Template Struct GhostIndex

• Defined in File ghost_index.hpp

Struct Documentation

template<size_t Dimensions>
struct ripple::GhostIndex

Forward declaration of the GhostIndex struct which stores the index of a ghost cell in a number of dimensions.

Implementation of the GhostIndex struct to store the index of a ghost cell in a number of dimensions.

For any dimension, the index of a ghost cell is the number of cells from which it needs to be offset in the given dimension to reach the first non ghost cell in the dimension. For example, in 2 dimensions, on the following 2 x 2 domain, with 2 padding (ghost) cells, the ghost cell indices would be:

Template Parameters

• Dimensions: The number of dimensions for the ghost indices.

• MaxPadding: The max padding value.

---------------------------------------------------------
| (2,2)  | (1,2)  |  (0,2) |  (0,2) |  (-1,2) |  (-2,2) |
---------------------------------------------------------
| (2,1)  | (1,1)  |  (0,1) |  (0,1) |  (-1,1) |  (-2,1) |
---------------------------------------------------------
| (2,0)  | (1,0)  |    x   |    x   |  (-1,0) |  (-2,0) |
---------------------------------------------------------
| (2,0)  | (1,0)  |    x   |    x   |  (-1,0) |  (-2,0) |
---------------------------------------------------------
| (2,-1) | (1,-1) | (0,-1) | (0,-1) | (-1,-1) | (-2,-1) |
---------------------------------------------------------
| (2,-2) | (1,-2) | (0,-2) | (0,-2) | (-1,-2) | (-2,-2) |
---------------------------------------------------------

Template Parameters

• Dimensions: The number of dimensions for the ghost indices.

Public Types

using Value = int8_t

Defines the type used for the indices.

Public Functions

template<typename Iterator>
constexpr auto init_as_global(Iterator &&it) noexcept -> bool

Initialises the indices from the iterator for the global domain, returning true if one of the indices for a dimension is valid, and hence that the index structure is valid (i.e that it defines a valid index for a ghost cell).

Return

true if one of the indicies for a dimension is valid.

Parameters

• it: The iterator to use to set the ghost cell.

• Iterator: The type of the iterator.

template<typename Iterator, typename Space>
constexpr auto init_as_block(Iterator &&it, Space &&space) noexcept -> bool

Initialises the indices from the iterator for the block level domain, returning true if one of the indices for a dimension is valid, and hence that the index structure is valid (i.e that it defines a valid index for a ghost cell).

Return

true if one of the indicies for a dimension is valid.

Parameters

• it: The iterator to use to set the ghost cell.

• space: The space which defines the size of the block.

• Iterator: The type of the iterator

constexpr auto dimensions() const noexcept -> size_t

Gets the number of dimensions for the ghost indices.

Return

The number of dimensions of ghost indices.

template<typename Dim>
constexpr auto index(Dim &&dim) const noexcept -> Value

Gets the value of the index in the dim dimension.

Return

The index in the dimension dim.

Parameters

• dim: The dimension to get the index for.

Template Parameters

• Dim: The type of the dimension specifier.

template<typename Dim>
constexpr auto index(Dim &&dim) noexcept -> Value&

Gets a reference to the value of the index in the dim dimension.

Return

An reference to the index for dimension dim.

Parameters

• dim: The dimension to get the index for.

Template Parameters

• Dim: The type of the dimension specifier.

template<typename Dim>
constexpr auto abs_index(Dim &&dim) const noexcept -> Value

Gets the absolute value of the index in the dim dimension.

Return

The abs value of the index in dimension dim.

Parameters

• dim: The dimension to get the index for.

Template Parameters

• Dim: The type of the dimension specifier.

template<typename Dim>
constexpr auto is_front(Dim &&dim) const noexcept -> bool

Determines if an index is at the from of the domain for dimension dim.

Return

true if the index is at the front of the dimension.

Parameters

• dim: The dimension to determine if is a front index.

Template Parameters

• Dim: The type of the dimension specifier.

template<typename Dim>
constexpr auto is_back(Dim &&dim) const noexcept -> bool

Determines if the index is at the back of the domain for dimension dim.

Return

true if the index is at the back of the dimension.

Parameters

• dim: The dimension to determine if is a front index.

Template Parameters

• Dim: The type of the dimension specifier.

template<typename Dim>
constexpr auto is_void(Dim &&dim) const noexcept -> bool

Determines if the index is void it is neither a front nor back index.

Return

true if the index is neither front nor back.

Parameters

• dim: The dimension to set as void.

Template Parameters

• Dim: The type of the dimension specifier.

template<typename Dim>
constexpr auto set_as_void(Dim &&dim) noexcept -> void

Sets the index in dimension dim as a void index.

Parameters

• dim: The dimension to set as a void index.

Template Parameters

• Dim: The type of the dimension specifier

Public Static Attributes

constexpr auto void_value = Value{0}

Defines the value of a void index.