BLT/include/blt/math/fixed_point.h

160 lines
4.4 KiB
C++

/*
* <Short Description>
* Copyright (C) 2024 Brett Terpstra
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#ifndef BLT_FIXED_POINT_H
#define BLT_FIXED_POINT_H
#include <blt/std/types.h>
#include <blt/std/utility.h>
#define BLT_DEBUG_NO_INLINE BLT_ATTRIB_NO_INLINE
namespace blt
{
struct fp64
{
private:
u64 v = 0;
fp64() = default;
explicit fp64(u64 v): v(v)
{}
public:
static fp64 from_u64(u64 ui)
{
fp64 fp;
fp.v = ui << 32;
return fp;
}
static fp64 from_i64(i64 si)
{
u64 ui = static_cast<u64>(si);
fp64 fp;
fp.v = ui << 32;
return fp;
}
static fp64 from_f64(f64 d)
{
fp64 fp;
fp.v = static_cast<u64>(d * (1ul << 32ul));
return fp;
}
static fp64 from_f32(f32 f)
{
return from_f64(static_cast<double>(f));
}
BLT_DEBUG_NO_INLINE friend fp64 operator+(fp64 left, fp64 right)
{
return fp64(left.v + right.v);
}
BLT_DEBUG_NO_INLINE friend fp64 operator-(fp64 left, fp64 right)
{
return fp64(left.v - right.v);
}
BLT_DEBUG_NO_INLINE friend fp64 operator*(fp64 left, fp64 right)
{
auto lhs = static_cast<unsigned __int128>(left.v);
auto rhs = static_cast<unsigned __int128>(right.v);
return fp64(static_cast<u64>((lhs * rhs) >> 32));
}
BLT_DEBUG_NO_INLINE friend fp64 operator/(fp64 left, fp64 right)
{
auto lhs = static_cast<unsigned __int128>(left.v) << 32;
auto rhs = static_cast<unsigned __int128>(right.v);
return fp64(static_cast<u64>(lhs / rhs));
}
[[nodiscard]] inline u64 as_u64() const
{
return v >> 32;
}
[[nodiscard]] inline i64 as_i64() const
{
return static_cast<i64>(as_u64());
}
[[nodiscard]] inline u32 as_u32() const
{
return static_cast<u32>(as_u64());
}
[[nodiscard]] inline i32 as_i32() const
{
return static_cast<i32>(as_u64());
}
[[nodiscard]] inline f64 as_f64() const
{
return static_cast<f64>(v) / static_cast<f64>(1ul << 32ul);
}
[[nodiscard]] inline f32 as_f32() const
{
return static_cast<f32>(as_f64());
}
inline explicit operator u64() const
{
return as_u64();
}
inline explicit operator i64() const
{
return as_i64();
}
inline explicit operator u32() const
{
return as_u32();
}
inline explicit operator i32() const
{
return as_i32();
}
inline explicit operator f32() const
{
return as_f32();
};
inline explicit operator f64() const
{
return as_f64();
}
[[nodiscard]] u64 raw() const
{
return v;
}
};
}
#endif //BLT_FIXED_POINT_H