OpenMesh

https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/
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### Install Optional Libraries on MacOS X

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a06305

Installs optional libraries required for specific OpenMesh functionalities using Homebrew. Googletest is needed for compiling tests, and Qt for UI examples.

```shell
brew install googletest
brew install qt
```

--------------------------------

### OpenMesh Class Member 'b' Examples

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/functions_b

Demonstrates the usage of class members starting with 'b' in OpenMesh. Includes examples for BaseProperty, begin, Binary options, binary_size for various writers, and bits for StatusInfo.

```cpp
BaseProperty() : OpenMesh::BaseProperty
```

```cpp
begin() : OpenMesh::StripifierT< Mesh >
```

```cpp
Binary : OpenMesh::IO::Options
```

```cpp
binary_size() : OpenMesh::IO::_OBJWriter_, OpenMesh::IO::_OFFWriter_, OpenMesh::IO::_OMWriter_, OpenMesh::IO::_PLYWriter_, OpenMesh::IO::_STLWriter_, OpenMesh::IO::_VTKWriter_, OpenMesh::IO::BaseWriter
```

```cpp
bits() : OpenMesh::Attributes::StatusInfo
```

--------------------------------

### Basic OpenMesh Triangle Mesh Example

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a06333

Demonstrates the setup and basic usage of OpenMesh with custom traits for a triangle mesh. It includes mesh loading, normal calculation, and vertex manipulation.

```C++
#include <iostream>
#include <typeinfo>
// --------------------
#include <OpenMesh/Core/IO/MeshIO.hh>
#include <OpenMesh/Core/Mesh/TriMesh_ArrayKernelT.hh>
#include <OpenMesh/Core/Geometry/VectorT.hh>
#ifndef DOXY_IGNORE_THIS
// Define my personal traits
struct MyTraits : OpenMesh::DefaultTraits
{
// Let Point and Normal be a vector of doubles
typedef OpenMesh::Vec3d Point;
typedef OpenMesh::Vec3d Normal;
// Already defined in OpenMesh::DefaultTraits
// HalfedgeAttributes( OpenMesh::Attributes::PrevHalfedge );
// Uncomment next line to disable attribute PrevHalfedge
// HalfedgeAttributes( OpenMesh::Attributes::None );
//
// or
//
// HalfedgeAttributes( 0 );
};
#endif
// Define my mesh with the new traits!
typedef OpenMesh::TriMesh_ArrayKernelT<MyTraits> MyMesh;
// ------------------------------------------------------------------ main ----
int main(int argc, char **argv)
{
MyMesh mesh;
if (argc!=2)
{
std::cerr << "Usage: " << argv[0] << " <input>\n";
return 1;
}
// Just make sure that point element type is double
if ( typeid( OpenMesh::vector_traits<MyMesh::Point>::value_type )
!= typeid(double) )
{
std::cerr << "Ouch! ERROR! Data type is wrong!\n";
return 1;
}
// Make sure that normal element type is double
if ( typeid( OpenMesh::vector_traits<MyMesh::Normal>::value_type )
!= typeid(double) )
{
std::cerr << "Ouch! ERROR! Data type is wrong!\n";
return 1;
}
// Add vertex normals as default property (ref. previous tutorial)
mesh.request_vertex_normals();
// Add face normals as default property
mesh.request_face_normals();
// load a mesh
OpenMesh::IO::Options opt;
if ( ! OpenMesh::IO::read_mesh(mesh,argv[1], opt))
{
std::cerr << "Error loading mesh from file " << argv[1] << std::endl;
return 1;
}
// If the file did not provide vertex normals, then calculate them
if ( !opt.check( OpenMesh::IO::Options::VertexNormal ) &&
mesh.has_face_normals() && mesh.has_vertex_normals() )
{
// let the mesh update the normals
mesh.update_normals();
}
// move all vertices one unit length along it's normal direction
for (MyMesh::VertexIter v_it = mesh.vertices_begin();
 v_it != mesh.vertices_end(); ++v_it)
{
std::cout << "Vertex #" << *v_it << ": " << mesh.point( *v_it );
mesh.set_point( *v_it, mesh.point(*v_it)+mesh.normal(*v_it) );
std::cout << " moved to " << mesh.point( *v_it ) << std::endl;
}
return 0;
}
```

--------------------------------

### Improve Decimater example documentation

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a06304

Enhanced the documentation for the Decimater example to provide clearer instructions and explanations. This improves the usability of the example for users.

```markdown
Fixed Decimater example documentation.
```

--------------------------------

### OpenMesh Final Implementation Example

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a06316

An example demonstrating a final implementation of a triangle mesh rendering application using OpenMesh, including defining custom traits and adding dynamic properties.

```APIDOC
## Final Implementation Example

### Description
This example considers an application that renders triangle meshes. It demonstrates selecting a triangle mesh, using the `ArrayKernelT`, and defining custom traits (`MyTraits`) for vertex and face attributes. It also shows how to add dynamic properties to the mesh at runtime.

### Method
N/A (Code Example)

### Endpoint
N/A

### Parameters
N/A

### Request Example
```cpp
#include <OpenMesh/Core/Mesh/TriMesh_ArrayKernelT.hh>
#include <string>

// Define traits
struct MyTraits : public OpenMesh::DefaultTraits
{
    // use double valued coordinates
    typedef OpenMesh::Vec3d Point;
    // use vertex normals and vertex colors
    VertexAttributes( OpenMesh::DefaultAttributer::Normal |
                      OpenMesh::DefaultAttributer::Color );
    // store the previous halfedge
    HalfedgeAttributes( OpenMesh::DefaultAttributer::PrevHalfedge );
    // use face normals
    FaceAttributes( OpenMesh::DefaultAttributer::Normal );
    // store a face handle for each vertex
    VertexTraits
    {
        typename Base::Refs::FaceHandle my_face_handle;
    };
};

// Select mesh type (TriMesh) and kernel (ArrayKernel)
// and define my personal mesh type (MyMesh)
typedef OpenMesh::TriMesh_ArrayKernelT<MyTraits> MyMesh;

int main(int argc, char **argv)
{
    MyMesh mesh;

    // Add dynamic data
    // for each vertex an extra double value
    OpenMesh::VPropHandleT< double > vprop_double;
    mesh.add_property( vprop_double );

    // for the mesh an extra string
    OpenMesh::MPropHandleT< std::string > mprop_string;
    mesh.add_property( mprop_string );

    // ... do something ...

    return 0;
}
```

### Response
N/A (Code Execution)
```

--------------------------------

### Basic Decimater Setup - C++

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a06307

Demonstrates the fundamental steps to initialize and use the OpenMesh decimater. It includes creating a mesh, instantiating the decimater, adding a quadric module, configuring it as a non-binary module, initializing the decimater, performing decimation, and cleaning up the mesh.

```cpp
using namespace OpenMesh;

typedef TriMesh_ArrayKernelT<> Mesh;
typedef Decimater::DecimaterT<Mesh> Decimater;
typedef Decimater::ModQuadricT<Mesh>::Handle HModQuadric;

Mesh mesh; // a mesh object
Decimater decimater(mesh); // a decimater object, connected to a mesh
HModQuadric hModQuadric; // use a quadric module

decimater.add(hModQuadric); // register module at the decimater
std::cout << decimater.module(hModQuadric).name() << std::endl; // module access

/*
* since we need exactly one priority module (non-binary)
* we have to call set_binary(false) for our priority module
* in the case of HModQuadric, unset_max_err() calls set_binary(false) internally
*/
decimater.module(hModQuadric).unset_max_err();
decimater.initialize();
decimater.decimate();

// after decimation: remove decimated elements from the mesh
mesh.garbage_collection();
```

--------------------------------

### Get Starting Vertex of a SmartHalfedgeHandle in OpenMesh

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a00224_source

Returns the vertex at the start of the halfedge.

```C++
SmartVertexHandle from() const
```

--------------------------------

### OpenMesh Namespace Functions

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/functions_func_q

This section details functions within the OpenMesh namespace, categorized by their starting letter. Below are examples for functions starting with 'q'.

```APIDOC
## GET /openmesh/namespace/functions/q

### Description
Retrieves a list of functions within the OpenMesh namespace that start with the letter 'q'. This includes functions for input/output filters and geometry quadrics.

### Method
GET

### Endpoint
/openmesh/namespace/functions/q

### Parameters
None

### Request Example
None

### Response
#### Success Response (200)
- **functions** (array) - A list of function names and their respective namespaces.

#### Response Example
```json
{
  "functions": [
    "OpenMesh::IO::_IOManager_::qt_read_filters()",
    "OpenMesh::IO::_IOManager_::qt_write_filters()",
    "OpenMesh::Geometry::QuadricT< Scalar >::QuadricT()"
  ]
}
```
```

--------------------------------

### Update decimation tutorial documentation

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a06304

The documentation for the decimation tutorial has been adjusted to correctly explain the initialization of the priority module. This improves clarity and accuracy for users following the tutorial.

```markdown
Updated decimation tutorial documentation regarding priority module initialization.
```

--------------------------------

### OpenMesh IOManager Quick Start

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a06319

This section provides a quick start example for using the OpenMesh IOManager to read and write mesh files.

```APIDOC
## IOManager Quick Start

### Description
This example demonstrates how to quickly integrate mesh reading and writing functionality using the OpenMesh IOManager.

### Method
Not Applicable (C++ code example)

### Endpoint
Not Applicable (C++ code example)

### Parameters
None for this specific code snippet, but the functions `read_mesh` and `write_mesh` take mesh objects and filenames as parameters.

### Request Example
```cpp
#include <OpenMesh/Core/IO/MeshIO.hh>

MyMesh mesh;
if (!OpenMesh::IO::read_mesh(mesh, "some input file")) 
{
    std::cerr << "read error\n";
    exit(1);
}

// do something with your mesh ...

if (!OpenMesh::IO::write_mesh(mesh, "some output file")) 
{
    std::cerr << "write error\n";
    exit(1);
}
```

### Response
#### Success Response
Mesh data is processed and written to the specified file.

#### Response Example
No direct response, but successful execution implies the mesh was read or written correctly.
```

--------------------------------

### OpenMesh Navigation with Smart Handles

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a06339

Demonstrates how to iterate over mesh elements and navigate using smart handles for simplified code.

```APIDOC
## OpenMesh Navigation with Smart Handles

### Description
This section illustrates advanced mesh navigation techniques in OpenMesh using smart handles and ranges. It shows how to efficiently access adjacent elements (vertices, edges, faces) of a mesh.

### Method
N/A (Illustrative code examples)

### Endpoint
N/A (C++ Library Documentation)

### Parameters
N/A

### Request Example
N/A

### Response
N/A

## Example 1: Basic Navigation using Halfedge Handles

### Description
Iterates over all vertices of a triangle mesh and for each vertex, finds all opposite vertices connected by edges in the vertex's ring.

### Method
N/A (C++ Code Example)

### Endpoint
N/A

### Parameters
N/A

### Request Example
```cpp
// iterate over vertices of the mesh
for (auto vh : mesh.vertices())
{
  std::vector<OpenMesh::VertexHandle> opposite_vertices;
  // iterate over all outgoing halfedges
  for (auto heh : mesh.voh_range(vh))
  {
    // navigate to the opposite vertex and store it in the vector
    opposite_vertices.push_back(mesh.to_vertex_handle(mesh.next_halfedge_handle(mesh.opposite_halfedge_handle(mesh.next_halfedge_handle(heh))))));
  }
}
```

### Response
N/A

## Example 2: Navigation using Smart Handles

### Description
Demonstrates the simplified navigation using OpenMesh's smart handles (e.g., `SmartHalfedgeHandle`), which encapsulate mesh context and provide intuitive navigation methods.

### Method
N/A (C++ Code Example)

### Endpoint
N/A

### Parameters
N/A

### Request Example
```cpp
// iterate over vertices of the mesh
for (auto vh : mesh.vertices())
{
  // iterate over all outgoing halfedges
  std::vector<OpenMesh::VertexHandle> opposite_vertices;
  for (auto heh : vh.outgoing_halfedges()) // Using SmartHalfedgeHandle
  {
    // navigate to the opposite vertex and store it in the vector
    opposite_vertices.push_back(heh.next().opp().next().to());
  }
}
```

### Response
N/A

## Example 3: Navigation with Ranges and Functors

### Description
Shows how to use `to_vector()` method on ranges returned by smart handles, applying a functor for concise element transformation.

### Method
N/A (C++ Code Example)

### Endpoint
N/A

### Parameters
N/A

### Request Example
```cpp
// iterate over vertices of the mesh
for (auto vh : mesh.vertices())
{
  // create lambda that returns opposite vertex
  auto opposite_vertex = [](OpenMesh::SmartHalfedgeHandle heh) { return heh.next().opp().next().to(); };
  // create vector containing all opposite vertices
  auto opposite_vertices = vh.outgoing_halfedges().to_vector(opposite_vertex);
}
```

### Response
N/A
```

--------------------------------

### Get Halfedges of Edge (from HalfedgeHandle)

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a02630

Returns a range object for iterating over the halfedges of a given edge, starting from a specific halfedge.

```APIDOC
## eh_range() [2/2]

### Description
Returns a range object for iterating over the halfedges of the specified edge, starting iteration at the provided halfedge.

### Method
`PolyConnectivity::ConstEdgeHalfedgeRange`

### Parameters
#### Path Parameters
- `__heh_` (HalfedgeHandle) - The halfedge handle from which to start iteration.

### Returns
A range object suitable for C++11 range-based for loops.
```

--------------------------------

### OpenMesh Testing Framework Usage Example

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a00458_source

Demonstrates how to set up and use the OpenMesh Testing Framework. It shows the creation of a custom test class inheriting from `TestingFramework::TestFunc`, implementing the `body()` method for test logic, and registering it with the `TestingFramework` in `main`.

```cpp
#include <iostream>
#include <.../TestingFramework.hh>

struct test_func : public TestingFramework::TestFunc
{
typedef test_func Self;

// define ctor and copy-ctor
test_func( TestingFramework& _th, std::string _n ) : TestingFramework::TestFunc( _th, _n ) { }
test_func( Self& _cpy ) : TestingFramework::TestFunc(_cpy) { }

// overload body()
void body()
{

// Do the tests
// direct call to verify
verify( testResult, expectedResult, "additional information" );

// or use the define TH_VERIFY. The test-expression will be used as the message string
TH_VERIFY( testResult, expectedResult );

...
}
};

int main(...)
{
TestingFramework testSuite(std::cout); // send output to stdout

new test_func(testSuite); // create new test instance. It registers with testSuite.
return testSuite.run();
}
```

--------------------------------

### Get Halfedge Handle for Face in C++

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a01154_source

Retrieves the handle of a halfedge that lies on the boundary of a given face. This is a starting point for iterating through the halfedges of a face.

```cpp
HalfedgeHandle halfedge_handle(FaceHandle _fh) const;
```

--------------------------------

### OpenMesh: Get Outgoing Halfedges Range (HalfedgeHandle)

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a02630

Provides a C++ range object for iterating through outgoing halfedges incident to a specified vertex, starting iteration at the given halfedge.

```cpp
inline PolyConnectivity::ConstVertexOHalfedgeRange OpenMesh::PolyConnectivity::voh_range(HalfedgeHandle __heh_) const
```

--------------------------------

### OpenMesh File List

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/dir_8a440bf75a6d313779e8057642fee177

Lists the header files associated with the Tutorial10 example in OpenMesh. These files likely contain declarations for mesh processing functionalities and utilities.

```text
fill_props.hh
generate_cube.hh
int2roman.hh
stats.hh
```

--------------------------------

### BaseDecimaterT Initialization and Setup

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a03370

Provides functions for initializing the decimater, checking its initialization status, and setting up an observer for monitoring the decimation process.

```cpp
BaseDecimaterT(Mesh &_mesh)
bool initialize()
bool is_initialized() const
void set_observer(Observer *_o)
Observer *observer()
```

--------------------------------

### OpenMesh: Get Incoming Halfedges Range (HalfedgeHandle)

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a02630

Provides a C++ range object for iterating through incoming halfedges incident to a specified vertex, starting iteration at the given halfedge.

```cpp
inline PolyConnectivity::ConstVertexIHalfedgeRange OpenMesh::PolyConnectivity::vih_range(HalfedgeHandle __heh_) const
```

--------------------------------

### OpenMesh Main Page

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a02927

Provides an overview of the OpenMesh library, including navigation to different sections like Modules, Namespaces, Classes, and Files.

```APIDOC
## OpenMesh Documentation

### Description
Welcome to the official documentation for the OpenMesh library. This site provides comprehensive information about the library's structure, classes, functions, and more.

### Navigation
Explore the documentation using the navigation menu on the left:

*   **Main Page**: Overview of OpenMesh.
*   **Related Pages**: Links to related documentation.
*   **Modules**: Groupings of related functionalities.
*   **Namespaces**: Organization of classes and functions.
    *   Namespace List
    *   Namespace Members (All, Functions, Variables, Typedefs, Enumerations, Enumerator)
*   **Classes**: Detailed information about each class.
    *   Class List
    *   Class Hierarchy
    *   Class Members (All, Functions, Variables, Typedefs, Enumerations, Enumerator, Related Functions)
*   **Files**: Information about the library's source files.
    *   File List
    *   File Members (All, Macros)

### Key Features
*   Efficient mesh data structures.
*   Support for various mesh operations.
*   Extensible through modules and concepts.

### Getting Started
*   How to create your own project inside OpenMesh
*   Todo List
*   Deprecated List
```

--------------------------------

### Get Halfedge Handle from Vertex in C++

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a01154_source

Retrieves the handle of a halfedge originating from a given vertex. This is a fundamental operation for navigating the mesh connectivity starting from a vertex.

```cpp
HalfedgeHandle halfedge_handle(VertexHandle _vh) const;
```

--------------------------------

### OpenMesh Halfedge Iteration and Traversal

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a02815

Functions for iterating over and traversing halfedges in OpenMesh. This includes getting iterators for the start and end of halfedge sequences and traversing halfedge loops in different directions.

```c++
halfedges() const
halfedges_begin()
halfedges_begin() const
halfedges_end()
halfedges_end() const
halfedges_sbegin()
halfedges_sbegin() const
hl_begin(HalfedgeHandle _heh)
hl_ccw_range(HalfedgeHandle _heh) const
hl_ccwbegin(HalfedgeHandle _heh)
hl_ccwend(HalfedgeHandle _heh)
hl_cw_range(HalfedgeHandle _heh) const
hl_cwbegin(HalfedgeHandle _heh)
hl_cwend(HalfedgeHandle _heh)
hl_end(HalfedgeHandle _heh)
hl_range(HalfedgeHandle _heh) const
```

--------------------------------

### Build OpenMesh Project with CMake

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a06341

These commands initiate the CMake build process for the OpenMesh project, including any added custom applications. First, a 'build' directory is created and entered. Then, 'cmake ..' configures the build, and 'make' compiles the project.

```bash
mkdir build
cd build
cmake ..
make
```

--------------------------------

### OpenMesh: Get Outgoing Halfedges CW Range (HalfedgeHandle)

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a02630

Provides a C++ range object for iterating through outgoing halfedges incident to a specified vertex in a clockwise direction, starting iteration at the given halfedge.

```cpp
inline PolyConnectivity::ConstVertexOHalfedgeCWRange OpenMesh::PolyConnectivity::voh_cw_range(HalfedgeHandle __heh_) const
```

--------------------------------

### Build OpenMesh and Documentation on MacOS X

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a06305

Commands to build the OpenMesh library and its documentation. 'make' compiles the library, and 'make doc' specifically builds the documentation.

```shell
make ## Build OpenMesh
make doc ## Build OpenMesh's documentation
```

--------------------------------

### OpenMesh: Get Outgoing Halfedges CCW Range (HalfedgeHandle)

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a02630

Provides a C++ range object for iterating through outgoing halfedges incident to a specified vertex in a counter-clockwise direction, starting iteration at the given halfedge.

```cpp
inline PolyConnectivity::ConstVertexOHalfedgeCCWRange OpenMesh::PolyConnectivity::voh_ccw_range(HalfedgeHandle __heh_) const
```

--------------------------------

### OpenMesh Singleton Pattern

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/functions_i

Documentation for the Singleton design pattern implementation.

```APIDOC
## OpenMesh Singleton Pattern

### Description
Details the implementation of the Singleton pattern for ensuring a single instance of a class.

### Singleton Class

- **`SingletonT< T >`**: Template for the Singleton pattern.
- **`Instance()`**: Returns the singleton instance.
```

--------------------------------

### BaseProperty Constructor and Destructor

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a02834

Documentation for the BaseProperty constructor and destructor, including default and copy constructors, and the virtual destructor.

```APIDOC
## BaseProperty Constructor & Destructor

### Default Constructor
**BaseProperty** (const std::string &_name="<unknown>", const std::string &_internal_type_name="<unknown>")
Default constructor. Allows specifying a name and internal type name for the property. If the property is intended for storage in the OM-format, it must be named and its persistent flag enabled using `set_persistent()`.

Parameters:
- `_name` (const std::string &): Optional textual name for the property.
- `_internal_type_name` (const std::string &): Internal type name used when storing data in OM format.

### Copy Constructor
**BaseProperty** (const BaseProperty &_rhs)
Copy constructor for creating a new BaseProperty object from an existing one.

### Destructor
virtual **~BaseProperty** ()
Virtual destructor for the BaseProperty class.
```

--------------------------------

### OpenMesh: Get Incoming Halfedges CW Range (HalfedgeHandle)

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a02630

Provides a C++ range object for iterating through incoming halfedges incident to a specified vertex in a clockwise direction, starting iteration at the given halfedge.

```cpp
inline PolyConnectivity::ConstVertexIHalfedgeCWRange OpenMesh::PolyConnectivity::vih_cw_range(HalfedgeHandle __heh_) const
```

--------------------------------

### Example Main Function for Mesh I/O (OpenMesh C++)

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a06336

A complete C++ `main` function demonstrating reading a mesh, displaying its properties (including binary format, byte order, and available features like vertex normals), and then writing the mesh with specified options. It includes error handling for both read and write operations.

```C++
#include <iostream>
#include <iterator>
#include <OpenMesh/Core/IO/MeshIO.hh>
#include <OpenMesh/Core/Mesh/TriMesh_ArrayKernelT.hh>
#include <OpenMesh/Tools/Utils/getopt.h>

// Define macros for checking and printing options
#define CHKROPT( Option ) std::cout << " provides " << #Option << (ropt.check(IO::Options:: Option)?": yes\n":": no\n")
#define CHKWOPT( Option ) std::cout << " write " << #Option << (wopt.check(IO::Options:: Option)?": yes\n":": no\n")
#define MESHOPT( msg, tf ) std::cout << " " << msg << ": " << ((tf) ? "yes\n" : "no\n")

// Typedef for the mesh kernel
typedef OpenMesh::TriMesh_ArrayKernelT<> MyMesh;

// Forward declarations for helper functions
void parse_commandline( int _argc, char **_argv, MyMesh& _mesh, IO::Options &ropt, IO::Options &wopt );
void usage_and_exit(int xcode);

int main(int argc, char **argv)
{
    MyMesh mesh;
    IO::Options ropt, wopt;

    // Evaluate command line arguments
    parse_commandline( argc, argv, mesh, ropt, wopt );

    // Read the mesh from the specified file
    if ( ! IO::read_mesh(mesh,argv[optind], ropt) )
    {
        std::cerr << "Error loading mesh from file " << argv[optind] << std::endl;
        return 1;
    }

    // Display read options and mesh properties
    std::cout << "File " << argv[optind] << std::endl;
    std::cout << " is binary: " << (ropt.check(IO::Options::Binary) ? " yes\n" : " no\n");
    std::cout << " byte order: ";
    if (ropt.check(IO::Options::Swap))
        std::cout << "swapped\n";
    else if (ropt.check(IO::Options::LSB))
        std::cout << "little endian\n";
    else if (ropt.check(IO::Options::MSB))
        std::cout << "big endian\n";
    else
        std::cout << "don't care\n";
    std::cout << " provides VertexNormal" << (ropt.check(IO::Options::VertexNormal) ? ": yes\n":"no\n");
    CHKROPT( VertexColor );
    CHKROPT( VertexTexCoord );
    CHKROPT( FaceNormal );
    CHKROPT( FaceColor );

    // Display mesh statistics
    std::cout << "# Vertices: " << mesh.n_vertices() << std::endl;
    std::cout << "# Edges : " << mesh.n_edges() << std::endl; // Corrected from n_faces() to n_edges()
    std::cout << "# Faces : " << mesh.n_faces() << std::endl;

    // Display selected write options
    std::cout << "Selected write options:\n";
    std::cout << " use binary: " << (wopt.check(IO::Options::Binary) ? " yes\n" : " no\n");
    std::cout << " byte order: ";
    if (wopt.check(IO::Options::Swap))
        std::cout << "swapped\n";
    else if (wopt.check(IO::Options::LSB))
        std::cout << "little endian\n";
    else if (wopt.check(IO::Options::MSB))
        std::cout << "big endian\n";
    else
        std::cout << "don't care\n";
    std::cout << " write VertexNormal" << (wopt.check(IO::Options::VertexNormal) ? ": yes\n":": no\n");
    CHKWOPT( VertexColor );
    CHKWOPT( VertexTexCoord );
    CHKWOPT( FaceNormal );
    CHKWOPT( FaceColor );

    // Display mesh capabilities
    std::cout << "Mesh supports\n";
    MESHOPT("vertex normals", mesh.has_vertex_normals());
    MESHOPT("vertex colors", mesh.has_vertex_colors());
    MESHOPT("texcoords", mesh.has_vertex_texcoords2D());
    MESHOPT("face normals", mesh.has_face_normals());
    MESHOPT("face colors", mesh.has_face_colors());

    // Write the mesh to the output file
    std::cout << "Write mesh to " << argv[optind+1] << "..";
    if ( !IO::write_mesh( mesh, argv[optind+1], wopt ) )
    {
        std::cerr << "Error" << std::endl;
        std::cerr << "Possible reasons:\n";
        std::cerr << "1. Chosen format cannot handle an option!\n";
        std::cerr << "2. Mesh does not provide necessary information!\n";
        std::cerr << "3. Or simply cannot open file for writing!\n";
        return 1;
    }
    else
        std::cout << "Ok.\n";

    return 0;
}
```

--------------------------------

### Get CCW Incoming Halfedge Range (OpenMesh)

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a02630

Returns a range object for incoming halfedges incident to a vertex in counter-clockwise order, starting iteration at a specified halfedge. Suitable for C++11 range-based for loops.

```C++
PolyConnectivity::ConstVertexIHalfedgeCCWRange OpenMesh::PolyConnectivity::vih_ccw_range  (   HalfedgeHandle   __heh_  )  const
```

--------------------------------

### Utility Functions

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a01254

Provides documentation for key utility functions such as kbhit, getch, getche, and GLenum_as_string.

```APIDOC
## kbhit()

### Description
Checks if characters are pending in standard input.

### Method
GET

### Endpoint
`/utils/kbhit`

### Parameters
#### Query Parameters
- **None**

### Request Example
```json
{
  "example": "No request body needed"
}
```

### Response
#### Success Response (200)
- **int** - Number of characters available to read.

#### Response Example
```json
{
  "result": 1
}
```

## ◆ getch()

### Description
Reads a single character from standard input in a blocking manner.

### Method
GET

### Endpoint
`/utils/getch`

### Parameters
#### Query Parameters
- **None**

### Request Example
```json
{
  "example": "No request body needed"
}
```

### Response
#### Success Response (200)
- **int** - The character read, or -1 if an input error occurs.

#### Response Example
```json
{
  "result": 97
}
```

## ◆ getche()

### Description
Reads a single character from standard input in a blocking manner with echo.

### Method
GET

### Endpoint
`/utils/getche`

### Parameters
#### Query Parameters
- **None**

### Request Example
```json
{
  "example": "No request body needed"
}
```

### Response
#### Success Response (200)
- **int** - The character read, or -1 if an input error occurs.

#### Response Example
```json
{
  "result": 97
}
```

## ◆ GLenum_as_string()

### Description
Converts a GLenum value to its string representation.

### Method
GET

### Endpoint
`/utils/glenum_as_string`

### Parameters
#### Query Parameters
- **_m** (GLenum) - The GLenum value to convert.

### Request Example
```json
{
  "example": "No request body needed"
}
```

### Response
#### Success Response (200)
- **const char*** - The string representation of the GLenum.

#### Response Example
```json
{
  "result": "GL_TRIANGLES"
}
```
```

--------------------------------

### OpenMesh MyMeshSmootherExampleTraits VertexT Example

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a03358

This snippet demonstrates the usage of the VertexT struct within the MyMeshSmootherExampleTraits namespace in OpenMesh. It includes public member functions for getting and setting the centroid (cog) of a vertex.

```C++
const Point & **cog** () const
void **set_cog** (const Point &_p)
```

--------------------------------

### OpenMesh Documentation Links

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a02702

Provides access to specific documentation pages and general information about OpenMesh.

```APIDOC
## GET /docs/openmesh

### Description
Retrieves information and links related to the main OpenMesh documentation.

### Method
GET

### Endpoint
/docs/openmesh

### Parameters
None

### Request Example
None

### Response
#### Success Response (200)
- **title** (string) - The title of the OpenMesh documentation page.
- **description** (string) - A brief description of the OpenMesh documentation.
- **links** (object) - Contains links to related pages like 'main_page', 'modules', 'classes', 'files'.

#### Response Example
{
  "title": "OpenMesh Documentation",
  "description": "Main entry point for OpenMesh documentation.",
  "links": {
    "main_page": "/docs/openmesh/main",
    "modules": "/docs/openmesh/modules",
    "classes": "/docs/openmesh/classes",
    "files": "/docs/openmesh/files"
  }
}

## GET /docs/openmesh/todo

### Description
Retrieves the 'Todo List' for OpenMesh development.

### Method
GET

### Endpoint
/docs/openmesh/todo

### Parameters
None

### Request Example
None

### Response
#### Success Response (200)
- **todo_list** (array) - A list of tasks or items in the OpenMesh todo list.

#### Response Example
[
  "Implement new meshing algorithm",
  "Refactor property handling"
]

## GET /docs/openmesh/deprecated

### Description
Retrieves the 'Deprecated List' for OpenMesh features.

### Method
GET

### Endpoint
/docs/openmesh/deprecated

### Parameters
None

### Request Example
None

### Response
#### Success Response (200)
- **deprecated_list** (array) - A list of deprecated features or functions in OpenMesh.

#### Response Example
[
  "OldMeshGenerator API",
  "LegacyIOStream"
]
```

--------------------------------

### OpenMesh Documentation Structure

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a00827_source

Overview of the OpenMesh documentation structure, including navigation for main pages, modules, namespaces, classes, and files.

```APIDOC
## OpenMesh Documentation Overview

### Description
Provides a hierarchical view of the OpenMesh C++ library's documentation.

### Method
N/A (Informational)

### Endpoint
N/A (Informational)

### Parameters
N/A

### Request Example
N/A

### Response
N/A

## OpenMesh File Structure

### Description
Details the file organization within the OpenMesh library, specifically focusing on the 'Core' module.

### Method
N/A (Informational)

### Endpoint
N/A (Informational)

### Parameters
N/A

### Request Example
N/A

### Response
N/A
```

--------------------------------

### OpenMesh Class Member Constants (l)

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/functions_l

Lists constants starting with 'l' within OpenMesh classes, specifying their associated classes. Examples include enumerations related to collapse legality and endianness.

```cpp
LEGAL_COLLAPSE : OpenMesh::Decimater::ModBaseT< MeshT >
LSB : OpenMesh::Endian, OpenMesh::IO::Options
```

--------------------------------

### Mesh Traversal and Element Access (OpenMesh)

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a01154_source

Functions related to traversing mesh elements and accessing related handles. This includes getting the next halfedge handle and retrieving the starting vertex of a halfedge.

```cpp
HalfedgeHandle next_halfedge_handle(HalfedgeHandle _heh) const
// Get the next halfedge handle.
```

```cpp
VertexHandle from_vertex_handle(HalfedgeHandle _heh) const
// Get the vertex the halfedge starts from (implemented as to-handle of the opposite halfedge,...
```

--------------------------------

### OpenMesh Smart Pointers and Taggers

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/functions_i

Documentation for smart handle and tagger functionalities.

```APIDOC
## OpenMesh Smart Pointers and Taggers

### Description
Covers smart handles and tagging mechanisms for mesh elements.

### Smart Handles and Taggers

- **`SmartVertexHandle`**: Smart handle for vertices.
- **`SmartHandleBoundaryPredicate< HandleType >`**: Predicate for checking boundary status of smart handles.
- **`SmartTaggerT< Mesh, EHandle, EPHandle >`**: Template for smart taggers.
```

--------------------------------

### OpenMesh Core Utils - System Helpers

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a00914_source

Documentation for system helper utilities, including non-copyable objects and random number generation.

```APIDOC
## GET /openmesh/core/utils/system-helpers

### Description
Details on system helper utilities like non-copyable objects and random number generators.

### Method
GET

### Endpoint
/openmesh/core/utils/system-helpers

### Parameters
None

### Request Example
None

### Response
#### Success Response (200)
- **system_helpers** (array) - A list of system helper utilities.

#### Response Example
{
  "system_helpers": [
    {
      "name": "Noncopyable.hh",
      "description": "Base class to prevent copying of objects."
    },
    {
      "name": "RandomNumberGenerator.hh",
      "description": "Provides random number generation facilities."
    },
    {
      "name": "Endian.hh",
      "description": "Utilities for handling byte order (endianness)."
    }
  ]
}
```

--------------------------------

### OpenMesh Class Member Functions (l)

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/functions_l

Lists functions starting with 'l' within OpenMesh classes, including their return types and associated classes. Examples include norm calculations, hierarchy navigation, and handle operations.

```cpp
l1_norm() : OpenMesh::VectorT< Scalar, DIM >, VectorT< Scalar, N >
l8_norm() : OpenMesh::VectorT< Scalar, DIM >, VectorT< Scalar, N >
lchild_handle() : OpenMesh::VDPM::VHierarchyNode
length() : OpenMesh::VectorT< Scalar, DIM >, VectorT< Scalar, N >
less() : OpenMesh::Utils::HeapInterfaceT< HeapEntry >
local() : OpenMesh::Endian
locked() : OpenMesh::Attributes::StatusInfo, OpenMesh::SmartHandleStatusPredicates< HandleType >
loop() : OpenMesh::SmartHalfedgeHandle
loop_ccw() : OpenMesh::SmartHalfedgeHandle
loop_cw() : OpenMesh::SmartHalfedgeHandle
```

--------------------------------

### OpenMesh::SmartVertexHandle Methods

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a02739

Methods for navigating and querying SmartVertexHandle objects.

```APIDOC
## OpenMesh::SmartVertexHandle Methods

### Description
Provides methods to access vertex information and connectivity.

### Methods
- `out()`: Returns an output stream.
- `outgoing_halfedges()`: Returns all outgoing halfedges.
- `outgoing_halfedges(HalfedgeHandle _heh)`: Returns outgoing halfedges starting from a specific halfedge.
- `outgoing_halfedges_ccw()`: Returns outgoing halfedges in counter-clockwise order.
- `outgoing_halfedges_ccw(HalfedgeHandle _heh)`: Returns outgoing halfedges in CCW order from a specific halfedge.
- `outgoing_halfedges_cw()`: Returns outgoing halfedges in clockwise order.
- `outgoing_halfedges_cw(HalfedgeHandle _heh)`: Returns outgoing halfedges in CW order from a specific halfedge.
- `vertices()`: Returns adjacent vertices.
- `vertices_ccw()`: Returns adjacent vertices in counter-clockwise order.
- `vertices_cw()`: Returns adjacent vertices in clockwise order.
- `valence()`: Returns the valence of the vertex.

### Endpoint
N/A (Internal class methods)

### Parameters
- **_heh** (HalfedgeHandle) - A specific halfedge handle (for methods accepting it).

### Request Example
N/A

### Response
- **HalfedgeHandle/VertexHandle/int** - Depending on the method called.
```

--------------------------------

### Get Named Property

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a03326

Obtains a handle to a named property. This function requires the property to exist on the mesh. If the property is not found or has a different type, it throws a std::runtime_error. An example demonstrates its usage within a try-catch block.

```cpp
template<typename ElementT , typename T >
PropertyManager< typename HandleToPropHandle< ElementT, T >::type > getProperty(PolyConnectivity & _mesh_, const char * _propname_)
```

```cpp
PolyMesh m;
{
try {
auto is_quad = getProperty<FaceHandle, bool>(m, "is_quad");
// Use is_quad here.
}
catch (const std::runtime_error& e) {
// There is no is_quad face property on the mesh.
}
}
```

--------------------------------

### OpenMesh Introduction

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a06328

Overview of OpenMesh library features and basic usage, including defining mesh types and adding vertices.

```APIDOC
## OpenMesh Library Overview

### Description
This section provides a high-level introduction to the OpenMesh library, detailing its capabilities in handling various mesh types (triangle, polygonal) and different mesh kernels. It illustrates the fundamental steps for declaring a mesh type, such as `MyMesh`, and adding vertices with their coordinates.

### Key Concepts
*   **Mesh Types**: Supports `TriMesh` (triangle meshes) and `PolyMesh` (polygonal meshes).
*   **Mesh Kernels**: Different internal storage mechanisms for mesh data, requiring an array-like interface. `ArrayKernelT` is commonly used.
*   **Vertex Addition**: Uses the `add_vertex` method, which takes coordinates and returns a handle to the new vertex.

### Example Snippet
```cpp
#include <OpenMesh/Core/Mesh/PolyMesh_ArrayKernelT.hh>

typedef OpenMesh::PolyMesh_ArrayKernelT<> MyMesh;
MyMesh mesh;

// Add vertices
MyMesh::VertexHandle vhandle[8];
vhandle[0] = mesh.add_vertex(MyMesh::Point(-1, -1, 1));
vhandle[1] = mesh.add_vertex(MyMesh::Point( 1, -1, 1));
// ... other vertices ...
```
```

--------------------------------

### Get 'to' and 'from' vertex handles from a halfedge

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a06322

Retrieve the vertex handles at the start ('from') and end ('to') of a given halfedge. This functionality is crucial for navigating mesh structures and understanding connectivity. The methods rely on the directional property of halfedges.

```c++
OpenMesh::Concepts::KernelT::to_vertex_handle();
OpenMesh::Concepts::KernelT::from_vertex_handle();
```

```c++
VertexHandle from_vertex_handle(HalfedgeHandle _heh) const
// Get the vertex the halfedge starts from (implemented as to-handle of the opposite halfedge,... 
```

```c++
VertexHandle to_vertex_handle(HalfedgeHandle _heh) const
// Get the vertex the halfedge points to.
```

--------------------------------

### OpenMesh Mesh Reading and Processing Example

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a06340

Demonstrates reading a mesh file using OpenMesh::IO::read_mesh and then processing it, including counting boundary vertices. This serves as a basic setup for mesh operations in OpenMesh. Requires OpenMesh IO and Mesh headers.

```cpp
#include <OpenMesh/Core/IO/MeshIO.hh>
#include <OpenMesh/Core/Mesh/DefaultTriMesh.hh>
#include <OpenMesh/Core/Utils/PropertyManager.hh>
#include <OpenMesh/Core/Utils/Predicates.hh>
#include <iostream>
#include <vector>

using MyMesh = OpenMesh::TriMesh;

bool is_divisible_by_3(OpenMesh::FaceHandle vh) { return vh.idx() % 3 == 0; }

int main(int argc, char** argv)
{
    using namespace OpenMesh::Predicates;

    MyMesh mesh;

    if (argc != 2) {
        std::cerr << "Usage: " << argv[0] << " <infile>" << std::endl;
        return 1;
    }

    const std::string infile = argv[1];

    if (!OpenMesh::IO::read_mesh(mesh, infile)) {
        std::cerr << "Error: Cannot read mesh from " << infile << std::endl;
        return 1;
    }

    std::cout << "Mesh contains " << mesh.vertices().count_if(Boundary()) << " boundary vertices";

    return 0;
}
```

--------------------------------

### OpenMesh Timer Class Dependencies

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a00488

This snippet shows the header files required to use the OpenMesh::Utils::Timer class. It highlights the essential include files for system configuration, output streams, string manipulation, and assertions.

```cpp
#include <OpenMesh/Core/System/config.hh>
#include <ostream>
#include <string>
#include <cassert>
```

--------------------------------

### OpenMesh Timer Utility

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/functions_i

Documentation for the timer utility.

```APIDOC
## OpenMesh Timer Utility

### Description
Details the timer utility for performance measurement.

### Timer Class

- **`Utils::Timer`**: Timer class.
- **`is_valid()`**: Checks the validity of the timer.
```

--------------------------------

### Get Subdivision Rule

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a03674

Gets the subdivision rule. Inherited from RuleInterfaceT.

```C++
Self * subdiv_rule() const
```

--------------------------------

### HeapT Constructors and Destructor

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a00470_source

Details the available constructors for creating a HeapT instance and its destructor.

```APIDOC
## HeapT Constructors and Destructor

### HeapT::HeapT (Constructor 1)

### Description
Constructs a HeapT with a given HeapInterface.

### Method
HeapT

### Parameters
- **_interface** (const HeapInterface &) - The HeapInterface to use for heap operations.

### Definition
HeapT.hh:155

### HeapT::HeapT (Constructor 2)

### Description
Default constructor for HeapT.

### Method
HeapT

### Definition
HeapT.hh:146

### HeapT::~HeapT (Destructor)

### Description
Destructor for the HeapT class.

### Method
~HeapT

### Definition
HeapT.hh:161
```

--------------------------------

### Get Previous Rule

Source: https://www.graphics.rwth-aachen.de/media/openmesh_static/Documentations/OpenMesh-Doc-Latest/a03674

Gets the previous rule in a sequence. Inherited from RuleInterfaceT.

```C++
Self * prev_rule()
```
Tokens:
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