Add OnePlugin read/write functions and remove redundant plugin attributes from mjCActuator.

PiperOrigin-RevId: 525708657
Change-Id: I762de238f989b13877d5f9198c83c16ea9dc1d8b

src/user/user_objects.h

@@ -929,12 +929,6 @@ class mjCActuator : public mjCBase {
   std::string slidersite;         // site defining cylinder, for slider-crank only
   std::string refsite;            // reference site, for site transmission only
 
-  // plugin support
-  bool is_plugin;
-  std::string plugin_name;
-  std::string plugin_instance_name;
-  mjCPlugin* plugin_instance;
-
  private:
   mjCActuator(mjCModel* = 0, mjCDef* = 0);// constructor
   void Compile(void);                     // compiler

src/xml/xml_native_reader.cc

@@ -1841,15 +1841,7 @@ void mjXReader::OneActuator(XMLElement* elem, mjCActuator* pact) {
   }
 
   else if (type == "plugin") {
-    pact->is_plugin = true;
+    OnePlugin(elem, pact);
-    ReadAttrTxt(elem, "plugin", pact->plugin_name);
-    ReadAttrTxt(elem, "instance", pact->plugin_instance_name);
-    if (pact->plugin_instance_name.empty()) {
-      pact->plugin_instance = model->AddPlugin();
-    } else {
-      model->hasImplicitPluginElem = true;
-    }
-    ReadPluginConfigs(elem, pact->plugin_instance);
   }
 
   else {          // SHOULD NOT OCCUR
@@ -2087,6 +2079,20 @@ void mjXReader::OneComposite(XMLElement* elem, mjCBody* pbody, mjCDef* def) {
 
 
 
+void mjXReader::OnePlugin(XMLElement* elem, mjCBase* object) {
+  object->is_plugin = true;
+  ReadAttrTxt(elem, "plugin", object->plugin_name);
+  ReadAttrTxt(elem, "instance", object->plugin_instance_name);
+  if (object->plugin_instance_name.empty()) {
+    object->plugin_instance = model->AddPlugin();
+  } else {
+    model->hasImplicitPluginElem = true;
+  }
+  ReadPluginConfigs(elem, object->plugin_instance);
+}
+
+
+
 //------------------ MJCF-specific sections --------------------------------------------------------
 
 // default section parser
@@ -2699,15 +2705,7 @@ void mjXReader::Body(XMLElement* section, mjCBody* pbody) {
 
     // plugin sub-element
     else if (name == "plugin") {
-      pbody->is_plugin = true;
+      OnePlugin(elem, pbody);
-      ReadAttrTxt(elem, "plugin", pbody->plugin_name);
-      ReadAttrTxt(elem, "instance", pbody->plugin_instance_name);
-      if (pbody->plugin_instance_name.empty()) {
-        pbody->plugin_instance = model->AddPlugin();
-      } else {
-        model->hasImplicitPluginElem = true;
-      }
-      ReadPluginConfigs(elem, pbody->plugin_instance);
     }
 
     // composite sub-element

src/xml/xml_native_reader.h

@@ -64,6 +64,7 @@ class mjXReader : public mjXBase {
   void OneTendon(tinyxml2::XMLElement* elem, mjCTendon* ptendon);
   void OneActuator(tinyxml2::XMLElement* elem, mjCActuator* pactuator);
   void OneComposite(tinyxml2::XMLElement* elem, mjCBody* pbody, mjCDef* def);
+  void OnePlugin(tinyxml2::XMLElement* elem, mjCBase* object);
 
   mjXSchema schema;                                                   // schema used for validation
   mjCDef* GetClass(tinyxml2::XMLElement* section);                    // get default class name

src/xml/xml_native_writer.cc

@@ -618,24 +618,7 @@ void mjXWriter::OneActuator(XMLElement* elem, mjCActuator* pact, mjCDef* def) {
 
   // plugins: write config attributes
   if (pact->is_plugin) {
-    if (!pact->plugin_instance_name.empty()) {
+    OnePlugin(elem, pact);
-      WriteAttrTxt(elem, "instance", pact->plugin_instance_name);
-    } else {
-      WriteAttrTxt(elem, "plugin", pact->plugin_name);
-      const mjpPlugin* plugin = mjp_getPluginAtSlot(
-          pact->plugin_instance->plugin_slot);
-      const char* c = &pact->plugin_instance->flattened_attributes[0];
-      for (int i = 0; i < plugin->nattribute; ++i) {
-        std::string value(c);
-        if (!value.empty()) {
-          XMLElement* config_elem = InsertEnd(elem, "config");
-          WriteAttrTxt(config_elem, "key", plugin->attributes[i]);
-          WriteAttrTxt(config_elem, "value", value);
-          c += value.size();
-        }
-        ++c;
-      }
-    }
   }
 
   // non-plugins: write actuator parameters
@@ -665,6 +648,30 @@ void mjXWriter::OneActuator(XMLElement* elem, mjCActuator* pact, mjCDef* def) {
 
 
 
+// write plugin
+void mjXWriter::OnePlugin(XMLElement* elem, mjCBase* object) {
+  if (!object->plugin_instance_name.empty()) {
+    WriteAttrTxt(elem, "instance", object->plugin_instance_name);
+  } else {
+    WriteAttrTxt(elem, "plugin", object->plugin_name);
+    const mjpPlugin* plugin = mjp_getPluginAtSlot(
+        object->plugin_instance->plugin_slot);
+    const char* c = &object->plugin_instance->flattened_attributes[0];
+    for (int i = 0; i < plugin->nattribute; ++i) {
+      std::string value(c);
+      if (!value.empty()) {
+        XMLElement* config_elem = InsertEnd(elem, "config");
+        WriteAttrTxt(config_elem, "key", plugin->attributes[i]);
+        WriteAttrTxt(config_elem, "value", value);
+        c += value.size();
+      }
+      ++c;
+    }
+  }
+}
+
+
+
 //---------------------------------- class mjXWriter: top-level API --------------------------------
 
 // constructor
@@ -1382,24 +1389,7 @@ void mjXWriter::Body(XMLElement* elem, mjCBody* body) {
 
   // write plugin
   if (body->is_plugin) {
-    XMLElement *child = InsertEnd(elem, "plugin");
+    OnePlugin(elem, body);
-    if (!body->plugin_instance_name.empty()) {
-      WriteAttrTxt(child, "instance", body->plugin_instance_name);
-    } else {
-      WriteAttrTxt(child, "plugin", body->plugin_name);
-      const mjpPlugin* plugin = mjp_getPluginAtSlot(
-          body->plugin_instance->plugin_slot);
-      const char* c = &body->plugin_instance->flattened_attributes[0];
-      for (int i = 0; i < plugin->nattribute; ++i) {
-        std::string value(c);
-        if (!value.empty()) {
-          WriteAttrTxt(child, std::string("plugin:") + plugin->attributes[i],
-                        value);
-          c += value.size();
-        }
-        ++c;
-      }
-    }
   }
 
   // write child bodies recursively

src/xml/xml_native_writer.h

@@ -61,6 +61,7 @@ class mjXWriter : public mjXBase {
   void OneEquality(tinyxml2::XMLElement* elem,  mjCEquality* pequality, mjCDef* def);
   void OneTendon(tinyxml2::XMLElement* elem,    mjCTendon* ptendon,     mjCDef* def);
   void OneActuator(tinyxml2::XMLElement* elem,  mjCActuator* pactuator, mjCDef* def);
+  void OnePlugin(tinyxml2::XMLElement* elem,    mjCBase* object);
 
   bool writingdefaults;                       // true during defaults write
 };