obj.group() else 2
+            token_begin, token_end = match_obj.span()
+            if token_end in brace_indices_dict:
+                content_span = (token_end, brace_indices_dict[token_end])
+            else:
+                content_match_obj = re.match(r"\w|\\[a-zA-Z]+", tex_string[token_end:])
+                if not content_match_obj:
+                    self.raise_tex_parsing_error()
+                content_span = tuple([
+                    index + token_end for index in content_match_obj.span()
+                ])
+                self.add_tex_span(content_span)
+            label = self.tex_spans_dict[content_span].label
+            self.add_tex_span(
+                (token_begin, content_span[1]),
+                script_type=script_type,
+                label=label
+            )
+
+    def break_up_by_additional_strings(self, strings_to_break_up):
+        tex_string = self.tex_string
+        all_span_tuples = []
+        for string in strings_to_break_up:
+            # Only matches non-crossing strings.
+            for match_obj in re.finditer(re.escape(string), tex_string):
+                all_span_tuples.append(match_obj.span())
+
+        script_spans_dict = dict([
+            span_tuple[::-1]
+            for span_tuple, tex_span in self.tex_spans_dict.items()
+            if tex_span.script_type != 0
+        ])
+        for span_begin, span_end in all_span_tuples:
+            if span_end in script_spans_dict.values():
+                # Deconstruct spans with subscripts & superscripts.
+                while span_end in script_spans_dict:
+                    span_end = script_spans_dict[span_end]
+                if span_begin >= span_end:
+                    continue
+            span_tuple = (span_begin, span_end)
+            if span_tuple not in self.tex_spans_dict:
+                self.add_tex_span(span_tuple)
+
+    def merge_unbreakable_commands(self, unbreakable_commands):
+        tex_string = self.tex_string
+        command_merge_spans = []
+        brace_indices_dict = dict(self.paired_braces_tuples)
+        # Braces leading by `unbreakable_commands` shouldn't be marked.
+        for command in unbreakable_commands:
+            for match_obj in re.finditer(re.escape(command), tex_string):
+                merge_begin_index = match_obj.span()[1]
+                merge_end_index = merge_begin_index
+                if merge_end_index not in brace_indices_dict:
+                    continue
+                while merge_end_index in brace_indices_dict:
+                    merge_end_index = brace_indices_dict[merge_end_index]
+                command_merge_spans.append((merge_begin_index, merge_end_index))
+
+        self.tex_spans_dict = {
+            span_tuple: tex_span
+            for span_tuple, tex_span in self.tex_spans_dict.items()
+            if all([
+                not _TexParser.contains(merge_span, span_tuple)
+                for merge_span in command_merge_spans
+            ])
+        }
+
+    def analyse_containing_labels(self):
+        for span_0, tex_span_0 in self.tex_spans_dict.items():
+            if tex_span_0.script_type != 0:
+                continue
+            for span_1, tex_span_1 in self.tex_spans_dict.items():
+                if _TexParser.contains(span_1, span_0):
+                    tex_span_1.containing_labels.append(tex_span_0.label)
+
+    def get_labelled_expression(self):
+        tex_string = self.tex_string
+        if not self.tex_spans_dict:
+            return tex_string
+
+        indices_with_labels = sorted([
+            (span_tuple[i], i, span_tuple[1 - i], tex_span.label)
+            for span_tuple, tex_span in self.tex_spans_dict.items()
+            if tex_span.script_type == 0
+            for i in range(2)
+        ], key=lambda t: (t[0], -t[1], -t[2]))
+        # Add one more item to ensure all the substrings are joined.
+        indices_with_labels.append((len(tex_string), 0, 0, 0))
+
+        result = tex_string[: indices_with_labels[0][0]]
+        index_with_label_pairs = _get_neighbouring_pairs(indices_with_labels)
+        for index_with_label, next_index_with_label in index_with_label_pairs:
+            index, flag, _, label = index_with_label
+            next_index, *_ = next_index_with_label
+            # Adding one more pair of braces will help maintain the glyghs of tex file...
+            if flag == 0:
+                color_tuple = _TexParser.label_to_color_tuple(label)
+                result += "".join([
+                    "{{",
+                    "\\color[RGB]",
+                    "{",
+                    ",".join(map(str, color_tuple)),
+                    "}"
+                ])
+            else:
+                result += "}}"
+            result += tex_string[index : next_index]
+        return result
+
+    def raise_tex_parsing_error(self):
+        raise ValueError(f"Failed to parse tex: \"{self.tex_string}\"")
+
+
+class MTex(VMobject):
+    CONFIG = {
+        "fill_opacity": 1.0,
+        "stroke_width": 0,
+        "should_center": True,
+        "font_size": 48,
+        "height": None,
+        "organize_left_to_right": False,
+        "alignment": "\\centering",
+        "tex_environment": "align*",
+        "isolate": [],
+        "unbreakable_commands": ["\\begin", "\\end"],
+        "tex_to_color_map": {},
+    }
+
+    def __init__(self, tex_string, **kwargs):
+        super().__init__(**kwargs)
+        self.tex_string = MTex.modify_tex_string(tex_string)
+
+        tex_parser = _TexParser(self)
+        self.tex_spans_dict = tex_parser.tex_spans_dict
+
+        new_tex = tex_parser.get_labelled_expression()
+        full_tex = self.get_tex_file_body(new_tex)
+        hash_val = hash(full_tex)
+        if hash_val not in tex_hash_to_mob_map:
+            with display_during_execution(f"Writing \"{tex_string}\""):
+                filename = tex_to_svg_file(full_tex)
+                svg_mob = _LabelledTex(filename)
+                tex_hash_to_mob_map[hash_val] = svg_mob
+        self.add(*[
+            submob.copy()
+            for submob in tex_hash_to_mob_map[hash_val]
+        ])
+        self.build_submobjects()
+
+        self.init_colors()
+        self.set_color_by_tex_to_color_map(self.tex_to_color_map)
+
+        if self.height is None:
+            self.scale(SCALE_FACTOR_PER_FONT_POINT * self.font_size)
+        if self.organize_left_to_right:
+            self.organize_submobjects_left_to_right()
+
+    @staticmethod
+    def modify_tex_string(tex_string):
+        result = tex_string.strip("\n")
+        # Prevent from passing an empty string.
+        if not result:
+            result = "\\quad"
+        return result
+
+    def get_tex_file_body(self, new_tex):
+        if self.tex_environment:
+            new_tex = "\n".join([
+                f"\\begin{{{self.tex_environment}}}",
+                new_tex,
+                f"\\end{{{self.tex_environment}}}"
+            ])
+        if self.alignment:
+            new_tex = "\n".join([self.alignment, new_tex])
+
+        tex_config = get_tex_config()
+        return tex_config["tex_body"].replace(
+            tex_config["text_to_replace"],
+            new_tex
+        )
+
+    def build_submobjects(self):
+        if not self.submobjects:
+            return
+        self.group_submobjects()
+        self.sort_scripts_in_tex_order()
+        self.assign_submob_tex_strings()
+
+    def group_submobjects(self):
+        # Simply pack together adjacent mobjects with the same label.
+        new_submobjects = []
+        def append_new_submobject(glyphs):
+            if glyphs:
+                submobject = VGroup(*glyphs)
+                submobject.submob_label = glyphs[0].glyph_label
+                new_submobjects.append(submobject)
+
+        new_glyphs = []
+        current_glyph_label = -1
+        for submob in self.submobjects:
+            if submob.glyph_label == current_glyph_label:
+                new_glyphs.append(submob)
+            else:
+                append_new_submobject(new_glyphs)
+                new_glyphs = [submob]
+                current_glyph_label = submob.glyph_label
+        append_new_submobject(new_glyphs)
+        self.set_submobjects(new_submobjects)
+
+    def sort_scripts_in_tex_order(self):
+        # LaTeX always puts superscripts before subscripts.
+        # This function sorts the submobjects of scripts in the order of tex given.
+        index_and_span_list = sorted([
+            (index, span_tuple)
+            for span_tuple, tex_span in self.tex_spans_dict.items()
+            if tex_span.script_type != 0
+            for index in span_tuple
+        ])
+        index_and_span_pair = _get_neighbouring_pairs(index_and_span_list)
+        for index_and_span_0, index_and_span_1 in index_and_span_pair:
+            index_0, span_tuple_0 = index_and_span_0
+            index_1, span_tuple_1 = index_and_span_1
+            if index_0 != index_1:
+                continue
+            if not all([
+                self.tex_spans_dict[span_tuple_0].script_type == 1,
+                self.tex_spans_dict[span_tuple_1].script_type == 2
+            ]):
+                continue
+            submob_slice_0 = self.slice_of_part(
+                self.get_part_by_span_tuples([span_tuple_0])
+            )
+            submob_slice_1 = self.slice_of_part(
+                self.get_part_by_span_tuples([span_tuple_1])
+            )
+            submobs = self.submobjects
+            self.set_submobjects([
+                *submobs[: submob_slice_1.start],
+                *submobs[submob_slice_0],
+                *submobs[submob_slice_1.stop : submob_slice_0.start],
+                *submobs[submob_slice_1],
+                *submobs[submob_slice_0.stop :]
+            ])
+
+    def assign_submob_tex_strings(self):
+        # Not sure whether this is the best practice...
+        # Just a temporary hack for supporting `TransformMatchingTex`.
+        tex_string = self.tex_string
+        # Use tex strings including "_", "^".
+        label_dict = {}
+        for span_tuple, tex_span in self.tex_spans_dict.items():
+            if tex_span.script_type != 0:
+                label_dict[tex_span.label] = span_tuple
+            else:
+                if tex_span.label not in label_dict:
+                    label_dict[tex_span.label] = span_tuple
+
+        curr_labels = [submob.submob_label for submob in self.submobjects]
+        prev_labels = [curr_labels[-1], *curr_labels[:-1]]
+        next_labels = [*curr_labels[1:], curr_labels[0]]
+        tex_string_spans = []
+        for curr_label, prev_label, next_label in zip(
+            curr_labels, prev_labels, next_labels
+        ):
+            curr_span_tuple = label_dict[curr_label]
+            prev_span_tuple = label_dict[prev_label]
+            next_span_tuple = label_dict[next_label]
+            containing_labels = self.tex_spans_dict[curr_span_tuple].containing_labels
+            tex_string_spans.append([
+                prev_span_tuple[1] if prev_label in containing_labels else curr_span_tuple[0],
+                next_span_tuple[0] if next_label in containing_labels else curr_span_tuple[1]
+            ])
+        tex_string_spans[0][0] = label_dict[curr_labels[0]][0]
+        tex_string_spans[-1][1] = label_dict[curr_labels[-1]][1]
+        for submob, tex_string_span in zip(self.submobjects, tex_string_spans):
+            submob.tex_string = tex_string[slice(*tex_string_span)]
+            # Support `get_tex()` method here.
+            submob.get_tex = MethodType(lambda inst: inst.tex_string, submob)
+
+    def get_part_by_span_tuples(self, span_tuples):
+        labels = remove_list_redundancies(list(it.chain(*[
+            self.tex_spans_dict[span_tuple].containing_labels
+            for span_tuple in span_tuples
+        ])))
+        return VGroup(*filter(
+            lambda submob: submob.submob_label in labels,
+            self.submobjects
+        ))
+
+    def find_span_components_of_custom_span(self, custom_span_tuple, partial_result=[]):
+        span_begin, span_end = custom_span_tuple
+        if span_begin == span_end:
+            return partial_result
+        next_begin_choices = sorted([
+            span_tuple[1]
+            for span_tuple in self.tex_spans_dict.keys()
+            if span_tuple[0] == span_begin and span_tuple[1] <= span_end
+        ], reverse=True)
+        for next_begin in next_begin_choices:
+            result = self.find_span_components_of_custom_span(
+                (next_begin, span_end), [*partial_result, (span_begin, next_begin)]
+            )
+            if result is not None:
+                return result
+        return None
+
+    def get_part_by_custom_span_tuple(self, custom_span_tuple):
+        span_tuples = self.find_span_components_of_custom_span(custom_span_tuple)
+        if span_tuples is None:
+            tex = self.tex_string[slice(*custom_span_tuple)]
+            raise ValueError(f"Failed to get span of tex: \"{tex}\"")
+        return self.get_part_by_span_tuples(span_tuples)
+
+    def get_parts_by_tex(self, tex):
+        return VGroup(*[
+            self.get_part_by_custom_span_tuple(match_obj.span())
+            for match_obj in re.finditer(re.escape(tex), self.tex_string)
+        ])
+
+    def get_part_by_tex(self, tex, index=0):
+        all_parts = self.get_parts_by_tex(tex)
+        return all_parts[index]
+
+    def set_color_by_tex(self, tex, color):
+        self.get_parts_by_tex(tex).set_color(color)
+        return self
+
+    def set_color_by_tex_to_color_map(self, tex_to_color_map):
+        for tex, color in list(tex_to_color_map.items()):
+            self.set_color_by_tex(tex, color)
+        return self
+
+    def indices_of_part(self, part):
+        indices = [
+            i for i, submob in enumerate(self.submobjects)
+            if submob in part
+        ]
+        if not indices:
+            raise ValueError("Failed to find part in tex")
+        return indices
+
+    def indices_of_part_by_tex(self, tex, index=0):
+        part = self.get_part_by_tex(tex, index=index)
+        return self.indices_of_part(part)
+
+    def slice_of_part(self, part):
+        indices = self.indices_of_part(part)
+        return slice(indices[0], indices[-1] + 1)
+
+    def slice_of_part_by_tex(self, tex, index=0):
+        part = self.get_part_by_tex(tex, index=index)
+        return self.slice_of_part(part)
+
+    def index_of_part(self, part):
+        return self.indices_of_part(part)[0]
+
+    def index_of_part_by_tex(self, tex, index=0):
+        part = self.get_part_by_tex(tex, index=index)
+        return self.index_of_part(part)
+
+    def get_tex(self):
+        return self.tex_string
+
+    def get_all_isolated_substrings(self):
+        tex_string = self.tex_string
+        return remove_list_redundancies([
+            tex_string[slice(*span_tuple)]
+            for span_tuple in self.tex_spans_dict.keys()
+        ])
+
+    def print_tex_strings_of_submobjects(self):
+        # For debugging
+        # Work with `index_labels()`
+        print("\n")
+        print(f"Submobjects of \"{self.get_tex()}\":")
+        for i, submob in enumerate(self.submobjects):
+            print(f"{i}: \"{submob.get_tex()}\"")
+        print("\n")
+
+
+class MTexText(MTex):
+    CONFIG = {
+        "tex_environment": None,
+    }

manimlib/mobject/svg/svg_mobject.py

@@ -11,6 +11,7 @@ from manimlib.constants import DEFAULT_STROKE_WIDTH
 from manimlib.constants import ORIGIN, UP, DOWN, LEFT, RIGHT
 from manimlib.constants import BLACK
 from manimlib.constants import WHITE
+from manimlib.constants import DEGREES, PI
 
 from manimlib.mobject.geometry import Circle
 from manimlib.mobject.geometry import Rectangle
@@ -21,6 +22,7 @@ from manimlib.utils.color import *
 from manimlib.utils.config_ops import digest_config
 from manimlib.utils.directories import get_mobject_data_dir
 from manimlib.utils.images import get_full_vector_image_path
+from manimlib.utils.simple_functions import clip
 
 
 def string_to_numbers(num_string):
@@ -86,10 +88,10 @@ class SVGMobject(VMobject):
         elif element.tagName == 'style':
             pass  # TODO, handle style
         elif element.tagName in ['g', 'svg', 'symbol']:
-            result += it.chain(*[
+            result += it.chain(*(
                 self.get_mobjects_from(child)
                 for child in element.childNodes
-            ])
+            ))
         elif element.tagName == 'path':
             result.append(self.path_string_to_mobject(
                 element.getAttribute('d')
@@ -182,8 +184,9 @@ class SVGMobject(VMobject):
         corner_radius = rect_element.getAttribute("rx")
 
         # input preprocessing
+        fill_opacity = 1
         if fill_color in ["", "none", "#FFF", "#FFFFFF"] or Color(fill_color) == Color(WHITE):
-            opacity = 0
+            fill_opacity = 0
             fill_color = BLACK  # shdn't be necessary but avoids error msgs
         if fill_color in ["#000", "#000000"]:
             fill_color = WHITE
@@ -211,7 +214,7 @@ class SVGMobject(VMobject):
                 stroke_width=stroke_width,
                 stroke_color=stroke_color,
                 fill_color=fill_color,
-                fill_opacity=opacity
+                fill_opacity=fill_opacity
             )
         else:
             mob = RoundedRectangle(
@@ -319,7 +322,7 @@ class SVGMobject(VMobject):
 
 class VMobjectFromSVGPathstring(VMobject):
     CONFIG = {
-        "long_lines": True,
+        "long_lines": False,
         "should_subdivide_sharp_curves": False,
         "should_remove_null_curves": False,
     }
@@ -339,11 +342,10 @@ class VMobjectFromSVGPathstring(VMobject):
 
         if os.path.exists(points_filepath) and os.path.exists(tris_filepath):
             self.set_points(np.load(points_filepath))
+            self.triangulation = np.load(tris_filepath)
+            self.needs_new_triangulation = False
         else:
-            self.relative_point = np.array(ORIGIN)
-            for command, coord_string in self.get_commands_and_coord_strings():
-                new_points = self.string_to_points(command, coord_string)
-                self.handle_command(command, new_points)
+            self.handle_commands()
             if self.should_subdivide_sharp_curves:
                 # For a healthy triangulation later
                 self.subdivide_sharp_curves()
@@ -354,6 +356,7 @@ class VMobjectFromSVGPathstring(VMobject):
             self.stretch(-1, 1, about_point=ORIGIN)
             # Save to a file for future use
             np.save(points_filepath, self.get_points())
+            np.save(tris_filepath, self.get_triangulation())
 
     def get_commands_and_coord_strings(self):
         all_commands = list(self.get_command_to_function_map().keys())
@@ -364,43 +367,141 @@ class VMobjectFromSVGPathstring(VMobject):
             re.split(pattern, self.path_string)[1:]
         )
 
-    def handle_command(self, command, new_points):
-        if command.islower():
-            # Treat it as a relative command
-            new_points += self.relative_point
+    def handle_commands(self):
+        relative_point = ORIGIN
+        for command, coord_string in self.get_commands_and_coord_strings():
+            func, number_types_str = self.command_to_function(command)
+            upper_command = command.upper()
+            if upper_command == "Z":
+                func()  # `close_path` takes no arguments
+                continue
 
-        func, n_points = self.command_to_function(command)
-        func(*new_points[:n_points])
-        leftover_points = new_points[n_points:]
+            number_types = np.array(list(number_types_str))
+            n_numbers = len(number_types_str)
+            number_groups = np.array(string_to_numbers(coord_string)).reshape((-1, n_numbers))
 
-        # Recursively handle the rest of the points
-        if len(leftover_points) > 0:
-            if command.upper() == "M":
-                # Treat following points as relative line coordinates
-                command = "l"
-            if command.islower():
-                leftover_points -= self.relative_point
-                self.relative_point = self.get_last_point()
-            self.handle_command(command, leftover_points)
-        else:
-            # Command is over, reset for future relative commands
-            self.relative_point = self.get_last_point()
+            for numbers in number_groups:
+                if command.islower():
+                    # Treat it as a relative command
+                    numbers[number_types == "x"] += relative_point[0]
+                    numbers[number_types == "y"] += relative_point[1]
 
-    def string_to_points(self, command, coord_string):
-        numbers = string_to_numbers(coord_string)
-        if command.upper() in ["H", "V"]:
-            i = {"H": 0, "V": 1}[command.upper()]
-            xy = np.zeros((len(numbers), 2))
-            xy[:, i] = numbers
-            if command.isupper():
-                xy[:, 1 - i] = self.relative_point[1 - i]
-        elif command.upper() == "A":
-            raise Exception("Not implemented")
-        else:
-            xy = np.array(numbers).reshape((len(numbers) // 2, 2))
-        result = np.zeros((xy.shape[0], self.dim))
-        result[:, :2] = xy
-        return result
+                if upper_command == "A":
+                    args = [*numbers[:5], np.array([*numbers[5:7], 0.0])]
+                elif upper_command == "H":
+                    args = [np.array([numbers[0], relative_point[1], 0.0])]
+                elif upper_command == "V":
+                    args = [np.array([relative_point[0], numbers[0], 0.0])]
+                else:
+                    args = list(np.hstack((
+                        numbers.reshape((-1, 2)), np.zeros((n_numbers // 2, 1))
+                    )))
+                func(*args)
+                relative_point = self.get_last_point()
+
+
+    def add_elliptical_arc_to(self, rx, ry, x_axis_rotation, large_arc_flag, sweep_flag, point):
+        def close_to_zero(a, threshold=1e-5):
+            return abs(a) < threshold
+
+        def solve_2d_linear_equation(a, b, c):
+            """
+            Using Crammer's rule to solve the linear equation `[a b]x = c`
+            where `a`, `b` and `c` are all 2d vectors.
+            """
+            def det(a, b):
+                return a[0] * b[1] - a[1] * b[0]
+            d = det(a, b)
+            if close_to_zero(d):
+                raise Exception("Cannot handle 0 determinant.")
+            return [det(c, b) / d, det(a, c) / d]
+
+        def get_arc_center_and_angles(x0, y0, rx, ry, phi, large_arc_flag, sweep_flag, x1, y1):
+            """
+            The parameter functions of an ellipse rotated `phi` radians counterclockwise is (on `alpha`):
+                x = cx + rx * cos(alpha) * cos(phi) + ry * sin(alpha) * sin(phi),
+                y = cy + rx * cos(alpha) * sin(phi) - ry * sin(alpha) * cos(phi).
+            Now we have two points sitting on the ellipse: `(x0, y0)`, `(x1, y1)`, corresponding to 4 equations,
+            and we want to hunt for 4 variables: `cx`, `cy`, `alpha0` and `alpha_1`.
+            Let `d_alpha = alpha1 - alpha0`, then:
+            if `sweep_flag = 0` and `large_arc_flag = 1`, then `PI <= d_alpha < 2 * PI`;
+            if `sweep_flag = 0` and `large_arc_flag = 0`, then `0 < d_alpha <= PI`;
+            if `sweep_flag = 1` and `large_arc_flag = 0`, then `-PI <= d_alpha < 0`;
+            if `sweep_flag = 1` and `large_arc_flag = 1`, then `-2 * PI < d_alpha <= -PI`.
+            """
+            xd = x1 - x0
+            yd = y1 - y0
+            if close_to_zero(xd) and close_to_zero(yd):
+                raise Exception("Cannot find arc center since the start point and the end point meet.")
+            # Find `p = cos(alpha1) - cos(alpha0)`, `q = sin(alpha1) - sin(alpha0)`
+            eq0 = [rx * np.cos(phi), ry * np.sin(phi), xd]
+            eq1 = [rx * np.sin(phi), -ry * np.cos(phi), yd]
+            p, q = solve_2d_linear_equation(*zip(eq0, eq1))
+            # Find `s = (alpha1 - alpha0) / 2`, `t = (alpha1 + alpha0) / 2`
+            # If `sin(s) = 0`, this requires `p = q = 0`,
+            # implying `xd = yd = 0`, which is impossible.
+            sin_s = (p ** 2 + q ** 2) ** 0.5 / 2
+            if sweep_flag:
+                sin_s = -sin_s
+            sin_s = clip(sin_s, -1, 1)
+            s = np.arcsin(sin_s)
+            if large_arc_flag:
+                if not sweep_flag:
+                    s = PI - s
+                else:
+                    s = -PI - s
+            sin_t = -p / (2 * sin_s)
+            cos_t = q / (2 * sin_s)
+            cos_t = clip(cos_t, -1, 1)
+            t = np.arccos(cos_t)
+            if sin_t <= 0:
+                t = -t
+            # We can make sure `0 < abs(s) < PI`, `-PI <= t < PI`.
+            alpha0 = t - s
+            alpha_1 = t + s
+            cx = x0 - rx * np.cos(alpha0) * np.cos(phi) - ry * np.sin(alpha0) * np.sin(phi)
+            cy = y0 - rx * np.cos(alpha0) * np.sin(phi) + ry * np.sin(alpha0) * np.cos(phi)
+            return cx, cy, alpha0, alpha_1
+
+        def get_point_on_ellipse(cx, cy, rx, ry, phi, angle):
+            return np.array([
+                cx + rx * np.cos(angle) * np.cos(phi) + ry * np.sin(angle) * np.sin(phi),
+                cy + rx * np.cos(angle) * np.sin(phi) - ry * np.sin(angle) * np.cos(phi),
+                0
+            ])
+
+        def convert_elliptical_arc_to_quadratic_bezier_curve(
+            cx, cy, rx, ry, phi, start_angle, end_angle, n_components=8
+        ):
+            theta = (end_angle - start_angle) / n_components / 2
+            handles = np.array([
+                get_point_on_ellipse(cx, cy, rx / np.cos(theta), ry / np.cos(theta), phi, a)
+                for a in np.linspace(
+                    start_angle + theta,
+                    end_angle - theta,
+                    n_components,
+                )
+            ])
+            anchors = np.array([
+                get_point_on_ellipse(cx, cy, rx, ry, phi, a)
+                for a in np.linspace(
+                    start_angle + theta * 2,
+                    end_angle,
+                    n_components,
+                )
+            ])
+            return handles, anchors
+
+        phi = x_axis_rotation * DEGREES
+        x0, y0 = self.get_last_point()[:2]
+        cx, cy, start_angle, end_angle = get_arc_center_and_angles(
+            x0, y0, rx, ry, phi, large_arc_flag, sweep_flag, point[0], point[1]
+        )
+        handles, anchors = convert_elliptical_arc_to_quadratic_bezier_curve(
+            cx, cy, rx, ry, phi, start_angle, end_angle
+        )
+        for handle, anchor in zip(handles, anchors):
+            self.add_quadratic_bezier_curve_to(handle, anchor)
 
     def command_to_function(self, command):
         return self.get_command_to_function_map()[command.upper()]
@@ -408,19 +509,19 @@ class VMobjectFromSVGPathstring(VMobject):
     def get_command_to_function_map(self):
         """
         Associates svg command to VMobject function, and
-        the number of arguments it takes in
+        the types of arguments it takes in
         """
         return {
-            "M": (self.start_new_path, 1),
-            "L": (self.add_line_to, 1),
-            "H": (self.add_line_to, 1),
-            "V": (self.add_line_to, 1),
-            "C": (self.add_cubic_bezier_curve_to, 3),
-            "S": (self.add_smooth_cubic_curve_to, 2),
-            "Q": (self.add_quadratic_bezier_curve_to, 2),
-            "T": (self.add_smooth_curve_to, 1),
-            "A": (self.add_quadratic_bezier_curve_to, 2),  # TODO
-            "Z": (self.close_path, 0),
+            "M": (self.start_new_path, "xy"),
+            "L": (self.add_line_to, "xy"),
+            "H": (self.add_line_to, "x"),
+            "V": (self.add_line_to, "y"),
+            "C": (self.add_cubic_bezier_curve_to, "xyxyxy"),
+            "S": (self.add_smooth_cubic_curve_to, "xyxy"),
+            "Q": (self.add_quadratic_bezier_curve_to, "xyxy"),
+            "T": (self.add_smooth_curve_to, "xy"),
+            "A": (self.add_elliptical_arc_to, "-----xy"),
+            "Z": (self.close_path, ""),
         }
 
     def get_original_path_string(self):

manimlib/mobject/svg/tex_mobject.py

@@ -1,7 +1,6 @@
 from functools import reduce
 import operator as op
 import re
-import itertools as it
 
 from manimlib.constants import *
 from manimlib.mobject.geometry import Line
@@ -130,15 +129,18 @@ class SingleStringTex(VMobject):
 
     def balance_braces(self, tex):
         """
-        Makes Tex resiliant to unmatched { at start
+        Makes Tex resiliant to unmatched braces
         """
-        num_lefts, num_rights = [tex.count(char) for char in "{}"]
-        while num_rights > num_lefts:
-            tex = "{" + tex
-            num_lefts += 1
-        while num_lefts > num_rights:
-            tex = tex + "}"
-            num_rights += 1
+        num_unclosed_brackets = 0
+        for char in tex:
+            if char == "{":
+                num_unclosed_brackets += 1
+            elif char == "}":
+                if num_unclosed_brackets == 0:
+                    tex = "{" + tex
+                else:
+                    num_unclosed_brackets -= 1
+        tex += num_unclosed_brackets * "}"
         return tex
 
     def get_tex(self):

manimlib/mobject/svg/text_mobject.py

@@ -1,4 +1,3 @@
-import copy
 import hashlib
 import os
 import re
@@ -7,6 +6,9 @@ import typing
 import warnings
 import xml.etree.ElementTree as ET
 import functools
+import pygments
+import pygments.lexers
+import pygments.styles
 
 from contextlib import contextmanager
 from pathlib import Path
@@ -22,7 +24,8 @@ from manimlib.utils.directories import get_downloads_dir, get_text_dir
 from manimpango import PangoUtils, TextSetting, MarkupUtils
 
 TEXT_MOB_SCALE_FACTOR = 0.0076
-DEFAULT_LINE_SPACING_SCALE = 0.3
+DEFAULT_LINE_SPACING_SCALE = 0.6
+
 
 class Text(SVGMobject):
     CONFIG = {
@@ -47,9 +50,9 @@ class Text(SVGMobject):
         "disable_ligatures": True,
     }
 
-    def __init__(self, text, **config):
-        self.full2short(config)
-        digest_config(self, config)
+    def __init__(self, text, **kwargs):
+        self.full2short(kwargs)
+        digest_config(self, kwargs)
         if self.size:
             warnings.warn(
                 "self.size has been deprecated and will "
@@ -68,7 +71,7 @@ class Text(SVGMobject):
         file_name = self.text2svg()
         PangoUtils.remove_last_M(file_name)
         self.remove_empty_path(file_name)
-        SVGMobject.__init__(self, file_name, **config)
+        SVGMobject.__init__(self, file_name, **kwargs)
         self.text = text
         if self.disable_ligatures:
             self.apply_space_chars()
@@ -145,13 +148,13 @@ class Text(SVGMobject):
 
     def set_color_by_t2c(self, t2c=None):
         t2c = t2c if t2c else self.t2c
-        for word, color in list(t2c.items()):
+        for word, color in t2c.items():
             for start, end in self.find_indexes(word):
                 self[start:end].set_color(color)
 
     def set_color_by_t2g(self, t2g=None):
         t2g = t2g if t2g else self.t2g
-        for word, gradient in list(t2g.items()):
+        for word, gradient in t2g.items():
             for start, end in self.find_indexes(word):
                 self[start:end].set_color_by_gradient(*gradient)
 
@@ -165,49 +168,62 @@ class Text(SVGMobject):
         return hasher.hexdigest()[:16]
 
     def text2settings(self):
+        """
+        Substrings specified in t2f, t2s, t2w can occupy each other.
+        For each category of style, a stack following first-in-last-out is constructed,
+        and the last value in each stack takes effect.
+        """
         settings = []
-        t2x = [self.t2f, self.t2s, self.t2w]
-        for i in range(len(t2x)):
-            fsw = [self.font, self.slant, self.weight]
-            if t2x[i]:
-                for word, x in list(t2x[i].items()):
-                    for start, end in self.find_indexes(word):
-                        fsw[i] = x
-                        settings.append(TextSetting(start, end, *fsw))
+        self.line_num = 0
+        def add_text_settings(start, end, style_stacks):
+            if start == end:
+                return
+            breakdown_indices = [start, *[
+                i + start + 1 for i, char in enumerate(self.text[start:end]) if char == "\n"
+            ], end]
+            style = [stack[-1] for stack in style_stacks]
+            for atom_start, atom_end in zip(breakdown_indices[:-1], breakdown_indices[1:]):
+                if atom_start < atom_end:
+                    settings.append(TextSetting(atom_start, atom_end, *style, self.line_num))
+                self.line_num += 1
+            self.line_num -= 1
 
-        # Set All text settings(default font slant weight)
-        fsw = [self.font, self.slant, self.weight]
-        settings.sort(key=lambda setting: setting.start)
-        temp_settings = settings.copy()
-        start = 0
-        for setting in settings:
-            if setting.start != start:
-                temp_settings.append(TextSetting(start, setting.start, *fsw))
-            start = setting.end
-        if start != len(self.text):
-            temp_settings.append(TextSetting(start, len(self.text), *fsw))
-        settings = sorted(temp_settings, key=lambda setting: setting.start)
+        # Set all the default and specified values.
+        len_text = len(self.text)
+        t2x_items = sorted([
+            *[
+                (0, len_text, t2x_index, value)
+                for t2x_index, value in enumerate([self.font, self.slant, self.weight])
+            ],
+            *[
+                (start, end, t2x_index, value)
+                for t2x_index, t2x in enumerate([self.t2f, self.t2s, self.t2w])
+                for word, value in t2x.items()
+                for start, end in self.find_indexes(word)
+            ]
+        ], key=lambda item: item[0])
 
-        if re.search(r'\n', self.text):
-            line_num = 0
-            for start, end in self.find_indexes('\n'):
-                for setting in settings:
-                    if setting.line_num == -1:
-                        setting.line_num = line_num
-                    if start < setting.end:
-                        line_num += 1
-                        new_setting = copy.copy(setting)
-                        setting.end = end
-                        new_setting.start = end
-                        new_setting.line_num = line_num
-                        settings.append(new_setting)
-                        settings.sort(key=lambda setting: setting.start)
-                        break
-
-        for setting in settings:
-            if setting.line_num == -1:
-                setting.line_num = 0
+        # Break down ranges and construct settings separately.
+        active_items = []
+        style_stacks = [[] for _ in range(3)]
+        for item, next_start in zip(t2x_items, [*[item[0] for item in t2x_items[1:]], len_text]):
+            active_items.append(item)
+            start, end, t2x_index, value = item
+            style_stacks[t2x_index].append(value)
+            halting_items = sorted(filter(
+                lambda item: item[1] <= next_start,
+                active_items
+            ), key=lambda item: item[1])
+            atom_start = start
+            for halting_item in halting_items:
+                active_items.remove(halting_item)
+                _, atom_end, t2x_index, _ = halting_item
+                add_text_settings(atom_start, atom_end, style_stacks)
+                style_stacks[t2x_index].pop()
+                atom_start = atom_end
+            add_text_settings(atom_start, next_start, style_stacks)
 
+        del self.line_num
         return settings
 
     def text2svg(self):
@@ -257,6 +273,7 @@ class MarkupText(SVGMobject):
         "gradient": None,
         "disable_ligatures": True,
     }
+
     def __init__(self, text, **config):
         digest_config(self, config)
         self.text = f'<span>{text}</span>'
@@ -303,6 +320,7 @@ class MarkupText(SVGMobject):
         # anti-aliasing
         if self.height is None:
             self.scale(TEXT_MOB_SCALE_FACTOR)
+
     def text2hash(self):
         """Generates ``sha256`` hash for file name."""
         settings = (
@@ -349,7 +367,6 @@ class MarkupText(SVGMobject):
             **extra_kwargs
         )
 
-
     def _parse_color(self, col):
         """Parse color given in ``<color>`` or ``<gradient>`` tags."""
         if re.match("#[0-9a-f]{6}", col):
@@ -472,6 +489,63 @@ class MarkupText(SVGMobject):
     def __repr__(self):
         return f"MarkupText({repr(self.original_text)})"
 
+
+class Code(Text):
+    CONFIG = {
+        "font": "Consolas",
+        "font_size": 24,
+        "lsh": 1.0,
+        "language": "python",
+        # Visit https://pygments.org/demo/ to have a preview of more styles.
+        "code_style": "monokai",
+        # If not None, then each character will cover a space of equal width.
+        "char_width": None
+    }
+
+    def __init__(self, code, **kwargs):
+        self.full2short(kwargs)
+        digest_config(self, kwargs)
+        code = code.lstrip("\n")  # avoid mismatches of character indices
+        lexer = pygments.lexers.get_lexer_by_name(self.language)
+        tokens_generator = pygments.lex(code, lexer)
+        styles_dict = dict(pygments.styles.get_style_by_name(self.code_style))
+        default_color_hex = styles_dict[pygments.token.Text]["color"]
+        if not default_color_hex:
+            default_color_hex = self.color[1:]
+        start_index = 0
+        t2c = {}
+        t2s = {}
+        t2w = {}
+        for pair in tokens_generator:
+            ttype, token = pair
+            end_index = start_index + len(token)
+            range_str = f"[{start_index}:{end_index}]"
+            style_dict = styles_dict[ttype]
+            t2c[range_str] = "#" + (style_dict["color"] or default_color_hex)
+            t2s[range_str] = ITALIC if style_dict["italic"] else NORMAL
+            t2w[range_str] = BOLD if style_dict["bold"] else NORMAL
+            start_index = end_index
+        t2c.update(self.t2c)
+        t2s.update(self.t2s)
+        t2w.update(self.t2w)
+        kwargs["t2c"] = t2c
+        kwargs["t2s"] = t2s
+        kwargs["t2w"] = t2w
+        Text.__init__(self, code, **kwargs)
+        if self.char_width is not None:
+            self.set_monospace(self.char_width)
+
+    def set_monospace(self, char_width):
+        current_char_index = 0
+        for i, char in enumerate(self.text):
+            if char == "\n":
+                current_char_index = 0
+                continue
+            self[i].set_x(current_char_index * char_width)
+            current_char_index += 1
+        self.center()
+
+
 @contextmanager
 def register_font(font_file: typing.Union[str, Path]):
     """Temporarily add a font file to Pango's search path.

manimlib/mobject/three_dimensions.py

@@ -5,16 +5,21 @@ from manimlib.mobject.types.surface import Surface
 from manimlib.mobject.types.surface import SGroup
 from manimlib.mobject.types.vectorized_mobject import VGroup
 from manimlib.mobject.types.vectorized_mobject import VMobject
+from manimlib.mobject.geometry import Square
+from manimlib.mobject.geometry import Polygon
+from manimlib.mobject.geometry import Line
+from manimlib.utils.bezier import interpolate
 from manimlib.utils.config_ops import digest_config
 from manimlib.utils.space_ops import get_norm
 from manimlib.utils.space_ops import z_to_vector
+from manimlib.utils.space_ops import compass_directions
 
 
 class SurfaceMesh(VGroup):
     CONFIG = {
-        "resolution": (21, 21),
+        "resolution": (21, 11),
         "stroke_width": 1,
-        "normal_nudge": 1e-3,
+        "normal_nudge": 1e-2,
         "depth_test": True,
         "flat_stroke": False,
     }
@@ -30,8 +35,11 @@ class SurfaceMesh(VGroup):
 
         full_nu, full_nv = uv_surface.resolution
         part_nu, part_nv = self.resolution
-        u_indices = np.linspace(0, full_nu, part_nu).astype(int)
-        v_indices = np.linspace(0, full_nv, part_nv).astype(int)
+        # 'indices' are treated as floats. Later, there will be
+        # an interpolation between the floor and ceiling of these
+        # indices
+        u_indices = np.linspace(0, full_nu - 1, part_nu)
+        v_indices = np.linspace(0, full_nv - 1, part_nv)
 
         points, du_points, dv_points = uv_surface.get_surface_points_and_nudged_points()
         normals = uv_surface.get_unit_normals()
@@ -40,12 +48,21 @@ class SurfaceMesh(VGroup):
 
         for ui in u_indices:
             path = VMobject()
-            full_ui = full_nv * ui
-            path.set_points_smoothly(nudged_points[full_ui:full_ui + full_nv])
+            low_ui = full_nv * int(math.floor(ui))
+            high_ui = full_nv * int(math.ceil(ui))
+            path.set_points_smoothly(interpolate(
+                nudged_points[low_ui:low_ui + full_nv],
+                nudged_points[high_ui:high_ui + full_nv],
+                ui % 1
+            ))
             self.add(path)
         for vi in v_indices:
             path = VMobject()
-            path.set_points_smoothly(nudged_points[vi::full_nv])
+            path.set_points_smoothly(interpolate(
+                nudged_points[int(math.floor(vi))::full_nv],
+                nudged_points[int(math.ceil(vi))::full_nv],
+                vi % 1
+            ))
             self.add(path)
 
 
@@ -161,15 +178,96 @@ class Cube(SGroup):
         "gloss": 0.5,
         "square_resolution": (2, 2),
         "side_length": 2,
+        "square_class": Square3D,
     }
 
     def init_points(self):
-        for vect in [OUT, RIGHT, UP, LEFT, DOWN, IN]:
-            face = Square3D(resolution=self.square_resolution)
-            face.shift(OUT)
-            face.apply_matrix(z_to_vector(vect))
-            self.add(face)
-        self.set_height(self.side_length)
+        face = Square3D(
+            resolution=self.square_resolution,
+            side_length=self.side_length,
+        )
+        self.add(*self.square_to_cube_faces(face))
+
+    @staticmethod
+    def square_to_cube_faces(square):
+        radius = square.get_height() / 2
+        square.move_to(radius * OUT)
+        result = [square]
+        result.extend([
+            square.copy().rotate(PI / 2, axis=vect, about_point=ORIGIN)
+            for vect in compass_directions(4)
+        ])
+        result.append(square.copy().rotate(PI, RIGHT, about_point=ORIGIN))
+        return result
+
+    def _get_face(self):
+        return Square3D(resolution=self.square_resolution)
+
+
+class VCube(VGroup):
+    CONFIG = {
+        "fill_color": BLUE_D,
+        "fill_opacity": 1,
+        "stroke_width": 0,
+        "gloss": 0.5,
+        "shadow": 0.5,
+    }
+
+    def __init__(self, side_length=2, **kwargs):
+        super().__init__(**kwargs)
+        face = Square(side_length=side_length)
+        face.get_triangulation()
+        self.add(*Cube.square_to_cube_faces(face))
+        self.init_colors()
+        self.apply_depth_test()
+        self.refresh_unit_normal()
+
+
+class Dodecahedron(VGroup):
+    CONFIG = {
+        "fill_color": BLUE_E,
+        "fill_opacity": 1,
+        "stroke_width": 1,
+        "reflectiveness": 0.2,
+        "gloss": 0.3,
+        "shadow": 0.2,
+        "depth_test": True,
+    }
+
+    def init_points(self):
+        # Star by creating two of the pentagons, meeting
+        # back to back on the positive x-axis
+        phi = (1 + math.sqrt(5)) / 2
+        x, y, z = np.identity(3)
+        pentagon1 = Polygon(
+            [phi, 1 / phi, 0],
+            [1, 1, 1],
+            [1 / phi, 0, phi],
+            [1, -1, 1],
+            [phi, -1 / phi, 0],
+        )
+        pentagon2 = pentagon1.copy().stretch(-1, 2, about_point=ORIGIN)
+        pentagon2.reverse_points()
+        x_pair = VGroup(pentagon1, pentagon2)
+        z_pair = x_pair.copy().apply_matrix(np.array([z, -x, -y]).T)
+        y_pair = x_pair.copy().apply_matrix(np.array([y, z, x]).T)
+
+        self.add(*x_pair, *y_pair, *z_pair)
+        for pentagon in list(self):
+            pc = pentagon.copy()
+            pc.apply_function(lambda p: -p)
+            pc.reverse_points()
+            self.add(pc)
+
+        # # Rotate those two pentagons by all the axis permuations to fill
+        # # out the dodecahedron
+        # Id = np.identity(3)
+        # for i in range(3):
+        #     perm = [j % 3 for j in range(i, i + 3)]
+        #     for b in [1, -1]:
+        #         matrix = b * np.array([Id[0][perm], Id[1][perm], Id[2][perm]])
+        #         self.add(pentagon1.copy().apply_matrix(matrix, about_point=ORIGIN))
+        #         self.add(pentagon2.copy().apply_matrix(matrix, about_point=ORIGIN))
 
 
 class Prism(Cube):

manimlib/mobject/types/dot_cloud.py

@@ -2,12 +2,14 @@ import numpy as np
 import moderngl
 
 from manimlib.constants import GREY_C
+from manimlib.constants import YELLOW
 from manimlib.constants import ORIGIN
 from manimlib.mobject.types.point_cloud_mobject import PMobject
 from manimlib.utils.iterables import resize_preserving_order
 
 
 DEFAULT_DOT_RADIUS = 0.05
+DEFAULT_GLOW_DOT_RADIUS = 0.2
 DEFAULT_GRID_HEIGHT = 6
 DEFAULT_BUFF_RATIO = 0.5
 
@@ -17,6 +19,7 @@ class DotCloud(PMobject):
         "color": GREY_C,
         "opacity": 1,
         "radius": DEFAULT_DOT_RADIUS,
+        "glow_factor": 0,
         "shader_folder": "true_dot",
         "render_primitive": moderngl.POINTS,
         "shader_dtype": [
@@ -36,6 +39,10 @@ class DotCloud(PMobject):
         self.data["radii"] = np.zeros((1, 1))
         self.set_radius(self.radius)
 
+    def init_uniforms(self):
+        super().init_uniforms()
+        self.uniforms["glow_factor"] = self.glow_factor
+
     def to_grid(self, n_rows, n_cols, n_layers=1,
                 buff_ratio=None,
                 h_buff_ratio=1.0,
@@ -68,7 +75,9 @@ class DotCloud(PMobject):
         return self
 
     def set_radii(self, radii):
-        self.data["radii"][:] = resize_preserving_order(radii, len(self.data["radii"]))
+        n_points = len(self.get_points())
+        radii = np.array(radii).reshape((len(radii), 1))
+        self.data["radii"] = resize_preserving_order(radii, n_points)
         self.refresh_bounding_box()
         return self
 
@@ -83,6 +92,12 @@ class DotCloud(PMobject):
     def get_radius(self):
         return self.get_radii().max()
 
+    def set_glow_factor(self, glow_factor):
+        self.uniforms["glow_factor"] = glow_factor
+
+    def get_glow_factor(self):
+        return self.uniforms["glow_factor"]
+
     def compute_bounding_box(self):
         bb = super().compute_bounding_box()
         radius = self.get_radius()
@@ -96,8 +111,8 @@ class DotCloud(PMobject):
             self.set_radii(scale_factor * self.get_radii())
         return self
 
-    def make_3d(self, gloss=0.5, shadow=0.2):
-        self.set_gloss(gloss)
+    def make_3d(self, reflectiveness=0.5, shadow=0.2):
+        self.set_reflectiveness(reflectiveness)
         self.set_shadow(shadow)
         self.apply_depth_test()
         return self
@@ -110,5 +125,13 @@ class DotCloud(PMobject):
 
 
 class TrueDot(DotCloud):
-    def __init__(self, center=ORIGIN, radius=DEFAULT_DOT_RADIUS, **kwargs):
-        super().__init__(points=[center], radius=radius, **kwargs)
+    def __init__(self, center=ORIGIN, **kwargs):
+        super().__init__(points=[center], **kwargs)
+
+
+class GlowDot(TrueDot):
+    CONFIG = {
+        "glow_factor": 2,
+        "radius": DEFAULT_GLOW_DOT_RADIUS,
+        "color": YELLOW,
+    }

manimlib/mobject/types/image_mobject.py

@@ -22,10 +22,13 @@ class ImageMobject(Mobject):
     }
 
     def __init__(self, filename, **kwargs):
-        path = get_full_raster_image_path(filename)
+        self.set_image_path(get_full_raster_image_path(filename))
+        super().__init__(**kwargs)
+
+    def set_image_path(self, path):
+        self.path = path
         self.image = Image.open(path)
         self.texture_paths = {"Texture": path}
-        super().__init__(**kwargs)
 
     def init_data(self):
         self.data = {

manimlib/mobject/types/point_cloud_mobject.py

@@ -14,10 +14,17 @@ class PMobject(Mobject):
     def resize_points(self, size, resize_func=resize_array):
         # TODO
         for key in self.data:
+            if key == "bounding_box":
+                continue
             if len(self.data[key]) != size:
                 self.data[key] = resize_array(self.data[key], size)
         return self
 
+    def set_points(self, points):
+        super().set_points(points)
+        self.resize_points(len(points))
+        return self
+
     def add_points(self, points, rgbas=None, color=None, opacity=None):
         """
         points must be a Nx3 numpy array, as must rgbas if it is not None
@@ -54,6 +61,8 @@ class PMobject(Mobject):
         for mob in self.family_members_with_points():
             to_keep = ~np.apply_along_axis(condition, 1, mob.get_points())
             for key in mob.data:
+                if key == "bounding_box":
+                    continue
                 mob.data[key] = mob.data[key][to_keep]
         return self
 
@@ -85,7 +94,9 @@ class PMobject(Mobject):
         lower_index = int(a * pmobject.get_num_points())
         upper_index = int(b * pmobject.get_num_points())
         for key in self.data:
-            self.data[key] = pmobject.data[key][lower_index:upper_index]
+            if key == "bounding_box":
+                continue
+            self.data[key] = pmobject.data[key][lower_index:upper_index].copy()
         return self
 
 

manimlib/mobject/types/surface.py

@@ -20,7 +20,8 @@ class Surface(Mobject):
         "resolution": (101, 101),
         "color": GREY,
         "opacity": 1.0,
-        "gloss": 0.3,
+        "reflectiveness": 0.3,
+        "gloss": 0.1,
         "shadow": 0.4,
         "prefered_creation_axis": 1,
         # For du and dv steps.  Much smaller and numerical error
@@ -161,6 +162,11 @@ class Surface(Mobject):
             tri_is[k::3] = tri_is[k::3][indices]
         return self
 
+    def always_sort_to_camera(self, camera):
+        self.add_updater(lambda m: m.sort_faces_back_to_front(
+            camera.get_location() - self.get_center()
+        ))
+
     # For shaders
     def get_shader_data(self):
         s_points, du_points, dv_points = self.get_surface_points_and_nudged_points()

manimlib/mobject/types/vectorized_mobject.py

@@ -12,6 +12,7 @@ from manimlib.utils.bezier import get_smooth_quadratic_bezier_handle_points
 from manimlib.utils.bezier import get_smooth_cubic_bezier_handle_points
 from manimlib.utils.bezier import get_quadratic_approximation_of_cubic
 from manimlib.utils.bezier import interpolate
+from manimlib.utils.bezier import inverse_interpolate
 from manimlib.utils.bezier import integer_interpolate
 from manimlib.utils.bezier import partial_quadratic_bezier_points
 from manimlib.utils.color import rgb_to_hex
@@ -54,7 +55,6 @@ class VMobject(Mobject):
         "joint_type": "auto",
         "flat_stroke": False,
         "render_primitive": moderngl.TRIANGLES,
-        "triangulation_locked": False,
         "fill_dtype": [
             ('point', np.float32, (3,)),
             ('unit_normal', np.float32, (3,)),
@@ -75,7 +75,6 @@ class VMobject(Mobject):
         self.needs_new_triangulation = True
         self.triangulation = np.zeros(0, dtype='i4')
         super().__init__(**kwargs)
-        self.refresh_unit_normal()
 
     def get_group_class(self):
         return VGroup
@@ -128,7 +127,7 @@ class VMobject(Mobject):
                 if isinstance(width, np.ndarray):
                     arr = width.reshape((len(width), 1))
                 else:
-                    arr = np.array([[w] for w in listify(width)])
+                    arr = np.array([[w] for w in listify(width)], dtype=float)
                 mob.data['stroke_width'] = arr
 
         if background is not None:
@@ -136,6 +135,10 @@ class VMobject(Mobject):
                 mob.draw_stroke_behind_fill = background
         return self
 
+    def set_backstroke(self, color=BLACK, width=3, background=True):
+        self.set_stroke(color, width, background=background)
+        return self
+
     def align_stroke_width_data_to_points(self, recurse=True):
         for mob in self.get_family(recurse):
             mob.data["stroke_width"] = resize_with_interpolation(
@@ -150,6 +153,8 @@ class VMobject(Mobject):
                   stroke_opacity=None,
                   stroke_rgba=None,
                   stroke_width=None,
+                  stroke_background=True,
+                  reflectiveness=None,
                   gloss=None,
                   shadow=None,
                   recurse=True):
@@ -164,15 +169,21 @@ class VMobject(Mobject):
 
         if stroke_rgba is not None:
             self.data['stroke_rgba'] = resize_with_interpolation(stroke_rgba, len(fill_rgba))
-            self.set_stroke(width=stroke_width)
+            self.set_stroke(
+                width=stroke_width,
+                background=stroke_background,
+            )
         else:
             self.set_stroke(
                 color=stroke_color,
                 width=stroke_width,
                 opacity=stroke_opacity,
                 recurse=recurse,
+                background=stroke_background,
             )
 
+        if reflectiveness is not None:
+            self.set_reflectiveness(reflectiveness, recurse=recurse)
         if gloss is not None:
             self.set_gloss(gloss, recurse=recurse)
         if shadow is not None:
@@ -181,9 +192,11 @@ class VMobject(Mobject):
 
     def get_style(self):
         return {
-            "fill_rgba": self.data['fill_rgba'],
-            "stroke_rgba": self.data['stroke_rgba'],
-            "stroke_width": self.data['stroke_width'],
+            "fill_rgba": self.data['fill_rgba'].copy(),
+            "stroke_rgba": self.data['stroke_rgba'].copy(),
+            "stroke_width": self.data['stroke_width'].copy(),
+            "stroke_background": self.draw_stroke_behind_fill,
+            "reflectiveness": self.get_reflectiveness(),
             "gloss": self.get_gloss(),
             "shadow": self.get_shadow(),
         }
@@ -213,16 +226,17 @@ class VMobject(Mobject):
         return self
 
     def fade(self, darkness=0.5, recurse=True):
-        factor = 1.0 - darkness
-        self.set_fill(
-            opacity=factor * self.get_fill_opacity(),
-            recurse=False,
-        )
-        self.set_stroke(
-            opacity=factor * self.get_stroke_opacity(),
-            recurse=False,
-        )
-        super().fade(darkness, recurse)
+        mobs = self.get_family() if recurse else [self]
+        for mob in mobs:
+            factor = 1.0 - darkness
+            mob.set_fill(
+                opacity=factor * mob.get_fill_opacity(),
+                recurse=False,
+            )
+            mob.set_stroke(
+                opacity=factor * mob.get_stroke_opacity(),
+                recurse=False,
+            )
         return self
 
     def get_fill_colors(self):
@@ -272,9 +286,9 @@ class VMobject(Mobject):
         return self.get_stroke_opacities()[0]
 
     def get_color(self):
-        if self.has_stroke():
-            return self.get_stroke_color()
-        return self.get_fill_color()
+        if self.has_fill():
+            return self.get_fill_color()
+        return self.get_stroke_color()
 
     def has_stroke(self):
         return self.get_stroke_widths().any() and self.get_stroke_opacities().any()
@@ -424,7 +438,10 @@ class VMobject(Mobject):
 
     def set_points_smoothly(self, points, true_smooth=False):
         self.set_points_as_corners(points)
-        self.make_smooth()
+        if true_smooth:
+            self.make_smooth()
+        else:
+            self.make_approximately_smooth()
         return self
 
     def change_anchor_mode(self, mode):
@@ -496,10 +513,10 @@ class VMobject(Mobject):
         nppc = self.n_points_per_curve
         remainder = len(points) % nppc
         points = points[:len(points) - remainder]
-        return [
+        return (
             points[i:i + nppc]
             for i in range(0, len(points), nppc)
-        ]
+        )
 
     def get_bezier_tuples(self):
         return self.get_bezier_tuples_from_points(self.get_points())
@@ -535,12 +552,35 @@ class VMobject(Mobject):
     def get_num_curves(self):
         return self.get_num_points() // self.n_points_per_curve
 
-    def point_from_proportion(self, alpha):
+    def quick_point_from_proportion(self, alpha):
+        # Assumes all curves have the same length, so is inaccurate
         num_curves = self.get_num_curves()
         n, residue = integer_interpolate(0, num_curves, alpha)
         curve_func = self.get_nth_curve_function(n)
         return curve_func(residue)
 
+    def point_from_proportion(self, alpha):
+        if alpha <= 0:
+            return self.get_start()
+        elif alpha >= 1:
+            return self.get_end()
+
+        partials = [0]
+        for tup in self.get_bezier_tuples():
+            # Approximate length with straight line from start to end
+            arclen = get_norm(tup[0] - tup[-1])
+            partials.append(partials[-1] + arclen)
+        full = partials[-1]
+        if full == 0:
+            return self.get_start()
+        # First index where the partial lenth is more alpha times the full length
+        i = next(
+            (i for i, x in enumerate(partials) if x >= full * alpha),
+            len(partials)  # Default
+        )
+        residue = inverse_interpolate(partials[i - 1] / full, partials[i] / full, alpha)
+        return self.get_nth_curve_function(i - 1)(residue)
+
     def get_anchors_and_handles(self):
         """
         returns anchors1, handles, anchors2,
@@ -621,17 +661,19 @@ class VMobject(Mobject):
         area_vect = self.get_area_vector()
         area = get_norm(area_vect)
         if area > 0:
-            return area_vect / area
+            normal = area_vect / area
         else:
             points = self.get_points()
-            return get_unit_normal(
+            normal = get_unit_normal(
                 points[1] - points[0],
                 points[2] - points[1],
             )
+        self.data["unit_normal"][:] = normal
+        return normal
 
     def refresh_unit_normal(self):
         for mob in self.get_family():
-            mob.data["unit_normal"][:] = mob.get_unit_normal(recompute=True)
+            mob.get_unit_normal(recompute=True)
         return self
 
     # Alignment
@@ -693,7 +735,7 @@ class VMobject(Mobject):
         if len(points) == 1:
             return np.repeat(points, nppc * n, 0)
 
-        bezier_groups = self.get_bezier_tuples_from_points(points)
+        bezier_groups = list(self.get_bezier_tuples_from_points(points))
         norms = np.array([
             get_norm(bg[nppc - 1] - bg[0])
             for bg in bezier_groups
@@ -789,7 +831,7 @@ class VMobject(Mobject):
         # how to send the points as to the vertex shader.
         # First triangles come directly from the points
         if normal_vector is None:
-            normal_vector = self.get_unit_normal()
+            normal_vector = self.get_unit_normal(recompute=True)
 
         if not self.needs_new_triangulation:
             return self.triangulation
@@ -845,7 +887,7 @@ class VMobject(Mobject):
     def triggers_refreshed_triangulation(func):
         @wraps(func)
         def wrapper(self, *args, **kwargs):
-            old_points = self.get_points()
+            old_points = self.get_points().copy()
             func(self, *args, **kwargs)
             if not np.all(self.get_points() == old_points):
                 self.refresh_unit_normal()
@@ -991,6 +1033,10 @@ class VGroup(VMobject):
         super().__init__(**kwargs)
         self.add(*vmobjects)
 
+    def __add__(self: 'VGroup', other: 'VMobject' or 'VGroup'):
+        assert(isinstance(other, VMobject))
+        return self.add(other)
+
 
 class VectorizedPoint(Point, VMobject):
     CONFIG = {
@@ -1002,7 +1048,8 @@ class VectorizedPoint(Point, VMobject):
     }
 
     def __init__(self, location=ORIGIN, **kwargs):
-        super().__init__(**kwargs)
+        Point.__init__(self, **kwargs)
+        VMobject.__init__(self, **kwargs)
         self.set_points(np.array([location]))
 
 

manimlib/mobject/value_tracker.py

@@ -1,6 +1,7 @@
 import numpy as np
 
 from manimlib.mobject.mobject import Mobject
+from manimlib.utils.iterables import listify
 
 
 class ValueTracker(Mobject):
@@ -15,18 +16,25 @@ class ValueTracker(Mobject):
     }
 
     def __init__(self, value=0, **kwargs):
+        self.value = value
         super().__init__(**kwargs)
-        self.set_value(value)
 
     def init_data(self):
         super().init_data()
-        self.data["value"] = np.zeros((1, 1), dtype=self.value_type)
+        self.data["value"] = np.array(
+            listify(self.value),
+            ndmin=2,
+            dtype=self.value_type,
+        )
 
     def get_value(self):
-        return self.data["value"][0, 0]
+        result = self.data["value"][0, :]
+        if len(result) == 1:
+            return result[0]
+        return result
 
     def set_value(self, value):
-        self.data["value"][0, 0] = value
+        self.data["value"][0, :] = value
         return self
 
     def increment_value(self, d_value):

manimlib/once_useful_constructs/graph_theory.py

@@ -333,7 +333,7 @@ class DiscreteGraphScene(Scene):
         x_coord_of = {root: 0}
         y_coord_of = {root: bottom}
         # width to allocate to a given node, computed as
-        # the maxium number of decendents in a single generation,
+        # the maximum number of decendents in a single generation,
         # minus 1, multiplied by x_sep
         width_of = {}
         for index in indices:

manimlib/once_useful_constructs/region.py

@@ -5,7 +5,7 @@ from manimlib.constants import *
 from manimlib.mobject.mobject import Mobject
 from manimlib.utils.iterables import adjacent_pairs
 
-# Warning: This is all now pretty depricated, and should not be expected to work
+# Warning: This is all now pretty deprecated, and should not be expected to work
 
 
 class Region(Mobject):

manimlib/scene/scene.py

@@ -2,7 +2,6 @@ import inspect
 import random
 import platform
 import itertools as it
-import logging
 from functools import wraps
 
 from tqdm import tqdm as ProgressDisplay
@@ -11,16 +10,17 @@ import time
 
 from manimlib.animation.animation import prepare_animation
 from manimlib.animation.transform import MoveToTarget
-from manimlib.mobject.mobject import Point
 from manimlib.camera.camera import Camera
 from manimlib.constants import DEFAULT_WAIT_TIME
 from manimlib.mobject.mobject import Mobject
+from manimlib.mobject.mobject import Point
 from manimlib.scene.scene_file_writer import SceneFileWriter
 from manimlib.utils.config_ops import digest_config
 from manimlib.utils.family_ops import extract_mobject_family_members
 from manimlib.utils.family_ops import restructure_list_to_exclude_certain_family_members
 from manimlib.event_handler.event_type import EventType
 from manimlib.event_handler import EVENT_DISPATCHER
+from manimlib.logger import log
 
 
 class Scene(object):
@@ -45,6 +45,7 @@ class Scene(object):
             from manimlib.window import Window
             self.window = Window(scene=self, **self.window_config)
             self.camera_config["ctx"] = self.window.ctx
+            self.camera_config["frame_rate"] = 30  # Where's that 30 from?
         else:
             self.window = None
 
@@ -55,6 +56,8 @@ class Scene(object):
         self.time = 0
         self.skip_time = 0
         self.original_skipping_status = self.skip_animations
+        if self.start_at_animation_number is not None:
+            self.skip_animations = True
 
         # Items associated with interaction
         self.mouse_point = Point()
@@ -100,10 +103,12 @@ class Scene(object):
         # If there is a window, enter a loop
         # which updates the frame while under
         # the hood calling the pyglet event loop
+        log.info("Tips: You are now in the interactive mode. Now you can use the keyboard"
+            " and the mouse to interact with the scene. Just press `q` if you want to quit.")
         self.quit_interaction = False
         self.lock_static_mobject_data()
         while not (self.window.is_closing or self.quit_interaction):
-            self.update_frame()
+            self.update_frame(1 / self.camera.frame_rate)
         if self.window.is_closing:
             self.window.destroy()
         if self.quit_interaction:
@@ -118,16 +123,21 @@ class Scene(object):
         self.linger_after_completion = False
         self.update_frame()
 
+        # Save scene state at the point of embedding
+        self.save_state()
+
         from IPython.terminal.embed import InteractiveShellEmbed
         shell = InteractiveShellEmbed()
         # Have the frame update after each command
         shell.events.register('post_run_cell', lambda *a, **kw: self.update_frame())
         # Use the locals of the caller as the local namespace
-        # once embeded, and add a few custom shortcuts
+        # once embedded, and add a few custom shortcuts
         local_ns = inspect.currentframe().f_back.f_locals
         local_ns["touch"] = self.interact
         for term in ("play", "wait", "add", "remove", "clear", "save_state", "restore"):
             local_ns[term] = getattr(self, term)
+        log.info("Tips: Now the embed iPython terminal is open. But you can't interact with"
+                 " the window directly. To do so, you need to type `touch()` or `self.interact()`")
         shell(local_ns=local_ns, stack_depth=2)
         # End scene when exiting an embed.
         raise EndSceneEarlyException()
@@ -176,6 +186,13 @@ class Scene(object):
             for mob in self.mobjects
         ])
 
+    def has_time_based_updaters(self):
+        return any([
+            sm.has_time_based_updater()
+            for mob in self.mobjects()
+            for sm in mob.get_family()
+        ])
+
     # Related to time
     def get_time(self):
         return self.time
@@ -247,63 +264,70 @@ class Scene(object):
     def get_mobject_copies(self):
         return [m.copy() for m in self.mobjects]
 
+    def point_to_mobject(self, point, search_set=None, buff=0):
+        """
+        E.g. if clicking on the scene, this returns the top layer mobject
+        under a given point
+        """
+        if search_set is None:
+            search_set = self.mobjects
+        for mobject in reversed(search_set):
+            if mobject.is_point_touching(point, buff=buff):
+                return mobject
+        return None
+
     # Related to skipping
     def update_skipping_status(self):
         if self.start_at_animation_number is not None:
             if self.num_plays == self.start_at_animation_number:
-                self.stop_skipping()
+                self.skip_time = self.time
+                if not self.original_skipping_status:
+                    self.stop_skipping()
         if self.end_at_animation_number is not None:
             if self.num_plays >= self.end_at_animation_number:
                 raise EndSceneEarlyException()
 
     def stop_skipping(self):
-        if self.skip_animations:
-            self.skip_animations = False
-            self.skip_time += self.time
+        self.virtual_animation_start_time = self.time
+        self.skip_animations = False
 
     # Methods associated with running animations
-    def get_time_progression(self, run_time, n_iterations=None, override_skip_animations=False):
+    def get_time_progression(self, run_time, n_iterations=None, desc="", override_skip_animations=False):
         if self.skip_animations and not override_skip_animations:
-            times = [run_time]
+            return [run_time]
         else:
             step = 1 / self.camera.frame_rate
             times = np.arange(0, run_time, step)
-        time_progression = ProgressDisplay(
+
+        if self.file_writer.has_progress_display:
+            self.file_writer.set_progress_display_subdescription(desc)
+            return times
+
+        return ProgressDisplay(
             times,
             total=n_iterations,
             leave=self.leave_progress_bars,
-            ascii=True if platform.system() == 'Windows' else None
+            ascii=True if platform.system() == 'Windows' else None,
+            desc=desc,
         )
-        return time_progression
 
     def get_run_time(self, animations):
         return np.max([animation.run_time for animation in animations])
 
     def get_animation_time_progression(self, animations):
         run_time = self.get_run_time(animations)
-        time_progression = self.get_time_progression(run_time)
-        time_progression.set_description("".join([
-            f"Animation {self.num_plays}: {animations[0]}",
-            ", etc." if len(animations) > 1 else "",
-        ]))
+        description = f"{self.num_plays} {animations[0]}"
+        if len(animations) > 1:
+            description += ", etc."
+        time_progression = self.get_time_progression(run_time, desc=description)
         return time_progression
 
-    def get_wait_time_progression(self, duration, stop_condition):
+    def get_wait_time_progression(self, duration, stop_condition=None):
+        kw = {"desc": f"{self.num_plays} Waiting"}
         if stop_condition is not None:
-            time_progression = self.get_time_progression(
-                duration,
-                n_iterations=-1,  # So it doesn't show % progress
-                override_skip_animations=True
-            )
-            time_progression.set_description(
-                "Waiting for {}".format(stop_condition.__name__)
-            )
-        else:
-            time_progression = self.get_time_progression(duration)
-            time_progression.set_description(
-                "Waiting {}".format(self.num_plays)
-            )
-        return time_progression
+            kw["n_iterations"] = -1  # So it doesn't show % progress
+            kw["override_skip_animations"] = True
+        return self.get_time_progression(duration, **kw)
 
     def anims_from_play_args(self, *args, **kwargs):
         """
@@ -443,10 +467,7 @@ class Scene(object):
     @handle_play_like_call
     def play(self, *args, **kwargs):
         if len(args) == 0:
-            logging.log(
-                logging.WARNING,
-                "Called Scene.play with no animations"
-            )
+            log.warning("Called Scene.play with no animations")
             return
         animations = self.anims_from_play_args(*args, **kwargs)
         self.lock_static_mobject_data(*animations)
@@ -458,27 +479,18 @@ class Scene(object):
     @handle_play_like_call
     def wait(self, duration=DEFAULT_WAIT_TIME, stop_condition=None):
         self.update_mobjects(dt=0)  # Any problems with this?
-        if self.should_update_mobjects():
-            self.lock_static_mobject_data()
-            time_progression = self.get_wait_time_progression(duration, stop_condition)
-            last_t = 0
-            for t in time_progression:
-                dt = t - last_t
-                last_t = t
-                self.update_frame(dt)
-                self.emit_frame()
-                if stop_condition is not None and stop_condition():
-                    time_progression.close()
-                    break
-            self.unlock_mobject_data()
-        elif self.skip_animations:
-            # Do nothing
-            return self
-        else:
-            self.update_frame(duration)
-            n_frames = int(duration * self.camera.frame_rate)
-            for n in range(n_frames):
-                self.emit_frame()
+        self.lock_static_mobject_data()
+        time_progression = self.get_wait_time_progression(duration, stop_condition)
+        last_t = 0
+        for t in time_progression:
+            dt = t - last_t
+            last_t = t
+            self.update_frame(dt)
+            self.emit_frame()
+            if stop_condition is not None and stop_condition():
+                time_progression.close()
+                break
+        self.unlock_mobject_data()
         return self
 
     def wait_until(self, stop_condition, max_time=60):
@@ -586,7 +598,7 @@ class Scene(object):
         try:
             char = chr(symbol)
         except OverflowError:
-            print(" Warning: The value of the pressed key is too large.")
+            log.warning("The value of the pressed key is too large.")
             return
 
         event_data = {"symbol": symbol, "modifiers": modifiers}

manimlib/scene/scene_file_writer.py

@@ -5,6 +5,7 @@ import subprocess as sp
 import os
 import sys
 import platform
+from tqdm import tqdm as ProgressDisplay
 
 from manimlib.constants import FFMPEG_BIN
 from manimlib.utils.config_ops import digest_config
@@ -12,6 +13,7 @@ from manimlib.utils.file_ops import guarantee_existence
 from manimlib.utils.file_ops import add_extension_if_not_present
 from manimlib.utils.file_ops import get_sorted_integer_files
 from manimlib.utils.sounds import get_full_sound_file_path
+from manimlib.logger import log
 
 
 class SceneFileWriter(object):
@@ -34,12 +36,15 @@ class SceneFileWriter(object):
         "open_file_upon_completion": False,
         "show_file_location_upon_completion": False,
         "quiet": False,
+        "total_frames": 0,
+        "progress_description_len": 60,
     }
 
     def __init__(self, scene, **kwargs):
         digest_config(self, kwargs)
         self.scene = scene
         self.writing_process = None
+        self.has_progress_display = False
         self.init_output_directories()
         self.init_audio()
 
@@ -71,10 +76,14 @@ class SceneFileWriter(object):
         return path
 
     def get_default_scene_name(self):
-        if self.file_name is None:
-            return self.scene.__class__.__name__
-        else:
-            return self.file_name
+        name = str(self.scene)
+        saan = self.scene.start_at_animation_number
+        eaan = self.scene.end_at_animation_number
+        if saan is not None:
+            name += f"_{saan}"
+        if eaan is not None:
+            name += f"_{eaan}"
+        return name
 
     def get_resolution_directory(self):
         pixel_height = self.scene.camera.pixel_height
@@ -183,7 +192,7 @@ class SceneFileWriter(object):
             '-s', f'{width}x{height}',  # size of one frame
             '-pix_fmt', 'rgba',
             '-r', str(fps),  # frames per second
-            '-i', '-',  # The imput comes from a pipe
+            '-i', '-',  # The input comes from a pipe
             '-vf', 'vflip',
             '-an',  # Tells FFMPEG not to expect any audio
             '-loglevel', 'error',
@@ -204,15 +213,39 @@ class SceneFileWriter(object):
         command += [self.temp_file_path]
         self.writing_process = sp.Popen(command, stdin=sp.PIPE)
 
+        if self.total_frames > 0:
+            self.progress_display = ProgressDisplay(
+                range(self.total_frames),
+                # bar_format="{l_bar}{bar}|{n_fmt}/{total_fmt}",
+                leave=False,
+                ascii=True if platform.system() == 'Windows' else None,
+                dynamic_ncols=True,
+            )
+            self.has_progress_display = True
+
+    def set_progress_display_subdescription(self, sub_desc):
+        desc_len = self.progress_description_len
+        file = os.path.split(self.get_movie_file_path())[1]
+        full_desc = f"Rendering {file} ({sub_desc})"
+        if len(full_desc) > desc_len:
+            full_desc = full_desc[:desc_len - 4] + "...)"
+        else:
+            full_desc += " " * (desc_len - len(full_desc))
+        self.progress_display.set_description(full_desc)
+
     def write_frame(self, camera):
         if self.write_to_movie:
             raw_bytes = camera.get_raw_fbo_data()
             self.writing_process.stdin.write(raw_bytes)
+            if self.has_progress_display:
+                self.progress_display.update()
 
     def close_movie_pipe(self):
         self.writing_process.stdin.close()
         self.writing_process.wait()
         self.writing_process.terminate()
+        if self.has_progress_display:
+            self.progress_display.close()
         shutil.move(self.temp_file_path, self.final_file_path)
 
     def combine_movie_files(self):
@@ -231,7 +264,7 @@ class SceneFileWriter(object):
             **kwargs
         )
         if len(partial_movie_files) == 0:
-            print("No animations in this scene")
+            log.warning("No animations in this scene")
             return
 
         # Write a file partial_file_list.txt containing all
@@ -300,7 +333,8 @@ class SceneFileWriter(object):
         self.print_file_ready_message(file_path)
 
     def print_file_ready_message(self, file_path):
-        print(f"\nFile ready at {file_path}\n")
+        if not self.quiet:
+            log.info(f"File ready at {file_path}")
 
     def should_open_file(self):
         return any([

manimlib/scene/three_d_scene.py

@@ -5,7 +5,6 @@ class ThreeDScene(Scene):
     CONFIG = {
         "camera_config": {
             "samples": 4,
-            "anti_alias_width": 0,
         }
     }
 

manimlib/shaders/inserts/add_light.glsl

@@ -1,43 +0,0 @@
-///// INSERT COLOR_MAP FUNCTION HERE /////
-
-vec4 add_light(vec4 color,
-               vec3 point,
-               vec3 unit_normal,
-               vec3 light_coords,
-               float gloss,
-               float shadow){
-    ///// INSERT COLOR FUNCTION HERE /////
-    // The line above may be replaced by arbitrary code snippets, as per
-    // the method Mobject.set_color_by_code
-    if(gloss == 0.0 && shadow == 0.0) return color;
-
-    // TODO, do we actually want this?  It effectively treats surfaces as two-sided
-    if(unit_normal.z < 0){
-            unit_normal *= -1;
-    }
-
-    // TODO, read this in as a uniform?
-    float camera_distance = 6;  
-    // Assume everything has already been rotated such that camera is in the z-direction
-    vec3 to_camera = vec3(0, 0, camera_distance) - point;
-    vec3 to_light = light_coords - point;
-    vec3 light_reflection = -to_light + 2 * unit_normal * dot(to_light, unit_normal);
-    float dot_prod = dot(normalize(light_reflection), normalize(to_camera));
-    float shine = gloss * exp(-3 * pow(1 - dot_prod, 2));
-    float dp2 = dot(normalize(to_light), unit_normal);
-    float darkening = mix(1, max(dp2, 0), shadow);
-    return vec4(
-            darkening * mix(color.rgb, vec3(1.0), shine),
-            color.a
-    );
-}
-
-vec4 finalize_color(vec4 color,
-                    vec3 point,
-                    vec3 unit_normal,
-                    vec3 light_coords,
-                    float gloss,
-                    float shadow){
-    // Put insertion here instead
-    return add_light(color, point, unit_normal, light_coords, gloss, shadow);
-}

manimlib/shaders/inserts/camera_uniform_declarations.glsl

@@ -1,6 +1,6 @@
 uniform vec2 frame_shape;
 uniform float anti_alias_width;
-uniform vec3 camera_center;
+uniform vec3 camera_offset;
 uniform mat3 camera_rotation;
 uniform float is_fixed_in_frame;
 uniform float focal_distance;

manimlib/shaders/inserts/complex_functions.glsl

@@ -0,0 +1,15 @@
+vec2 complex_mult(vec2 z, vec2 w){
+    return vec2(z.x * w.x - z.y * w.y, z.x * w.y + z.y * w.x);
+}
+
+vec2 complex_div(vec2 z, vec2 w){
+    return complex_mult(z, vec2(w.x, -w.y)) / (w.x * w.x + w.y * w.y);
+}
+
+vec2 complex_pow(vec2 z, int n){
+    vec2 result = vec2(1.0, 0.0);
+    for(int i = 0; i < n; i++){
+        result = complex_mult(result, z);
+    }
+    return result;
+}

manimlib/shaders/inserts/finalize_color.glsl

@@ -13,39 +13,56 @@ vec4 add_light(vec4 color,
                vec3 point,
                vec3 unit_normal,
                vec3 light_coords,
+               vec3 cam_coords,
+               float reflectiveness,
                float gloss,
                float shadow){
-    if(gloss == 0.0 && shadow == 0.0) return color;
+    if(reflectiveness == 0.0 && gloss == 0.0 && shadow == 0.0) return color;
 
-    float camera_distance = focal_distance;
+    vec4 result = color;
     // Assume everything has already been rotated such that camera is in the z-direction
-    vec3 to_camera = vec3(0, 0, camera_distance) - point;
-    vec3 to_light = light_coords - point;
+    // cam_coords = vec3(0, 0, focal_distance);
+    vec3 to_camera = normalize(cam_coords - point);
+    vec3 to_light = normalize(light_coords - point);
 
-    // TODO, do we actually want this?  It effectively treats surfaces as two-sided
-    if(dot(to_camera,unit_normal) < 0){
-            unit_normal *= -1;
-    }
+    // Note, this effectively treats surfaces as two-sided
+    // if(dot(to_camera, unit_normal) < 0) unit_normal *= -1;
 
+    float light_to_normal = dot(to_light, unit_normal);
+    // When unit normal points towards light, brighten
+    float bright_factor = max(light_to_normal, 0) * reflectiveness;
+    // For glossy surface, add extra shine if light beam go towards camera
     vec3 light_reflection = -to_light + 2 * unit_normal * dot(to_light, unit_normal);
-    float dot_prod = dot(normalize(light_reflection), normalize(to_camera));
-    float shine = gloss * exp(-3 * pow(1 - dot_prod, 2));
-    float dp2 = dot(normalize(to_light), unit_normal);
-    float darkening = mix(1, max(dp2, 0), shadow);
-    return vec4(
-            darkening * mix(color.rgb, vec3(1.0), shine),
-            color.a
-    );
+    float light_to_cam = dot(light_reflection, to_camera);
+    float shine = gloss * exp(-3 * pow(1 - light_to_cam, 2));
+    bright_factor += shine;
+
+    result.rgb = mix(result.rgb, vec3(1.0), bright_factor);
+    if (light_to_normal < 0){
+        // Darken
+        result.rgb = mix(result.rgb, vec3(0.0), -light_to_normal * shadow);
+    }
+    // float darkening = mix(1, max(light_to_normal, 0), shadow);
+    // return vec4(
+    //     darkening * mix(color.rgb, vec3(1.0), shine),
+    //     color.a
+    // );
+    return result;
 }
 
 vec4 finalize_color(vec4 color,
                     vec3 point,
                     vec3 unit_normal,
                     vec3 light_coords,
+                    vec3 cam_coords,
+                    float reflectiveness,
                     float gloss,
                     float shadow){
     ///// INSERT COLOR FUNCTION HERE /////
     // The line above may be replaced by arbitrary code snippets, as per
     // the method Mobject.set_color_by_code
-    return add_light(color, point, unit_normal, light_coords, gloss, shadow);
+    return add_light(
+        color, point, unit_normal, light_coords, cam_coords,
+        reflectiveness, gloss, shadow
+    );
 }

manimlib/shaders/inserts/get_rotated_surface_unit_normal_vector.glsl

@@ -1,5 +1,5 @@
 // Assumes the following uniforms exist in the surrounding context:
-// uniform vec3 camera_center;
+// uniform vec3 camera_offset;
 // uniform mat3 camera_rotation;
 
 vec3 get_rotated_surface_unit_normal_vector(vec3 point, vec3 du_point, vec3 dv_point){

manimlib/shaders/inserts/position_point_into_frame.glsl

@@ -1,6 +1,6 @@
 // Assumes the following uniforms exist in the surrounding context:
 // uniform float is_fixed_in_frame;
-// uniform vec3 camera_center;
+// uniform vec3 camera_offset;
 // uniform mat3 camera_rotation;
 
 vec3 rotate_point_into_frame(vec3 point){
@@ -15,5 +15,5 @@ vec3 position_point_into_frame(vec3 point){
     if(bool(is_fixed_in_frame)){
         return point;
     }
-    return rotate_point_into_frame(point - camera_center);
+    return rotate_point_into_frame(point - camera_offset);
 }

manimlib/shaders/mandelbrot_fractal/frag.glsl

@@ -0,0 +1,81 @@
+#version 330
+
+uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
+uniform float gloss;
+uniform float shadow;
+uniform float focal_distance;
+
+uniform vec2 parameter;
+uniform float opacity;
+uniform float n_steps;
+uniform float mandelbrot;
+
+uniform vec3 color0;
+uniform vec3 color1;
+uniform vec3 color2;
+uniform vec3 color3;
+uniform vec3 color4;
+uniform vec3 color5;
+uniform vec3 color6;
+uniform vec3 color7;
+uniform vec3 color8;
+
+uniform vec2 frame_shape;
+
+in vec3 xyz_coords;
+
+out vec4 frag_color;
+
+#INSERT finalize_color.glsl
+#INSERT complex_functions.glsl
+
+const int MAX_DEGREE = 5;
+
+void main() {
+    vec3 color_map[9] = vec3[9](
+        color0, color1, color2, color3,
+        color4, color5, color6, color7, color8
+    );
+    vec3 color;
+
+    vec2 z;
+    vec2 c;
+
+    if(bool(mandelbrot)){
+        c = xyz_coords.xy;
+        z = vec2(0.0, 0.0);
+    }else{
+        c = parameter;
+        z = xyz_coords.xy;
+    }
+
+    float outer_bound = 2.0;
+    bool stable = true;
+    for(int n = 0; n < int(n_steps); n++){
+        z = complex_mult(z, z) + c;
+        if(length(z) > outer_bound){
+            float float_n = float(n);
+            float_n += log(outer_bound) / log(length(z));
+            float_n += 0.5 * length(c);
+            color = float_to_color(sqrt(float_n), 1.5, 8.0, color_map);
+            stable = false;
+            break;
+        }
+    }
+    if(stable){
+        color = vec3(0.0, 0.0, 0.0);
+    }
+
+    frag_color = finalize_color(
+        vec4(color, opacity),
+        xyz_coords,
+        vec3(0.0, 0.0, 1.0),
+        light_source_position,
+        camera_position,
+        reflectiveness,
+        gloss,
+        shadow
+    );
+ }

manimlib/shaders/mandelbrot_fractal/vert.glsl

@@ -0,0 +1,17 @@
+#version 330
+
+#INSERT camera_uniform_declarations.glsl
+
+in vec3 point;
+out vec3 xyz_coords;
+
+uniform float scale_factor;
+uniform vec3 offset;
+
+#INSERT position_point_into_frame.glsl
+#INSERT get_gl_Position.glsl
+
+void main(){
+    xyz_coords = (point - offset) / scale_factor;
+    gl_Position = get_gl_Position(position_point_into_frame(point));
+}

manimlib/shaders/newton_fractal/frag.glsl

@@ -0,0 +1,161 @@
+#version 330
+
+uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
+uniform float gloss;
+uniform float shadow;
+uniform float focal_distance;
+
+uniform vec4 color0;
+uniform vec4 color1;
+uniform vec4 color2;
+uniform vec4 color3;
+uniform vec4 color4;
+
+uniform vec2 coef0;
+uniform vec2 coef1;
+uniform vec2 coef2;
+uniform vec2 coef3;
+uniform vec2 coef4;
+uniform vec2 coef5;
+
+uniform vec2 root0;
+uniform vec2 root1;
+uniform vec2 root2;
+uniform vec2 root3;
+uniform vec2 root4;
+
+uniform float n_roots;
+uniform float n_steps;
+uniform float julia_highlight;
+uniform float saturation_factor;
+uniform float black_for_cycles;
+uniform float is_parameter_space;
+
+uniform vec2 frame_shape;
+
+in vec3 xyz_coords;
+
+out vec4 frag_color;
+
+#INSERT finalize_color.glsl
+#INSERT complex_functions.glsl
+
+const int MAX_DEGREE = 5;
+const float CLOSE_ENOUGH = 1e-3;
+
+
+vec2 poly(vec2 z, vec2[MAX_DEGREE + 1] coefs){
+    vec2 result = vec2(0.0);
+    for(int n = 0; n < int(n_roots) + 1; n++){
+        result += complex_mult(coefs[n], complex_pow(z, n));
+    }
+    return result;
+}
+
+vec2 dpoly(vec2 z, vec2[MAX_DEGREE + 1] coefs){
+    vec2 result = vec2(0.0);
+    for(int n = 1; n < int(n_roots) + 1; n++){
+        result += n * complex_mult(coefs[n], complex_pow(z, n - 1));
+    }
+    return result;
+}
+
+vec2 seek_root(vec2 z, vec2[MAX_DEGREE + 1] coefs, int max_steps, out float n_iters){
+    float last_len;
+    float curr_len;
+    float threshold = CLOSE_ENOUGH;
+
+    for(int i = 0; i < max_steps; i++){
+        last_len = curr_len;
+        n_iters = float(i);
+        vec2 step = complex_div(poly(z, coefs), dpoly(z, coefs));
+        curr_len = length(step);
+        if(curr_len < threshold){
+            break;
+        }
+        z = z - step;
+    }
+    n_iters -= log(curr_len) / log(threshold);
+
+    return z;
+}
+
+
+void main() {
+    vec2[MAX_DEGREE + 1] coefs = vec2[MAX_DEGREE + 1](coef0, coef1, coef2, coef3, coef4, coef5);
+    vec2[MAX_DEGREE] roots = vec2[MAX_DEGREE](root0, root1, root2, root3, root4);
+    vec4[MAX_DEGREE] colors = vec4[MAX_DEGREE](color0, color1, color2, color3, color4);
+
+    vec2 z = xyz_coords.xy;
+
+    if(is_parameter_space > 0){
+        // In this case, pixel should correspond to one of the roots
+        roots[2] = xyz_coords.xy;
+        vec2 r0 = roots[0];
+        vec2 r1 = roots[1];
+        vec2 r2 = roots[2];
+
+        // It is assumed that the polynomial is cubid...
+        coefs[0] = -complex_mult(complex_mult(r0, r1), r2);
+        coefs[1] = complex_mult(r0, r1) + complex_mult(r0, r2) + complex_mult(r1, r2);
+        coefs[2] = -(r0 + r1 + r2);
+        coefs[3] = vec2(1.0, 0.0);
+
+        // Seed value is always center of the roots
+        z = -coefs[2] / 3.0;
+    }
+
+    float n_iters;
+    vec2 found_root = seek_root(z, coefs, int(n_steps), n_iters);
+
+    vec4 color = vec4(0.0);
+    float min_dist = 1e10;
+    float dist;
+    for(int i = 0; i < int(n_roots); i++){
+        dist = distance(roots[i], found_root);
+        if(dist < min_dist){
+            min_dist = dist;
+            color = colors[i];
+        }
+    }
+    color *= 1.0 + (0.01 * saturation_factor) * (n_iters - 2 * saturation_factor);
+
+    if(black_for_cycles > 0 && min_dist > CLOSE_ENOUGH){
+        color = vec4(0.0, 0.0, 0.0, 1.0);
+    }
+
+    if(julia_highlight > 0.0){
+        float radius = julia_highlight;
+        vec2[4] samples = vec2[4](
+            z + vec2(radius, 0.0),
+            z + vec2(-radius, 0.0),
+            z + vec2(0.0, radius),
+            z + vec2(0.0, -radius)
+        );
+        for(int i = 0; i < 4; i++){
+            for(int j = 0; j < n_steps; j++){
+                vec2 z = samples[i];
+                z = z - complex_div(poly(z, coefs), dpoly(z, coefs));
+                samples[i] = z;
+            }
+        }
+        float max_dist = 0.0;
+        for(int i = 0; i < 4; i++){
+            max_dist = max(max_dist, distance(samples[i], samples[(i + 1) % 4]));
+        }
+        color *= 1.0 * smoothstep(0, 0.1, max_dist);
+    }
+
+    frag_color = finalize_color(
+        color,
+        xyz_coords,
+        vec3(0.0, 0.0, 1.0),
+        light_source_position,
+        camera_position,
+        reflectiveness,
+        gloss,
+        shadow
+    );
+ }

manimlib/shaders/newton_fractal/vert.glsl

@@ -0,0 +1,17 @@
+#version 330
+
+#INSERT camera_uniform_declarations.glsl
+
+in vec3 point;
+out vec3 xyz_coords;
+
+uniform float scale_factor;
+uniform vec3 offset;
+
+#INSERT position_point_into_frame.glsl
+#INSERT get_gl_Position.glsl
+
+void main(){
+    xyz_coords = (point - offset) / scale_factor;
+    gl_Position = get_gl_Position(position_point_into_frame(point));
+}

manimlib/shaders/quadratic_bezier_fill/frag.glsl

@@ -3,7 +3,7 @@
 #INSERT camera_uniform_declarations.glsl
 
 in vec4 color;
-in float fill_all;  // Either 0 or 1e
+in float fill_all;  // Either 0 or 1
 in float uv_anti_alias_width;
 
 in vec3 xyz_coords;

manimlib/shaders/quadratic_bezier_fill/geom.glsl

@@ -11,6 +11,8 @@ uniform float focal_distance;
 uniform float is_fixed_in_frame;
 // Needed for finalize_color
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 
@@ -44,6 +46,8 @@ void emit_vertex_wrapper(vec3 point, int index){
         point,
         v_global_unit_normal[index],
         light_source_position,
+        camera_position,
+        reflectiveness,
         gloss,
         shadow
     );

manimlib/shaders/quadratic_bezier_stroke/geom.glsl

@@ -13,7 +13,9 @@ uniform float flat_stroke;
 
 //Needed for lighting
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
 uniform float joint_type;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 
@@ -259,6 +261,8 @@ void main() {
             xyz_coords,
             v_global_unit_normal[index_map[i]],
             light_source_position,
+            camera_position,
+            reflectiveness,
             gloss,
             shadow
         );

manimlib/shaders/surface/frag.glsl

@@ -1,6 +1,8 @@
 #version 330
 
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 uniform float focal_distance;
@@ -19,6 +21,8 @@ void main() {
         xyz_coords,
         normalize(v_normal),
         light_source_position,
+        camera_position,
+        reflectiveness,
         gloss,
         shadow
     );

manimlib/shaders/textured_surface/frag.glsl

@@ -4,6 +4,8 @@ uniform sampler2D LightTexture;
 uniform sampler2D DarkTexture;
 uniform float num_textures;
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 uniform float focal_distance;
@@ -36,6 +38,8 @@ void main() {
         xyz_coords,
         normalize(v_normal),
         light_source_position,
+        camera_position,
+        reflectiveness,
         gloss,
         shadow
     );

manimlib/shaders/true_dot/frag.glsl

@@ -1,10 +1,13 @@
 #version 330
 
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 uniform float anti_alias_width;
 uniform float focal_distance;
+uniform float glow_factor;
 
 in vec4 color;
 in float radius;
@@ -22,14 +25,23 @@ void main() {
     if (signed_dist > 0.5 * anti_alias_width){
         discard;
     }
-    vec3 normal = vec3(diff / radius, sqrt(1 - (dist * dist) / (radius * radius)));
-    frag_color = finalize_color(
-        color,
-        vec3(point.xy, 0.0),
-        normal,
-        light_source_position,
-        gloss,
-        shadow
-    );
+    frag_color = color;
+    if(gloss > 0 || shadow > 0){
+        vec3 normal = vec3(diff / radius, sqrt(1 - (dist * dist) / (radius * radius)));
+        frag_color = finalize_color(
+            frag_color,
+            vec3(point.xy, 0.0),
+            normal,
+            light_source_position,
+            camera_position,
+            reflectiveness,
+            gloss,
+            shadow
+        );
+    }
+    if(glow_factor > 0){
+        frag_color.a *= pow(1 - dist / radius, glow_factor);
+    }
+
     frag_color.a *= smoothstep(0.5, -0.5, signed_dist / anti_alias_width);
 }

manimlib/utils/bezier.py

@@ -4,6 +4,8 @@ import numpy as np
 from manimlib.utils.simple_functions import choose
 from manimlib.utils.space_ops import find_intersection
 from manimlib.utils.space_ops import cross2d
+from manimlib.utils.space_ops import midpoint
+from manimlib.logger import log
 
 CLOSED_THRESHOLD = 0.001
 
@@ -67,9 +69,9 @@ def interpolate(start, end, alpha):
     try:
         return (1 - alpha) * start + alpha * end
     except TypeError:
-        print(type(start), start.dtype)
-        print(type(end), start.dtype)
-        print(alpha)
+        log.debug(f"`start` parameter with type `{type(start)}` and dtype `{start.dtype}`")
+        log.debug(f"`end` parameter with type `{type(end)}` and dtype `{end.dtype}`")
+        log.debug(f"`alpha` parameter with value `{alpha}`")
         import sys
         sys.exit(2)
 
@@ -130,6 +132,8 @@ def get_smooth_quadratic_bezier_handle_points(points):
     another that would produce a parabola passing through P0, call it smooth_to_left,
     and use the midpoint between the two.
     """
+    if len(points) == 2:
+        return midpoint(*points)
     smooth_to_right, smooth_to_left = [
         0.25 * ps[0:-2] + ps[1:-1] - 0.25 * ps[2:]
         for ps in (points, points[::-1])
@@ -157,7 +161,7 @@ def get_smooth_cubic_bezier_handle_points(points):
     l, u = 2, 1
     # diag is a representation of the matrix in diagonal form
     # See https://www.particleincell.com/2012/bezier-splines/
-    # for how to arive at these equations
+    # for how to arrive at these equations
     diag = np.zeros((l + u + 1, 2 * num_handles))
     diag[0, 1::2] = -1
     diag[0, 2::2] = 1

manimlib/utils/debug.py

@@ -3,11 +3,12 @@ import time
 from manimlib.constants import BLACK
 from manimlib.mobject.numbers import Integer
 from manimlib.mobject.types.vectorized_mobject import VGroup
+from manimlib.logger import log
 
 
 def print_family(mobject, n_tabs=0):
     """For debugging purposes"""
-    print("\t" * n_tabs, mobject, id(mobject))
+    log.debug("\t" * n_tabs + str(mobject) + " " + str(id(mobject)))
     for submob in mobject.submobjects:
         print_family(submob, n_tabs + 1)
 

manimlib/utils/init_config.py

@@ -46,6 +46,7 @@ def init_customization():
         }
     }
 
+    print("Initialize configuration")
     scope = input(" Please select the scope of the configuration [global/local]: ")
     if scope == "global":
         from manimlib.config import get_manim_dir

manimlib/utils/iterables.py

@@ -5,7 +5,7 @@ import numpy as np
 def remove_list_redundancies(l):
     """
     Used instead of list(set(l)) to maintain order
-    Keeps the last occurance of each element
+    Keeps the last occurrence of each element
     """
     reversed_result = []
     used = set()

manimlib/utils/space_ops.py

@@ -1,5 +1,6 @@
 import numpy as np
-import itertools as it
+import operator as op
+from functools import reduce
 import math
 from mapbox_earcut import triangulate_float32 as earcut
 
@@ -9,10 +10,19 @@ from manimlib.constants import OUT
 from manimlib.constants import PI
 from manimlib.constants import TAU
 from manimlib.utils.iterables import adjacent_pairs
+from manimlib.utils.simple_functions import clip
+
+
+def cross(v1, v2):
+    return [
+        v1[1] * v2[2] - v1[2] * v2[1],
+        v1[2] * v2[0] - v1[0] * v2[2],
+        v1[0] * v2[1] - v1[1] * v2[0]
+    ]
 
 
 def get_norm(vect):
-    return sum([x**2 for x in vect])**0.5
+    return sum((x**2 for x in vect))**0.5
 
 
 # Quaternions
@@ -146,6 +156,15 @@ def z_to_vector(vector):
     return rotation_matrix(angle, axis=axis)
 
 
+def rotation_between_vectors(v1, v2):
+    if np.all(np.isclose(v1, v2)):
+        return np.identity(3)
+    return rotation_matrix(
+        angle=angle_between_vectors(v1, v2),
+        axis=normalize(np.cross(v1, v2))
+    )
+
+
 def angle_of_vector(vector):
     """
     Returns polar coordinate theta when vector is project on xy plane
@@ -158,8 +177,7 @@ def angle_between_vectors(v1, v2):
     Returns the angle between two 3D vectors.
     This angle will always be btw 0 and pi
     """
-    diff = (angle_of_vector(v2) - angle_of_vector(v1)) % TAU
-    return min(diff, TAU - diff)
+    return math.acos(clip(np.dot(normalize(v1), normalize(v2)), -1, 1))
 
 
 def project_along_vector(point, vector):
@@ -185,14 +203,6 @@ def normalize_along_axis(array, axis, fall_back=None):
     return array
 
 
-def cross(v1, v2):
-    return np.array([
-        v1[1] * v2[2] - v1[2] * v2[1],
-        v1[2] * v2[0] - v1[0] * v2[2],
-        v1[0] * v2[1] - v1[1] * v2[0]
-    ])
-
-
 def get_unit_normal(v1, v2, tol=1e-6):
     v1 = normalize(v1)
     v2 = normalize(v2)
@@ -376,8 +386,8 @@ def earclip_triangulation(verts, ring_ends):
 
     # Points at the same position may cause problems
     for i in rings:
-        verts[i[0]] += (verts[i[1]]-verts[i[0]]) * 1e-6
-        verts[i[-1]] += (verts[i[-2]]-verts[i[-1]]) * 1e-6
+        verts[i[0]] += (verts[i[1]] - verts[i[0]]) * 1e-6
+        verts[i[-1]] += (verts[i[-2]] - verts[i[-1]]) * 1e-6
 
     # First, we should know which rings are directly contained in it for each ring
 
@@ -393,9 +403,11 @@ def earclip_triangulation(verts, ring_ends):
 
     def is_in_fast(ring_a, ring_b):
         # Whether a is in b
-        return (left[ring_b] <= left[ring_a] <= right[ring_a] <= right[ring_b] and
-                bottom[ring_b] <= bottom[ring_a] <= top[ring_a] <= top[ring_b] and
-                is_in(verts[rings[ring_a][0]], ring_b))
+        return reduce(op.and_, (
+            left[ring_b] <= left[ring_a] <= right[ring_a] <= right[ring_b],
+            bottom[ring_b] <= bottom[ring_a] <= top[ring_a] <= top[ring_b],
+            is_in(verts[rings[ring_a][0]], ring_b)
+        ))
 
     chilren = [[] for i in rings]
     for idx, i in enumerate(rings_sorted):

manimlib/utils/tex_file_writing.py

@@ -1,4 +1,3 @@
-import logging
 import sys
 import os
 import hashlib
@@ -7,6 +6,7 @@ from contextlib import contextmanager
 from manimlib.utils.directories import get_tex_dir
 from manimlib.config import get_manim_dir
 from manimlib.config import get_custom_config
+from manimlib.logger import log
 
 
 SAVED_TEX_CONFIG = {}
@@ -87,15 +87,11 @@ def tex_to_dvi(tex_file):
         exit_code = os.system(" ".join(commands))
         if exit_code != 0:
             log_file = tex_file.replace(".tex", ".log")
-            logging.log(
-                logging.ERROR,
-                "\n\n LaTeX Error!  Not a worry, it happens to the best of us.\n"
-            )
+            log.error("LaTeX Error!  Not a worry, it happens to the best of us.")
             with open(log_file, "r") as file:
                 for line in file.readlines():
                     if line.startswith("!"):
-                        print(line[1:])
-                        logging.log(logging.INFO, line)
+                        log.debug(f"The error could be: `{line[2:-1]}`")
             sys.exit(2)
     return result
 

manimlib/window.py

@@ -1,3 +1,4 @@
+import numpy as np
 import moderngl_window as mglw
 from moderngl_window.context.pyglet.window import Window as PygletWindow
 from moderngl_window.timers.clock import Timer
@@ -48,7 +49,7 @@ class Window(PygletWindow):
             return tuple(map(int, custom_position.split(",")))
 
         # Alternatively, it might be specified with a string like
-        # UR, OO, DL, etc. specifiying what corner it should go to
+        # UR, OO, DL, etc. specifying what corner it should go to
         char_to_n = {"L": 0, "U": 0, "O": 1, "R": 2, "D": 2}
         width_diff = monitor.width - window_width
         height_diff = monitor.height - window_height
@@ -59,7 +60,17 @@ class Window(PygletWindow):
 
     # Delegate event handling to scene
     def pixel_coords_to_space_coords(self, px, py, relative=False):
-        return self.scene.camera.pixel_coords_to_space_coords(px, py, relative)
+        pw, ph = self.size
+        fw, fh = self.scene.camera.get_frame_shape()
+        fc = self.scene.camera.get_frame_center()
+        if relative:
+            return np.array([px / pw, py / ph, 0])
+        else:
+            return np.array([
+                fc[0] + px * fw / pw - fw / 2,
+                fc[1] + py * fh / ph - fh / 2,
+                0
+            ])
 
     def on_mouse_motion(self, x, y, dx, dy):
         super().on_mouse_motion(x, y, dx, dy)

pyproject.toml

@@ -1,3 +1,2 @@
 [build-system]
-requires = ["setuptools", "wheel"]
-build-backend = "setuptools.build_meta"
+requires = ["setuptools", "wheel"]

requirements.txt

@@ -9,8 +9,11 @@ mapbox-earcut
 matplotlib
 moderngl
 moderngl_window
+skia-pathops
 pydub
+pygments
 pyyaml
+rich
 screeninfo
 pyreadline; sys_platform == 'win32'
 validators

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = manimgl
-version = 1.1.0
+version = 1.3.0
 author = Grant Sanderson
 author_email= grant@3blue1brown.com
 description = Animation engine for explanatory math videos
@@ -28,8 +28,11 @@ install_requires =
     matplotlib
     moderngl
     moderngl_window
+    skia-pathops
     pydub
+    pygments
     pyyaml
+    rich
     screeninfo
     pyreadline; sys_platform == 'win32'
     validators

setup.py

@@ -0,0 +1,2 @@
+import setuptools
+setuptools.setup()