new file mode 100644
@@ -0,0 +1,98 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2019, Raspberry Pi Ltd
+ * Copyright (C) 2024, Paul Elder <paul.elder@ideasonboard.com>
+ *
+ * Matrix and related operations
+ */
+
+#include "matrix.h"
+
+#include <libcamera/base/log.h>
+
+/**
+ * \file matrix.h
+ * \brief Matrix class
+ */
+
+namespace libcamera {
+
+LOG_DEFINE_CATEGORY(Matrix)
+
+namespace ipa {
+
+/**
+ * \class Matrix
+ * \brief Matrix class
+ */
+
+/**
+ * \fn Matrix()
+ * \brief Construct an identity matrix
+ */
+
+/**
+ * \fn Matrix(const std::vector<T> &data)
+ * \brief Construct matrix from supplied data
+ * \param data Data from which to construct a matrix
+ *
+ * \a data is a one-dimensional vector and will be turned into a matrix in
+ * row-major order. The size of \a data must be equal to the product of the
+ * number of rows and columns of the matrix (\ta R x \ta C).
+ */
+
+/**
+ * \fn readYaml
+ * \brief Populate the matrix with yaml data
+ * \param yaml Yaml data to populate the matrix with
+ *
+ * Any existing data in the matrix will be overwritten. The size of the data
+ * read from \a yaml must be equal to the product of the number of rows and
+ * columns of the matrix (\ta R x \ta C).
+ *
+ * The yaml data is expected to be a list with elements of type \ta T.
+ *
+ * \return 0 on success, negative error code otherwise
+ */
+
+/**
+ * \fn operator[]
+ * \brief Index to a row in the matrix
+ * \param i Index of row to retrieve
+ *
+ * This operator[] returns a Span, which can then be indexed into again with
+ * another operator[], allowing a convenient m[i][j] to access elements of the
+ * matrix. Note that the lifetime of the Span returned by this first-level
+ * operator[] is bound to that of the Matrix itself, so it is not recommended
+ * to save the Span that is the result of this operator[].
+ *
+ * \return Row \a i from the matrix, as a Span
+ */
+
+/**
+ * \fn Matrix<U, R, C> operator*(T d, const Matrix<U, R, C> &m)
+ * \brief Scalar product
+ * \param d Scalar
+ * \param m Matrix
+ * \return Product of scalar \a d and matrix \a m
+ */
+
+/**
+ * \fn Matrix<T, R1, C2> operator*(const Matrix<T, R1, C1> &m1, const Matrix<T, R2, C2> &m2)
+ * \brief Matrix multiplication
+ * \param m1 Multiplicand matrix
+ * \param m2 Multiplier matrix
+ * \return Matrix product of matrices \a m1 and \a m2
+ */
+
+/**
+ * \fn Matrix<T, R, C> operator+(const Matrix<T, R, C> &m1, const Matrix<T, R, C> &m2)
+ * \brief Matrix addition
+ * \param m1 Summand matrix
+ * \param m2 Summand matrix
+ * \return Matrix sum of matrices \a m1 and \a m2
+ */
+
+} /* namespace ipa */
+
+} /* namespace libcamera */
new file mode 100644
@@ -0,0 +1,161 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2019, Raspberry Pi Ltd
+ * Copyright (C) 2024, Paul Elder <paul.elder@ideasonboard.com>
+ *
+ * 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
+ {
+ 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 };
+ }
+
+ 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 */
@@ -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'
])