Added functionality for user payload data in mjSpec.

PiperOrigin-RevId: 738343134
Change-Id: I6217362ced9993afcd5a2914c78718ffe3bf753a

doc/APIreference/functions.rst

@@ -4458,6 +4458,33 @@ Resolve alternative orientations to quat, return error if any.
 
 Transform body into a frame.
 
+.. _mjs_setUserValue:
+
+`mjs_setUserValue <#mjs_setUserValue>`__
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. mujoco-include:: mjs_setUserValue
+
+Set user payload, overriding the existing value for the specified key if present.
+
+.. _mjs_getUserValue:
+
+`mjs_getUserValue <#mjs_getUserValue>`__
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. mujoco-include:: mjs_getUserValue
+
+Return user payload or NULL if none found.
+
+.. _mjs_deleteUserValue:
+
+`mjs_deleteUserValue <#mjs_deleteUserValue>`__
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. mujoco-include:: mjs_deleteUserValue
+
+Delete user payload.
+
 .. _ElementInitialization:
 
 Element initialization

doc/includes/references.h

@@ -3677,6 +3677,9 @@ void mjs_setFrame(mjsElement* dest, mjsFrame* frame);
 const char* mjs_resolveOrientation(double quat[4], mjtByte degree, const char* sequence,
                                    const mjsOrientation* orientation);
 mjsFrame* mjs_bodyToFrame(mjsBody** body);
+void mjs_setUserValue(mjsElement* element, const char* key, const void* data);
+const void* mjs_getUserValue(mjsElement* element, const char* key);
+void mjs_deleteUserValue(mjsElement* element, const char* key);
 void mjs_defaultSpec(mjSpec* spec);
 void mjs_defaultOrientation(mjsOrientation* orient);
 void mjs_defaultBody(mjsBody* body);