Make it an option (default to false) to prerun a scene to calculate i…

…ts number of frames
KristelCocoli · Feb 3, 2023 · b25f022 · b25f022
1 parent 7c561d3
commit b25f022
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Showing 3 changed files with 16 additions and 7 deletions.
diff --git a/manimlib/config.py b/manimlib/config.py
@@ -160,6 +160,12 @@ def parse_cli():
             action="store_true",
             help="Show progress bar for each animation",
         )
+        parser.add_argument(
+            "--prerun",
+            action="store_true",
+            help="Calculate total framecount, to display in a progress bar, by doing " + \
+                 "an initial run of the scene which skips animations."
+        )
         parser.add_argument(
             "--video_dir",
             help="Directory to write video",
@@ -489,6 +495,7 @@ def get_configuration(args: Namespace) -> dict:
         "presenter_mode": args.presenter_mode,
         "leave_progress_bars": args.leave_progress_bars,
         "show_animation_progress": args.show_animation_progress,
+        "prerun": args.prerun,
         "embed_exception_mode": custom_config["embed_exception_mode"],
         "embed_error_sound": custom_config["embed_error_sound"],
     }
diff --git a/manimlib/extract_scene.py b/manimlib/extract_scene.py
@@ -61,13 +61,15 @@ def get_scene_config(config):
     }
 
 
-def compute_total_frames(scene_class, scene_config):
+def compute_total_frames(scene_class, scene_config, config):
     """
     When a scene is being written to file, a copy of the scene is run with
     skip_animations set to true so as to count how many frames it will require.
     This allows for a total progress bar on rendering, and also allows runtime
     errors to be exposed preemptively for long running scenes.
     """
+    if not config["prerun"]:
+        return -1
     pre_config = copy.deepcopy(scene_config)
     pre_config["file_writer_config"]["write_to_movie"] = False
     pre_config["file_writer_config"]["save_last_frame"] = False
@@ -90,7 +92,7 @@ def get_scenes_to_render(scene_classes, scene_config, config):
             if scene_class.__name__ == scene_name:
                 fw_config = scene_config["file_writer_config"]
                 if fw_config["write_to_movie"]:
-                    fw_config["total_frames"] = compute_total_frames(scene_class, scene_config)
+                    fw_config["total_frames"] = compute_total_frames(scene_class, scene_config, config)
                 scene = scene_class(**scene_config)
                 result.append(scene)
                 found = True
@@ -109,7 +111,7 @@ def get_scenes_to_render(scene_classes, scene_config, config):
     for scene_class in scene_classes:
         fw_config = scene_config["file_writer_config"]
         if fw_config["write_to_movie"]:
-            fw_config["total_frames"] = compute_total_frames(scene_class, scene_config)
+            fw_config["total_frames"] = compute_total_frames(scene_class, scene_config, config)
         scene = scene_class(**scene_config)
         result.append(scene)
     return result

diff --git a/manimlib/scene/scene_file_writer.py b/manimlib/scene/scene_file_writer.py
@@ -46,7 +46,7 @@ def __init__(
         show_file_location_upon_completion: bool = False,
         quiet: bool = False,
         total_frames: int = 0,
-        progress_description_len: int = 40,
+        progress_description_len: int | None = None,
     ):
         self.scene: Scene = scene
         self.write_to_movie = write_to_movie
@@ -62,7 +62,8 @@ def __init__(
         self.show_file_location_upon_completion = show_file_location_upon_completion
         self.quiet = quiet
         self.total_frames = total_frames
-        self.progress_description_len = progress_description_len
+        self.progress_description_len = progress_description_len or \
+            40 if total_frames > 0 else 80
 
         # State during file writing
         self.writing_process: sp.Popen | None = None
@@ -278,10 +279,9 @@ def open_movie_pipe(self, file_path: str) -> None:
         command += [self.temp_file_path]
         self.writing_process = sp.Popen(command, stdin=sp.PIPE)
 
-        if self.total_frames > 0 and not self.quiet:
+        if not self.quiet:
             self.progress_display = ProgressDisplay(
                 range(self.total_frames),
-                # bar_format="{l_bar}{bar}|{n_fmt}/{total_fmt}",
                 leave=False,
                 ascii=True if platform.system() == 'Windows' else None,
                 dynamic_ncols=True,