[PATCH v3 1/3] ipa: libipa: Add Matrix class
Barnabás Pőcze
pobrn at protonmail.com
Wed May 15 11:31:55 CEST 2024
Hi
2024. május 7., kedd 8:10 keltezéssel, Paul Elder <paul.elder at ideasonboard.com> írta:
> Add a class to represent a Matrix object and operations for adding
> matrices, multipling a matrix by a scalar, and multiplying two matrices.
>
> Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>
> ---
> Changes in v3:
> - fix template parameters of operator* to allow different types for the
> scalar multiplier and the matrix's number type
> - clear data in constructors
> - fix assert in constructor
>
> Changes v2:
> - make rows and columns into template arguments
> - initialize to identity matrix on construction
> - add getter and setter
> - change from struct to class
> - fix matrix multiplication
> - clean up unused includes
> - avoid dereferencing an absent std::optional
> ---
> src/ipa/libipa/matrix.cpp | 17 +++++
> src/ipa/libipa/matrix.h | 146 +++++++++++++++++++++++++++++++++++++
> src/ipa/libipa/meson.build | 2 +
> 3 files changed, 165 insertions(+)
> create mode 100644 src/ipa/libipa/matrix.cpp
> create mode 100644 src/ipa/libipa/matrix.h
>
> diff --git a/src/ipa/libipa/matrix.cpp b/src/ipa/libipa/matrix.cpp
> new file mode 100644
> index 00000000..c222c3f0
> --- /dev/null
> +++ b/src/ipa/libipa/matrix.cpp
> @@ -0,0 +1,17 @@
> +/* SPDX-License-Identifier: BSD-2-Clause */
> +/*
> + * Copyright (C) 2019, Raspberry Pi Ltd
> + * Copyright (C) 2024, Paul Elder <paul.elder at ideasonboard.com>
> + *
> + * matrix.cpp - Matrix and related operations
> + */
> +
> +#include "matrix.h"
> +
> +#include <libcamera/base/log.h>
> +
> +namespace libcamera {
> +
> +LOG_DEFINE_CATEGORY(Matrix)
> +
> +} /* namespace libcamera */
> diff --git a/src/ipa/libipa/matrix.h b/src/ipa/libipa/matrix.h
> new file mode 100644
> index 00000000..bbdb838b
> --- /dev/null
> +++ b/src/ipa/libipa/matrix.h
> @@ -0,0 +1,146 @@
> +/* SPDX-License-Identifier: BSD-2-Clause */
> +/*
> + * Copyright (C) 2019, Raspberry Pi Ltd
> + * Copyright (C) 2024, Paul Elder <paul.elder at ideasonboard.com>
> + *
> + * matrix.cpp - Matrix and related operations
> + */
> +#pragma once
> +
> +#include <algorithm>
> +#include <cmath>
> +#include <sstream>
> +#include <vector>
> +
> +#include <libcamera/base/log.h>
> +
> +#include "libcamera/internal/yaml_parser.h"
> +
> +namespace libcamera {
> +
> +LOG_DECLARE_CATEGORY(Matrix)
> +
> +namespace ipa {
> +
> +template<typename T, unsigned int R, unsigned int C,
> + std::enable_if_t<std::is_arithmetic_v<T>> * = nullptr>
> +class Matrix
> +{
> +public:
> + Matrix()
> + {
> + data_.clear();
> + for (unsigned int i = 0; i < R; i++)
> + for (unsigned int j = 0; j < C; j++)
> + data_.push_back(static_cast<T>(i == j));
Matrix()
: data_(R * C, static_cast<T>(false))
{
for (std::size_t i = 0; i < std::min(R, C); i++)
(*this)[i][i] = static_cast<T>(true); // see below for indexing
}
> + };
`;` not needed.
> +
> + Matrix(const std::vector<T> &data)
Any reason why `Span<const T, R * C>` (or just `Span<const T>`) is not acceptable?
> + {
> + ASSERT(data.size() == R * C);
> +
> + data_.clear();
> + for (const T &x : data)
> + data_.push_back(x);
> + }
> +
> + ~Matrix(){};
`= default;` or just omit it completely please.
> [...]
> +
> + const T &get(unsigned int i, unsigned int j) const { return data_.at(i * C + j); }
> + void set(unsigned int i, unsigned int j, T value) { data_[i * C + j] = value; }
Maybe
const T& operator()(std::size_t i, std::size_t j) const { return data[i * C + ]; }
T& operator()(std::size_t i, std::size_t j) { return data[i * C + ]; }
?
I believe this is a pretty standard way to implement n-dimensional indexing in C++
since operator[] cannot have multiple arguments until C++23.
Or I think the following also works, which might be "better":
Span<const T, C> operator[](std::size_t i) const { return { &data[i * C], C }; }
Span<T, C> operator[](std::size_t i) { return { &data[i * C], C }; }
> +
> +private:
> + std::vector<T> data_;
> +};
> [...]
Regards,
Barnabás Pőcze
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