update documentation of new property manager

Doc/tutorial_03.docu

@@ -11,34 +11,33 @@ let %OpenMesh manage the data.
 It would be even more helpful if we could attach such properties
 dynamically to the mesh.
 
-Custom properties can be conveniently created and attached to meshes with the following functions:
-- makeTemporaryProperty() creates a property that is temporary to the current scope.
-- getOrMakeProperty() is used for creating and accessing permanent named properties on a mesh.
-- getProperty() is used for accessing an existing permanent named property on a mesh.
+Custom properties can be conveniently created and attached to meshes by creating an object of type OpenMesh::PropertyManager. A PropertyManager manages the lifetime of the property and provides read / write access to its values.
 
-All three functions take two template arguments:
-- First, the type of the mesh element that the property is attached to (i.e. OpenMesh::VertexHandle, OpenMesh::HalfedgeHandle, OpenMesh::EdgeHandle, or OpenMesh::FaceHandle). <em>Mesh properties</em> (i.e. singleton properties that are attached to an entire mesh instead of individual elements) are accessed by passing \c void instead of a handle type.
-- Second, the type of the property value that is attached to each element (e.g., \p int, \p double, etc.).
+You can use the typedefs VProp, HProp, EProp, FProp, and MProp in order to create a PropertyManager attached to vertices, halfedge, edges, faces and the mesh respectively. Each of these takes as template argument the type of the property value that is attached to each element (e.g., \p int, \p double, etc.).
+
+We differentiate between two kinds of properties. <em>Named</em> and <em>temporary</em> properties. Temporary properties are created by just providing the constructor with a mesh on which the property should be created. These properties will be removed as soon as the PropertyManager goes out of scope. If in addition to the mesh a property name is provided, a named property will be created which will stay alive even after the PropertyManager goes out of scope. If a PropertyManager is given a name of an already existing property, it will provide read and write access to the same property.
+
+Finally, an optional first parameter can be given containing a value that will be used to initialize the property for all elements if the property is freshly created (i.e. always for temporary properties, and only the first time a specific name is used).
 
-All three functions return a handle object (of type OpenMesh::PropertyManager) that manages the lifetime of the property and provides read / write access to its values.
 
 Here are a few examples of how to create and access mesh properties:
 
 \code
 // Add a temporary mesh property that stores a double value for every vertex
-auto temperature = OpenMesh::getOrMakeProperty<OpenMesh::VertexHandle, double>(mesh, "temperature");
+auto temperature = OpenMesh::VProp<double>(mesh);
 OpenMesh::VertexHandle vh = ...;
 temperature[vh] = 1.0;
 // The temperature property will be removed from the mesh when the handle reaches the end of the scope.
 
-// Obtain an existing mesh property that stores a 2D vector for every halfedge
-// (Beware: the next line might throw if the expected property doesn't exist.)
-auto uv = OpenMesh::getProperty<OpenMesh::HalfedgeHandle, OpenMesh::Vec2d>(mesh, "uv");
+// Obtain an existing property that stores a 2D vector for every halfedge
+// (or create that property if it does not exist already) and initilize it with the Vector(1,1))
+auto uv = OpenMesh::HProp<OpenMesh::Vec2d>(mesh, "uv", OpenMesh::Vec2d(1,1));
 OpenMesh::VertexHandle heh = ...;
 std::cout << temperature[heh][0] << " " << temperature[heh][1] << std::endl;
 
-// Add a permanent mesh property containing a description string
-auto desc = OpenMesh::getOrMakeProperty<void, std::string>(mesh, "desc");
+// Obtain an existing mesh property (or create that property if it does not exist already)
+// containing a description string
+auto desc = OpenMesh::MProp<std::string>(mesh, "desc");
 *desc = "This is a very nice mesh.";
 \endcode