feat(lib): add zoom animation (#230)

* feat(lib): add zoom animation

* chore(lib): fix zoom animation

.github/workflows/pages.yml

@@ -47,7 +47,7 @@ jobs:
         sudo apt-get update
         sudo apt-get install libcairo2-dev libpango1.0-dev ffmpeg freeglut3-dev
     - name: Install local Python package
-      run: poetry install --extras=manim --with docs
+      run: poetry install --with docs
     - name: Restore cached media
       id: cache-media-restore
       uses: actions/cache/restore@v3

docs/source/reference/api.md

@@ -18,6 +18,7 @@ Therefore, we only document here the methods we think the end-user will ever use
         start_loop,
         wait_time_between_slides,
         wipe,
+        zoom,
 
 .. autoclass:: manim_slides.ThreeDSlide
     :members:

manim_slides/slide.py

@@ -606,7 +606,7 @@ class Slide(Scene):  # type:ignore
                     text = Text("This is a wipe example").next_to(square, DOWN)
                     beautiful = Text("Beautiful, no?")
 
-                    self.play(Create(circle))
+                    self.play(FadeIn(circle))
                     self.next_slide()
 
                     self.play(self.wipe(circle, Group(square, text)))
@@ -631,6 +631,69 @@ class Slide(Scene):  # type:ignore
 
         return AnimationGroup(*animations, **kwargs)
 
+    def zoom(
+        self,
+        current: Sequence[Mobject] = [],
+        future: Sequence[Mobject] = [],
+        scale: float = 4.0,
+        out: bool = False,
+        fade_in_kwargs: Mapping[str, Any] = {},
+        fade_out_kwargs: Mapping[str, Any] = {},
+        **kwargs: Any,
+    ) -> AnimationGroup:
+        """
+        Returns a zoom animation that will fade out all the current objects,
+        and fade in all the future objects. Objects are faded in a direction
+        that goes towards the camera.
+
+        :param current: A sequence of mobjects to remove from the scene.
+        :param future: A sequence of mobjects to add to the scene.
+        :param scale: How much the objects are scaled (up or down).
+        :param out: If set, the objects fade in the opposite direction.
+        :param fade_in_kwargs: Keyword arguments passed to
+            :class:`FadeIn<manim.animation.fading.FadeIn>`.
+        :param fade_out_kwargs: Keyword arguments passed to
+            :class:`FadeOut<manim.animation.fading.FadeOut>`.
+        :param kwargs: Keyword arguments passed to
+            :class:`AnimationGroup<manim.animation.composition.AnimationGroup>`.
+
+        Examples
+        --------
+
+        .. manim-slides:: ZoomExample
+
+            from manim import *
+            from manim_slides import Slide
+
+            class ZoomExample(Slide):
+                def construct(self):
+                    circle = Circle(radius=3, color=BLUE)
+                    square = Square()
+
+                    self.play(FadeIn(circle))
+                    self.next_slide()
+
+                    self.play(self.zoom(circle, square))
+                    self.next_slide()
+
+                    self.play(self.zoom(square, circle, out=True, scale=10.))
+        """
+        scale_in = 1.0 / scale
+        scale_out = scale
+
+        if out:
+            scale_in, scale_out = scale_out, scale_in
+
+        animations = []
+
+        for mobject in future:
+            animations.append(FadeIn(mobject, scale=scale_in, **fade_in_kwargs))
+
+        for mobject in current:
+            animations.append(FadeOut(mobject, scale=scale_out, **fade_out_kwargs))
+
+        return AnimationGroup(*animations, **kwargs)
+
 
 class ThreeDSlide(Slide, ThreeDScene):  # type: ignore
     """

pyproject.toml

@@ -49,7 +49,7 @@ version = "4.14.0"
 click = "^8.1.3"
 click-default-group = "^1.2.2"
 lxml = "^4.9.2"
-manim = {version = "^0.17.0", optional = true}
+manim = {version = "^0.17.3", optional = true}
 manimgl = {version = "^1.6.1", optional = true}
 numpy = "^1.19"
 opencv-python = "^4.6.0.66"
@@ -78,7 +78,7 @@ ruff = "^0.0.219"
 
 [tool.poetry.group.docs.dependencies]
 furo = "^2023.5.20"
-manim = "^0.17.0"
+manim = "^0.17.3"
 myst-parser = "^2.0.0"
 sphinx = "^7.0.1"
 sphinx-click = "^4.4.0"