Hi Paul,
thanks for the patch.
On Fri, May 17, 2024 at 05:01:27PM +0900, Paul Elder wrote:
> 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>
> Reviewed-by: Stefan Klug <stefan.klug at ideasonboard.com>
>
> ---
> Changes in v4:
> - remove stray semicolons
> - add operator<<
> - clean up/optimize constructor
> - replace get() and set() with operator[] (and a second [] can be used
> as operator[] returns a Span)
>
> 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 | 161 +++++++++++++++++++++++++++++++++++++
> src/ipa/libipa/meson.build | 2 +
> 3 files changed, 180 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 000000000..c222c3f03
> --- /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 000000000..1bb794870
> --- /dev/null
> +++ b/src/ipa/libipa/matrix.h
> @@ -0,0 +1,161 @@
> +/* 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/base/span.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_(R * C, static_cast<T>(false))
> + {
> + for (size_t i = 0; i < std::min(R, C); i++)
> + (*this)[i][i] = static_cast<T>(true);
> + }
> +
> + Matrix(const std::vector<T> &data)
> + {
> + ASSERT(data.size() == R * C);
> +
> + data_.clear();
> + for (const T &x : data)
> + data_.push_back(x);
> + }
> +
> + ~Matrix() = default;
> +
> + int readYaml(const libcamera::YamlObject &yaml)
> + {
> + if (yaml.size() != R * C) {
> + LOG(Matrix, Error)
> + << "Wrong number of values in matrix: expected "
> + << R * C << ", got " << yaml.size();
> + return -EINVAL;
> + }
> +
> + unsigned int i = 0;
> + for (const auto &x : yaml.asList()) {
> + auto value = x.get<T>();
> + if (!value) {
> + LOG(Matrix, Error) << "Failed to read matrix value";
> + return -EINVAL;
> + }
> +
> + data_[i++] = *value;
> + }
> +
> + return 0;
> + }
> +
> + const std::string toString() const
As operator<< is implemented now, the code could go there, and this
function can be dropped, as there is no reason to keep it.
> + {
> + std::stringstream out;
> +
> + out << "Matrix { ";
> + for (unsigned int i = 0; i < R; i++) {
> + out << "[ ";
> + for (unsigned int j = 0; j < C; j++) {
> + out << (*this)[i][j];
> + out << ((j + 1 < C) ? ", " : " ");
> + }
> + out << ((i + 1 < R) ? "], " : "]");
> + }
> + out << " }";
> +
> + return out.str();
> + }
> +
> + Span<const T, C> operator[](size_t i) const
> + {
> + return Span<const T, C>{ &data_.data()[i * C], C };
> + }
I see, this was the last proposal from Barnabás. Actually, I like the
(i,j) version better, as the span now points to data of the matrix, but
its lifetime is not tied to the matrix... but that shouldn't be
a blocker.
Reviewed-by: Stefan Klug <stefan.klug at ideasonboard.com>
Cheers,
Stefan
> +
> + Span<T, C> operator[](size_t i)
> + {
> + return Span<T, C>{ &data_.data()[i * C], C };
> + }
> +
> +private:
> + std::vector<T> data_;
> +};
> +
> +template<typename T, typename U, unsigned int R, unsigned int C,
> + std::enable_if_t<std::is_arithmetic_v<T> && std::is_arithmetic_v<U>> * = nullptr>
> +Matrix<U, R, C> operator*(T d, const Matrix<U, R, C> &m)
> +{
> + Matrix<U, R, C> result;
> +
> + for (unsigned int i = 0; i < R; i++)
> + for (unsigned int j = 0; j < C; j++)
> + result[i][j] = d * m[i][j];
> +
> + return result;
> +}
> +
> +template<typename T,
> + unsigned int R1, unsigned int C1,
> + unsigned int R2, unsigned int C2,
> + std::enable_if_t<std::is_arithmetic_v<T> && C1 == R2> * = nullptr>
> +Matrix<T, R1, C2> operator*(const Matrix<T, R1, C1> &m1, const Matrix<T, R2, C2> &m2)
> +{
> + Matrix<T, R1, C2> result;
> +
> + for (unsigned int i = 0; i < R1; i++) {
> + for (unsigned int j = 0; j < C2; j++) {
> + T sum = 0;
> +
> + for (unsigned int k = 0; k < C1; k++)
> + sum += m1[i][k] * m2[k][j];
> +
> + result[i][j] = sum;
> + }
> + }
> +
> + return result;
> +}
> +
> +template<typename T, unsigned int R, unsigned int C,
> + std::enable_if_t<std::is_arithmetic_v<T>> * = nullptr>
> +Matrix<T, R, C> operator+(const Matrix<T, R, C> &m1, const Matrix<T, R, C> &m2)
> +{
> + Matrix<T, R, C> result;
> +
> + for (unsigned int i = 0; i < R; i++)
> + for (unsigned int j = 0; j < C; j++)
> + result[i][j] = m1[i][j] + m2[i][j];
> +
> + return result;
> +}
> +
> +} /* namespace ipa */
> +
> +template<typename T, unsigned int R, unsigned int C>
> +std::ostream &operator<<(std::ostream &out, const ipa::Matrix<T, R, C> &m)
> +{
> + out << m.toString();
> + return out;
> +}
> +
> +} /* namespace libcamera */
> diff --git a/src/ipa/libipa/meson.build b/src/ipa/libipa/meson.build
> index 1b3faf8d5..1e34355fe 100644
> --- a/src/ipa/libipa/meson.build
> +++ b/src/ipa/libipa/meson.build
> @@ -7,6 +7,7 @@ libipa_headers = files([
> 'exposure_mode_helper.h',
> 'fc_queue.h',
> 'histogram.h',
> + 'matrix.h',
> 'module.h',
> 'pwl.h',
> ])
> @@ -18,6 +19,7 @@ libipa_sources = files([
> 'exposure_mode_helper.cpp',
> 'fc_queue.cpp',
> 'histogram.cpp',
> + 'matrix.cpp',
> 'module.cpp',
> 'pwl.cpp'
> ])
> --
> 2.39.2
>