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) {

src/user/user_api.h

@@ -63,6 +63,9 @@ MJAPI void mj_deleteSpec(mjSpec* s);
 // Add spec (model asset) to spec.
 MJAPI void mjs_addSpec(mjSpec* s, mjSpec* child);
 
+// Activate plugin, return slot number.
+MJAPI int mjs_activatePlugin(mjSpec* s, const char* name);
+
 
 //---------------------------------- Attachment ----------------------------------------------------
 
@@ -347,9 +350,6 @@ MJAPI const double* mjs_getDouble(const mjDoubleVec* source, int* size);
 
 //---------------------------------- Other utilities -----------------------------------------------
 
-// Set active plugins.
-MJAPI void mjs_setActivePlugins(mjSpec* s, void* activeplugins);
-
 // Set element's default.
 MJAPI void mjs_setDefault(mjsElement* element, mjsDefault* def);
 

src/user/user_model.cc

@@ -29,6 +29,7 @@
 #include <string_view>
 #include <thread>
 #include <unordered_map>
+#include <utility>
 #include <vector>
 
 #include <mujoco/mjdata.h>
@@ -4450,6 +4451,23 @@ bool mjCModel::CopyBack(const mjModel* m) {
   return true;
 }
 
+
+
+void mjCModel::ActivatePlugin(const mjpPlugin* plugin, int slot) {
+  bool already_declared = false;
+  for (const auto& [existing_plugin, existing_slot] : active_plugins_) {
+    if (plugin == existing_plugin) {
+      already_declared = true;
+      break;
+    }
+  }
+  if (!already_declared) {
+    active_plugins_.emplace_back(std::make_pair(plugin, slot));
+  }
+}
+
+
+
 void mjCModel::ResolvePlugin(mjCBase* obj, const std::string& plugin_name,
                              const std::string& plugin_instance_name, mjCPlugin** plugin_instance) {
   // if plugin_name is specified, check if it is in the list of active plugins

src/user/user_model.h

@@ -233,9 +233,7 @@ class mjCModel : public mjCModel_, private mjSpec {
   mjCBase* FindObject(mjtObj type, std::string name) const;         // find object given type and name
   mjCBase* FindTree(mjCBody* body, mjtObj type, std::string name);  // find tree object given name
   mjSpec* FindSpec(std::string name) const;                         // find spec given name
-  void SetActivePlugins(const std::vector<std::pair<const mjpPlugin*, int>>&& active_plugins) {
-    active_plugins_ = std::move(active_plugins);
-  }
+  void ActivatePlugin(const mjpPlugin* plugin, int slot);           // activate plugin
 
   // accessors
   std::string get_meshdir() const { return meshdir_; }

src/xml/xml_native_reader.cc

@@ -2882,7 +2882,6 @@ void mjXReader::Default(XMLElement* section, const mjsDefault* def, const mjVFS*
 // extension section parser
 void mjXReader::Extension(XMLElement* section) {
   XMLElement* elem = FirstChildElement(section);
-  std::vector<std::pair<const mjpPlugin*, int>> active_plugins;
 
   while (elem) {
     // get sub-element name
@@ -2890,23 +2889,8 @@ void mjXReader::Extension(XMLElement* section) {
 
     if (name == "plugin") {
       string plugin_name;
-      int plugin_slot = -1;
       ReadAttrTxt(elem, "plugin", plugin_name, /* required = */ true);
-      const mjpPlugin* plugin = mjp_getPlugin(plugin_name.c_str(), &plugin_slot);
-      if (!plugin) {
-        throw mjXError(elem, "unknown plugin '%s'", plugin_name.c_str());
-      }
-
-      bool already_declared = false;
-      for (const auto& [existing_plugin, existing_slot] : active_plugins) {
-        if (plugin == existing_plugin) {
-          already_declared = true;
-          break;
-        }
-      }
-      if (!already_declared) {
-        active_plugins.emplace_back(std::make_pair(plugin, plugin_slot));
-      }
+      int plugin_slot = mjs_activatePlugin(spec, plugin_name.c_str());
 
       XMLElement* child = FirstChildElement(elem);
       while (child) {
@@ -2933,8 +2917,6 @@ void mjXReader::Extension(XMLElement* section) {
     // advance to next element
     elem = NextSiblingElement(elem);
   }
-
-  mjs_setActivePlugins(spec, &active_plugins);
 }