Add childclass support to frames.

PiperOrigin-RevId: 615487831
Change-Id: I0e4d2efd52211701b4286a0b0de84424470a3a47

src/user/user_api.h

@@ -156,7 +156,7 @@ typedef struct _mjmPlugin {        // plugin specification
 typedef struct _mjmBody {          // body specification
   mjElement element;               // internal, do not modify
   mjString name;                   // name
-  mjString classname;              // childclass name
+  mjString childclass;             // childclass name
 
   // body frame
   double pos[3];                   // frame position
@@ -183,6 +183,8 @@ typedef struct _mjmBody {          // body specification
 
 typedef struct _mjmFrame {         // frame specification
   mjElement element;               // internal, do not modify
+  mjString name;                   // name
+  mjString childclass;             // childclass name
   double pos[3];                   // position
   double quat[4];                  // orientation
   mjmOrientation alt;              // alternative orientation

src/user/user_model.cc

@@ -636,6 +636,7 @@ void mjCModel::MakeLists(mjCBody* body) {
   for (int i=0; i<body->sites.size(); i++) sites.push_back(body->sites[i]);
   for (int i=0; i<body->cameras.size(); i++) cameras.push_back(body->cameras[i]);
   for (int i=0; i<body->lights.size(); i++) lights.push_back(body->lights[i]);
+  for (int i=0; i<body->frames.size(); i++) frames.push_back(body->frames[i]);
 
   // recursive call to all child bodies
   for (int i=0; i<body->bodies.size(); i++) MakeLists(body->bodies[i]);
@@ -2679,18 +2680,20 @@ static void reassignid(vector<T*>& list) {
 template <class T>
 static void processlist(mjListKeyMap& ids, vector<T*>& list,
                         mjtObj type, bool checkrepeat = true) {
-  // loop over list elements
-  for (size_t i=0; i < list.size(); i++) {
-    // check for incompatible id setting; SHOULD NOT OCCUR
-    if (list[i]->id!=-1 && list[i]->id!=i) {
-      throw mjCError(list[i], "incompatible id in %s array, position %d", mju_type2Str(type), i);
+  // assign ids for regular elements
+  if (type < mjNOBJECT) {
+    for (size_t i=0; i < list.size(); i++) {
+      // check for incompatible id setting; SHOULD NOT OCCUR
+      if (list[i]->id!=-1 && list[i]->id!=i) {
+        throw mjCError(list[i], "incompatible id in %s array, position %d", mju_type2Str(type), i);
+      }
+
+      // id equals position in array
+      list[i]->id = i;
+
+      // add to ids map
+      ids[type][list[i]->name] = i;
     }
-
-    // id equals position in array
-    list[i]->id = i;
-
-    // add to ids map
-    ids[type][list[i]->name] = i;
   }
 
   // check for repeated names
@@ -2855,6 +2858,9 @@ void mjCModel::TryCompile(mjModel*& m, mjData*& d, const mjVFS* vfs) {
     }
   }
 
+  // check repeated names in meta elements
+  processlist(ids, frames, mjOBJ_FRAME);
+
   // delete visual assets
   if (discardvisual) {
     DeleteAll(materials);

src/user/user_model.h

@@ -250,6 +250,7 @@ class mjCModel : private mjSpec {
   std::vector<mjCSite*>   sites;    // list of sites attached to this body
   std::vector<mjCCamera*> cameras;  // list of cameras
   std::vector<mjCLight*>  lights;   // list of lights
+  std::vector<mjCFrame*>  frames;   // list of frames
 
   // array of pointers to each object list (enumerated by type)
   std::array<std::vector<mjCBase*>*, mjNOBJECT> object_lists;

src/user/user_objects.cc

@@ -765,7 +765,7 @@ mjCBody& mjCBody::operator=(const mjCBody& other) {
 void mjCBody::PointToLocal() {
   spec.element = (mjElement)this;
   spec.name = (mjString)&name;
-  spec.classname = (mjString)&classname;
+  spec.childclass = (mjString)&classname;
   spec.userdata = (mjDoubleVec)&spec_userdata_;
   spec.plugin.name = (mjString)&plugin_name;
   spec.plugin.instance_name = (mjString)&plugin_instance_name;
@@ -1375,6 +1375,8 @@ mjCFrame& mjCFrame::operator=(const mjCFrame& other) {
 
 void mjCFrame::PointToLocal() {
   spec.element = (mjElement)this;
+  spec.name = (mjString)&name;
+  spec.childclass = (mjString)&classname;
   spec.info = (mjString)&info;
 }
 

src/user/user_objects.h

@@ -321,6 +321,8 @@ class mjCFrame : public mjCFrame_, private mjmFrame {
 
  public:
   mjmFrame spec;
+  using mjCBase::name;
+  using mjCBase::classname;
   using mjCBase::info;
 
   void CopyFromSpec(void);