ipa: libipa: Add Matrix class

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@ideasonboard.com>
Reviewed-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 149 insertions, 0 deletions

diff --git a/src/ipa/libipa/matrix.cpp b/src/ipa/libipa/matrix.cpp
new file mode 100644
index 00000000..7f000382
--- /dev/null
+++ b/src/ipa/libipa/matrix.cpp
@@ -0,0 +1,149 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * 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
+ * \tparam T Type of numerical values to be stored in the matrix
+ * \tparam Rows Number of rows in the matrix
+ * \tparam Cols Number of columns in the matrix
+ */
+
+/**
+ * \fn Matrix::Matrix()
+ * \brief Construct a zero matrix
+ */
+
+/**
+ * \fn Matrix::Matrix(const std::vector<T> &data)
+ * \brief Construct a matrix from supplied data
+ * \param[in] 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 (Rows x Cols).
+ */
+
+/**
+ * \fn Matrix::identity()
+ * \brief Construct an identity matrix
+ */
+
+/**
+ * \fn Matrix::toString()
+ * \brief Assemble and return a string describing the matrix
+ * \return A string describing the matrix
+ */
+
+/**
+ * \fn Span<const T, Cols> Matrix::operator[](size_t i) const
+ * \brief Index to a row in the matrix
+ * \param[in] 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::operator[](size_t i)
+ * \copydoc Matrix::operator[](size_t i) const
+ */
+
+/**
+ * \fn Matrix<T, Rows, Cols> &Matrix::operator*=(U d)
+ * \brief Multiply the matrix by a scalar in-place
+ * \tparam U Type of the numerical scalar value
+ * \param d The scalar multiplier
+ * \return Product of this matrix and scalar \a d
+ */
+
+/**
+ * \fn Matrix::Matrix<U, Rows, Cols> operator*(T d, const Matrix<U, Rows, Cols> &m)
+ * \brief Multiply the matrix by a scalar
+ * \tparam T Type of the numerical scalar value
+ * \tparam U Type of numerical values in the matrix
+ * \tparam Rows Number of rows in the matrix
+ * \tparam Cols Number of columns in the matrix
+ * \param d The scalar multiplier
+ * \param m The matrix
+ * \return Product of scalar \a d and matrix \a m
+ */
+
+/**
+ * \fn Matrix::Matrix<U, Rows, Cols> operator*(const Matrix<U, Rows, Cols> &m, T d)
+ * \copydoc operator*(T d, const Matrix<U, Rows, Cols> &m)
+ */
+
+/**
+ * \fn Matrix<T, R1, C2> operator*(const Matrix<T, R1, C1> &m1, const Matrix<T, R2, C2> &m2)
+ * \brief Matrix multiplication
+ * \tparam T Type of numerical values in the matrices
+ * \tparam R1 Number of rows in the first matrix
+ * \tparam C1 Number of columns in the first matrix
+ * \tparam R2 Number of rows in the second matrix
+ * \tparam C2 Number of columns in the second matrix
+ * \param m1 Multiplicand matrix
+ * \param m2 Multiplier matrix
+ * \return Matrix product of matrices \a m1 and \a m2
+ */
+
+/**
+ * \fn Matrix<T, Rows, Cols> operator+(const Matrix<T, Rows, Cols> &m1, const Matrix<T, Rows, Cols> &m2)
+ * \brief Matrix addition
+ * \tparam T Type of numerical values in the matrices
+ * \tparam Rows Number of rows in the matrices
+ * \tparam Cols Number of columns in the matrices
+ * \param m1 Summand matrix
+ * \param m2 Summand matrix
+ * \return Matrix sum of matrices \a m1 and \a m2
+ */
+
+} /* namespace ipa */
+
+#ifndef __DOXYGEN__
+/*
+ * The YAML data shall be a list of numerical values. Its size shall be equal
+ * to the product of the number of rows and columns of the matrix (Rows x
+ * Cols). The values shall be stored in row-major order.
+ */
+bool matrixValidateYaml(const YamlObject &obj, unsigned int size)
+{
+	if (!obj.isList())
+		return false;
+
+	if (obj.size() != size) {
+		LOG(Matrix, Error)
+			<< "Wrong number of values in matrix: expected "
+			<< size << ", got " << obj.size();
+		return false;
+	}
+
+	return true;
+}
+#endif /* __DOXYGEN__ */
+
+} /* namespace libcamera */