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);
+  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_deleteModel(copy_model);
-  mj_deleteSpec(copy);
+  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) {