scummvm/math/matrix.h
Einar Johan Trøan Sømåen fcb8eda978 MATH: Add some constexpr to the Matrix base-classes.
Currently we can't quite make Matrix3's default constructor constexpr,
as the setToIdentity-call requires C++14.
2023-04-29 13:10:23 +02:00

511 lines
14 KiB
C++

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#ifndef MATH_MATRIX_H
#define MATH_MATRIX_H
#include <string.h>
#include <assert.h>
#include "common/streamdebug.h"
/**
* \namespace Math
* This namespace contains some useful classes dealing with math and geometry.
*
* The most important classes are Matrix and its base classes.
* MatrixBase is a template class which is the base of all the matrices with
* many convenient functions.
* MatrixType is an intermediate class that, using template specialization,
* is able to create different kinds of matrices, like vectors or
* square matrices.
* Matrix is the actual matrix class and it is derived from MatrixType.
*
* MatrixBase and MatrixType have their constructors protected, so they can't
* be instantiated. But while MatrixBase is just a backend class, MatrixType
* can be used to create new kinds of matrices:
* \code
template<int dim>
class MatrixType<1, dim> : public MatrixBase<1, dim> {
...
};
* \endcode
* Given that declaration, every Matrix<1, dim>, with "dim" whatever positive
* number, will have the methods and members defined in MatrixType<1, dim>.
*
* This design allows us to have the equality of, say, the class "three-dimensional
* vector" and Matrix<3, 1>. Vector3d is not <b>a</b> Matrix<3, 1>, it <b>is</b> Matrix<3, 1>.
* Every method in MatrixBase and MatrixType returning a matrix returns a Matrix<\r, c>,
* and not a MatrixBase<\r, c>. This reduces code duplication, since otherwise many
* functions declared for Matrix would need to be declared for MatrixBase too,
* like many operators.
*/
namespace Math {
template<int rows, int cols> class Matrix;
/**
* \class MatrixBase
* The base class for all the matrices.
*/
template<int rows, int cols>
class MatrixBase {
public:
/**
* Convenient class for feeding a matrix.
*/
class Row {
public:
Row &operator<<(float value);
private:
Row(MatrixBase<rows, cols> *m, int row);
MatrixBase<rows, cols> *_matrix;
int _row;
int _col;
friend class MatrixBase<rows, cols>;
};
/**
* Returns true if this matrix's values are all 0.
*/
bool isZero() const;
Matrix<rows, cols> getNegative() const;
/**
* Returns an instance of Row for a particular row of this matrix.
* Row is a convenient class for feeding a matrix.
* \code
Matrix<3, 3> m;
m.getRow(0) << 0 << 0 << 0;
m.getRow(1) << 1 << 2 << 0;
m.getRow(2) << 0 << 0.5 << 1;
* \endcode
*
* \param row The row to be feeded.
*/
Row getRow(int row);
/**
* Returns a pointer to the internal data of this matrix.
*/
inline float *getData();
/**
* Returns a pointer to the internal data of this matrix.
*/
inline const float *getData() const;
/**
* Sets the internal data of this matrix.
*/
void setData(const float *data);
inline float getValue(int row, int col) const;
inline void setValue(int row, int col, float value);
inline float &operator()(int row, int col);
inline float operator()(int row, int col) const;
inline operator const Matrix<rows, cols>&() const { return getThis(); }
inline operator Matrix<rows, cols>&() { return getThis(); }
static Matrix<rows, cols> sum(const Matrix<rows, cols> &m1, const Matrix<rows, cols> &m2);
static Matrix<rows, cols> difference(const Matrix<rows, cols> &m1, const Matrix<rows, cols> &m2);
static Matrix<rows, cols> product(const Matrix<rows, cols> &m1, float factor);
static Matrix<rows, cols> product(const Matrix<rows, cols> &m1, const Matrix<rows, cols> &m2);
static Matrix<rows, cols> quotient(const Matrix<rows, cols> &m1, float factor);
static Matrix<rows, cols> quotient(const Matrix<rows, cols> &m1, const Matrix<rows, cols> &m2);
Matrix<rows, cols> &operator=(const Matrix<rows, cols> &m);
Matrix<rows, cols> &operator+=(const Matrix<rows, cols> &m);
Matrix<rows, cols> &operator-=(const Matrix<rows, cols> &m);
Matrix<rows, cols> &operator*=(float factor);
Matrix<rows, cols> &operator*=(const Matrix<rows, cols> &m);
Matrix<rows, cols> &operator/=(float factor);
Matrix<rows, cols> &operator/=(const Matrix<rows, cols> &m);
protected:
constexpr MatrixBase() = default;
MatrixBase(const float *data);
MatrixBase(const MatrixBase<rows, cols> &m);
MatrixBase &operator=(const MatrixBase<rows, cols> &m);
inline const Matrix<rows, cols> &getThis() const {
return *static_cast<const Matrix<rows, cols> *>(this); }
inline Matrix<rows, cols> &getThis() {
return *static_cast<Matrix<rows, cols> *>(this); }
private:
float _values[rows * cols] = { 0.0f };
};
/**
* \class MatrixType
* MatrixType is a class used to create different kinds of matrices.
*/
template<int r, int c>
class MatrixType : public MatrixBase<r, c> {
protected:
constexpr MatrixType() : MatrixBase<r, c>() { }
MatrixType(const float *data) : MatrixBase<r, c>(data) { }
MatrixType(const MatrixBase<r, c> &m) : MatrixBase<r, c>(m) { }
};
#define Vector(dim) Matrix<dim, 1>
/**
* \class Matrix The actual Matrix class.
* This template class must be instantiated passing it the number of the rows
* and the number of the columns.
*/
template<int r, int c>
class Matrix : public MatrixType<r, c> {
public:
constexpr Matrix() : MatrixType<r, c>() { }
Matrix(const float *data) : MatrixType<r, c>(data) { }
Matrix(const MatrixBase<r, c> &m) : MatrixType<r, c>(m) { }
};
template <int m, int n, int p>
Matrix<m, n> operator*(const Matrix<m, p> &m1, const Matrix<p, n> &m2);
template <int r, int c>
inline Matrix<r, c> operator+(const Matrix<r, c> &m1, const Matrix<r, c> &m2);
template <int r, int c>
inline Matrix<r, c> operator-(const Matrix<r, c> &m1, const Matrix<r, c> &m2);
template <int r, int c>
inline Matrix<r, c> operator*(const Matrix<r, c> &m1, float factor);
template <int r, int c>
inline Matrix<r, c> operator/(const Matrix<r, c> &m1, float factor);
template <int r, int c>
Matrix<r, c> operator*(float factor, const Matrix<r, c> &m1);
template <int r, int c>
Matrix<r, c> operator-(const Matrix<r, c> &m);
template <int r, int c>
bool operator==(const Matrix<r, c> &m1, const Matrix<r, c> &m2);
template <int r, int c>
bool operator!=(const Matrix<r, c> &m1, const Matrix<r, c> &m2);
// Constructors
template<int rows, int cols>
MatrixBase<rows, cols>::MatrixBase(const float *data) {
setData(data);
}
template<int rows, int cols>
MatrixBase<rows, cols>::MatrixBase(const MatrixBase<rows, cols> &m) {
setData(m._values);
}
template<int rows, int cols>
MatrixBase<rows, cols> &MatrixBase<rows, cols>::operator=(const MatrixBase<rows, cols> &m) {
setData(m._values);
return *this;
}
// Data management
template<int rows, int cols>
float *MatrixBase<rows, cols>::getData() {
return _values;
}
template<int rows, int cols>
const float *MatrixBase<rows, cols>::getData() const {
return _values;
}
template<int rows, int cols>
void MatrixBase<rows, cols>::setData(const float *data) {
::memcpy(_values, data, rows * cols * sizeof(float));
}
template<int rows, int cols>
float MatrixBase<rows, cols>::getValue(int row, int col) const {
assert(rows > row && cols > col && row >= 0 && col >= 0);
return _values[row * cols + col];
}
template<int rows, int cols>
void MatrixBase<rows, cols>::setValue(int row, int col, float v) {
operator()(row, col) = v;
}
// Operations helpers
template<int rows, int cols>
bool MatrixBase<rows, cols>::isZero() const {
for (int i = 0; i < rows * cols; ++i) {
if (_values[i] != 0.f) {
return false;
}
}
return true;
}
template <int r, int c>
Matrix<r, c> MatrixBase<r, c>::getNegative() const {
Matrix<r, c> result;
for (int i = 0; i < r * c; ++i) {
result._values[i] = -_values[i];
}
return result;
}
template <int r, int c>
Matrix<r, c> MatrixBase<r, c>::sum(const Matrix<r, c> &m1, const Matrix<r, c> &m2) {
Matrix<r, c> result;
for (int i = 0; i < r * c; ++i) {
result._values[i] = m1._values[i] + m2._values[i];
}
return result;
}
template <int r, int c>
Matrix<r, c> MatrixBase<r, c>::difference(const Matrix<r, c> &m1, const Matrix<r, c> &m2) {
Matrix<r, c> result;
for (int i = 0; i < r * c; ++i) {
result._values[i] = m1._values[i] - m2._values[i];
}
return result;
}
template <int r, int c>
Matrix<r, c> MatrixBase<r, c>::product(const Matrix<r, c> &m1, float factor) {
Matrix<r, c> result;
for (int i = 0; i < r * c; ++i) {
result._values[i] = m1._values[i] * factor;
}
return result;
}
template <int r, int c>
Matrix<r, c> MatrixBase<r, c>::product(const Matrix<r, c> &m1, const Matrix<r, c> &m2) {
Matrix<r, c> result;
for (int i = 0; i < r * c; ++i) {
result._values[i] = m1._values[i] * m2._values[i];
}
return result;
}
template <int r, int c>
Matrix<r, c> MatrixBase<r, c>::quotient(const Matrix<r, c> &m1, float factor) {
Matrix<r, c> result;
for (int i = 0; i < r * c; ++i) {
result._values[i] = m1._values[i] / factor;
}
return result;
}
template <int r, int c>
Matrix<r, c> MatrixBase<r, c>::quotient(const Matrix<r, c> &m1, const Matrix<r, c> &m2) {
Matrix<r, c> result;
for (int i = 0; i < r * c; ++i) {
result._values[i] = m1._values[i] / m2._values[i];
}
return result;
}
// Member operators
template<int rows, int cols>
float &MatrixBase<rows, cols>::operator()(int row, int col) {
assert(rows > row && cols > col && row >= 0 && col >= 0);
return _values[row * cols + col];
}
template<int rows, int cols>
float MatrixBase<rows, cols>::operator()(int row, int col) const {
return getValue(row, col);
}
template<int rows, int cols>
Matrix<rows, cols> &MatrixBase<rows, cols>::operator=(const Matrix<rows, cols> &m) {
setData(m._values);
return getThis();
}
template<int rows, int cols>
Matrix<rows, cols> &MatrixBase<rows, cols>::operator+=(const Matrix<rows, cols> &m) {
for (int i = 0; i < rows * cols; ++i) {
_values[i] += m._values[i];
}
return getThis();
}
template<int rows, int cols>
Matrix<rows, cols> &MatrixBase<rows, cols>::operator-=(const Matrix<rows, cols> &m) {
for (int i = 0; i < rows * cols; ++i) {
_values[i] -= m._values[i];
}
return getThis();
}
template<int rows, int cols>
Matrix<rows, cols> &MatrixBase<rows, cols>::operator*=(float factor) {
for (int i = 0; i < rows * cols; ++i) {
_values[i] *= factor;
}
return getThis();
}
template<int rows, int cols>
Matrix<rows, cols> &MatrixBase<rows, cols>::operator/=(float factor) {
for (int i = 0; i < rows * cols; ++i) {
_values[i] /= factor;
}
return getThis();
}
// Row
template<int rows, int cols>
typename MatrixBase<rows, cols>::Row MatrixBase<rows, cols>::getRow(int row) {
return Row(this, row);
}
template<int rows, int cols>
MatrixBase<rows, cols>::Row::Row(MatrixBase<rows, cols> *m, int row) :
_matrix(m), _row(row), _col(0) {
}
template<int rows, int cols>
typename MatrixBase<rows, cols>::Row &MatrixBase<rows, cols>::Row::operator<<(float value) {
assert(_col < cols);
_matrix->setValue(_row, _col++, value);
return *this;
}
// Global operators
template <int m, int n, int p>
Matrix<m, n> operator*(const Matrix<m, p> &m1, const Matrix<p, n> &m2) {
Matrix<m, n> result;
for (int row = 0; row < m; ++row) {
for (int col = 0; col < n; ++col) {
float sum(0.0f);
for (int j = 0; j < p; ++j)
sum += m1(row, j) * m2(j, col);
result(row, col) = sum;
}
}
return result;
}
template <int r, int c>
inline Matrix<r, c> operator+(const Matrix<r, c> &m1, const Matrix<r, c> &m2) {
return Matrix<r, c>::sum(m1, m2);
}
template <int r, int c>
inline Matrix<r, c> operator-(const Matrix<r, c> &m1, const Matrix<r, c> &m2) {
return Matrix<r, c>::difference(m1, m2);
}
template <int r, int c>
inline Matrix<r, c> operator*(const Matrix<r, c> &m1, const Matrix<r, c> &m2) {
return Matrix<r, c>::product(m1, m2);
}
template <int r, int c>
inline Matrix<r, c> operator*(const Matrix<r, c> &m1, float factor) {
return Matrix<r, c>::product(m1, factor);
}
template <int r, int c>
inline Matrix<r, c> operator/(const Matrix<r, c> &m1, const Matrix<r, c> &m2) {
return Matrix<r, c>::quotient(m1, m2);
}
template <int r, int c>
inline Matrix<r, c> operator/(const Matrix<r, c> &m1, float factor) {
return Matrix<r, c>::quotient(m1, factor);
}
template <int r, int c>
Matrix<r, c> operator*(float factor, const Matrix<r, c> &m1) {
return Matrix<r, c>::product(m1, factor);
}
template <int r, int c>
Matrix<r, c> operator-(const Matrix<r, c> &m) {
return m.getNegative();
}
template <int r, int c>
bool operator==(const Matrix<r, c> &m1, const Matrix<r, c> &m2) {
for (int row = 0; row < r; ++row) {
for (int col = 0; col < c; ++col) {
if (m1(row, col) != m2(row, col)) {
return false;
}
}
}
return true;
}
template <int r, int c>
bool operator!=(const Matrix<r, c> &m1, const Matrix<r, c> &m2) {
return !(m1 == m2);
}
template<int r, int c>
Common::StreamDebug &operator<<(Common::StreamDebug &dbg, const Math::Matrix<r, c> &m) {
dbg.nospace() << "Matrix<" << r << ", " << c << ">(";
for (int col = 0; col < c; ++col) {
dbg << m(0, col) << ", ";
}
for (int row = 1; row < r; ++row) {
dbg << "\n ";
for (int col = 0; col < c; ++col) {
dbg << m(row, col) << ", ";
}
}
dbg << ')';
return dbg.space();
}
}
#endif