Add missing global fields to mjmModel.

PiperOrigin-RevId: 610415124
Change-Id: I07f284804bf73cb67703597973b50b8c00ea8deb

src/user/user_api.cc

@@ -510,6 +510,9 @@ void mjm_setDouble(mjDoubleVec dest, const double* array, int size) {
 // get string
 const char* mjm_getString(const mjString source) {
   std::string* str = reinterpret_cast<std::string*>(source);
+  if (!str) {
+    return nullptr;
+  }
   return str->c_str();
 }
 

src/user/user_api.h

@@ -125,6 +125,13 @@ typedef struct _mjmModel {         // model specification
 
   // sizes
   int nkey;                       // number of keyframes
+
+  // global data
+  mjString comment;               // comment at top of XML
+  mjString modelfiledir;          // path to model file
+
+  // other
+  bool hasImplicitPluginElem;     // already encountered an implicit plugin sensor/actuator
 } mjmModel;
 
 

src/user/user_flexcomp.cc

@@ -837,7 +837,8 @@ bool mjCFlexcomp::MakeMesh(mjCModel* model, char* error, int error_sz) {
   }
 
   // load resource
-  string filename = mjuu_makefullname(model->modelfiledir, mjm_getString(model->spec.meshdir), file);
+  string filename = mjuu_makefullname(mjm_getString(model->spec.modelfiledir),
+                                      mjm_getString(model->spec.meshdir), file);
   mjResource* resource = nullptr;
 
   try {
@@ -943,7 +944,8 @@ bool mjCFlexcomp::MakeGMSH(mjCModel* model, char* error, int error_sz) {
   }
 
   // open resource
-  string filename = mjuu_makefullname(model->modelfiledir, mjm_getString(model->spec.meshdir), file);
+  string filename = mjuu_makefullname(mjm_getString(model->spec.modelfiledir),
+                                      mjm_getString(model->spec.meshdir), file);
   mjResource* resource = nullptr;
 
   try {

src/user/user_mesh.cc

@@ -348,7 +348,7 @@ void mjCMesh::Compile(const mjVFS* vfs) {
       throw mjCError(this, "unsupported content type: '%s'", asset_type.c_str());
     }
 
-    string filename = mjuu_makefullname(model->modelfiledir, model->meshdir_, file_);
+    string filename = mjuu_makefullname(model->modelfiledir_, model->meshdir_, file_);
     mjResource* resource = LoadResource(filename, vfs);
 
     try {
@@ -1951,7 +1951,7 @@ void mjCSkin::Compile(const mjVFS* vfs) {
       throw mjCError(this, "Unknown skin file type: %s", file_.c_str());
     }
 
-    string filename = mjuu_makefullname(model->modelfiledir, model->meshdir_, file_);
+    string filename = mjuu_makefullname(model->modelfiledir_, model->meshdir_, file_);
     mjResource* resource = LoadResource(filename, vfs);
 
     try {

src/user/user_model.cc

@@ -84,8 +84,8 @@ static void copyvec(T1* dest, T2* src, int n) {
 // constructor
 mjCModel::mjCModel() {
   mjm_defaultModel(spec);
-  comment.clear();
+  spec_comment_.clear();
-  modelfiledir.clear();
+  spec_modelfiledir_.clear();
   spec_meshdir_.clear();
   spec_texturedir_.clear();
   spec_modelname_ = "MuJoCo Model";
@@ -177,6 +177,8 @@ mjCModel::mjCModel() {
 
 void mjCModel::PointToLocal() {
   spec.element = (mjElement)this;
+  spec.comment = (mjString)&spec_comment_;
+  spec.modelfiledir = (mjString)&spec_modelfiledir_;
   spec.modelname = (mjString)&spec_modelname_;
   spec.meshdir = (mjString)&spec_meshdir_;
   spec.texturedir = (mjString)&spec_texturedir_;
@@ -186,9 +188,13 @@ void mjCModel::PointToLocal() {
 
 void mjCModel::CopyFromSpec() {
   *static_cast<mjmModel*>(this) = spec;
+  comment_ = spec_comment_;
+  modelfiledir_ = spec_modelfiledir_;
   modelname_ = spec_modelname_;
   meshdir_ = spec_meshdir_;
   texturedir_ = spec_texturedir_;
+  comment = (mjString)&comment_;
+  modelfiledir = (mjString)&modelfiledir_;
   modelname = (mjString)&modelname_;
   meshdir = (mjString)&meshdir_;
   texturedir = (mjString)&texturedir_;

src/user/user_model.h

@@ -129,9 +129,8 @@ class mjCModel : private mjmModel {
 
 
   //------------------------ global data
-  std::string comment;            // comment at top of XML
-  std::string modelfiledir;       // path to model file
   std::vector<mjCDef*> defaults;  // settings for each defaults class
+  std::vector<std::pair<const mjpPlugin*, int>> active_plugins;  // list of active plugins
 
  private:
   void TryCompile(mjModel*& m, mjData*& d, const mjVFS* vfs);
@@ -245,8 +244,6 @@ class mjCModel : private mjmModel {
   std::vector<mjCText*>     texts;       // list of text fields
   std::vector<mjCTuple*>    tuples;      // list of tuple fields
   std::vector<mjCKey*>      keys;        // list of keyframe fields
-
-  std::vector<std::pair<const mjpPlugin*, int>> active_plugins;  // list of active plugins
   std::vector<mjCPlugin*>   plugins;     // list of plugin instances
 
   // pointers to objects created inside kinematic tree
@@ -272,16 +269,19 @@ class mjCModel : private mjmModel {
   // map from object names to ids
   mjListKeyMap ids;
 
-  bool hasImplicitPluginElem;     // already encountered an implicit plugin sensor/actuator
   bool compiled;                  // already compiled flag (cannot be compiled again)
   mjCError errInfo;               // last error info
   int fixCount;                   // how many bodies have been fixed
   std::vector<mjtNum> qpos0;      // save qpos0, to recognize changed key_qpos in write
 
   // variable-size attributes
+  std::string comment_;           // comment at top of XML
+  std::string modelfiledir_;      // path to model file
   std::string modelname_;
   std::string meshdir_;
   std::string texturedir_;
+  std::string spec_comment_;
+  std::string spec_modelfiledir_;
   std::string spec_modelname_;
   std::string spec_meshdir_;
   std::string spec_texturedir_;

src/user/user_objects.cc

@@ -2654,7 +2654,7 @@ void mjCHField::Compile(const mjVFS* vfs) {
       throw mjCError(this, "unsupported content type: '%s'", asset_type.c_str());
     }
 
-    string filename = mjuu_makefullname(model->modelfiledir, model->meshdir_, file_);
+    string filename = mjuu_makefullname(model->modelfiledir_, model->meshdir_, file_);
     mjResource* resource = LoadResource(filename, vfs);
 
     try {
@@ -3273,7 +3273,7 @@ void mjCTexture::LoadCubeSeparate(const mjVFS* vfs) {
       }
 
       // make filename
-      string filename = mjuu_makefullname(model->modelfiledir, model->texturedir_, cubefiles_[i]);
+      string filename = mjuu_makefullname(model->modelfiledir_, model->texturedir_, cubefiles_[i]);
 
       // load PNG or custom
       unsigned int w, h;
@@ -3373,7 +3373,7 @@ void mjCTexture::Compile(const mjVFS* vfs) {
     }
 
     // make filename
-    string filename = mjuu_makefullname(model->modelfiledir, model->texturedir_, file_);
+    string filename = mjuu_makefullname(model->modelfiledir_, model->texturedir_, file_);
 
     // dispatch
     if (type==mjTEXTURE_2D) {

src/xml/xml.cc

@@ -15,6 +15,7 @@
 #include "xml/xml.h"
 
 #include <locale.h>
+#include "user/user_api.h"
 
 #if defined(__APPLE__) || defined(__FreeBSD__)
 #include <xlocale.h>
@@ -348,9 +349,9 @@ mjCModel* mjParseXML(const char* filename, const mjVFS* vfs,
   int ndir = 0;
   mju_getResourceDir(resource, &dir, &ndir);
   if (dir != nullptr) {
-    model->modelfiledir = std::string(dir, ndir);
+    mjm_setString(model->spec.modelfiledir, std::string(dir, ndir).c_str());
   } else {
-    model->modelfiledir = "";
+    mjm_setString(model->spec.modelfiledir, "");
   }
 
   // close resource
@@ -362,8 +363,8 @@ mjCModel* mjParseXML(const char* filename, const mjVFS* vfs,
       // find include elements, replace them with subtree from xml file
       std::unordered_set<std::string> included = {filename};
       mjXReader parser;
-      parser.SetModelFileDir(model->modelfiledir);
+      parser.SetModelFileDir(mjm_getString(model->spec.modelfiledir));
-      mjIncludeXML(parser, root, model->modelfiledir, vfs, included);
+      mjIncludeXML(parser, root, mjm_getString(model->spec.modelfiledir), vfs, included);
 
       // parse MuJoCo model
       parser.SetModel(model);

src/xml/xml_native_reader.cc

@@ -811,9 +811,9 @@ void mjXReader::Parse(XMLElement* root) {
 
   // get comment
   if (root->FirstChild() && root->FirstChild()->ToComment()) {
-    model->comment = root->FirstChild()->Value();
+    mjm_setString(model->spec.comment, root->FirstChild()->Value());
   } else {
-    model->comment.clear();
+    mjm_setString(model->spec.comment, "");
   }
 
   //------------------- parse MuJoCo sections embedded in all XML formats

src/xml/xml_native_writer.cc

@@ -781,8 +781,9 @@ string mjXWriter::Write(char *error, size_t error_sz) {
   doc.InsertFirstChild(root);
 
   // write comment if present
-  if (!model->comment.empty()) {
+  string text = mjm_getString(model->comment);
-    XMLComment* comment = doc.NewComment(model->comment.c_str());
+  if (!text.empty()) {
+    XMLComment* comment = doc.NewComment(text.c_str());
     root->LinkEndChild(comment);
   }