python: expose trade.AbstractSceneConverter batch mode for files.

Just meshes for now.

doc/python/magnum.trade.rst

@@ -513,3 +513,21 @@
     all backslashes in :p:`filename` to forward slashes before passing it to
     :dox:`Trade::AbstractSceneConverter::convertToFile()`, which expects
     forward slashes as directory separators on all platforms.
+
+.. py:function:: magnum.trade.AbstractSceneConverter.begin_file
+    :raise RuntimeError: If beginning the conversion fails
+
+.. py:function:: magnum.trade.AbstractSceneConverter.end_file
+    :raise AssertionError: If no conversion is in progress
+    :raise RuntimeError: If ending the conversion fails
+
+.. py:property:: magnum.trade.AbstractSceneConverter.mesh_count
+    :raise AssertionError: If no conversion is in progress
+
+.. py:function:: magnum.trade.AbstractSceneConverter.add
+    :raise AssertionError: If no conversion is in progress
+    :raise RuntimeError: If adding the data fails
+
+.. py:function:: magnum.trade.AbstractSceneConverter.set_mesh_attribute_name
+    :raise AssertionError: If no conversion is in progress
+    :raise AssertionError: If :p:`attribute` is not custom

package/ci/appveyor-desktop-gles.bat

@@ -78,6 +78,7 @@ cmake .. ^
     -DMAGNUM_BUILD_STATIC=%BUILD_STATIC% ^
     -DMAGNUM_WITH_DDSIMPORTER=ON ^
     -DMAGNUM_WITH_GLTFIMPORTER=ON ^
+    -DMAGNUM_WITH_GLTFSCENECONVERTER=ON ^
     -DMAGNUM_WITH_MESHOPTIMIZERSCENECONVERTER=ON ^
     -DMAGNUM_WITH_STANFORDSCENECONVERTER=ON ^
     -DMAGNUM_WITH_STBIMAGECONVERTER=ON ^

package/ci/appveyor-desktop.bat

@@ -88,6 +88,7 @@ cmake .. ^
     -DMAGNUM_BUILD_STATIC=%BUILD_STATIC% ^
     -DMAGNUM_WITH_DDSIMPORTER=ON ^
     -DMAGNUM_WITH_GLTFIMPORTER=ON ^
+    -DMAGNUM_WITH_GLTFSCENECONVERTER=ON ^
     -DMAGNUM_WITH_MESHOPTIMIZERSCENECONVERTER=%EXCEPT_MSVC2017% ^
     -DMAGNUM_WITH_STANFORDSCENECONVERTER=ON ^
     -DMAGNUM_WITH_STBIMAGECONVERTER=ON ^

package/ci/unix-desktop-gles.sh

@@ -65,6 +65,7 @@ cmake .. \
     -DMAGNUM_BUILD_STATIC=$BUILD_STATIC \
     -DMAGNUM_WITH_DDSIMPORTER=ON \
     -DMAGNUM_WITH_GLTFIMPORTER=ON \
+    -DMAGNUM_WITH_GLTFSCENECONVERTER=ON \
     -DMAGNUM_WITH_MESHOPTIMIZERSCENECONVERTER=ON \
     -DMAGNUM_WITH_STANFORDSCENECONVERTER=ON \
     -DMAGNUM_WITH_STBIMAGECONVERTER=ON \

package/ci/unix-desktop.sh

@@ -69,6 +69,7 @@ cmake .. \
     -DMAGNUM_BUILD_STATIC=$BUILD_STATIC \
     -DMAGNUM_WITH_DDSIMPORTER=ON \
     -DMAGNUM_WITH_GLTFIMPORTER=ON \
+    -DMAGNUM_WITH_GLTFSCENECONVERTER=ON \
     -DMAGNUM_WITH_MESHOPTIMIZERSCENECONVERTER=ON \
     -DMAGNUM_WITH_STANFORDSCENECONVERTER=ON \
     -DMAGNUM_WITH_STBIMAGECONVERTER=ON \

src/python/magnum/test/mesh.gltf

@@ -39,6 +39,27 @@
           "mode": 666
         }
       ]
+    },
+    {
+      "name": "Point mesh",
+      "primitives": [
+        {
+          "attributes": {
+            "POSITION": 1
+          },
+          "mode": 0
+        }
+      ]
+    },
+    {
+      "name": "Custom mesh attribute",
+      "primitives": [
+        {
+          "attributes": {
+            "_FOOBARTHINGY": 1
+          }
+        }
+      ]
     }
   ],
   "accessors": [

src/python/magnum/test/test_trade.py

@@ -1306,7 +1306,7 @@ class Importer(unittest.TestCase):
         self.assertIsNone(importer.mesh_attribute_for_name("_CUSTOM_ATTRIBUTE"))
 
         importer.open_file(os.path.join(os.path.dirname(__file__), 'mesh.gltf'))
-        self.assertEqual(importer.mesh_count, 3)
+        self.assertEqual(importer.mesh_count, 5)
         self.assertEqual(importer.mesh_level_count(0), 1)
         self.assertEqual(importer.mesh_name(0), 'Indexed mesh')
         self.assertEqual(importer.mesh_for_name('Indexed mesh'), 0)
@@ -1542,3 +1542,102 @@ class SceneConverter(unittest.TestCase):
         with tempfile.TemporaryDirectory() as tmp:
             with self.assertRaisesRegex(RuntimeError, "conversion failed"):
                 converter.convert_to_file(mesh, os.path.join(tmp, "mesh.obj"))
+
+    def test_batch_file(self):
+        importer = trade.ImporterManager().load_and_instantiate('GltfImporter')
+        importer.open_file(os.path.join(os.path.dirname(__file__), 'mesh.gltf'))
+        mesh = importer.mesh(1)
+
+        converter = trade.SceneConverterManager().load_and_instantiate('StanfordSceneConverter')
+
+        with tempfile.TemporaryDirectory() as tmp:
+            converter.begin_file(os.path.join(tmp, "mesh.ply"))
+            self.assertTrue(converter.is_converting)
+            self.assertEqual(converter.mesh_count, 0)
+
+            self.assertEqual(converter.add(mesh), 0)
+            self.assertEqual(converter.mesh_count, 1)
+
+            converter.end_file()
+            self.assertFalse(converter.is_converting)
+
+            self.assertTrue(os.path.exists(os.path.join(tmp, "mesh.ply")))
+
+    def test_batch_file_begin_failed(self):
+        importer = trade.ImporterManager().load_and_instantiate('GltfImporter')
+        importer.open_file(os.path.join(os.path.dirname(__file__), 'mesh.gltf'))
+        mesh = importer.mesh(1)
+
+        converter = trade.SceneConverterManager().load_and_instantiate('AnySceneConverter')
+
+        with tempfile.TemporaryDirectory() as tmp:
+            with self.assertRaisesRegex(RuntimeError, "beginning the conversion failed"):
+                converter.begin_file(os.path.join(tmp, "mesh.obj"))
+
+    def test_batch_file_end_failed(self):
+        importer = trade.ImporterManager().load_and_instantiate('GltfImporter')
+        importer.open_file(os.path.join(os.path.dirname(__file__), 'mesh.gltf'))
+        mesh = importer.mesh(1)
+
+        converter = trade.SceneConverterManager().load_and_instantiate('StanfordSceneConverter')
+
+        with tempfile.TemporaryDirectory() as tmp:
+            converter.begin_file(os.path.join(tmp, "mesh.ply"))
+            with self.assertRaisesRegex(RuntimeError, "ending the conversion failed"):
+                converter.end_file()
+
+    def test_batch_add_mesh_failed(self):
+        importer = trade.ImporterManager().load_and_instantiate('GltfImporter')
+        importer.open_file(os.path.join(os.path.dirname(__file__), 'mesh.gltf'))
+        mesh = importer.mesh('Point mesh')
+
+        converter = trade.SceneConverterManager().load_and_instantiate('StanfordSceneConverter')
+
+        with tempfile.TemporaryDirectory() as tmp:
+            converter.begin_file(os.path.join(tmp, "mesh.ply"))
+            with self.assertRaisesRegex(RuntimeError, "adding the mesh failed"):
+                converter.add(mesh)
+
+    def test_batch_set_mesh_attribute_name(self):
+        importer = trade.ImporterManager().load_and_instantiate('GltfImporter')
+        importer.open_file(os.path.join(os.path.dirname(__file__), 'mesh.gltf'))
+        mesh = importer.mesh('Custom mesh attribute')
+
+        converter = trade.SceneConverterManager().load_and_instantiate('GltfSceneConverter')
+
+        with tempfile.TemporaryDirectory() as tmp:
+            filename = os.path.join(tmp, "mesh.gltf")
+            converter.begin_file(filename)
+            converter.set_mesh_attribute_name(importer.mesh_attribute_for_name('_FOOBARTHINGY'), '_FOOBARTHINGY')
+            converter.add(mesh)
+            converter.end_file()
+
+            with open(filename, 'r') as f:
+                self.assertIn('_FOOBARTHINGY', f.read())
+
+    def test_batch_set_mesh_attribute_name_not_custom(self):
+        converter = trade.SceneConverterManager().load_and_instantiate('GltfSceneConverter')
+
+        with tempfile.TemporaryDirectory() as tmp:
+            filename = os.path.join(tmp, "mesh.gltf")
+            converter.begin_file(filename)
+
+            with self.assertRaisesRegex(AssertionError, "not a custom attribute"):
+                converter.set_mesh_attribute_name(trade.MeshAttribute.POSITION, 'foo')
+
+    def test_batch_no_conversion_in_progress(self):
+        importer = trade.ImporterManager().load_and_instantiate('GltfImporter')
+        importer.open_file(os.path.join(os.path.dirname(__file__), 'mesh.gltf'))
+        mesh = importer.mesh('Custom mesh attribute')
+
+        converter = trade.SceneConverterManager().load_and_instantiate('GltfSceneConverter')
+        self.assertFalse(converter.is_converting)
+
+        with self.assertRaisesRegex(AssertionError, "no conversion in progress"):
+            converter.end_file()
+        with self.assertRaisesRegex(AssertionError, "no conversion in progress"):
+            converter.mesh_count
+        with self.assertRaisesRegex(AssertionError, "no conversion in progress"):
+            converter.add(mesh)
+        with self.assertRaisesRegex(AssertionError, "no conversion in progress"):
+            converter.set_mesh_attribute_name(trade.MeshAttribute.CUSTOM(1), 'foobar')

src/python/magnum/trade.cpp

@@ -1676,7 +1676,60 @@ void trade(py::module_& m) {
                 PyErr_SetString(PyExc_RuntimeError, "conversion failed");
                 throw py::error_already_set{};
             }
-        }, "Convert a mesh to a file", py::arg("mesh"), py::arg("filename"));
+        }, "Convert a mesh to a file", py::arg("mesh"), py::arg("filename"))
+        .def_property_readonly("is_converting", &Trade::AbstractSceneConverter::isConverting, "Whether any conversion is in progress")
+        .def("abort", &Trade::AbstractSceneConverter::abort, "Abort any in-progress conversion")
+        /** @todo begin/end (MeshOptimizer), begin/end data */
+        /** @todo drop std::string in favor of our own string caster */
+        .def("begin_file", [](Trade::AbstractSceneConverter& self, const std::string& filename) {
+            if(!self.beginFile(filename)) {
+                PyErr_SetString(PyExc_RuntimeError, "beginning the conversion failed");
+                throw py::error_already_set{};
+            }
+        }, "Begin converting a scene to a file", py::arg("filename"))
+        .def("end_file", [](Trade::AbstractSceneConverter& self) {
+            /** @todo this doesn't catch a mismatch (e.g., when beginData() was
+                called instead */
+            if(!self.isConverting()) {
+                PyErr_SetString(PyExc_AssertionError, "no conversion in progress");
+                throw py::error_already_set{};
+            }
+            if(!self.endFile()) {
+                PyErr_SetString(PyExc_RuntimeError, "ending the conversion failed");
+                throw py::error_already_set{};
+            }
+        }, "End converting a scene to a file")
+        .def_property_readonly("mesh_count", [](Trade::AbstractSceneConverter& self) {
+            if(!self.isConverting()) {
+                PyErr_SetString(PyExc_AssertionError, "no conversion in progress");
+                throw py::error_already_set{};
+            }
+            return self.meshCount();
+        }, "Count of added meshes")
+        /** @todo drop std::string in favor of our own string caster */
+        .def("add", [](Trade::AbstractSceneConverter& self, const Trade::MeshData& mesh, const std::string& name) {
+            if(!self.isConverting()) {
+                PyErr_SetString(PyExc_AssertionError, "no conversion in progress");
+                throw py::error_already_set{};
+            }
+            if(const Containers::Optional<UnsignedInt> out = self.add(mesh, name))
+                return *out;
+
+            PyErr_SetString(PyExc_RuntimeError, "adding the mesh failed");
+            throw py::error_already_set{};
+        }, "Add a mesh", py::arg("mesh"), py::arg("name") = std::string{})
+        /** @todo mesh levels */
+        .def("set_mesh_attribute_name", [](Trade::AbstractSceneConverter& self, const Trade::MeshAttribute attribute, const std::string& name) {
+            if(!Trade::isMeshAttributeCustom(attribute)) {
+                PyErr_SetString(PyExc_AssertionError, "not a custom attribute");
+                throw py::error_already_set{};
+            }
+            if(!self.isConverting()) {
+                PyErr_SetString(PyExc_AssertionError, "no conversion in progress");
+                throw py::error_already_set{};
+            }
+            self.setMeshAttributeName(attribute, name);
+        }, "Set name of a custom mesh attribute", py::arg("attribute"), py::arg("name"));
     corrade::plugin(abstractSceneConverter);
 
     py::class_<PluginManager::Manager<Trade::AbstractSceneConverter>, PluginManager::AbstractManager> sceneConverterManager{m, "SceneConverterManager", "Manager for scene converter plugins"};