Add TransformMatchingShapes and TransformMatchingTex

manimlib/animation/transform_matching_parts.py

@@ -1,13 +1,26 @@
 from manimlib.animation.composition import AnimationGroup
 from manimlib.animation.fading import FadeTransformPieces
+from manimlib.animation.fading import FadeInFromPoint
+from manimlib.animation.fading import FadeOutToPoint
 from manimlib.animation.transform import Transform
 
+from manimlib.mobject.mobject import Mobject
+from manimlib.mobject.mobject import Group
 from manimlib.mobject.types.vectorized_mobject import VGroup
 from manimlib.mobject.types.vectorized_mobject import VMobject
+from manimlib.mobject.svg.tex_mobject import TexMobject
+from manimlib.utils.config_ops import digest_config
 
 
 class TransformMatchingParts(AnimationGroup):
+    CONFIG = {
+        "mobject_type": Mobject,
+        "group_type": Group,
+        "fade_transform_mismatches": False,
+    }
+
     def __init__(self, mobject, target_mobject, **kwargs):
+        digest_config(self, kwargs)
         assert(isinstance(mobject, VMobject) and isinstance(target_mobject, VMobject))
         source_map = self.get_shape_map(mobject)
         target_map = self.get_shape_map(target_mobject)
@@ -17,27 +30,36 @@ class TransformMatchingParts(AnimationGroup):
         fade_source = VGroup()
         fade_target = VGroup()
 
+        kwargs["final_alpha_value"] = 0
         for key in set(source_map).intersection(target_map):
             transform_source.add(source_map[key])
             transform_target.add(target_map[key])
+        anims = [Transform(transform_source, transform_target, **kwargs)]
+
         for key in set(source_map).difference(target_map):
             fade_source.add(source_map[key])
         for key in set(target_map).difference(source_map):
             fade_target.add(target_map[key])
 
-        kwargs["final_alpha_value"] = 0
+        if self.fade_transform_mismatches:
-        super().__init__(
+            anims.append(FadeTransformPieces(fade_source, fade_target, **kwargs))
-            Transform(transform_source, transform_target, **kwargs),
+        else:
-            FadeTransformPieces(fade_source, fade_target, **kwargs),
+            anims.append(FadeOutToPoint(
-        )
+                fade_source, fade_target.get_center(), **kwargs
+            ))
+            anims.append(FadeInFromPoint(
+                fade_target.copy(), fade_source.get_center(), **kwargs
+            ))
+
+        super().__init__(*anims)
 
         self.to_remove = mobject
         self.to_add = target_mobject
 
     def get_shape_map(self, mobject):
         shape_map = {}
-        for sm in mobject.family_members_with_points():
+        for sm in self.get_mobject_parts(mobject):
-            key = hash(sm.get_triangulation().tobytes())
+            key = self.get_mobject_key(sm)
             if key not in shape_map:
                 shape_map[key] = VGroup()
             shape_map[key].add(sm)
@@ -49,3 +71,37 @@ class TransformMatchingParts(AnimationGroup):
         scene.remove(self.mobject)
         scene.remove(self.to_remove)
         scene.add(self.to_add)
+
+    def get_mobject_parts(self, mobject):
+        # To be implemented in subclass
+        return mobject
+
+    def get_mobject_key(self, mobject):
+        # To be implemented in subclass
+        return hash(mobject)
+
+
+class TransformMatchingShapes(TransformMatchingParts):
+    CONFIG = {
+        "mobject_type": VMobject,
+        "group_type": VGroup,
+    }
+
+    def get_mobject_parts(self, mobject):
+        return mobject.family_members_with_points()
+
+    def get_mobject_key(self, mobject):
+        return hash(mobject.get_triangulation().tobytes())
+
+
+class TransformMatchingTex(TransformMatchingParts):
+    CONFIG = {
+        "mobject_type": TexMobject,
+        "group_type": VGroup,
+    }
+
+    def get_mobject_parts(self, mobject):
+        return mobject.submobjects
+
+    def get_mobject_key(self, mobject):
+        return mobject.get_tex_string()