Add mjmHField to C API.

PiperOrigin-RevId: 606933108
Change-Id: I21c895ed3e137dab8f57e2d0bcfb558aae2b971a

src/user/user_api.cc

@@ -147,6 +147,15 @@ mjmMesh* mjm_addMesh(void* model, void* defspec) {
 
 
 
+// add height field to model
+mjmHField* mjm_addHField(void* model) {
+  mjCModel* modelC = static_cast<mjCModel*>(model);
+  mjCHField* heightField = modelC->AddHField();
+  return &heightField->spec;
+}
+
+
+
 // add texture to model
 mjmTexture* mjm_addTexture(void* model) {
   mjCModel* modelC = static_cast<mjCModel*>(model);

src/user/user_api.h

@@ -346,6 +346,19 @@ typedef struct _mjmMesh {          // mesh specification
 } mjmMesh;
 
 
+typedef struct _mjmHField {        // height field specification
+  mjElement element;               // internal, do not modify
+  mjString name;                   // name
+  mjString content_type;           // content type of file
+  mjString file;                   // file: (nrow, ncol, [elevation data])
+  double size[4];                  // hfield size (ignore referencing geom size)
+  int nrow;                        // number of rows
+  int ncol;                        // number of columns
+  mjFloatVec userdata;             // user-provided elevation data
+  mjString info;                   // message appended to compiler errors
+} mjmHField;
+
+
 typedef struct _mjmTexture {       // texture specification
   mjElement element;               // internal, do not modify
   mjString name;                   // name
@@ -623,6 +636,9 @@ MJAPI mjmFlex* mjm_addFlex(void* model);
 // Add mesh to model.
 MJAPI mjmMesh* mjm_addMesh(void* model, void* defspec);
 
+// Add height field to model.
+MJAPI mjmHField* mjm_addHField(void* model);
+
 // Add texture to model.
 MJAPI mjmTexture* mjm_addTexture(void* model);
 
@@ -752,6 +768,9 @@ MJAPI void mjm_defaultFlex(mjmFlex& flex);
 // Default mesh attributes.
 MJAPI void mjm_defaultMesh(mjmMesh& mesh);
 
+// Default height field attributes.
+MJAPI void mjm_defaultHField(mjmHField& hfield);
+
 // Default texture attributes.
 MJAPI void mjm_defaultTexture(mjmTexture& texture);
 

src/user/user_init.cc

@@ -203,6 +203,13 @@ void mjm_defaultMesh(mjmMesh& mesh) {
 
 
 
+// default height field attributes
+void mjm_defaultHField(mjmHField& hfield) {
+  memset(&hfield, 0, sizeof(mjmHField));
+}
+
+
+
 // default texture attributes
 void mjm_defaultTexture(mjmTexture& texture) {
   memset(&texture, 0, sizeof(mjmTexture));

src/user/user_model.cc

@@ -3387,11 +3387,11 @@ bool mjCModel::CopyBack(const mjModel* m) {
   mjCHField* phf;
   for (int i=0; i<nhfield; i++) {
     phf = hfields[i];
-    int size = phf->userdata().size();
+    int size = phf->get_userdata().size();
     if (size) {
       int nrow = m->hfield_nrow[i];
       int ncol = m->hfield_ncol[i];
-      float* userdata = phf->userdata().data();
+      float* userdata = phf->get_userdata().data();
       float* modeldata = m->hfield_data + m->hfield_adr[i];
       // copy back in reverse row order
       for (int j=0; j<nrow; j++) {

src/user/user_objects.cc

@@ -2384,16 +2384,44 @@ void mjCLight::Compile(void) {
 
 // constructor
 mjCHField::mjCHField(mjCModel* _model) {
+  mjm_defaultHField(spec);
+
   // set model pointer
   model = _model;
 
   // clear variables
-  mjuu_setvec(size, 0, 0, 0, 0);
-  file.clear();
-  nrow = 0;
-  ncol = 0;
   data = 0;
-  userdata_.clear();
+  spec_file_.clear();
+  spec_userdata_.clear();
+
+  // point to local
+  PointToLocal();
+
+  // copy from spec
+  CopyFromSpec();
+}
+
+
+
+void mjCHField::PointToLocal() {
+  spec.element = (mjElement)this;
+  spec.name = (mjString)&name;
+  spec.file = (mjString)&spec_file_;
+  spec.content_type = (mjString)&spec_content_type_;
+  spec.userdata = (mjFloatVec)&spec_userdata_;
+  spec.info = (mjString)&info;
+}
+
+
+
+void mjCHField::CopyFromSpec() {
+  *static_cast<mjmHField*>(this) = spec;
+  file_ = spec_file_;
+  content_type_ = spec_content_type_;
+  userdata_ = spec_userdata_;
+  file = (mjString)&file_;
+  content_type = (mjString)&content_type_;
+  userdata = (mjFloatVec)&userdata_;
 }
 
 
@@ -2403,6 +2431,8 @@ mjCHField::~mjCHField() {
   if (data) {
     mju_free(data);
   }
+  userdata_.clear();
+  spec_userdata_.clear();
 }
 
 
@@ -2496,16 +2526,19 @@ void mjCHField::LoadPNG(mjResource* resource) {
 
 
 
-// user data setter
-void mjCHField::set_userdata(std::optional<std::vector<float>>&& userdata) {
-  if (userdata.has_value()) {
-    userdata_ = std::move(userdata.value());
-  }
-}
-
-
 // compiler
 void mjCHField::Compile(const mjVFS* vfs) {
+  CopyFromSpec();
+
+  // copy userdata into data
+  if (!userdata_.empty()) {
+    data = (float*) mju_malloc(nrow*ncol*sizeof(float));
+    if (!data) {
+      throw mjCError(this, "could not allocate buffers in hfield");
+    }
+    memcpy(data, userdata_.data(), nrow*ncol*sizeof(float));
+  }
+
   // check size parameters
   for (int i=0; i<4; i++)
     if (size[i]<=0)
@@ -2514,18 +2547,18 @@ void mjCHField::Compile(const mjVFS* vfs) {
 
   // remove path from file if necessary
   if (model->strippath) {
-    file = mjuu_strippath(file);
+    file_ = mjuu_strippath(file_);
   }
 
   // load from file if specified
-  if (!file.empty()) {
+  if (!file_.empty()) {
     // make sure hfield was not already specified manually
     if (nrow || ncol || data) {
       throw mjCError(this,
                      "hfield '%s' (id = %d) specified from file and manually", name.c_str(), id);
     }
 
-    std::string asset_type = GetAssetContentType(file, content_type);
+    std::string asset_type = GetAssetContentType(file_, content_type_);
 
     // fallback to custom
     if (asset_type.empty()) {
@@ -2536,7 +2569,7 @@ 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 {
@@ -2564,7 +2597,7 @@ void mjCHField::Compile(const mjVFS* vfs) {
     emax = mjMAX(emax, data[i]);
   }
   if (emin>emax) {
-    throw mjCError(this, "invalid data range in hfield '%s'", file.c_str());
+    throw mjCError(this, "invalid data range in hfield '%s'", file_.c_str());
   }
   for (int i=0; i<nrow*ncol; i++) {
     data[i] -= emin;

src/user/user_objects.h

@@ -816,34 +816,39 @@ class mjCSkin: public mjCBase {
 //------------------------- class mjCHField --------------------------------------------------------
 // Describes a height field
 
-class mjCHField : public mjCBase {
+class mjCHField : public mjCBase, private mjmHField {
+  friend class mjCGeom;
   friend class mjCModel;
   friend class mjXWriter;
 
  public:
-  std::string get_file() const { return file; }
+  mjmHField spec;
+  using mjCBase::name;
+  using mjCBase::info;
 
-  std::string content_type;       // content type of file
+  void CopyFromSpec(void);
-  std::string file;               // file: (nrow, ncol, [elevation data])
+  void PointToLocal(void);
-  double size[4];                 // hfield size (ignore referencing geom size)
+
-  int nrow;                       // number of rows
+  std::string get_file() const { return file_; }
-  int ncol;                       // number of columns
-  float* data;                    // elevation data, row-major format
 
   // getter for user data
-  std::vector<float>& userdata() { return userdata_; }
+  std::vector<float>& get_userdata() { return userdata_; }
-
-  // setter for user data
-  void set_userdata(std::optional<std::vector<float>>&& userdata);
 
  private:
   mjCHField(mjCModel* model);             // constructor
   ~mjCHField();                           // destructor
-  std::vector<float> userdata_;           // user-provided elevation data
+  float* data;                            // elevation data, row-major format
   void Compile(const mjVFS* vfs);         // compiler
 
   void LoadCustom(mjResource* resource);  // load from custom format
   void LoadPNG(mjResource* resource);     // load from PNG format
+
+  std::string file_;
+  std::string content_type_;
+  std::vector<float> userdata_;
+  std::string spec_file_;
+  std::string spec_content_type_;
+  std::vector<float> spec_userdata_;
 };
 
 

src/xml/xml_native_reader.cc

@@ -3136,43 +3136,57 @@ void mjXReader::Asset(XMLElement* section) {
     // hfield sub-element
     else if (name=="hfield") {
       // create hfield
-      mjCHField* phf = model->AddHField();
+      mjmHField* phf = mjm_addHField(model);
-      GetXMLPos(elem, phf);
+
+      // write error info
+      mjm_setString(phf->info,
+          std::string("line = " + std::to_string(elem->GetLineNum()) + ", column = -1").c_str());
 
       // read attributes
-      ReadAttrTxt(elem, "name", phf->name);
+      string name, content_type, file;
-      ReadAttrTxt(elem, "content_type", phf->content_type);
+      if (ReadAttrTxt(elem, "name", name)) {
-      ReadAttrTxt(elem, "file", phf->file);
+        mjm_setString(phf->name, name.c_str());
+      }
+      if (ReadAttrTxt(elem, "content_type", content_type)) {
+        mjm_setString(phf->content_type, content_type.c_str());
+      }
+      if (ReadAttrTxt(elem, "file", file)) {
+        mjm_setString(phf->file, file.c_str());
+      }
       ReadAttrInt(elem, "nrow", &phf->nrow);
       ReadAttrInt(elem, "ncol", &phf->ncol);
       ReadAttr(elem, "size", 4, phf->size, text, true);
 
       // allocate buffer for dynamic hfield, copy user data if given
-      if (phf->file.empty() && phf->nrow>0 && phf->ncol>0) {
+      if (file.empty() && phf->nrow>0 && phf->ncol>0) {
         int nrow = phf->nrow;
         int ncol = phf->ncol;
-        phf->data = (float*) mju_malloc(nrow*ncol*sizeof(float));
 
         // read user data
-        phf->set_userdata(ReadAttrVec<float>(elem, "elevation"));
+        auto userdata = ReadAttrVec<float>(elem, "elevation");
 
         // user data given, copy into data
-        if (!phf->userdata().empty()) {
+        if (userdata.has_value()) {
-          if (phf->userdata().size() != nrow*ncol) {
+          if (userdata->size() != nrow*ncol) {
             throw mjXError(elem, "elevation data length must match nrow*ncol");
           }
 
           // copy in reverse row order, so XML string is top-to-bottom
-          const float* userdata = phf->userdata().data();
+          std::vector<float> flipped(nrow*ncol);
           for (int i = 0; i < nrow; i++) {
             int flip = nrow-1-i;
-            memcpy(phf->data + flip*ncol, userdata + i*ncol, ncol*sizeof(float));
+            for (int j = 0; j < ncol; j++) {
+              flipped[flip*ncol + j] = userdata->data()[i*ncol + j];
+            }
           }
+
+          mjm_setFloat(phf->userdata, flipped.data(), flipped.size());
         }
 
         // user data not given, set to 0
         else {
-          memset(phf->data, 0, phf->nrow*phf->ncol*sizeof(float));
+          std::vector<float> zero(nrow*ncol);
+          mjm_setFloat(phf->userdata, zero.data(), zero.size());
         }
       }
     }

src/xml/xml_native_writer.cc

@@ -1416,15 +1416,15 @@ void mjXWriter::Asset(XMLElement* root) {
     // write attributes
     WriteAttrTxt(elem, "name", phf->name);
     WriteAttr(elem, "size", 4, phf->size);
-    if (!phf->file.empty()) {
+    if (!phf->file_.empty()) {
-      WriteAttrTxt(elem, "content_type", phf->content_type);
+      WriteAttrTxt(elem, "content_type", phf->content_type_);
-      WriteAttrTxt(elem, "file", phf->file);
+      WriteAttrTxt(elem, "file", phf->file_);
     } else {
       WriteAttrInt(elem, "nrow", phf->nrow);
       WriteAttrInt(elem, "ncol", phf->ncol);
-      if (!phf->userdata().empty()) {
+      if (!phf->get_userdata().empty()) {
         string text;
-        Vector2String(text, phf->userdata(), phf->ncol);
+        Vector2String(text, phf->get_userdata(), phf->ncol);
         WriteAttrTxt(elem, "elevation", text);
       }
     }