Fix vfs load for mesh gmeshs type

src/user/user_flexcomp.cc

@@ -99,7 +99,7 @@ mjCFlexcomp::mjCFlexcomp(void) {
 
 
 // make flexcomp object
-bool mjCFlexcomp::Make(mjsBody* body, char* error, int error_sz) {
+bool mjCFlexcomp::Make(mjsBody* body, char* error, int error_sz, const mjVFS* vfs) {
   mjCModel* model = static_cast<mjCBody*>(body->element)->model;
   mjsCompiler* compiler = static_cast<mjCBody*>(body->element)->compiler;
   mjsFlex* dflex = def.spec.flex;
@@ -170,11 +170,11 @@ bool mjCFlexcomp::Make(mjsBody* body, char* error, int error_sz) {
       break;
 
     case mjFCOMPTYPE_MESH:
-      res = MakeMesh(model, compiler, error, error_sz);
+      res = MakeMesh(model, compiler, error, error_sz, vfs);
       break;
 
     case mjFCOMPTYPE_GMSH:
-      res = MakeGMSH(model, compiler, error, error_sz);
+      res = MakeGMSH(model, compiler, error, error_sz, vfs);
       break;
 
     case mjFCOMPTYPE_DIRECT:
@@ -1129,7 +1129,7 @@ template <typename T> static T* VecToArray(std::vector<T>& vector, bool clear =
 
 
 // make mesh
-bool mjCFlexcomp::MakeMesh(mjCModel* model, mjsCompiler* compiler, char* error, int error_sz) {
+bool mjCFlexcomp::MakeMesh(mjCModel* model, mjsCompiler* compiler, char* error, int error_sz, const mjVFS* vfs) {
   // strip path
   if (!file.empty() && model->spec.strippath) {
     file = mjuu_strippath(file);
@@ -1156,7 +1156,7 @@ bool mjCFlexcomp::MakeMesh(mjCModel* model, mjsCompiler* compiler, char* error,
 
   try {
     resource = mjCBase::LoadResource(mjs_getString(model->spec.modelfiledir),
-                                     filename, 0);
+                                     filename, vfs);
   } catch (mjCError err) {
     return comperr(error, err.message, error_sz);
   }
@@ -1248,7 +1248,7 @@ static int findstring(const char* buffer, int buffer_sz, const char* str) {
 
 
 // load points and elements from GMSH file
-bool mjCFlexcomp::MakeGMSH(mjCModel* model, mjsCompiler* compiler, char* error, int error_sz) {
+bool mjCFlexcomp::MakeGMSH(mjCModel* model, mjsCompiler* compiler, char* error, int error_sz, const mjVFS* vfs) {
   // strip path
   if (!file.empty() && model->spec.strippath) {
     file = mjuu_strippath(file);
@@ -1264,7 +1264,7 @@ bool mjCFlexcomp::MakeGMSH(mjCModel* model, mjsCompiler* compiler, char* error,
   try {
     std::string filename = mjuu_combinePaths(mjs_getString(compiler->meshdir), file);
     resource = mjCBase::LoadResource(mjs_getString(model->spec.modelfiledir),
-                                     filename, 0);
+                                     filename, vfs);
   } catch (mjCError err) {
     return comperr(error, err.message, error_sz);
   }

src/user/user_flexcomp.h

@@ -53,13 +53,15 @@ typedef enum _mjtDof {
 class mjCFlexcomp {
  public:
   mjCFlexcomp(void);
-  bool Make(mjsBody* body, char* error, int error_sz);
+  bool Make(mjsBody* body, char* error, int error_sz, const mjVFS* vfs = nullptr);
 
   bool MakeGrid(char* error, int error_sz);
   bool MakeBox(char* error, int error_sz, int dim, bool open = true);
   bool MakeSquare(char* error, int error_sz);
-  bool MakeMesh(mjCModel* model, mjsCompiler* compiler, char* error, int error_sz);
-  bool MakeGMSH(mjCModel* model, mjsCompiler* compiler, char* error, int error_sz);
+  bool MakeMesh(mjCModel* model, mjsCompiler* compiler, char* error, int error_sz,
+                const mjVFS* vfs = nullptr);
+  bool MakeGMSH(mjCModel* model, mjsCompiler* compiler, char* error, int error_sz,
+                const mjVFS* vfs = nullptr);
   void LoadGMSH(mjCModel* model, mjResource* resource);
   void LoadGMSH41(char* buffer, int binary, int nodeend, int nodebegin,
                   int elemend, int elembegin);

src/xml/xml_native_reader.cc

@@ -2849,7 +2849,7 @@ void mjXReader::OneFlexcomp(XMLElement* elem, mjsBody* body, const mjVFS* vfs) {
 
   // make flexcomp
   char error[200];
-  bool res = fcomp.Make(body, error, 200);
+  bool res = fcomp.Make(body, error, 200, vfs);
 
   // throw error
   if (!res) {

test/user/user_flex_test.cc

@@ -15,6 +15,7 @@
 // Tests for user/user_model.cc.
 
 #include <array>
+#include <cstdio>
 #include <string>
 
 #include <gmock/gmock.h>
@@ -876,5 +877,47 @@ TEST_F(UserFlexTest, MeshNodePinning) {
   mj_deleteModel(m);
 }
 
+TEST_F(UserFlexTest, FlexcompMeshLoadsFromVFS) {
+  // read cube.stl from testdata into a buffer
+  const std::string stl_path =
+      GetTestDataFilePath("user/testdata/cube.stl");
+  FILE* f = fopen(stl_path.c_str(), "rb");
+  ASSERT_THAT(f, NotNull()) << "Could not open " << stl_path;
+  fseek(f, 0, SEEK_END);
+  long stl_size = ftell(f);
+  fseek(f, 0, SEEK_SET);
+  std::string stl_data(stl_size, '\0');
+  fread(stl_data.data(), 1, stl_size, f);
+  fclose(f);
+
+  // add the STL data to a VFS
+  mjVFS vfs;
+  mj_defaultVFS(&vfs);
+  mj_addBufferVFS(&vfs, "cube.stl", stl_data.data(), stl_size);
+
+  // XML that uses flexcomp type="mesh" referencing the VFS file
+  static constexpr char xml[] = R"(
+  <mujoco>
+    <worldbody>
+      <body name="flex_body" pos="0 0 1">
+        <flexcomp name="flex_object" type="mesh" file="cube.stl" rigid="true">
+          <contact contype="1" conaffinity="1"/>
+        </flexcomp>
+      </body>
+    </worldbody>
+  </mujoco>
+  )";
+
+  // cleanup
+  std::array<char, 1024> error;
+  mjModel* m = LoadModelFromString(xml, error.data(), error.size(), &vfs);
+  ASSERT_THAT(m, NotNull()) << error.data();
+  mjData* d = mj_makeData(m);
+  mj_step(m, d);
+  mj_deleteData(d);
+  mj_deleteModel(m);
+  mj_deleteVFS(&vfs);
+}
+
 }  // namespace
 }  // namespace mujoco