Fixed behavior of config.background_opacity < 1 and duplicated log …

…messages (#3680)

* Fixes #3614

Setting background_transparency=0.0 should have the same effect than
setting transparent=True. The output format must be compatible
with transparency (.mov, .webm). Otherwise ffpmeg fails.

This patch ensures that background_transparency=0.0 triggers the
change of the output format. Also a WARNING is raised about
the change in the output format.

I want to thank @SirJamesClarkMaxwell for inspiring me to tackle
this issue.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* test config.background_opacity < 1

* fix config behavior for config.background_opacity < 1

* fix logger messages being emitted twice

* actually cleanup usage of loggers, remove logger-imports; black

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* dry_run fixture

* remove debug print

* applied suggestion from review

* remove custom fixture from test_deprecation, use manim_caplog

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: Benjamin Hackl <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

manim/_config/logger_utils.py

@@ -99,6 +99,7 @@ def make_logger(
     logger = logging.getLogger("manim")
     logger.addHandler(rich_handler)
     logger.setLevel(verbosity)
+    logger.propagate = False
 
     if not (libav_logger := logging.getLogger()).hasHandlers():
         libav_logger.addHandler(rich_handler)

manim/_config/utils.py

@@ -40,6 +40,8 @@
 
 __all__ = ["config_file_paths", "make_config_parser", "ManimConfig", "ManimFrame"]
 
+logger = logging.getLogger("manim")
+
 
 def config_file_paths() -> list[Path]:
     """The paths where ``.cfg`` files will be searched for.
@@ -799,7 +801,7 @@ def digest_args(self, args: argparse.Namespace) -> Self:
             try:
                 self.upto_animation_number = nflag[1]
             except Exception:
-                logging.getLogger("manim").info(
+                logger.info(
                     f"No end scene number specified in -n option. Rendering from {nflag[0]} onwards...",
                 )
 
@@ -1038,7 +1040,7 @@ def verbosity(self, val: str) -> None:
             val,
             ["DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"],
         )
-        logging.getLogger("manim").setLevel(val)
+        logger.setLevel(val)
 
     @property
     def format(self) -> str:
@@ -1054,7 +1056,7 @@ def format(self, val: str) -> None:
         )
         self.resolve_movie_file_extension(self.transparent)
         if self.format == "webm":
-            logging.getLogger("manim").warning(
+            logger.warning(
                 "Output format set as webm, this can be slower than other formats",
             )
 
@@ -1272,6 +1274,8 @@ def background_opacity(self) -> float:
     @background_opacity.setter
     def background_opacity(self, value: float) -> None:
         self._set_between("background_opacity", value, 0, 1)
+        if self.background_opacity < 1:
+            self.resolve_movie_file_extension(is_transparent=True)
 
     @property
     def frame_size(self) -> tuple[int, int]:
@@ -1306,8 +1310,8 @@ def quality(self, value: str | None) -> None:
 
     @property
     def transparent(self) -> bool:
-        """Whether the background opacity is 0.0 (-t)."""
-        return self._d["background_opacity"] == 0.0
+        """Whether the background opacity is less than 1.0 (-t)."""
+        return self._d["background_opacity"] < 1.0
 
     @transparent.setter
     def transparent(self, value: bool) -> None:
@@ -1425,6 +1429,7 @@ def window_size(self, value: str) -> None:
         self._d.__setitem__("window_size", value)
 
     def resolve_movie_file_extension(self, is_transparent: bool) -> None:
+        prev_file_extension = self.movie_file_extension
         if is_transparent:
             self.movie_file_extension = ".webm" if self.format == "webm" else ".mov"
         elif self.format == "webm":
@@ -1433,6 +1438,11 @@ def resolve_movie_file_extension(self, is_transparent: bool) -> None:
             self.movie_file_extension = ".mov"
         else:
             self.movie_file_extension = ".mp4"
+        if self.movie_file_extension != prev_file_extension:
+            logger.warning(
+                f"Output format changed to '{self.movie_file_extension}' "
+                "to support transparency",
+            )
 
     @property
     def enable_gui(self) -> bool:
@@ -1778,7 +1788,7 @@ def tex_template_file(self) -> Path:
     def tex_template_file(self, val: str) -> None:
         if val:
             if not os.access(val, os.R_OK):
-                logging.getLogger("manim").warning(
+                logger.warning(
                     f"Custom TeX template {val} not found or not readable.",
                 )
             else:

manim/cli/render/global_options.py

@@ -1,13 +1,14 @@
 from __future__ import annotations
 
+import logging
 import re
 
 from cloup import Choice, option, option_group
 
-from ... import logger
-
 __all__ = ["global_options"]
 
+logger = logging.getLogger("manim")
+
 
 def validate_gui_location(ctx, param, value):
     if value:

manim/cli/render/render_options.py

@@ -1,15 +1,16 @@
 from __future__ import annotations
 
+import logging
 import re
 
 from cloup import Choice, option, option_group
 
 from manim.constants import QUALITIES, RendererType
 
-from ... import logger
-
 __all__ = ["render_options"]
 
+logger = logging.getLogger("manim")
+
 
 def validate_scene_range(ctx, param, value):
     try:

manim/renderer/shader_wrapper.py

@@ -1,14 +1,13 @@
 from __future__ import annotations
 
 import copy
+import logging
 import re
 from pathlib import Path
 
 import moderngl
 import numpy as np
 
-from .. import logger
-
 # Mobjects that should be rendered with
 # the same shader will be organized and
 # clumped together based on keeping track
@@ -17,6 +16,8 @@
 
 __all__ = ["ShaderWrapper"]
 
+logger = logging.getLogger("manim")
+
 
 def get_shader_dir():
     return Path(__file__).parent / "shaders"

manim/utils/deprecation.py

@@ -6,13 +6,14 @@
 
 
 import inspect
+import logging
 import re
 from collections.abc import Iterable
 from typing import Any, Callable
 
 from decorator import decorate, decorator
 
-from .. import logger
+logger = logging.getLogger("manim")
 
 
 def _get_callable_info(callable: Callable) -> tuple[str, str]:

manim/utils/testing/_frames_testers.py

@@ -1,18 +1,19 @@
 from __future__ import annotations
 
 import contextlib
+import logging
 import warnings
 from pathlib import Path
 
 import numpy as np
 
-from manim import logger
-
 from ._show_diff import show_diff_helper
 
 FRAME_ABSOLUTE_TOLERANCE = 1.01
 FRAME_MISMATCH_RATIO_TOLERANCE = 1e-5
 
+logger = logging.getLogger("manim")
+
 
 class _FramesTester:
     def __init__(self, file_path: Path, show_diff=False) -> None:

tests/conftest.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import logging
 import sys
 from pathlib import Path
 
@@ -45,6 +46,15 @@ def pytest_collection_modifyitems(config, items):
                 item.add_marker(slow_skip)
 
 
+@pytest.fixture
+def manim_caplog(caplog):
+    logger = logging.getLogger("manim")
+    logger.propagate = True
+    caplog.set_level(logging.INFO, logger="manim")
+    yield caplog
+    logger.propagate = False
+
+
 @pytest.fixture
 def config():
     saved = manim.config.copy()

tests/helpers/graphical_units.py

@@ -2,14 +2,16 @@
 
 from __future__ import annotations
 
+import logging
 import tempfile
 from pathlib import Path
 
 import numpy as np
 
-from manim import logger
 from manim.scene.scene import Scene
 
+logger = logging.getLogger("manim")
+
 
 def set_test_scene(scene_object: type[Scene], module_name: str, config):
     """Function used to set up the test data for a new feature. This will basically set up a pre-rendered frame for a scene. This is meant to be used only

tests/module/animation/test_animation.py

@@ -15,20 +15,20 @@ def test_animation_forbidden_run_time(run_time):
         test_scene.play(FadeIn(None, run_time=run_time))
 
 
-def test_animation_run_time_shorter_than_frame_rate(caplog, config):
+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 caplog.text
+        in manim_caplog.text
     )
 
 
 @pytest.mark.parametrize("frozen_frame", [False, True])
-def test_wait_run_time_shorter_than_frame_rate(caplog, frozen_frame):
+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 caplog.text
+        in manim_caplog.text
     )

tests/module/mobject/geometry/test_unit_geometry.py

@@ -15,14 +15,13 @@ def test_get_arc_center():
     )
 
 
-def test_BackgroundRectangle(caplog):
-    caplog.set_level(logging.INFO)
+def test_BackgroundRectangle(manim_caplog):
     c = Circle()
     bg = BackgroundRectangle(c)
     bg.set_style(fill_opacity=0.42)
     assert bg.get_fill_opacity() == 0.42
     bg.set_style(fill_opacity=1, hello="world")
     assert (
         "Argument {'hello': 'world'} is ignored in BackgroundRectangle.set_style."
-        in caplog.text
+        in manim_caplog.text
     )