Replace mjs_setActivePlugins with mjs_activatePlugin.

PiperOrigin-RevId: 680613007
Change-Id: Ic03e0dc42a1f5f083e313672bc6e3ccebadc58b3

src/user/user_api.cc

@@ -205,6 +205,21 @@ void mjs_addSpec(mjSpec* s, mjSpec* child) {
 
 
 
+// activate plugin
+int mjs_activatePlugin(mjSpec* s, const char* name) {
+  int plugin_slot = -1;
+  const mjpPlugin* plugin = mjp_getPlugin(name, &plugin_slot);
+  if (!plugin) {
+    mju_error("unknown plugin '%s'", name);
+    return -1;
+  }
+  mjCModel* model = static_cast<mjCModel*>(s->element);
+  model->ActivatePlugin(plugin, plugin_slot);
+  return plugin_slot;
+}
+
+
+
 // delete object, it will call the appropriate destructor since ~mjCBase is virtual
 void mjs_delete(mjsElement* element) {
   mjCBase* object = static_cast<mjCBase*>(element);
@@ -1027,16 +1042,6 @@ void mjs_setPluginAttributes(mjsPlugin* plugin, void* attributes) {
 
 
 
-// Set active plugins.
-void mjs_setActivePlugins(mjSpec* s, void* activeplugins) {
-  mjCModel* modelC = static_cast<mjCModel*>(s->element);
-  std::vector<std::pair<const mjpPlugin*, int>>* active_plugins =
-      reinterpret_cast<std::vector<std::pair<const mjpPlugin*, int>>*>(activeplugins);
-  modelC->SetActivePlugins(std::move(*active_plugins));
-}
-
-
-
 // -------------------------- GLOBAL ASSET CACHE -------------------------------
 
 void mj_setCacheSize(mjCache cache, std::size_t size) {