Rename mj_stackAllocByte to mj_stackAlloc and make it public.

PiperOrigin-RevId: 561133040
Change-Id: I4f5ffe51c1287aa0c82af68bfe17ed6dd2ad09da

doc/APIreference/functions.rst

@@ -1232,6 +1232,15 @@ mj_resetDataKeyframe
 
 Reset data, set fields from specified keyframe.
 
+.. _mj_stackAlloc:
+
+mj_stackAlloc
+~~~~~~~~~~~~~
+
+.. mujoco-include:: mj_stackAlloc
+
+Allocate a specific number of bytes on :ref:`mjData` stack. Call mju_error on stack overflow.
+
 .. _mj_stackAllocNum:
 
 mj_stackAllocNum

doc/changelog.rst

@@ -38,20 +38,22 @@ General
    Euler integrator. See the :ref:`Numerical Integration<geIntegration>` section for more details.
 #. Added the flag :ref:`invdiscrete<option-flag-invdiscrete>`, which enables discrete-time inverse dynamics for all
    :ref:`integrators<option-integrator>` other than ``RK4``. See the flag documentation for more details.
-#. Renamed the function ``mj_stackAlloc`` to ``mj_stackAllocNum``.
+#. Changed the function ``mj_stackAlloc`` to allocate an arbitrary number of bytes, rather than in multiples of
+   ``sizeof(mjtNum)``, and add an additional argument for specifying the alignment of the returned pointer. The existing
+   functionality of allocating ``mjtNum`` arrays is still available through the new function ``mj_stackAllocNum``.
 #. Renamed the ``nstack`` field in ``mjModel`` and ``mjData`` to ``narena``. Changed ``narena``, ``pstack``, and
    ``maxuse_stack`` to count number of bytes rather than number of ``mjtNum``s.
 
 Python bindings
 ^^^^^^^^^^^^^^^
 
-9. Fixed `#870 <https://github.com/deepmind/mujoco/issues/870>`__ where calling ``update_scene`` with an invalid
-   camera name used the default camera.
+10. Fixed `#870 <https://github.com/deepmind/mujoco/issues/870>`__ where calling ``update_scene`` with an invalid
+    camera name used the default camera.
 
 Bug fixes
 ^^^^^^^^^
 
-10. Fixed a bug that was causing the geom margins to be ignored during the midphase.
+11. Fixed a bug that was causing the geom margins to be ignored during the midphase.
 
 
 Version 2.3.7 (July 20, 2023)

doc/includes/references.h

@@ -2213,6 +2213,7 @@ mjData* mj_copyData(mjData* dest, const mjModel* m, const mjData* src);
 void mj_resetData(const mjModel* m, mjData* d);
 void mj_resetDataDebug(const mjModel* m, mjData* d, unsigned char debug_value);
 void mj_resetDataKeyframe(const mjModel* m, mjData* d, int key);
+void* mj_stackAlloc(mjData* d, size_t bytes, size_t alignment);
 mjtNum* mj_stackAllocNum(mjData* d, int size);
 int* mj_stackAllocInt(mjData* d, int size);
 void mj_deleteData(mjData* d);

doc/programming/simulation.rst

@@ -722,9 +722,8 @@ the scope. If not, saving and restoring the stack pointer should be done manuall
 The function :ref:`mj_stackAllocNum` checks if there is enough space, and if so it advances the stack pointer,
 otherwise it triggers an error. It also keeps track of the maximum stack allocation;
 see :ref:`diagnostics <siDiagnostics>` below. Note that :ref:`mj_stackAllocNum` is only used for allocating
-``mjtNum`` arrays, the most common type of array. :ref:`mj_stackAllocInt` is provided for integer array allocation.
-Allocators for other types are also possible, as in
-`engine_collision_driver.c <https://github.com/deepmind/mujoco/blob/main/src/engine/engine_collision_driver.c>`__.
+``mjtNum`` arrays, the most common type of array. :ref:`mj_stackAllocInt` is provided for integer array allocation,
+and :ref:`mj_stackAlloc` is provided for allocation of arbitrary number of bytes and alignment.
 
 .. _siError: