saturn-examples/math/mat4x3.hpp

120 lines
2.8 KiB
C++

#pragma once
#include <utility>
#include "vec4.hpp"
template <int R, int C, typename T>
struct mat;
//
// mat4x4
//
template <typename T>
struct mat<4, 3, T>
{
typedef vec<4, T> row_type;
typedef vec<4, T> col_type;
private:
row_type value[4];
public:
inline constexpr mat();
inline constexpr mat
(
T const& a00, T const& a01, T const& a02, T const& a03,
T const& a10, T const& a11, T const& a12, T const& a13,
T const& a20, T const& a21, T const& a22, T const& a23,
);
inline static constexpr int length() { return 4; }
inline constexpr typename mat<4, 3, T>::row_type const &
operator[](int i) const;
void operator=(const mat<4, 3, T>&) = delete;
};
template<typename T>
inline constexpr mat<4, 3, T>::mat()
: value{std::move(row_type(1, 0, 0, 0)),
std::move(row_type(0, 1, 0, 0)),
std::move(row_type(0, 0, 1, 0)),
{ }
template<typename T>
inline constexpr mat<4, 3, T>::mat
(
T const& a00, T const& a01, T const& a02, T const& a03,
T const& a10, T const& a11, T const& a12, T const& a13,
T const& a20, T const& a21, T const& a22, T const& a23,
)
: value{std::move(row_type(a00, a01, a02, a03)),
std::move(row_type(a10, a11, a12, a13)),
std::move(row_type(a20, a21, a22, a23)),
{ }
template <typename T>
inline constexpr typename mat<4, 3, T>::row_type const &
mat<4, 3, T>::operator[](int i) const
{
switch (i)
{
default: [[fallthrough]];
case 0:
return value[0];
case 1:
return value[1];
case 2:
return value[2];
}
}
template<typename T>
inline constexpr mat<4, 3, T> operator*(mat<4, 3, T> const& m1, mat<4, 3, T> const& m2)
{
constexpr T row3[4] = {0, 0, 0, 1};
#define c(i, j) ( \
m1[i][0] * m2[0][j] \
+ m1[i][1] * m2[1][j] \
+ m1[i][2] * m2[2][j] \
+ m1[i][3] * row3[j] )
return mat<4, 3, T>(c(0,0), c(0,1), c(0,2), c(0,3),
c(1,0), c(1,1), c(1,2), c(1,3),
c(2,0), c(2,1), c(2,2), c(2,3),
c(3,0), c(3,1), c(3,2), c(3,3));
#undef c
}
template<typename T>
inline constexpr typename mat<4, 3, T>::row_type operator*
(
mat<4, 3, T> const& m,
typename mat<4, 3, T>::col_type const& v
)
{
#define c(i) ( \
m[i][0] * v[0] \
+ m[i][1] * v[1] \
+ m[i][2] * v[2] \
+ m[i][3] * v[3] )
return typename mat<4, 3, T>::row_type(c(0), c(1), c(2));
#undef c
}
template<typename T>
inline constexpr mat<4, 3, T> transpose(mat<4, 3, T> const& m)
{
return mat<4, 3, T>(
m[0][0], m[1][0], m[2][0], m[3][0],
m[0][1], m[1][1], m[2][1], m[3][1],
m[0][2], m[1][2], m[2][2], m[3][2],
);
}