| OpenCV 4.3.0 Open Source Computer Vision

Public Types | Public Member Functions | Static Public Member Functions | List of all members
cv::ogl::Buffer Class Reference
Core functionality » OpenGL interoperability

Smart pointer for OpenGL buffer object with reference counting. More...

`#include <opencv2/core/opengl.hpp>`

## Public Types
enum | Access { READ_ONLY = 0x88B8, WRITE_ONLY = 0x88B9, READ_WRITE = 0x88BA }
enum | Target { ARRAY_BUFFER = 0x8892, ELEMENT_ARRAY_BUFFER = 0x8893, PIXEL_PACK_BUFFER = 0x88EB, PIXEL_UNPACK_BUFFER = 0x88EC }
| The target defines how you intend to use the buffer object. More...

## Public Member Functions
| Buffer ()
| The constructors. More...
| Buffer (int arows, int acols, int atype, unsigned int abufId, bool autoRelease=false)
| Buffer (Size asize, int atype, unsigned int abufId, bool autoRelease=false)
| Buffer (int arows, int acols, int atype, Target target=ARRAY_BUFFER, bool autoRelease=false)
| Buffer (Size asize, int atype, Target target=ARRAY_BUFFER, bool autoRelease=false)
| Buffer (InputArray arr, Target target=ARRAY_BUFFER, bool autoRelease=false)
void | bind (Target target) const
| Binds OpenGL buffer to the specified buffer binding point. More...
unsigned int | bufId () const
| get OpenGL opject id More...
int | channels () const
Buffer | clone (Target target=ARRAY_BUFFER, bool autoRelease=false) const
| Creates a full copy of the buffer object and the underlying data. More...
int | cols () const
void | copyFrom (InputArray arr, Target target=ARRAY_BUFFER, bool autoRelease=false)
| Copies from host/device memory to OpenGL buffer. More...
void | copyFrom (InputArray arr, cuda::Stream &stream, Target target=ARRAY_BUFFER, bool autoRelease=false)
void | copyTo (OutputArray arr) const
| Copies from OpenGL buffer to host/device memory or another OpenGL buffer object. More...
void | copyTo (OutputArray arr, cuda::Stream &stream) const
void | create (int arows, int acols, int atype, Target target=ARRAY_BUFFER, bool autoRelease=false)
| Allocates memory for ogl::Buffer object. More...
void | create (Size asize, int atype, Target target=ARRAY_BUFFER, bool autoRelease=false)
int | depth () const
int | elemSize () const
int | elemSize1 () const
bool | empty () const
cuda::GpuMat | mapDevice ()
| map to device memory (blocking) More...
cuda::GpuMat | mapDevice (cuda::Stream &stream)
| Maps OpenGL buffer to CUDA device memory. More...
Mat | mapHost (Access access)
| Maps OpenGL buffer to host memory. More...
void | release ()
| Decrements the reference counter and destroys the buffer object if needed. More...
int | rows () const
void | setAutoRelease (bool flag)
| Sets auto release mode. More...
Size | size () const
int | type () const
void | unmapDevice ()
void | unmapDevice (cuda::Stream &stream)
| Unmaps OpenGL buffer. More...
void | unmapHost ()
| Unmaps OpenGL buffer. More...

## Static Public Member Functions
static void | unbind (Target target)
| Unbind any buffers from the specified binding point. More...

## Detailed Description

Smart pointer for OpenGL buffer object with reference counting.

Buffer Objects are OpenGL objects that store an array of unformatted memory allocated by the OpenGL context. These can be used to store vertex data, pixel data retrieved from images or the framebuffer, and a variety of other things.

ogl::Buffer has interface similar with Mat interface and represents 2D array memory.

ogl::Buffer supports memory transfers between host and device and also can be mapped to CUDA memory.

## Member Enumeration Documentation

## ◆ Access

enum cv::ogl::Buffer::Access

Enumerator
READ_ONLY |
WRITE_ONLY |
READ_WRITE |

## ◆ Target

enum cv::ogl::Buffer::Target

The target defines how you intend to use the buffer object.

Enumerator
ARRAY_BUFFER | The buffer will be used as a source for vertex data.
ELEMENT_ARRAY_BUFFER | The buffer will be used for indices (in glDrawElements, for example)
PIXEL_PACK_BUFFER | The buffer will be used for reading from OpenGL textures.
PIXEL_UNPACK_BUFFER | The buffer will be used for writing to OpenGL textures.

## Constructor & Destructor Documentation

## ◆ Buffer() [1/6]

cv::ogl::Buffer::Buffer | ( |  | ) |

The constructors.

Creates empty ogl::Buffer object, creates ogl::Buffer object from existed buffer ( abufId parameter), allocates memory for ogl::Buffer object or copies from host/device memory.

## ◆ Buffer() [2/6]

cv::ogl::Buffer::Buffer | ( | int | arows,
|  | int | acols,
|  | int | atype,
|  | unsigned int | abufId,
|  | bool | autoRelease = `false`
| ) |  |

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

  arows | Number of rows in a 2D array.
  acols | Number of columns in a 2D array.
  atype | Array type ( CV_8UC1, ..., CV_64FC4 ). See Mat for details.
  abufId | Buffer object name.
  autoRelease | Auto release mode (if true, release will be called in object's destructor).

## ◆ Buffer() [3/6]

cv::ogl::Buffer::Buffer | ( | Size | asize,
|  | int | atype,
|  | unsigned int | abufId,
|  | bool | autoRelease = `false`
| ) |  |

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

  asize | 2D array size.
  atype | Array type ( CV_8UC1, ..., CV_64FC4 ). See Mat for details.
  abufId | Buffer object name.
  autoRelease | Auto release mode (if true, release will be called in object's destructor).

## ◆ Buffer() [4/6]

cv::ogl::Buffer::Buffer | ( | int | arows,
|  | int | acols,
|  | int | atype,
|  | Target | target = `ARRAY_BUFFER`,
|  | bool | autoRelease = `false`
| ) |  |

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

  arows | Number of rows in a 2D array.
  acols | Number of columns in a 2D array.
  atype | Array type ( CV_8UC1, ..., CV_64FC4 ). See Mat for details.
  target | Buffer usage. See cv::ogl::Buffer::Target .
  autoRelease | Auto release mode (if true, release will be called in object's destructor).

## ◆ Buffer() [5/6]

cv::ogl::Buffer::Buffer | ( | Size | asize,
|  | int | atype,
|  | Target | target = `ARRAY_BUFFER`,
|  | bool | autoRelease = `false`
| ) |  |

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

  asize | 2D array size.
  atype | Array type ( CV_8UC1, ..., CV_64FC4 ). See Mat for details.
  target | Buffer usage. See cv::ogl::Buffer::Target .
  autoRelease | Auto release mode (if true, release will be called in object's destructor).

## ◆ Buffer() [6/6]

cv::ogl::Buffer::Buffer | ( | InputArray | arr,
|  | Target | target = `ARRAY_BUFFER`,
|  | bool | autoRelease = `false`
| ) |  |
| explicit

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

  arr | Input array (host or device memory, it can be Mat , cuda::GpuMat or std::vector ).
  target | Buffer usage. See cv::ogl::Buffer::Target .
  autoRelease | Auto release mode (if true, release will be called in object's destructor).

## Member Function Documentation

## ◆ bind()

void cv::ogl::Buffer::bind | ( | Target | target | ) | const

Binds OpenGL buffer to the specified buffer binding point.

Parameters

  target | Binding point. See cv::ogl::Buffer::Target .

## ◆ bufId()

unsigned int cv::ogl::Buffer::bufId | ( |  | ) | const

get OpenGL opject id

## ◆ channels()

int cv::ogl::Buffer::channels | ( |  | ) | const

## ◆ clone()

Buffer cv::ogl::Buffer::clone | ( | Target | target = `ARRAY_BUFFER`,
|  | bool | autoRelease = `false`
| ) |  | const

Creates a full copy of the buffer object and the underlying data.

Parameters

  target | Buffer usage for destination buffer.
  autoRelease | Auto release mode for destination buffer.

## ◆ cols()

int cv::ogl::Buffer::cols | ( |  | ) | const

## ◆ copyFrom() [1/2]

void cv::ogl::Buffer::copyFrom | ( | InputArray | arr,
|  | Target | target = `ARRAY_BUFFER`,
|  | bool | autoRelease = `false`
| ) |  |

Copies from host/device memory to OpenGL buffer.

Parameters

  arr | Input array (host or device memory, it can be Mat , cuda::GpuMat or std::vector ).
  target | Buffer usage. See cv::ogl::Buffer::Target .
  autoRelease | Auto release mode (if true, release will be called in object's destructor).

## ◆ copyFrom() [2/2]

void cv::ogl::Buffer::copyFrom | ( | InputArray | arr,
|  | cuda::Stream & | stream,
|  | Target | target = `ARRAY_BUFFER`,
|  | bool | autoRelease = `false`
| ) |  |

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

## ◆ copyTo() [1/2]

void cv::ogl::Buffer::copyTo | ( | OutputArray | arr | ) | const

Copies from OpenGL buffer to host/device memory or another OpenGL buffer object.

Parameters

  arr | Destination array (host or device memory, can be Mat , cuda::GpuMat , std::vector or ogl::Buffer ).

## ◆ copyTo() [2/2]

void cv::ogl::Buffer::copyTo | ( | OutputArray | arr,
|  | cuda::Stream & | stream
| ) |  | const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

## ◆ create() [1/2]

void cv::ogl::Buffer::create | ( | int | arows,
|  | int | acols,
|  | int | atype,
|  | Target | target = `ARRAY_BUFFER`,
|  | bool | autoRelease = `false`
| ) |  |

Allocates memory for ogl::Buffer object.

Parameters

  arows | Number of rows in a 2D array.
  acols | Number of columns in a 2D array.
  atype | Array type ( CV_8UC1, ..., CV_64FC4 ). See Mat for details.
  target | Buffer usage. See cv::ogl::Buffer::Target .
  autoRelease | Auto release mode (if true, release will be called in object's destructor).

## ◆ create() [2/2]

void cv::ogl::Buffer::create | ( | Size | asize,
|  | int | atype,
|  | Target | target = `ARRAY_BUFFER`,
|  | bool | autoRelease = `false`
| ) |  |

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Parameters

  asize | 2D array size.
  atype | Array type ( CV_8UC1, ..., CV_64FC4 ). See Mat for details.
  target | Buffer usage. See cv::ogl::Buffer::Target .
  autoRelease | Auto release mode (if true, release will be called in object's destructor).

## ◆ depth()

int cv::ogl::Buffer::depth | ( |  | ) | const

## ◆ elemSize()

int cv::ogl::Buffer::elemSize | ( |  | ) | const

## ◆ elemSize1()

int cv::ogl::Buffer::elemSize1 | ( |  | ) | const

## ◆ empty()

bool cv::ogl::Buffer::empty | ( |  | ) | const

## ◆ mapDevice() [1/2]

cuda::GpuMat cv::ogl::Buffer::mapDevice | ( |  | ) |

map to device memory (blocking)

## ◆ mapDevice() [2/2]

cuda::GpuMat cv::ogl::Buffer::mapDevice | ( | cuda::Stream & | stream | ) |

Maps OpenGL buffer to CUDA device memory.

This operation doesn't copy data. Several buffer objects can be mapped to CUDA memory at a time.

A mapped data store must be unmapped with ogl::Buffer::unmapDevice before its buffer object is used.

## ◆ mapHost()

Mat cv::ogl::Buffer::mapHost | ( | Access | access | ) |

Maps OpenGL buffer to host memory.

mapHost maps to the client's address space the entire data store of the buffer object. The data can then be directly read and/or written relative to the returned pointer, depending on the specified access policy.

A mapped data store must be unmapped with ogl::Buffer::unmapHost before its buffer object is used.

This operation can lead to memory transfers between host and device.

Only one buffer object can be mapped at a time.

Parameters

  access | Access policy, indicating whether it will be possible to read from, write to, or both read from and write to the buffer object's mapped data store. The symbolic constant must be ogl::Buffer::READ_ONLY , ogl::Buffer::WRITE_ONLY or ogl::Buffer::READ_WRITE .

## ◆ release()

void cv::ogl::Buffer::release | ( |  | ) |

Decrements the reference counter and destroys the buffer object if needed.

The function will call setAutoRelease(true) .

## ◆ rows()

int cv::ogl::Buffer::rows | ( |  | ) | const

## ◆ setAutoRelease()

void cv::ogl::Buffer::setAutoRelease | ( | bool | flag | ) |

Sets auto release mode.

The lifetime of the OpenGL object is tied to the lifetime of the context. If OpenGL context was bound to a window it could be released at any time (user can close a window). If object's destructor is called after destruction of the context it will cause an error. Thus ogl::Buffer doesn't destroy OpenGL object in destructor by default (all OpenGL resources will be released with OpenGL context). This function can force ogl::Buffer destructor to destroy OpenGL object.

Parameters

  flag | Auto release mode (if true, release will be called in object's destructor).

## ◆ size()

Size cv::ogl::Buffer::size | ( |  | ) | const

## ◆ type()

int cv::ogl::Buffer::type | ( |  | ) | const

## ◆ unbind()

static void cv::ogl::Buffer::unbind | ( | Target | target | ) |
| static

Unbind any buffers from the specified binding point.

Parameters

  target | Binding point. See cv::ogl::Buffer::Target .

## ◆ unmapDevice() [1/2]

void cv::ogl::Buffer::unmapDevice | ( |  | ) |

## ◆ unmapDevice() [2/2]

void cv::ogl::Buffer::unmapDevice | ( | cuda::Stream & | stream | ) |

Unmaps OpenGL buffer.

## ◆ unmapHost()

void cv::ogl::Buffer::unmapHost | ( |  | ) |

Unmaps OpenGL buffer.

The documentation for this class was generated from the following file:

- opencv2/core/opengl.hpp