50 lines
1.6 KiB
Plaintext
50 lines
1.6 KiB
Plaintext
|
/** \page tutorial_04 Using STL algorithms
|
||
|
|
|
||
|
|
Since the %OpenMesh iterators are (almost) conformant to STL iterators,
|
||
|
|
one can apply the STL algorithms on meshes. The following example
|
||
|
|
shows how to use the STL \c for_each construct, since it is
|
||
|
|
easier to read and may be more efficient than hand-written loops.
|
||
|
|
|
||
|
|
We will define a class which provides the smoothing algorithm, hence
|
||
|
|
define a reusable component. The class must be template class because there
|
||
|
|
is no such thing as a class %OpenMesh, but many different types of %OpenMesh:
|
||
|
|
|
||
|
|
\dontinclude 04-stl_algorithms/smooth_algo.hh
|
||
|
|
\skipline template
|
||
|
|
|
||
|
|
The class SmootherT has two functors, one that computes the barycenter
|
||
|
|
for a given vertex, and a second that sets the vertex position to the
|
||
|
|
corresponding barycenter. A functor is simply a class with a function
|
||
|
|
<tt>operator()(...)</tt>. The first functor \c ComputeCOG
|
||
|
|
computes the barycenter and store it in a custom vertex property \c
|
||
|
|
cog_:
|
||
|
|
|
||
|
|
\skipline operator
|
||
|
|
\until }
|
||
|
|
\until }
|
||
|
|
|
||
|
|
Note, that \c ComputeCOG needs to have access to the mesh object and
|
||
|
|
the property handle. Here, both are references to member variables of
|
||
|
|
the smoother object.
|
||
|
|
|
||
|
|
The second functor \c class \c SetCOG, which sets the vertex position,
|
||
|
|
is constructed analogical.
|
||
|
|
|
||
|
|
Using these functors and <tt>std::for_each</tt> from the STL
|
||
|
|
the smoothing algorithm can be realized in a member function of
|
||
|
|
\c SmootherT:
|
||
|
|
|
||
|
|
\dontinclude 04-stl_algorithms/smooth_algo.hh
|
||
|
|
\skipline void smooth
|
||
|
|
\until }
|
||
|
|
\until }
|
||
|
|
|
||
|
|
<br>The complete example looks like this:
|
||
|
|
|
||
|
|
\include 04-stl_algorithms/smooth_algo.hh
|
||
|
|
|
||
|
|
<br>and
|
||
|
|
|
||
|
|
\include 04-stl_algorithms/smooth.cc
|
||
|
|
|
||
|
|
*/
|