Add type annotations to opengl_mobject.py

manim/mobject/opengl/opengl_compatibility.py

@@ -1,27 +1,33 @@
 from __future__ import annotations
 
 from abc import ABCMeta
+from typing import TypeVar
 
 from manim import config
 from manim.mobject.opengl.opengl_mobject import OpenGLMobject
 from manim.mobject.opengl.opengl_point_cloud_mobject import OpenGLPMobject
-from manim.mobject.opengl.opengl_three_dimensions import OpenGLSurface
+from manim.mobject.opengl.opengl_surface import OpenGLSurface
 from manim.mobject.opengl.opengl_vectorized_mobject import OpenGLVMobject
 
 from ...constants import RendererType
 
 __all__ = ["ConvertToOpenGL"]
 
 
+_Class = TypeVar("_Class", bound=type)
+
+
 class ConvertToOpenGL(ABCMeta):
     """Metaclass for swapping (V)Mobject with its OpenGL counterpart at runtime
     depending on config.renderer. This metaclass should only need to be inherited
     on the lowest order inheritance classes such as Mobject and VMobject.
     """
 
-    _converted_classes = []
+    _converted_classes: list[ConvertToOpenGL] = []
 
-    def __new__(mcls, name, bases, namespace):
+    def __new__(
+        mcls: _Class, name: str, bases: tuple[type, ...], namespace: dict[str, object]
+    ) -> _Class:  # this would ideally be something like `_Type & OpenGLMobject`, but we don't have intersections yet
         if config.renderer == RendererType.OPENGL:
             # Must check class names to prevent
             # cyclic importing.
@@ -40,6 +46,8 @@
 
         return super().__new__(mcls, name, bases, namespace)
 
-    def __init__(cls, name, bases, namespace):
+    def __init__(
+        cls, name: str, bases: tuple[type, ...], namespace: dict[str, object]
+    ) -> None:
         super().__init__(name, bases, namespace)
         cls._converted_classes.append(cls)