ipa: libipa: Add Vector class

Add a vector class to libipa. The original purpose of this is to replace
the floating-point Point class that Raspberry Pi used in their Pwl, as
that implementation of Point seemed more akin to a Vector than a Point.

This is added to libipa instead of to geometry.h to avoid public API
issues, plus this is not expected to be needed by applications.

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>

src/ipa/libipa/vector.cpp

@@ -0,0 +1,153 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Paul Elder <paul.elder@ideasonboard.com>
+ *
+ * Vector and related operations
+ */
+
+#include "vector.h"
+
+#include <libcamera/base/log.h>
+
+/**
+ * \file vector.h
+ * \brief Vector class
+ */
+
+namespace libcamera {
+
+LOG_DEFINE_CATEGORY(Vector)
+
+namespace ipa {
+
+/**
+ * \class Vector
+ * \brief Vector class
+ * \tparam T Type of numerical values to be stored in the vector
+ * \tparam Rows Number of dimension of the vector (= number of elements)
+ */
+
+/**
+ * \fn Vector::Vector()
+ * \brief Construct a zero vector
+ */
+
+/**
+ * \fn Vector::Vector(const std::array<T, Rows> &data)
+ * \brief Construct vector from supplied data
+ * \param data Data from which to construct a vector
+ *
+ * The size of \a data must be equal to the dimension size Rows of the vector.
+ */
+
+/**
+ * \fn Vector::readYaml
+ * \brief Populate the vector with yaml data
+ * \param yaml Yaml data to populate the vector with
+ *
+ * Any existing data in the vector will be overwritten. The size of the data
+ * read from \a yaml must be equal to the dimension size Rows of the vector.
+ *
+ * The yaml data is expected to be a list with elements of type T.
+ *
+ * \return 0 on success, negative error code otherwise
+ */
+
+/**
+ * \fn T Vector::operator[](size_t i) const
+ * \brief Index to an element in the vector
+ * \param i Index of element to retrieve
+ * \return Element at index \a i from the vector
+ */
+
+/**
+ * \fn T &Vector::operator[](size_t i)
+ * \copydoc Vector::operator[](size_t i) const
+ */
+
+/**
+ * \fn Vector::x()
+ * \brief Convenience function to access the first element of the vector
+ * \return The first element of the vector
+ */
+
+/**
+ * \fn Vector::y()
+ * \brief Convenience function to access the second element of the vector
+ * \return The second element of the vector
+ */
+
+/**
+ * \fn Vector::z()
+ * \brief Convenience function to access the third element of the vector
+ * \return The third element of the vector
+ */
+
+/**
+ * \fn Vector::operator-() const
+ * \brief Negate a Vector by negating both all of its coordinates
+ * \return The negated vector
+ */
+
+/**
+ * \fn Vector::operator-(Vector const &other) const
+ * \brief Subtract one vector from another
+ * \param[in] other The other vector
+ * \return The difference of \a other from this vector
+ */
+
+/**
+ * \fn Vector::operator+()
+ * \brief Add two vectors together
+ * \param[in] other The other vector
+ * \return The sum of the two vectors
+ */
+
+/**
+ * \fn Vector::operator*(const Vector<T, Rows> &other) const
+ * \brief Compute the dot product
+ * \param[in] other The other vector
+ * \return The dot product of the two vectors
+ */
+
+/**
+ * \fn Vector::operator*(T factor) const
+ * \brief Multiply the vector by a scalar
+ * \param[in] factor The factor
+ * \return The vector multiplied by \a factor
+ */
+
+/**
+ * \fn Vector::operator/()
+ * \brief Divide the vector by a scalar
+ * \param[in] factor The factor
+ * \return The vector divided by \a factor
+ */
+
+/**
+ * \fn Vector::length2()
+ * \brief Get the squared length of the vector
+ * \return The squared length of the vector
+ */
+
+/**
+ * \fn Vector::length()
+ * \brief Get the length of the vector
+ * \return The length of the vector
+ */
+
+/**
+ * \fn bool operator==(const Vector<T, Rows> &lhs, const Vector<T, Rows> &rhs)
+ * \brief Compare vectors for equality
+ * \return True if the two vectors are equal, false otherwise
+ */
+
+/**
+ * \fn bool operator!=(const Vector<T, Rows> &lhs, const Vector<T, Rows> &rhs)
+ * \brief Compare vectors for inequality
+ * \return True if the two vectors are not equal, false otherwise
+ */
+
+} /* namespace ipa */
+
+} /* namespace libcamera */