xenia-canary/third_party/crunch/crnlib/crn_packed_uint.h

92 lines
2.1 KiB
C++

// File: crn_packed_uint
// See Copyright Notice and license at the end of inc/crnlib.h
#pragma once
namespace crnlib
{
template<unsigned int N>
struct packed_uint
{
inline packed_uint() { }
inline packed_uint(unsigned int val) { *this = val; }
inline packed_uint(const packed_uint& other) { *this = other; }
inline packed_uint& operator= (const packed_uint& rhs)
{
if (this != &rhs)
memcpy(m_buf, rhs.m_buf, sizeof(m_buf));
return *this;
}
inline packed_uint& operator= (unsigned int val)
{
#ifdef CRNLIB_BUILD_DEBUG
if (N == 1)
{
CRNLIB_ASSERT(val <= 0xFFU);
}
else if (N == 2)
{
CRNLIB_ASSERT(val <= 0xFFFFU);
}
else if (N == 3)
{
CRNLIB_ASSERT(val <= 0xFFFFFFU);
}
#endif
val <<= (8U * (4U - N));
for (unsigned int i = 0; i < N; i++)
{
m_buf[i] = static_cast<unsigned char>(val >> 24U);
val <<= 8U;
}
return *this;
}
inline operator unsigned int() const
{
switch (N)
{
case 1: return m_buf[0];
case 2: return (m_buf[0] << 8U) | m_buf[1];
case 3: return (m_buf[0] << 16U) | (m_buf[1] << 8U) | (m_buf[2]);
default: return (m_buf[0] << 24U) | (m_buf[1] << 16U) | (m_buf[2] << 8U) | (m_buf[3]);
}
}
unsigned char m_buf[N];
};
template<typename T>
class packed_value
{
public:
packed_value() { }
packed_value(T val) { *this = val; }
inline operator T() const
{
T result = 0;
for (int i = sizeof(T) - 1; i >= 0; i--)
result = static_cast<T>((result << 8) | m_bytes[i]);
return result;
}
packed_value& operator= (T val)
{
for (int i = 0; i < sizeof(T); i++)
{
m_bytes[i] = static_cast<uint8>(val);
val >>= 8;
}
return *this;
}
private:
uint8 m_bytes[sizeof(T)];
};
} // namespace crnlib