[PATCH v4 1/3] ipa: libipa: Add Matrix class
Paul Elder
paul.elder at ideasonboard.com
Wed May 29 09:59:11 CEST 2024
On Mon, May 20, 2024 at 03:08:37PM +0100, Dan Scally wrote:
> Hi Paul - thanks for the patch
>
> On 17/05/2024 09:01, 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 */
>
>
> Do we not need Doxygen comments in here?
Technically it's not required since it's not public API but it's
probably better to have them yeah...
>
> > 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
> > + {
> > + 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)
> Don't we want to restrict this operation to matrices with matching
> dimensions? I would expect a single set of R and C for both of the matrices.
On one hand yeah, but on the other hand I thought this was more
thorough. SFINAE ought to protect us against non-matching dimensions.
Paul
> > +{
> > + 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'
> > ])
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