fix(lib): prevent filename collision

Apparently, ManimCE can produce two different animations with the same name (i.e., the same hash). As documented, ManimGL would any produce files with the same name so this fix was needed.

Closes #428

manim_slides/config.py

@@ -324,15 +324,19 @@ def to_file(self, path: Path) -> None:
             f.write(self.model_dump_json(indent=2))
 
     def copy_to(
-        self, folder: Path, use_cached: bool = True, include_reversed: bool = True
+        self,
+        folder: Path,
+        use_cached: bool = True,
+        include_reversed: bool = True,
+        prefix: str = "",
     ) -> "PresentationConfig":
         """Copy the files to a given directory."""
         for slide_config in self.slides:
             file = slide_config.file
             rev_file = slide_config.rev_file
 
-            dest = folder / file.name
-            rev_dest = folder / rev_file.name
+            dest = folder / f"{prefix}{file.name}"
+            rev_dest = folder / f"{prefix}{rev_file.name}"
 
             slide_config.file = dest
             slide_config.rev_file = rev_dest

manim_slides/convert.py

@@ -404,8 +404,27 @@ def convert_to(self, dest: Path) -> None:
 
             full_assets_dir.mkdir(parents=True, exist_ok=True)
 
-            for presentation_config in self.presentation_configs:
-                presentation_config.copy_to(full_assets_dir, include_reversed=False)
+            num_presentation_configs = len(self.presentation_configs)
+
+            if num_presentation_configs > 1:
+                # Prevent possible name collision, see:
+                # https://github.com/jeertmans/manim-slides/issues/428
+                # With ManimCE, this should not happen (but happens...)
+                # With ManimGL, this can easily occur since filenames are just basic integers...
+                num_digits = len(str(num_presentation_configs - 1))
+
+                def prefix(i: int) -> str:
+                    return f"s{i:0{num_digits}d}_"
+
+            else:
+
+                def prefix(i: int) -> str:
+                    return ""
+
+            for i, presentation_config in enumerate(self.presentation_configs):
+                presentation_config.copy_to(
+                    full_assets_dir, include_reversed=False, prefix=prefix(i)
+                )
 
         dest.parent.mkdir(parents=True, exist_ok=True)