libcruft-util/fixed.cpp
2015-02-06 16:34:30 +11:00

179 lines
4.3 KiB
C++

/*
* This file is part of libgim.
*
* libgim 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.
*
* libgim 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 libgim. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright 2011-2015 Danny Robson <danny@nerdcruft.net>
*/
#include "fixed.hpp"
#include "maths.hpp"
#include <cmath>
using namespace util;
///////////////////////////////////////////////////////////////////////////////
// Constructors
template <unsigned I, unsigned E>
fixed<I,E>::fixed (uint_t val):
m_value (val << E)
{
static_assert (I > 0, "must use positive integer bits");
static_assert (E > 0, "must use positive fractional bits");
static_assert (I + E == sizeof (m_value) * 8,
"underlying storage must be exactly I+E sized");
}
///////////////////////////////////////////////////////////////////////////////
// Conversions
template <unsigned I, unsigned E>
double
fixed<I,E>::to_double (void) const
{
return static_cast<double> (m_value) / pow (2, E);
}
//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
float
fixed<I,E>::to_float (void) const
{
return static_cast<float> (m_value) / pow (2, E);
}
//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
typename fixed<I,E>::uint_t
fixed<I,E>::to_integral (void) const
{
return m_value >> E;
}
//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
typename fixed<I,E>::uint_t
fixed<I,E>::to_native (void) const
{
return m_value;
}
//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
fixed<I,E>
fixed<I,E>::from_native (uint_t i)
{
return fixed<I,E> {i};
}
//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
typename fixed<I,E>::uint_t
fixed<I,E>::to_integral (uint_t v)
{
return v >> E;
}
///////////////////////////////////////////////////////////////////////////////
// Integer operators
template <unsigned I, unsigned E>
fixed<I,E>&
fixed<I,E>::operator+= (uint_t val)
{
m_value += val << E;
return *this;
}
//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
fixed<I,E>&
fixed<I,E>::operator-= (uint_t val)
{
m_value -= val << E;
return *this;
}
//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
fixed<I,E>&
fixed<I,E>::operator*= (uint_t val)
{
m_value *= val;
return *this;
}
//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
fixed<I,E>&
fixed<I,E>::operator/= (uint_t val)
{
m_value /= val;
return *this;
}
//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
fixed<I,E>
fixed<I,E>::operator+ (uint_t val) const
{
return fixed<I,E> (m_value + val << E);
}
//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
fixed<I,E>
fixed<I,E>::operator- (uint_t val) const
{
return fixed<I,E> (m_value - val << E);
}
//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
fixed<I,E>
fixed<I,E>::operator* (uint_t val) const
{
return fixed<I,E> (m_value * val);
}
//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
fixed<I,E>
fixed<I,E>::operator /(uint_t val) const
{
return fixed<I,E> (m_value / val);
}
//-----------------------------------------------------------------------------
template class util::fixed<16,16>;
template class util::fixed<32,32>;
template class util::fixed<26, 6>;