supercell-wx/wxdata/source/scwx/util/float.cpp
2024-02-25 18:18:50 -06:00

66 lines
1.4 KiB
C++

#include <scwx/util/float.hpp>
#include <cmath>
#include <cstring>
#ifdef _WIN32
# include <WinSock2.h>
#else
# include <arpa/inet.h>
#endif
namespace scwx
{
namespace util
{
float DecodeFloat16(std::uint16_t hex)
{
static constexpr std::uint16_t S_MASK = 0x8000;
static constexpr std::uint16_t S_LSB = 0;
static constexpr std::uint16_t S_SHIFT = 15 - S_LSB;
static constexpr std::uint16_t E_MASK = 0x7c00;
static constexpr std::uint16_t E_LSB = 5;
static constexpr std::uint16_t E_SHIFT = 15 - E_LSB;
static constexpr std::uint16_t F_MASK = 0x03ff;
static constexpr std::uint16_t F_LSB = 15;
static constexpr std::uint16_t F_SHIFT = 15 - F_LSB;
std::uint16_t sHex = (hex & S_MASK) >> S_SHIFT;
std::uint16_t eHex = (hex & E_MASK) >> E_SHIFT;
std::uint16_t fHex = (hex & F_MASK) >> F_SHIFT;
float value;
float s = std::pow(-1.0f, static_cast<float>(sHex));
float e;
float f;
if (eHex == 0)
{
e = 2.0f;
f = (fHex / std::pow(2.0f, 10.0f));
}
else
{
e = std::pow(2.0f, eHex - 16.0f);
f = (1 + fHex / std::pow(2.0f, 10.0f));
}
value = s * e * f;
return value;
}
float DecodeFloat32(std::uint16_t msw, std::uint16_t lsw)
{
std::uint32_t value = msw << 16 | lsw;
float floatValue;
std::memcpy(&floatValue, &value, sizeof(float));
return floatValue;
}
} // namespace util
} // namespace scwx