Add spec lookup in the attached spec array using the compiler option …

…pointer.

This enables to find the spec associated with the compiler option stored in the objects, which do not necessarily belong to the model that owns them.

PiperOrigin-RevId: 713259419
Change-Id: I579c770147ff07ed2a5edd20e7a795ee7cc27147

doc/programming/modeledit.rst

@@ -117,6 +117,8 @@ to :ref:`attach a body to a site<mjs_attachToSite>`:
 
    mjSpec* parent = mj_makeSpec();
    mjSpec* child = mj_makeSpec();
+   parent->compiler.degree = 0;
+   child->compiler.degree = 1;
    mjsFrame* frame = mjs_addFrame(mjs_findBody(parent, "world"), NULL);
    mjsSite* site = mjs_addSite(mjs_findBody(parent, "world"), NULL);
    mjsBody* body = mjs_addBody(mjs_findBody(child, "world"), NULL);
@@ -133,6 +135,11 @@ or :ref:`attach a frame to a body<mjs_attachFrame>`:
    mjsFrame* frame = mjs_addFrame(mjs_findBody(child, "world"), NULL);
    mjsFrame* attached_frame = mjs_attachFrame(body, frame, "attached-", "-1");
 
+Note that in the above examples, the parent and child models have different values for ``compiler.degree``,
+corresponding to the :ref:`compiler/angle<compiler-angle>` attribute, specifying the units in which angles are
+interperted. Compiler options are carried over during attachment, so the child model will be compiled using X, while the
+parent will be compiled using Y.
+
 .. _meDefault:
 
 Default classes

src/user/user_model.cc

@@ -146,6 +146,9 @@ mjCModel::mjCModel() {
   defaults_.push_back(new mjCDef);
   defaults_.back()->name = "main";
 
+  // point to model from spec
+  PointToLocal();
+
   // world body
   mjCBody* world = new mjCBody(this);
   mjuu_zerovec(world->pos, 3);
@@ -163,14 +166,15 @@ mjCModel::mjCModel() {
   // create mjCBase lists from children lists
   CreateObjectLists();
 
-  // point to model from spec
-  PointToLocal();
+  // the source spec is the model itself, overwritten in the copy constructor
+  source_spec_ = &spec;
 }
 
 
 
 mjCModel::mjCModel(const mjCModel& other) {
   CreateObjectLists();
+  source_spec_ = (mjSpec*)&other.spec;
   *this = other;
 }
 
@@ -1222,6 +1226,25 @@ mjSpec* mjCModel::FindSpec(std::string name) const {
 
 
 
+// find spec by mjsCompiler pointer
+mjSpec* mjCModel::FindSpec(const mjsCompiler* compiler_) const {
+  for (auto spec : specs_) {
+    if (&(static_cast<const mjCModel*>(spec->element)->GetSourceSpec()->compiler) == compiler_) {
+      return spec;
+    }
+  }
+  return nullptr;
+}
+
+
+
+// get the spec from which this model was created
+mjSpec* mjCModel::GetSourceSpec() const {
+  return source_spec_;
+}
+
+
+
 //------------------------------- COMPILER PHASES --------------------------------------------------
 
 // make lists of objects in tree: bodies, geoms, joints, sites, cameras, lights

src/user/user_model.h

@@ -236,6 +236,7 @@ class mjCModel : public mjCModel_, private mjSpec {
   mjCBase* FindObject(mjtObj type, std::string name) const;         // find object given type and name
   mjCBase* FindTree(mjCBody* body, mjtObj type, std::string name);  // find tree object given name
   mjSpec* FindSpec(std::string name) const;                         // find spec given name
+  mjSpec* FindSpec(const mjsCompiler* compiler_) const;             // find spec given mjsCompiler
   void ActivatePlugin(const mjpPlugin* plugin, int slot);           // activate plugin
 
   // accessors
@@ -303,10 +304,16 @@ class mjCModel : public mjCModel_, private mjSpec {
   // map from default class name to default class pointer
   std::unordered_map<std::string, mjCDef*> def_map;
 
+  // get the spec from which this model was created
+  mjSpec* GetSourceSpec() const;
+
  private:
   // settings for each defaults class
   std::vector<mjCDef*> defaults_;
 
+  // spec from which this model was created in copy constructor
+  mjSpec* source_spec_;
+
   // list of active plugins
   std::vector<std::pair<const mjpPlugin*, int>> active_plugins_;
 

src/user/user_objects.cc

@@ -798,7 +798,7 @@ mjCBody::mjCBody(mjCModel* _model) {
 
 mjCBody::mjCBody(const mjCBody& other, mjCModel* _model) {
   model = _model;
-  mjSpec* origin = model->FindSpec(mjs_getString(other.model->spec.modelname));
+  mjSpec* origin = model->FindSpec(other.compiler);
   compiler = origin ? &origin->compiler : &model->spec.compiler;
   *this = other;
   CopyPlugin();
@@ -881,7 +881,7 @@ mjCBody& mjCBody::operator+=(const mjCFrame& other) {
   }
 
   // copy input frame
-  mjSpec* origin = model->FindSpec(mjs_getString(other.model->spec.modelname));
+  mjSpec* origin = model->FindSpec(other.compiler);
   frames.push_back(new mjCFrame(other));
   frames.back()->body = this;
   frames.back()->model = model;
@@ -947,7 +947,7 @@ void mjCBody::CopyList(std::vector<T*>& dst, const std::vector<T*>& src,
     if (pframe && !pframe->IsAncestor(src[i]->frame)) {
       continue;  // skip if the element is not inside pframe
     }
-    mjSpec* origin = model->FindSpec(mjs_getString(src[i]->model->spec.modelname));
+    mjSpec* origin = model->FindSpec(src[i]->compiler);
     dst.push_back(new T(*src[i]));
     dst.back()->body = this;
     dst.back()->model = model;

test/user/user_api_test.cc

@@ -2033,52 +2033,71 @@ TEST_F(MujocoTest, ResizeParentKeyframe) {
 }
 
 TEST_F(MujocoTest, DifferentUnitsAllowed) {
-  mjSpec* child = mj_makeSpec();
-  child->compiler.degree = 0;
-  mjsBody* body = mjs_addBody(mjs_findBody(child, "world"), 0);
-  body->alt.type = mjORIENTATION_EULER;
-  body->alt.euler[0] = -mjPI / 2;
-  mjsGeom* geom = mjs_addGeom(body, 0);
-  geom->size[0] = 1;
-  mjsJoint* joint = mjs_addJoint(body, 0);
-  joint->type = mjJNT_HINGE;
-  joint->range[0] = -mjPI / 4;
-  joint->range[1] = mjPI / 4;
+  static constexpr char child_xml[] = R"(
+  <mujoco>
+    <compiler angle="radian"/>
 
-  mjSpec* parent = mj_makeSpec();
-  parent->compiler.degree = 1;
-  mjsFrame* frame = mjs_addFrame(mjs_findBody(parent, "world"), 0);
-  frame->alt.type = mjORIENTATION_EULER;
-  frame->alt.euler[0] = 90;
+    <worldbody>
+      <body name="child" euler="-1.5707963 0 0">
+        <geom type="box" size="1 1 1"/>
+        <joint name="child_joint" range="-3.1415926 3.1415926"/>
+      </body>
+    </worldbody>
+  </mujoco>
+  )";
 
-  EXPECT_THAT(mjs_attachBody(frame, body, "child-", ""), NotNull());
-  mjModel* model = mj_compile(parent, 0);
+  static constexpr char parent_xml[] = R"(
+  <mujoco>
+    <worldbody>
+      <body name="parent">
+        <geom type="box" size="1 1 1"/>
+        <joint name="parent_joint" range="-180 180"/>
+        <frame name="frame" euler="90 0 0"/>
+      </body>
+    </worldbody>
+  </mujoco>
+  )";
+
+  std::array<char, 1024> error;
+  mjSpec* child = mj_parseXMLString(child_xml, 0, error.data(), error.size());
+  mjSpec* spec = mj_parseXMLString(parent_xml, 0, error.data(), error.size());
+  ASSERT_THAT(spec, NotNull()) << error.data();
+  mjs_attachBody(mjs_findFrame(spec, "frame"), mjs_findBody(child, "child"),
+                 "child_", "");
+
+  mjModel* model = mj_compile(spec, 0);
   EXPECT_THAT(model, NotNull());
+  EXPECT_THAT(model->njnt, 2);
+  EXPECT_NEAR(model->jnt_range[0], -mjPI, 1e-6);
+  EXPECT_NEAR(model->jnt_range[1], mjPI, 1e-6);
+  EXPECT_NEAR(model->jnt_range[2], -mjPI, 1e-6);
+  EXPECT_NEAR(model->jnt_range[3], mjPI, 1e-6);
   EXPECT_NEAR(model->body_quat[4], 1, 1e-12);
   EXPECT_NEAR(model->body_quat[5], 0, 1e-12);
   EXPECT_NEAR(model->body_quat[6], 0, 1e-12);
   EXPECT_NEAR(model->body_quat[7], 0, 1e-12);
-  EXPECT_NEAR(model->jnt_range[0], -mjPI / 4, 1e-7);
-  EXPECT_NEAR(model->jnt_range[1], mjPI / 4, 1e-7);
 
-  mjSpec* copy = mj_copySpec(parent);
-  EXPECT_THAT(copy, NotNull());
-  mj_deleteModel(model);
+  mjSpec* copied_spec = mj_copySpec(spec);
+  ASSERT_THAT(copied_spec, NotNull());
   mj_deleteSpec(child);
-  mj_deleteSpec(parent);
+  mj_deleteSpec(spec);
+  mj_deleteModel(model);
 
   // check that deleting `parent` or `child` does not invalidate the copy
-  mjModel* copy_model = mj_compile(copy, 0);
-  EXPECT_THAT(copy_model, NotNull());
-  EXPECT_NEAR(copy_model->body_quat[0], 1, 1e-12);
-  EXPECT_NEAR(copy_model->body_quat[1], 0, 1e-12);
-  EXPECT_NEAR(copy_model->body_quat[2], 0, 1e-12);
-  EXPECT_NEAR(copy_model->body_quat[3], 0, 1e-12);
-  EXPECT_NEAR(copy_model->jnt_range[0], -mjPI / 4, 1e-7);
-  EXPECT_NEAR(copy_model->jnt_range[1], mjPI / 4, 1e-7);
-
-  mj_deleteModel(copy_model);
-  mj_deleteSpec(copy);
+  mjModel* copied_model = mj_compile(copied_spec, 0);
+  EXPECT_THAT(copied_model, NotNull());
+  EXPECT_THAT(copied_model->njnt, 2);
+  EXPECT_NEAR(copied_model->jnt_range[0], -mjPI, 1e-6);
+  EXPECT_NEAR(copied_model->jnt_range[1], mjPI, 1e-6);
+  EXPECT_NEAR(copied_model->jnt_range[2], -mjPI, 1e-6);
+  EXPECT_NEAR(copied_model->jnt_range[3], mjPI, 1e-6);
+  EXPECT_NEAR(copied_model->body_quat[4], 1, 1e-12);
+  EXPECT_NEAR(copied_model->body_quat[5], 0, 1e-12);
+  EXPECT_NEAR(copied_model->body_quat[6], 0, 1e-12);
+  EXPECT_NEAR(copied_model->body_quat[7], 0, 1e-12);
+
+  mj_deleteSpec(copied_spec);
+  mj_deleteModel(copied_model);
 }
 
 TEST_F(MujocoTest, CopyAttachedSpec) {

test/xml/xml_native_reader_test.cc

@@ -1579,6 +1579,72 @@ TEST_F(XMLReaderTest, InvalidAttach) {
   mj_deleteVFS(vfs.get());
 }
 
+TEST_F(XMLReaderTest, LookupCompilerOptionWithoutSpecCopy) {
+  static constexpr char child_xml[] = R"(
+  <mujoco>
+    <compiler angle="radian"/>
+
+    <worldbody>
+      <body name="child">
+        <geom type="box" size="1 1 1"/>
+        <joint name="child_joint" range="-3.1415926 3.1415926"/>
+      </body>
+    </worldbody>
+  </mujoco>
+  )";
+
+  static constexpr char parent_xml[] = R"(
+  <mujoco>
+    <asset>
+      <model name="child" file="child.xml"/>
+    </asset>
+
+    <worldbody>
+      <body name="parent">
+        <geom type="box" size="1 1 1"/>
+        <joint name="parent_joint" range="-180 180"/>
+        <attach model="child" body="child" prefix="child_"/>
+      </body>
+    </worldbody>
+  </mujoco>
+  )";
+
+  auto vfs = std::make_unique<mjVFS>();
+  mj_defaultVFS(vfs.get());
+  mj_addBufferVFS(vfs.get(), "child.xml", child_xml, sizeof(child_xml));
+  mj_addBufferVFS(vfs.get(), "parent.xml", parent_xml, sizeof(parent_xml));
+
+  std::array<char, 1024> error;
+  auto* spec = mj_parseXMLString(parent_xml, vfs.get(), error.data(),
+                                 error.size());
+  ASSERT_THAT(spec, NotNull()) << error.data();
+
+  mjModel* model = mj_compile(spec, vfs.get());
+  EXPECT_THAT(model, NotNull());
+  EXPECT_THAT(model->njnt, 2);
+  EXPECT_NEAR(model->jnt_range[0], -3.14159, 1e-5);
+  EXPECT_NEAR(model->jnt_range[1], 3.14159, 1e-5);
+  EXPECT_NEAR(model->jnt_range[2], -3.14159, 1e-5);
+  EXPECT_NEAR(model->jnt_range[3], 3.14159, 1e-5);
+
+  mjSpec* copied_spec = mj_copySpec(spec);
+  ASSERT_THAT(copied_spec, NotNull());
+  mjModel* copied_model = mj_compile(copied_spec, vfs.get());
+  EXPECT_THAT(copied_model, NotNull());
+  EXPECT_THAT(copied_model->njnt, 2);
+  EXPECT_NEAR(copied_model->jnt_range[0], -3.14159, 1e-5);
+  EXPECT_NEAR(copied_model->jnt_range[1], 3.14159, 1e-5);
+  EXPECT_NEAR(copied_model->jnt_range[2], -3.14159, 1e-5);
+  EXPECT_NEAR(copied_model->jnt_range[3], 3.14159, 1e-5);
+
+  mj_deleteSpec(spec);
+  mj_deleteSpec(copied_spec);
+  mj_deleteModel(model);
+  mj_deleteModel(copied_model);
+
+  mj_deleteVFS(vfs.get());
+}
+
 // ----------------------- test camera parsing ---------------------------------
 
 TEST_F(XMLReaderTest, CameraInvalidFovyAndSensorsize) {