Refactored run_time validation for Animation and Scene.wait() (#3982)

* Refactored Animation run_time validation

* Rewrite error and warning messages, and add validations to wait(), pause() and wait_until()

* Undo rewriting of imports

Author: chopan050

manim/animation/animation.py

@@ -194,6 +194,7 @@ def begin(self) -> None:
         method.
 
         """
+        self.run_time = validate_run_time(self.run_time, str(self))
         self.starting_mobject = self.create_starting_mobject()
         if self.suspend_mobject_updating:
             # All calls to self.mobject's internal updaters
@@ -568,6 +569,33 @@ def prepare_animation(
     raise TypeError(f"Object {anim} cannot be converted to an animation")
 
 
+def validate_run_time(
+    run_time: float, caller_name: str, parameter_name: str = "run_time"
+) -> float:
+    if run_time <= 0:
+        raise ValueError(
+            f"{caller_name} has a {parameter_name} of {run_time:g} <= 0 "
+            f"seconds which Manim cannot render. Please set the "
+            f"{parameter_name} to a positive number."
+        )
+
+    # config.frame_rate holds the number of frames per second
+    fps = config.frame_rate
+    seconds_per_frame = 1 / fps
+    if run_time < seconds_per_frame:
+        logger.warning(
+            f"The original {parameter_name} of {caller_name}, {run_time:g} "
+            f"seconds, is too short for the current frame rate of {fps:g} "
+            f"FPS. Rendering with the shortest possible {parameter_name} of "
+            f"{seconds_per_frame:g} seconds instead."
+        )
+        new_run_time = seconds_per_frame
+    else:
+        new_run_time = run_time
+
+    return new_run_time
+
+
 class Wait(Animation):
     """A "no operation" animation.
 
@@ -610,7 +638,7 @@ def __init__(
         self.mobject.shader_wrapper_list = []
 
     def begin(self) -> None:
-        pass
+        self.run_time = validate_run_time(self.run_time, str(self))
 
     def finish(self) -> None:
         pass

manim/animation/composition.py

@@ -9,7 +9,7 @@
 import numpy as np
 
 from manim._config import config
-from manim.animation.animation import Animation, prepare_animation
+from manim.animation.animation import Animation, prepare_animation, validate_run_time
 from manim.constants import RendererType
 from manim.mobject.mobject import Group, Mobject
 from manim.mobject.opengl.opengl_mobject import OpenGLGroup
@@ -87,7 +87,7 @@ def begin(self) -> None:
                 f"Trying to play {self} without animations, this is not supported. "
                 "Please add at least one subanimation."
             )
-
+        self.run_time = validate_run_time(self.run_time, str(self))
         self.anim_group_time = 0.0
         if self.suspend_mobject_updating:
             self.group.suspend_updating()
@@ -235,6 +235,7 @@ def begin(self) -> None:
                 f"Trying to play {self} without animations, this is not supported. "
                 "Please add at least one subanimation."
             )
+        self.run_time = validate_run_time(self.run_time, str(self))
         self.update_active_animation(0)
 
     def finish(self) -> None:

manim/scene/scene.py

@@ -37,7 +37,7 @@
 from manim.mobject.opengl.opengl_mobject import OpenGLPoint
 
 from .. import config, logger
-from ..animation.animation import Animation, Wait, prepare_animation
+from ..animation.animation import Animation, Wait, prepare_animation, validate_run_time
 from ..camera.camera import Camera
 from ..constants import *
 from ..gui.gui import configure_pygui
@@ -1030,28 +1030,7 @@ def get_run_time(self, animations: list[Animation]):
         float
             The total ``run_time`` of all of the animations in the list.
         """
-        max_run_time = 0
-        frame_rate = (
-            1 / config.frame_rate
-        )  # config.frame_rate holds the number of frames per second
-        for animation in animations:
-            if animation.run_time <= 0:
-                raise ValueError(
-                    f"{animation} has a run_time of <= 0 seconds which Manim cannot render. "
-                    "Please set the run_time to be positive."
-                )
-            elif animation.run_time < frame_rate:
-                logger.warning(
-                    f"Original run time of {animation} is shorter than current frame "
-                    f"rate (1 frame every {frame_rate:.2f} sec.) which cannot be rendered. "
-                    "Rendering with the shortest possible duration instead."
-                )
-                animation.run_time = frame_rate
-
-            if animation.run_time > max_run_time:
-                max_run_time = animation.run_time
-
-        return max_run_time
+        return max(animation.run_time for animation in animations)
 
     def play(
         self,
@@ -1147,6 +1126,7 @@ def wait(
         --------
         :class:`.Wait`, :meth:`.should_mobjects_update`
         """
+        duration = validate_run_time(duration, str(self) + ".wait()", "duration")
         self.play(
             Wait(
                 run_time=duration,
@@ -1170,6 +1150,7 @@ def pause(self, duration: float = DEFAULT_WAIT_TIME):
         --------
         :meth:`.wait`, :class:`.Wait`
         """
+        duration = validate_run_time(duration, str(self) + ".pause()", "duration")
         self.wait(duration=duration, frozen_frame=True)
 
     def wait_until(self, stop_condition: Callable[[], bool], max_time: float = 60):
@@ -1183,6 +1164,7 @@ def wait_until(self, stop_condition: Callable[[], bool], max_time: float = 60):
         max_time
             The maximum wait time in seconds.
         """
+        max_time = validate_run_time(max_time, str(self) + ".wait_until()", "max_time")
         self.wait(max_time, stop_condition=stop_condition)
 
     def compile_animation_data(

tests/module/animation/test_animation.py

@@ -11,24 +11,20 @@
 )
 def test_animation_forbidden_run_time(run_time):
     test_scene = Scene()
-    with pytest.raises(ValueError, match="Please set the run_time to be positive"):
+    with pytest.raises(
+        ValueError, match="Please set the run_time to a positive number."
+    ):
         test_scene.play(FadeIn(None, run_time=run_time))
 
 
 def test_animation_run_time_shorter_than_frame_rate(manim_caplog, config):
     test_scene = Scene()
     test_scene.play(FadeIn(None, run_time=1 / (config.frame_rate + 1)))
-    assert (
-        "Original run time of FadeIn(Mobject) is shorter than current frame rate"
-        in manim_caplog.text
-    )
+    assert "too short for the current frame rate" in manim_caplog.text
 
 
 @pytest.mark.parametrize("frozen_frame", [False, True])
 def test_wait_run_time_shorter_than_frame_rate(manim_caplog, frozen_frame):
     test_scene = Scene()
     test_scene.wait(1e-9, frozen_frame=frozen_frame)
-    assert (
-        "Original run time of Wait(Mobject) is shorter than current frame rate"
-        in manim_caplog.text
-    )
+    assert "too short for the current frame rate" in manim_caplog.text