Add mjd_quatIntegrate, expose mjd_subQuat.

PiperOrigin-RevId: 546252926
Change-Id: I7d6b2bd6536e7e8afc368f3c46037c20f6a1cb5e

python/mujoco/bindings_test.py

@@ -1113,6 +1113,21 @@ Euler integrator, semi-implicit in velocity.
     self.assertGreater(np.linalg.norm(ds_dv), eps)
     self.assertGreater(np.linalg.norm(ds_da), eps)
 
+  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))
+    d1 = np.empty(9, np.float64)
+    d2 = np.empty(9, np.float64)
+    mujoco.mjd_subQuat(quat1, quat2, d1, d2)
+
+  def test_mjd_quat_intergrate(self):
+    scale = 0.1
+    vel = np.array((0.2, 0.3, 0.3))
+    d_quat = np.empty(9, np.float64)
+    d_vel = np.empty(9, np.float64)
+    d_h = np.empty(3, np.float64)
+    mujoco.mjd_quatIntegrate(vel, scale, d_quat, d_vel, d_h)
+
   def test_banded(self):
     n_total = 4
     n_band = 1

python/mujoco/functions.cc

@@ -1239,6 +1239,11 @@ PYBIND11_MODULE(_functions, pymodule) {
         return InterceptMjErrors(::mju_insertionSortInt)(
             res.data(), res.size());
       });
+  Def<traits::mju_Halton>(pymodule);
+  // Skipped: mju_strncpy (doesn't make sense in Python)
+  Def<traits::mju_sigmoid>(pymodule);
+
+  // Derivatives
   Def<traits::mjd_transitionFD>(
       pymodule,
       [](const raw::MjModel* m, raw::MjData* d,
@@ -1319,9 +1324,8 @@ PYBIND11_MODULE(_functions, pymodule) {
             DsDa.has_value() ? DsDa->data() : nullptr,
             DmDq.has_value() ? DmDq->data() : nullptr);
       });
-  Def<traits::mju_Halton>(pymodule);
-  // Skipped: mju_strncpy (doesn't make sense in Python)
-  Def<traits::mju_sigmoid>(pymodule);
+  Def<traits::mjd_subQuat>(pymodule);
+  Def<traits::mjd_quatIntegrate>(pymodule);
 }  // PYBIND11_MODULE NOLINT(readability/fn_size)
 }  // namespace
 }  // namespace mujoco::python