.. SPDX-FileCopyrightText: 2021 Intel Corporation
..
.. SPDX-License-Identifier: CC-BY-4.0

.. _usm-image-accessor:

USM Image Accessor
==================


.. rubric:: Description
  :class: sectiontitle

USM Image accessor provides access to a USM image.


.. rubric:: Include Files
  :class: sectiontitle

``oneapi/ipl.hpp``


.. rubric:: Domain Dependencies
  :class: sectiontitle

Headers: ``oneapi/ipl.hpp``

Libraries: ``oneipl.lib``


.. rubric:: Syntax
   :class: sectiontitle

.. doxygenclass:: oneapi::ipl::usm_image_accessor
  :project: oneIPL
  :members:


Supported values for AccessMode:

.. list-table::
    :header-rows: 0

    * -     ``sycl::access_mode::write``
    * -     ``sycl::access_mode::read``


Supported values for AccessDataT:

.. list-table::
    :header-rows: 0

    * -     ``std::int8_t``
    * -     ``std::uint8_t``
    * -     ``std::int16_t``
    * -     ``std::uint16_t``
    * -     ``std::int32_t``
    * -     ``std::uint32_t``
    * -     ``float``


The code example below demonstrates how to use the
``oneapi::ipl::usm_image_accessor``:

.. code-block:: cpp

  using image_t = image<formats::rgb, std::uint8_t>;

  const roi_rect roi_rect{ image_size / 6, image_size / 3 };
  
  // Create queue
  sycl::queue queue{};
  
  // Create allocator
  shared_usm_allocator_t allocator{ queue };
  
  // RGB image (usm_image)
  image_t usm_image{ queue, image_data_pointer, image_size, allocator };
  
  // USM image accessor
  const image_t::accessor_t<sycl::access_mode::read, float> usm_image_accessor(usm_image);
  
  // Reading first pixel
  const sycl::int2 coords2d{ 0, 0 };
  const auto       pixel = usm_image_accessor.read(coords2d);
  
  std::cout << "Pixel: " << pixel[0] << " " << pixel[1] << " " << pixel[2] << std::endl;