ENH: Add test implementations of pointsets in test_pointset.py

Author: effigies

nibabel/tests/test_pointset.py

@@ -182,3 +182,177 @@ def test_to_mask(self):
             ],
         )
         assert np.array_equal(mask_img.affine, np.eye(4))
+
+
+class H5ArrayProxy:
+    def __init__(self, file_like, dataset_name):
+        self.file_like = file_like
+        self.dataset_name = dataset_name
+        with h5.File(file_like, 'r') as h5f:
+            arr = h5f[dataset_name]
+            self._shape = arr.shape
+            self._dtype = arr.dtype
+
+    @property
+    def is_proxy(self):
+        return True
+
+    @property
+    def shape(self):
+        return self._shape
+
+    @property
+    def ndim(self):
+        return len(self.shape)
+
+    @property
+    def dtype(self):
+        return self._dtype
+
+    def __array__(self, dtype=None):
+        with h5.File(self.file_like, 'r') as h5f:
+            return np.asanyarray(h5f[self.dataset_name], dtype)
+
+    def __slicer__(self, slicer):
+        with h5.File(self.file_like, 'r') as h5f:
+            return h5f[self.dataset_name][slicer]
+
+
+class H5Geometry(ps.TriangularMesh):
+    """Simple Geometry file structure that combines a single topology
+    with one or more coordinate sets
+    """
+
+    @classmethod
+    def from_filename(klass, pathlike):
+        meshes = {}
+        with h5.File(pathlike, 'r') as h5f:
+            triangles = h5f['topology']
+            for name, coords in h5f['coordinates'].items():
+                meshes[name] = (coords, triangles)
+        return klass(meshes)
+
+    def to_filename(self, pathlike):
+        topology = None
+        coordinates = {}
+        for name, mesh in self.meshes.items():
+            coords, faces = mesh
+            if topology is None:
+                topology = faces
+            elif not np.array_equal(faces, topology):
+                raise ValueError('Inconsistent topology')
+            coordinates[name] = coords
+
+        with h5.File(pathlike, 'w') as h5f:
+            h5f.create_dataset('/topology', topology)
+            for name, coord in coordinates.items():
+                h5f.create_dataset(f'/coordinates/{name}', coord)
+
+    def get_coords(self, name=None):
+        if name is None:
+            name = next(iter(self._meshes))
+        coords, _ = self._meshes[name]
+        return coords
+
+    def get_triangles(self, name=None):
+        if name is None:
+            name = next(iter(self._meshes))
+        _, triangles = self._meshes[name]
+        return triangles
+
+
+class FSGeometryProxy:
+    def __init__(self, pathlike):
+        self._file_like = str(Path(pathlike))
+        self._offset = None
+        self._vnum = None
+        self._fnum = None
+
+    def _peek(self):
+        from nibabel.freesurfer.io import _fread3
+
+        with open(self._file_like, 'rb') as fobj:
+            magic = _fread3(fobj)
+            if magic != 16777214:
+                raise NotImplementedError('Triangle files only!')
+            fobj.readline()
+            fobj.readline()
+            self._vnum = np.fromfile(fobj, '>i4', 1)[0]
+            self._fnum = np.fromfile(fobj, '>i4', 1)[0]
+            self._offset = fobj.tell()
+
+    @property
+    def vnum(self):
+        if self._vnum is None:
+            self._peek()
+        return self._vnum
+
+    @property
+    def fnum(self):
+        if self._fnum is None:
+            self._peek()
+        return self._fnum
+
+    @property
+    def offset(self):
+        if self._offset is None:
+            self._peek()
+        return self._offset
+
+    @property
+    def coords(self):
+        ap = ArrayProxy(self._file_like, ((self.vnum, 3), '>f4', self.offset))
+        ap.order = 'C'
+        return ap
+
+    @property
+    def triangles(self):
+        offset = self.offset + 12 * self.vnum
+        ap = ArrayProxy(self._file_like, ((self.fnum, 3), '>i4', offset))
+        ap.order = 'C'
+        return ap
+
+
+class FreeSurferHemisphere(ps.TriangularMesh):
+    @classmethod
+    def from_filename(klass, pathlike):
+        path = Path(pathlike)
+        hemi, default = path.name.split('.')
+        mesh_names = (
+            'orig',
+            'white',
+            'smoothwm',
+            'pial',
+            'inflated',
+            'sphere',
+            'midthickness',
+            'graymid',
+        )  # Often created
+        if default not in mesh_names:
+            mesh_names.append(default)
+        meshes = {}
+        for mesh in mesh_names:
+            fpath = path.parent / f'{hemi}.{mesh}'
+            if fpath.exists():
+                meshes[mesh] = FSGeometryProxy(fpath)
+        hemi = klass(meshes)
+        hemi._default = default
+        return hemi
+
+    def get_coords(self, name=None):
+        if name is None:
+            name = self._default
+        return self._meshes[name].coords
+
+    def get_triangles(self, name=None):
+        if name is None:
+            name = self._default
+        return self._meshes[name].triangles
+
+    @property
+    def n_coords(self):
+        return self.meshes[self._default].vnum
+
+    @property
+    def n_triangles(self):
+        return self.meshes[self._default].fnum