McRogueFace/deps_linux/libtcod/matrix.hpp

251 lines
10 KiB
C++

/* BSD 3-Clause License
*
* Copyright © 2008-2022, Jice and the libtcod contributors.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
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*
* 3. Neither the name of the copyright holder nor the names of its
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* this software without specific prior written permission.
*
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#ifndef LIBTCOD_MATRIX_HPP_
#define LIBTCOD_MATRIX_HPP_
#include <array>
#include <stdexcept>
#include <string>
#include <vector>
namespace tcod {
namespace internal {
/// Return a small array has a human readable string.
template <typename ArrayType>
[[nodiscard]] static std::string array_as_string(const ArrayType& arr) {
std::string result{"{"};
for (const auto& it : arr) {
result += std::to_string(it);
if (&it != &arr.back()) {
result += ", ";
}
}
result += "}";
return result;
}
} // namespace internal
/***************************************************************************
@brief A view into a strided multi-dimensional array.
@tparam T The type viewed by this object.
@tparam Dimensions The number of dimensions of the view.
This class is a work-in-progress.
*/
template <typename T, size_t Dimensions>
class MatrixView {
public:
using size_type = int; // The int size of indexes.
using shape_type = std::array<size_type, Dimensions>; // The type used to store the matrixes shape.
using stride_type = std::array<size_type, Dimensions>; // The type used to store strides.
using index_type = std::array<size_type, Dimensions>; // The type used to index the container.
using reference = T&;
using const_reference = const T&;
/// Default constructor.
constexpr MatrixView() = default;
/// Create a new multi-dimensional view.
constexpr MatrixView(const shape_type& shape_xy, const stride_type& strides_xy, T* data) noexcept
: shape_xy_{shape_xy}, strides_xy_{strides_xy}, data_{reinterpret_cast<data_ptr>(data)} {};
/// Get the item at index.
[[nodiscard]] constexpr reference operator[](const index_type& index) noexcept {
return *reinterpret_cast<T*>(data_ + get_offset(index));
}
/// Get the const item at index.
[[nodiscard]] constexpr const_reference operator[](const index_type& index) const noexcept {
return *reinterpret_cast<const T*>(data_ + get_offset(index));
}
/// Get the item at index, checking bounds.
[[nodiscard]] constexpr reference at(const index_type& index) {
return *reinterpret_cast<T*>(data_ + check_range(index));
}
/// Get the const item at index, checking bounds.
[[nodiscard]] constexpr const_reference at(const index_type& index) const {
return *reinterpret_cast<const T*>(data_ + check_range(index));
}
/// Return true if index is within the bounds of this matrix.
[[nodiscard]] constexpr bool in_bounds(const index_type& index) const noexcept {
for (size_t dimension = 0; dimension < Dimensions; ++dimension) {
if (!(0 <= index.at(dimension) && index.at(dimension) < shape_xy_.at(dimension))) return false;
}
return true;
}
private:
// `unsigned char*` pointer which has the same const as `T`.
using data_ptr = typename std::conditional<std::is_const<T>::value, const unsigned char*, unsigned char*>::type;
/// Return the byte offset of `data_` for the index for this view.
[[nodiscard]] constexpr size_t get_offset(const index_type& index) const noexcept {
size_t data_index = 0;
for (size_t dimension{0}; dimension < Dimensions; ++dimension) {
data_index += strides_xy_.at(dimension) * index.at(dimension);
}
return data_index;
}
/// Check for out-of-bounds, then return the data offset for `index`.
constexpr size_t check_range(const index_type& index) const {
using internal::array_as_string;
if (!in_bounds(index)) {
throw std::out_of_range(
std::string("Out of bounds lookup ") + array_as_string(index) + " on matrix of shape " +
array_as_string(shape_xy_) + ".");
}
return get_offset(index);
}
shape_type shape_xy_; // The shape of this view.
stride_type strides_xy_; // The strides of this view in bytes.
data_ptr data_; // A pointer to the viewed memory.
};
/*****************************************************************************
@brief A template container for holding a multi-dimensional array of items.
@tparam T The type of value contained by this matrix.
@tparam Dimensions The number of dimensions of this matrix type.
@tparam Container The `std::vector`-like container used for this matrix.
This class is a work-in-progress.
*/
template <typename T, size_t Dimensions, typename Container = std::vector<T>>
class Matrix {
public:
using size_type = int; // The int size of indexes.
using shape_type = std::array<size_type, Dimensions>; // The type used to measure the matrixes shape.
using index_type = std::array<size_type, Dimensions>; // The type used to index the container.
using reference = typename Container::reference;
using const_reference = typename Container::const_reference;
/// Default constructor.
constexpr Matrix() = default;
/// Create a matrix of the given shape.
constexpr explicit Matrix(const shape_type& shape) : shape_{shape}, data_(get_size_from_shape(shape)) {}
/// Create a matrix of the given shape filled with a default value.
constexpr Matrix(const shape_type& shape, const T& fill_value)
: shape_{shape}, data_(get_size_from_shape(shape), fill_value) {}
/// Return the iterator beginning.
[[nodiscard]] constexpr auto begin() noexcept { return data_.begin(); }
/// Return the iterator beginning.
[[nodiscard]] constexpr auto begin() const noexcept { return data_.cbegin(); }
/// Return the iterator end.
[[nodiscard]] constexpr auto end() noexcept { return data_.end(); }
/// Return the iterator end.
[[nodiscard]] constexpr auto end() const noexcept { return data_.cend(); }
/// Get the item at index.
[[nodiscard]] constexpr reference operator[](const index_type& index) noexcept { return data_[get_index(index)]; }
/// Get the const item at index.
[[nodiscard]] constexpr const_reference operator[](const index_type& index) const noexcept {
return data_[get_index(index)];
}
/// Get the item at index, checking bounds.
[[nodiscard]] constexpr reference at(const index_type& index) { return data_.at(check_range(index)); }
/// Get the const item at index, checking bounds.
[[nodiscard]] constexpr const_reference at(const index_type& index) const { return data_.at(check_range(index)); }
/// Return the shape of this matrix.
[[nodiscard]] constexpr const shape_type& get_shape() const noexcept { return shape_; }
/// Return true if index is within the bounds of this matrix.
[[nodiscard]] constexpr bool in_bounds(const index_type& index) const noexcept {
for (size_t dimension = 0; dimension < Dimensions; ++dimension) {
if (!(0 <= index.at(dimension) && index.at(dimension) < shape_.at(dimension))) return false;
}
return true;
}
/// Implicit cast to a view of this matrix.
[[nodiscard]] constexpr operator MatrixView<T, Dimensions>() noexcept {
return {get_shape(), get_strides(), data_.data()};
}
/// Implicit cast to a const view of this matrix.
[[nodiscard]] constexpr operator MatrixView<const T, Dimensions>() const noexcept {
return {get_shape(), get_strides(), data_.data()};
}
/// Get the flat container for this matrix.
[[nodiscard]] constexpr Container& get_container() noexcept { return data_; }
/// Get the const flat container for this matrix.
[[nodiscard]] constexpr const Container& get_container() const noexcept { return data_; }
template <class Archive>
void serialize(Archive& archive) {
archive(shape_, data_);
}
private:
/// Return the total number of items in a given shape.
[[nodiscard]] static constexpr size_t get_size_from_shape(const shape_type& shape) noexcept {
size_t size = 1;
for (auto& it : shape) size *= it;
return size;
}
/// Return the 1D index to the flat container of this matrix.
[[nodiscard]] constexpr size_t get_index(const index_type& index) const noexcept {
size_t stride = 1;
size_t data_index = 0;
for (size_t dimension = 0; dimension < Dimensions; ++dimension) {
data_index += stride * index.at(dimension);
stride *= shape_.at(dimension);
}
return data_index;
}
/// Return the 1D index to the flat container. Throw if out-of-bounds.
constexpr size_t check_range(const index_type& index) const {
using internal::array_as_string;
if (!in_bounds(index)) {
throw std::out_of_range(
std::string("Out of bounds lookup ") + array_as_string(index) + " on matrix of shape " +
array_as_string(shape_) + ".");
}
return get_index(index);
}
/// Return the byte-strides of this matrix.
[[nodiscard]] constexpr index_type get_strides() const noexcept {
index_type strides{};
int stride = static_cast<int>(sizeof(T));
for (size_t dimension = 0; dimension < Dimensions; ++dimension) {
strides.at(dimension) = stride;
stride *= shape_.at(dimension);
}
return strides;
}
shape_type shape_;
Container data_;
};
} // namespace tcod
#endif // LIBTCOD_MATRIX_HPP_