Add numfig_restart option to make it possible to restart figure numbering

AUTHORS.rst

@@ -50,6 +50,7 @@ Contributors
 * Dimitri Papadopoulos Orfanos -- linting and spelling
 * Dmitry Shachnev -- modernisation and reproducibility
 * Doug Hellmann -- graphviz improvements
+* Elijah Greenstein -- numfig_restart option
 * Eric Larson -- better error messages
 * Eric N. Vander Weele -- autodoc improvements
 * Eric Wieser -- autodoc improvements

CHANGES.rst

@@ -68,6 +68,9 @@ Features added
   Patch by Jean-François B.
 * #13508: Initial support for :pep:`695` type aliases.
   Patch by Martin Matouš, Jeremy Maitin-Shepard, and Adam Turner.
+* #14081: Add :confval:`numfig_restart` option to make it possible to restart
+  figure numbering at each ``:numbered:`` toctree.
+  Patch by Elijah Greenstein.
 * #14023: Add the new :confval:`mathjax_config_path` option
   to load MathJax configuration from a file.
   Patch by Randolf Scholz and Adam Turner.

doc/usage/configuration.rst

@@ -359,6 +359,25 @@ Options for figure numbering
 
    .. versionadded:: 1.3
 
+
+.. confval:: numfig_restart
+   :type: :code-py:`bool`
+   :default: :code-py:`False`
+
+   If :code-py:`True`, then Sphinx restarts figure numbering every time Sphinx
+   encounters a :rst:dir:`toctree` directive with the ``:numbered:`` option
+   activated. You can use this option to make HTML/EPUB figure numbers
+   correspond to LaTeX figure numbers when using :confval:`latex_documents` to
+   group files into multiple LaTeX documents.
+
+   .. note::
+
+      This option does not change the figure numbers assigned by the LaTeX
+      builder.
+
+   .. versionadded:: 8.3
+
+
 .. confval:: numfig_secnum_depth
    :type: :code-py:`int`
    :default: :code-py:`1`

sphinx/config.py

@@ -288,6 +288,7 @@ class Config:
         'numfig_secnum_depth': _Opt(1, 'env', frozenset((int, types.NoneType))),
         # numfig_format will be initialized in init_numfig_format()
         'numfig_format': _Opt({}, 'env', frozenset((dict,))),
+        'numfig_restart': _Opt(False, 'env', frozenset((bool,))),
         'maximum_signature_line_length': _Opt(
             None, 'env', frozenset((int, types.NoneType))
         ),

sphinx/environment/collectors/toctree.py

@@ -349,6 +349,8 @@ def _walk_doctree(
                     else:
                         _walk_doctree(docname, subnode, secnum)
                 elif isinstance(subnode, addnodes.toctree):
+                    if docname in env.numbered_toctrees and env.config.numfig_restart:
+                        fignum_counter.clear()
                     for _title, subdocname in subnode['entries']:
                         if url_re.match(subdocname) or subdocname == 'self':
                             # don't mess with those