Pixel concepts
==============

.. contents:: Table of Contents
    :local:


.. _concept-Pixel:

Pixel
-----

Let `Pix` be a type that models :ref:`Pixel (details) <concept-details-Pixel>`.

Then `Pix` also models :ref:`Regular (fundamentals) <concept-fundamentals-object-Regular>`

.. _concept-Pixel-types:
.. rubric:: Types

Then we can define :

+-------------------+--------------------------------+---------------------------------------+
|    Definition     |          Description           |              Requirement              |
+===================+================================+=======================================+
| `Pix::point_type` | type of a point                | models :ref:`concept-Point` concept   |
+-------------------+--------------------------------+---------------------------------------+
| `Pix::value_type` | type of a value                | - models :ref:`concept-Value` concept |
|                   |                                | - non-const                           |
|                   |                                | - not a reference                     |
+-------------------+--------------------------------+---------------------------------------+
| `Pix::image_type` | type of the image              | models :ref:`concept-Image` concept   |
+-------------------+--------------------------------+---------------------------------------+
| `Pix::reference`  | type of a reference on a value |                                       |
+-------------------+--------------------------------+---------------------------------------+

.. _concept-Pixel-expressions:
.. rubric:: Expressions

Let : 
    - ``pix`` be an instance of `Pix`.
    - ``pix_cpy`` be an instance of `Pix`.
    - ``cpix`` be an instance of `const Pix`.
    - ``lhs`` be an instance of `const Pix`.
    - ``rhs`` be an instance of `const Pix`.

Then we have the following valid expressions :

+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
|       Expression        |    Return type     | Pre-condition | Post-condition |                    Description                    |
+=========================+====================+===============+================+===================================================+
| ``pix()``               | `Pix`              | none          | none           | Constructs a pixel ``pix`` of type `Pix`          |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``cpix()``              | `const Pix`        | none          | none           | Constructs a pixel ``cpix`` of type `Pix`         |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``pix_cpy(pix)``        | `Pix`              | none          | none           | Copy-constructs a pixel ``pix_cpy`` from ``pix``  |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``pix_cpy(cpix)``       | `Pix`              | none          | none           | Copy-constructs a pixel ``pix_cpy`` from ``cpix`` |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``pix_cpy(move(pix))``  | `Pix`              | none          | none           | Move-constructs a pixel ``pix_cpy`` from ``pix``  |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``pix_cpy = pix``       | `Pix&`             | none          | none           | Assign ``pix`` to ``pix_cpy``                     |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``pix_cpy = cpix``      | `Pix&`             | none          | none           | Assign ``cpix`` to ``pix_cpy``                    |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``pix_cpy = move(pix)`` | `Pix&`             | none          | none           | Move-assign ``pix`` to ``pix_cpy``                |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``lhs == rhs``          | `bool`             | none          | none           | Compare wether two pixels are equal               |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``lhs != rhs``          | `bool`             | none          | none           | Compare wether two pixels are different           |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``rhs == lhs``          | `bool`             | none          | none           | Compare wether two pixels are equal               |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``rhs != lhs``          | `bool`             | none          | none           | Compare wether two pixels are different           |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``pix.value()``         | `reference`        | none          | none           | Access the value of the pixel ``pix``             |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``pix.point()``         | `point_type`       | none          | none           | Access the point of the pixel ``pix``             |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``pix.image()``         | `image_type`       | none          | none           | Access the image of the pixel ``pix``             |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``cpix.value()``        | `const reference`  | none          | none           | Access the value of the pixel ``pix``             |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``cpix.point()``        | `const point_type` | none          | none           | Access the point of the pixel ``pix``             |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+
| ``cpix.image()``        | `const image_type` | none          | none           | Access the image of the pixel ``pix``             |
+-------------------------+--------------------+---------------+----------------+---------------------------------------------------+


.. _concept-TransformedPixel:

TransformedPixel
----------------

Let `(TPix, FromPix)` be a couple of types that models :ref:`TransformedPixel (details) <concept-details-TransformedPixel>`.

Then `TPix` also models :ref:`Pixel <concept-Pixel>`

Then `FromPix` also models :ref:`Pixel <concept-Pixel>`

.. _concept-TransformedPixel-types:
.. rubric:: Types

Let `TPix` inherit all types defined for :ref:`Pixel <concept-Pixel-types>`.

Then we can define :

+-----------------------------------+------------------------------------+-------------------------------------+
|            Definition             |            Description             |             Requirement             |
+===================================+====================================+=====================================+
| `TPix::from_pixel_type = FromPix` | type of the pixel transformed from | models :ref:`concept-Pixel` concept |
+-----------------------------------+------------------------------------+-------------------------------------+

.. _concept-TransformedPixel-expressions:
.. rubric:: Expressions

Let `TPix` inherit all valid expressions defined for :ref:`Pixel <concept-Pixel-expressions>`.


.. _concept-ProjectedPixel:

ProjectedPixel
--------------

Let `(PPix, FromPix)` be a couple of types that models :ref:`ProjectedPixel (details) <concept-details-ProjectedPixel>`.

Then `(PPix, FromPix)` also models :ref:`TransformedPixel <concept-TransformedPixel>`

.. _concept-ProjectedPixel-types:
.. rubric:: Types

Let `(PPix, FromPix)` inherit all types defined for :ref:`TransformedPixel <concept-TransformedPixel-types>`.

.. _concept-ProjectedPixel-expressions:
.. rubric:: Expressions

Let `(PPix, FromPix)` inherit all valid expressions defined for :ref:`TransformedPixel <concept-TransformedPixel-expressions>`.


.. _concept-ZippedPixel:

ZippedPixel
-----------

Let `(ZPix, FromPixs...)` be a type-list that models :ref:`ZippedPixel (details) <concept-details-ZippedPixel>`.

Then `ZPix` also models :ref:`Pixel <concept-Pixel>`

Then `FromPixs...` also all model :ref:`Pixel <concept-Pixel>`

.. _concept-ZippedPixel-types:
.. rubric:: Types

Let `ZPix` inherit all types defined for :ref:`Pixel <concept-Pixel-types>`.

Then we can define :

+---------------------------------------------+---------------------------------------------+--------------------------------------------------------------------------------------------------------------+
|                 Definition                  |                 Description                 |                                                 Requirement                                                  |
+=============================================+=============================================+==============================================================================================================+
| `ZPix::zipped_pixel_type_list<FromPixs...>` | type-list of the pixel zipped inside `ZPix` | models :ref:`ConvertibleTo (fundamentals) <concept-fundamentals-core-language-ConvertibleTo>` concept with : |
|                                             |                                             | ``template <typename...> basic_type_list {};``                                                               |
+---------------------------------------------+---------------------------------------------+--------------------------------------------------------------------------------------------------------------+

.. _concept-ZippedPixel-expressions:
.. rubric:: Expressions

Let `ZPix` inherit all valid expressions defined for :ref:`Pixel <concept-Pixel-expressions>`.