update readwrite.rst

docs/readwrite.rst

@@ -3,70 +3,16 @@
 I/O Functions
 *************
 
-OpenMesh provides two functions that read and write meshes from and to files:
-:func:`~openmesh.read_mesh` and :func:`~openmesh.write_mesh`
+OpenMesh provides functions that read and write meshes from and to files:
+:func:`~openmesh.read_trimesh`, :func:`~openmesh.read_polymesh` and :func:`~openmesh.write_mesh`
 
 .. code:: python
 
     import openmesh as om
 
-    mesh = om.TriMesh()
-
-    om.read_mesh(mesh, "bunny.ply")
+    trimesh = om.read_trimesh("bunny.ply")
+    polymesh = om.read_polymesh("bunny.ply")
     # modify mesh ...
-    om.write_mesh(mesh, "bunny.ply")
-
-The file type is automatically deduced from the file extension. OpenMesh
-currently supports five file types: .obj, .off, .ply, .stl and .om
-
-The behaviour of the I/O functions can be fine-tuned by passing an instance of
-the :class:`~openmesh.Options` class to either :func:`~openmesh.read_mesh` or
-:func:`~openmesh.write_mesh`. When reading a file the options are used as hints,
-i.e. depending on the format we can help the reader to interpret the data
-correctly. When writing a file the options determine whether or not to use the
-binary variant of the respective file format and the desired byte-ordering.
-
-.. code:: python
-
-    import openmesh as om
-
-    mesh = om.TriMesh()
-
-    # hint: read vertex normals
-    options = om.Options()
-    options += om.Options.VertexNormal
-    om.read_mesh(mesh, "bunny.ply", options)
-
-    # write binary file
-    options = om.Options()
-    options += om.Options.Binary
-    om.write_mesh(mesh, "bunny_binary.ply", options)
-
-The :class:`~openmesh.Options` class controls the behaviour of the I/O functions
-by means of enabled/disabled bits in a bitset. The following list contains all
-available option bits:
-
-- mode bits - control binary reading/writing
-
-    - Options.Binary
-    - Options.MSB
-    - Options.LSB
-    - Options.Swap (MSB|LSB)
-
-- property bits - controls which standard properties to read/write
-
-    - Options.VertexNormal
-    - Options.VertexTexCoord
-    - Options.VertexColor
-    - Options.FaceNormal
-    - Options.FaceColor
-    - Options.ColorAlpha
-    - Options.ColorFloat
-
-Multiple options can be combined using simple arithmetic:
-
-.. code:: python
+    om.write_mesh(trimesh, "bunny.ply")
 
-    options = om.Options()
-    options += om.Options.VertexNormal
-    options += om.Options.VertexColor
+OpenMesh currently supports five file types: .obj, .off, .ply, .stl and .om