axmol/thirdparty/openal/common/vecmat.h

121 lines
3.8 KiB
C++

#ifndef COMMON_VECMAT_H
#define COMMON_VECMAT_H
#include <array>
#include <cmath>
#include <cstddef>
#include <limits>
#include "alspan.h"
namespace alu {
template<typename T>
class VectorR {
static_assert(std::is_floating_point<T>::value, "Must use floating-point types");
alignas(16) T mVals[4];
public:
constexpr VectorR() noexcept = default;
constexpr VectorR(const VectorR&) noexcept = default;
constexpr explicit VectorR(T a, T b, T c, T d) noexcept : mVals{a, b, c, d} { }
constexpr VectorR& operator=(const VectorR&) noexcept = default;
constexpr T& operator[](size_t idx) noexcept { return mVals[idx]; }
constexpr const T& operator[](size_t idx) const noexcept { return mVals[idx]; }
constexpr VectorR& operator+=(const VectorR &rhs) noexcept
{
mVals[0] += rhs.mVals[0];
mVals[1] += rhs.mVals[1];
mVals[2] += rhs.mVals[2];
mVals[3] += rhs.mVals[3];
return *this;
}
constexpr VectorR operator-(const VectorR &rhs) const noexcept
{
return VectorR{mVals[0] - rhs.mVals[0], mVals[1] - rhs.mVals[1],
mVals[2] - rhs.mVals[2], mVals[3] - rhs.mVals[3]};
}
constexpr T normalize(T limit = std::numeric_limits<T>::epsilon())
{
limit = std::max(limit, std::numeric_limits<T>::epsilon());
const T length_sqr{mVals[0]*mVals[0] + mVals[1]*mVals[1] + mVals[2]*mVals[2]};
if(length_sqr > limit*limit)
{
const T length{std::sqrt(length_sqr)};
T inv_length{T{1}/length};
mVals[0] *= inv_length;
mVals[1] *= inv_length;
mVals[2] *= inv_length;
return length;
}
mVals[0] = mVals[1] = mVals[2] = T{0};
return T{0};
}
constexpr VectorR cross_product(const alu::VectorR<T> &rhs) const noexcept
{
return VectorR{
mVals[1]*rhs.mVals[2] - mVals[2]*rhs.mVals[1],
mVals[2]*rhs.mVals[0] - mVals[0]*rhs.mVals[2],
mVals[0]*rhs.mVals[1] - mVals[1]*rhs.mVals[0],
T{0}};
}
constexpr T dot_product(const alu::VectorR<T> &rhs) const noexcept
{ return mVals[0]*rhs.mVals[0] + mVals[1]*rhs.mVals[1] + mVals[2]*rhs.mVals[2]; }
};
using Vector = VectorR<float>;
template<typename T>
class MatrixR {
static_assert(std::is_floating_point<T>::value, "Must use floating-point types");
alignas(16) T mVals[16];
public:
constexpr MatrixR() noexcept = default;
constexpr MatrixR(const MatrixR&) noexcept = default;
constexpr explicit MatrixR(
T aa, T ab, T ac, T ad,
T ba, T bb, T bc, T bd,
T ca, T cb, T cc, T cd,
T da, T db, T dc, T dd) noexcept
: mVals{aa,ab,ac,ad, ba,bb,bc,bd, ca,cb,cc,cd, da,db,dc,dd}
{ }
constexpr MatrixR& operator=(const MatrixR&) noexcept = default;
constexpr auto operator[](size_t idx) noexcept { return al::span<T,4>{&mVals[idx*4], 4}; }
constexpr auto operator[](size_t idx) const noexcept
{ return al::span<const T,4>{&mVals[idx*4], 4}; }
static constexpr MatrixR Identity() noexcept
{
return MatrixR{
T{1}, T{0}, T{0}, T{0},
T{0}, T{1}, T{0}, T{0},
T{0}, T{0}, T{1}, T{0},
T{0}, T{0}, T{0}, T{1}};
}
};
using Matrix = MatrixR<float>;
template<typename T>
constexpr VectorR<T> operator*(const MatrixR<T> &mtx, const VectorR<T> &vec) noexcept
{
return VectorR<T>{
vec[0]*mtx[0][0] + vec[1]*mtx[1][0] + vec[2]*mtx[2][0] + vec[3]*mtx[3][0],
vec[0]*mtx[0][1] + vec[1]*mtx[1][1] + vec[2]*mtx[2][1] + vec[3]*mtx[3][1],
vec[0]*mtx[0][2] + vec[1]*mtx[1][2] + vec[2]*mtx[2][2] + vec[3]*mtx[3][2],
vec[0]*mtx[0][3] + vec[1]*mtx[1][3] + vec[2]*mtx[2][3] + vec[3]*mtx[3][3]};
}
} // namespace alu
#endif /* COMMON_VECMAT_H */