Improve bindings for mjd_subQuat.

- Accept `None` for optional arguments.
- Accept 3x3 matrices for matrix arguments.

PiperOrigin-RevId: 611000820
Change-Id: Id28cdb2ae574f372ff251f94ab4557d9d2eaa80b

python/mujoco/bindings_test.py

@@ -1205,10 +1205,16 @@ Euler integrator, semi-implicit in velocity.
 
   def test_mjd_sub_quat(self):
     quat1 = np.array((0.2, 0.3, 0.3, 0.4))
-    quat2 = np.array((0.2, 0.3, 0.3, 0.4))
+    quat2 = np.array((0.1, 0.2, 0.4, 0.5))
     d1 = np.empty(9, np.float64)
     d2 = np.empty(9, np.float64)
     mujoco.mjd_subQuat(quat1, quat2, d1, d2)
+    d3 = np.empty((3, 3), np.float64)
+    d4 = np.empty((3, 3), np.float64)
+    mujoco.mjd_subQuat(quat1, quat2, None, d3)
+    mujoco.mjd_subQuat(quat1, quat2, d4, None)
+    np.testing.assert_array_equal(d2, d3.flatten())
+    np.testing.assert_array_equal(d1, d4.flatten())
 
   def test_mjd_quat_intergrate(self):
     scale = 0.1

python/mujoco/functions.cc

@@ -1353,7 +1353,28 @@ PYBIND11_MODULE(_functions, pymodule) {
             DsDa.has_value() ? DsDa->data() : nullptr,
             DmDq.has_value() ? DmDq->data() : nullptr);
       });
-  Def<traits::mjd_subQuat>(pymodule);
+  Def<traits::mjd_subQuat>(
+      pymodule,
+      [](Eigen::Ref<const EigenVectorX> qa, Eigen::Ref<const EigenVectorX> qb,
+         std::optional<Eigen::Ref<EigenArrayXX>> Da,
+         std::optional<Eigen::Ref<EigenArrayXX>> Db) {
+        if (qa.size() != 4) {
+          throw py::type_error("qa must have size 4");
+        }
+        if (qb.size() != 4) {
+          throw py::type_error("qb must have size 4");
+        }
+        if (Da.has_value() && Da->size() != 9) {
+          throw py::type_error("Da must have size 9");
+        }
+        if (Db.has_value() && Db->size() != 9) {
+          throw py::type_error("Db must have size 9");
+        }
+        return InterceptMjErrors(::mjd_subQuat)(
+            qa.data(), qb.data(),
+            Da.has_value() ? Da->data() : nullptr,
+            Db.has_value() ? Db->data() : nullptr);
+      });
   Def<traits::mjd_quatIntegrate>(pymodule);
 
   pymodule.def(