Loading...
Searching...
No Matches
matrix.h
Go to the documentation of this file.
/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
* Copyright (C) 2024, Paul Elder <paul.elder@ideasonboard.com>
*
* Matrix and related operations
*/
#pragma once
#include <algorithm>
#include <sstream>
#include <type_traits>
#include <vector>
#include <libcamera/base/log.h>
#include <libcamera/base/span.h>
#include "libcamera/internal/yaml_parser.h"
namespace libcamera {
LOG_DECLARE_CATEGORY(Matrix)
#ifndef __DOXYGEN__
template<typename T>
bool matrixInvert(Span<const T> dataIn, Span<T> dataOut, unsigned int dim,
Span<T> scratchBuffer, Span<unsigned int> swapBuffer);
#endif /* __DOXYGEN__ */
template<typename T, unsigned int Rows, unsigned int Cols>
class Matrix
{
static_assert(std::is_arithmetic_v<T>, "Matrix type must be arithmetic");
public:
constexpr Matrix()
{
}
Matrix(const std::array<T, Rows * Cols> &data)
{
std::copy(data.begin(), data.end(), data_.begin());
}
Matrix(const Span<const T, Rows * Cols> data)
{
std::copy(data.begin(), data.end(), data_.begin());
}
static constexpr Matrix identity()
{
Matrix ret;
for (size_t i = 0; i < std::min(Rows, Cols); i++)
ret[i][i] = static_cast<T>(1);
return ret;
}
~Matrix() = default;
std::string toString() const
{
std::stringstream out;
out << "Matrix { ";
for (unsigned int i = 0; i < Rows; i++) {
out << "[ ";
for (unsigned int j = 0; j < Cols; j++) {
out << (*this)[i][j];
out << ((j + 1 < Cols) ? ", " : " ");
}
out << ((i + 1 < Rows) ? "], " : "]");
}
out << " }";
return out.str();
}
constexpr Span<const T, Rows * Cols> data() const { return data_; }
constexpr Span<const T, Cols> operator[](size_t i) const
{
return Span<const T, Cols>{ &data_.data()[i * Cols], Cols };
}
constexpr Span<T, Cols> operator[](size_t i)
{
return Span<T, Cols>{ &data_.data()[i * Cols], Cols };
}
#ifndef __DOXYGEN__
template<typename U, std::enable_if_t<std::is_arithmetic_v<U>>>
#else
template<typename U>
#endif /* __DOXYGEN__ */
Matrix<T, Rows, Cols> &operator*=(U d)
{
for (unsigned int i = 0; i < Rows * Cols; i++)
data_[i] *= d;
return *this;
}
Matrix<T, Rows, Cols> inverse(bool *ok = nullptr) const
{
static_assert(Rows == Cols, "Matrix must be square");
Matrix<T, Rows, Cols> inverse;
std::array<T, Rows * Cols * 2> scratchBuffer;
std::array<unsigned int, Rows> swapBuffer;
bool res = matrixInvert(Span<const T>(data_),
Span<T>(inverse.data_),
Rows,
Span<T>(scratchBuffer),
Span<unsigned int>(swapBuffer));
if (ok)
*ok = res;
return inverse;
}
private:
/*
* \todo The initializer is only necessary for the constructor to be
* constexpr in C++17. Remove the initializer as soon as we are on
* C++20.
*/
std::array<T, Rows * Cols> data_ = {};
};
#ifndef __DOXYGEN__
template<typename T, typename U, unsigned int Rows, unsigned int Cols,
std::enable_if_t<std::is_arithmetic_v<T>> * = nullptr>
#else
template<typename T, typename U, unsigned int Rows, unsigned int Cols>
#endif /* __DOXYGEN__ */
Matrix<U, Rows, Cols> operator*(T d, const Matrix<U, Rows, Cols> &m)
{
Matrix<U, Rows, Cols> result;
for (unsigned int i = 0; i < Rows; i++) {
for (unsigned int j = 0; j < Cols; j++)
result[i][j] = d * m[i][j];
}
return result;
}
#ifndef __DOXYGEN__
template<typename T, typename U, unsigned int Rows, unsigned int Cols,
std::enable_if_t<std::is_arithmetic_v<T>> * = nullptr>
#else
template<typename T, typename U, unsigned int Rows, unsigned int Cols>
#endif /* __DOXYGEN__ */
Matrix<U, Rows, Cols> operator*(const Matrix<U, Rows, Cols> &m, T d)
{
return d * m;
}
template<typename T1, unsigned int R1, unsigned int C1, typename T2, unsigned int R2, unsigned int C2>
constexpr Matrix<std::common_type_t<T1, T2>, R1, C2> operator*(const Matrix<T1, R1, C1> &m1,
const Matrix<T2, R2, C2> &m2)
{
static_assert(C1 == R2, "Matrix dimensions must match for multiplication");
Matrix<std::common_type_t<T1, T2>, R1, C2> result;
for (unsigned int i = 0; i < R1; i++) {
for (unsigned int j = 0; j < C2; j++) {
std::common_type_t<T1, T2> 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 Rows, unsigned int Cols>
constexpr Matrix<T, Rows, Cols> operator+(const Matrix<T, Rows, Cols> &m1, const Matrix<T, Rows, Cols> &m2)
{
Matrix<T, Rows, Cols> result;
for (unsigned int i = 0; i < Rows; i++) {
for (unsigned int j = 0; j < Cols; j++)
result[i][j] = m1[i][j] + m2[i][j];
}
return result;
}
#ifndef __DOXYGEN__
bool matrixValidateYaml(const YamlObject &obj, unsigned int size);
#endif /* __DOXYGEN__ */
#ifndef __DOXYGEN__
template<typename T, unsigned int Rows, unsigned int Cols>
std::ostream &operator<<(std::ostream &out, const Matrix<T, Rows, Cols> &m)
{
out << m.toString();
return out;
}
template<typename T, unsigned int Rows, unsigned int Cols>
struct YamlObject::Getter<Matrix<T, Rows, Cols>> {
std::optional<Matrix<T, Rows, Cols>> get(const YamlObject &obj) const
{
if (!matrixValidateYaml(obj, Rows * Cols))
return std::nullopt;
Matrix<T, Rows, Cols> matrix;
T *data = &matrix[0][0];
unsigned int i = 0;
for (const YamlObject &entry : obj.asList()) {
const auto value = entry.get<T>();
if (!value)
return std::nullopt;
data[i++] = *value;
}
return matrix;
}
};
#endif /* __DOXYGEN__ */
} /* namespace libcamera */
libcamera::Matrix
Matrix class.
Definition matrix.h:31
libcamera::Matrix::Matrix
Matrix(const std::array< T, Rows *Cols > &data)
Construct a matrix from supplied data.
Definition matrix.h:39
libcamera::Matrix::operator*=
Matrix< T, Rows, Cols > & operator*=(U d)
Multiply the matrix by a scalar in-place.
Definition matrix.h:94
libcamera::Matrix::operator[]
constexpr Span< const T, Cols > operator[](size_t i) const
Index to a row in the matrix.
Definition matrix.h:79
libcamera::Matrix::identity
static constexpr Matrix identity()
Construct an identity matrix.
Definition matrix.h:49
libcamera::Matrix::inverse
Matrix< T, Rows, Cols > inverse(bool *ok=nullptr) const
Compute the inverse of the matrix.
Definition matrix.h:101
libcamera::Matrix::operator[]
constexpr Span< T, Cols > operator[](size_t i)
Index to a row in the matrix.
Definition matrix.h:84
libcamera::Matrix::data
constexpr Span< const T, Rows *Cols > data() const
Access the matrix data as a linear array.
Definition matrix.h:77
libcamera::Matrix::Matrix
Matrix(const Span< const T, Rows *Cols > data)
Construct a matrix from supplied data.
Definition matrix.h:44
libcamera::Matrix::Matrix
constexpr Matrix()
Construct a zero matrix.
Definition matrix.h:35
libcamera::Matrix::toString
std::string toString() const
Assemble and return a string describing the matrix.
Definition matrix.h:59
libcamera::YamlObject::get
std::optional< T > get() const
Parse the YamlObject as a T value.
Definition yaml_parser.h:175
log.h
Logging infrastructure.
LOG_DECLARE_CATEGORY
#define LOG_DECLARE_CATEGORY(name)
Declare a category of log messages.
Definition log.h:51
libcamera
Top-level libcamera namespace.
Definition backtrace.h:17
libcamera::operator<<
std::ostream & operator<<(std::ostream &out, const Point &p)
Insert a text representation of a Point into an output stream.
Definition geometry.cpp:91
libcamera::operator*
Matrix< U, Rows, Cols > operator*(T d, const Matrix< U, Rows, Cols > &m)
Multiply the matrix by a scalar.
Definition matrix.h:133
libcamera::operator+
constexpr Matrix< T, Rows, Cols > operator+(const Matrix< T, Rows, Cols > &m1, const Matrix< T, Rows, Cols > &m2)
Matrix addition.
Definition matrix.h:178
yaml_parser.h
A YAML parser helper.