libcruft-util/fixed.cpp

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/*
* 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/>.
*
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* Copyright 2011-2015 Danny Robson <danny@nerdcruft.net>
*/
#include "fixed.hpp"
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#include "maths.hpp"
#include <cmath>
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using namespace util;
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///////////////////////////////////////////////////////////////////////////////
// Constructors
template <unsigned I, unsigned E>
fixed<I,E>::fixed (uint_t val):
m_value (val << E)
{
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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");
}
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///////////////////////////////////////////////////////////////////////////////
// Conversions
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template <unsigned I, unsigned E>
double
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fixed<I,E>::to_double (void) const
{
return static_cast<double> (m_value) / pow (2, E);
}
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//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
float
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fixed<I,E>::to_float (void) const
{
return static_cast<float> (m_value) / pow (2, E);
}
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//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
typename fixed<I,E>::uint_t
fixed<I,E>::to_integral (void) const
{
return m_value >> E;
}
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//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
typename fixed<I,E>::uint_t
fixed<I,E>::to_native (void) const
{
return m_value;
}
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//-----------------------------------------------------------------------------
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template <unsigned I, unsigned E>
fixed<I,E>
fixed<I,E>::from_native (uint_t i)
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{
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return fixed<I,E> {i};
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}
//-----------------------------------------------------------------------------
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template <unsigned I, unsigned E>
typename fixed<I,E>::uint_t
fixed<I,E>::to_integral (uint_t v)
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{
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return v >> E;
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}
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///////////////////////////////////////////////////////////////////////////////
// Integer operators
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template <unsigned I, unsigned E>
fixed<I,E>&
fixed<I,E>::operator+= (uint_t val)
{
m_value += val << E;
return *this;
}
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//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
fixed<I,E>&
fixed<I,E>::operator-= (uint_t val)
{
m_value -= val << E;
return *this;
}
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//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
fixed<I,E>&
fixed<I,E>::operator*= (uint_t val)
{
m_value *= val;
return *this;
}
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//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
fixed<I,E>&
fixed<I,E>::operator/= (uint_t val)
{
m_value /= val;
return *this;
}
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//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
fixed<I,E>
fixed<I,E>::operator+ (uint_t val) const
{
return fixed<I,E> (m_value + val << E);
}
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//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
fixed<I,E>
fixed<I,E>::operator- (uint_t val) const
{
return fixed<I,E> (m_value - val << E);
}
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//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
fixed<I,E>
fixed<I,E>::operator* (uint_t val) const
{
return fixed<I,E> (m_value * val);
}
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//-----------------------------------------------------------------------------
template <unsigned I, unsigned E>
fixed<I,E>
fixed<I,E>::operator /(uint_t val) const
{
return fixed<I,E> (m_value / val);
}
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///////////////////////////////////////////////////////////////////////////////
// logical operators
#define LOGIC_OP(OP) \
template <unsigned I, unsigned E> \
bool \
util::operator OP (util::fixed<I,E> a, \
util::fixed<I,E> b) \
{ \
return a.to_native () OP b.to_native (); \
}
LOGIC_OP(==)
LOGIC_OP(!=)
LOGIC_OP(<)
LOGIC_OP(<=)
LOGIC_OP(>)
LOGIC_OP(>=)
///////////////////////////////////////////////////////////////////////////////
// Instantiations
#define INSTANTIATE(I,E) \
template class util::fixed<(I),(E)>; \
template bool util::operator== (util::fixed<(I),(E)>, util::fixed<(I),(E)>); \
template bool util::operator!= (util::fixed<(I),(E)>, util::fixed<(I),(E)>); \
template bool util::operator< (util::fixed<(I),(E)>, util::fixed<(I),(E)>); \
template bool util::operator<= (util::fixed<(I),(E)>, util::fixed<(I),(E)>); \
template bool util::operator> (util::fixed<(I),(E)>, util::fixed<(I),(E)>); \
template bool util::operator>= (util::fixed<(I),(E)>, util::fixed<(I),(E)>);
INSTANTIATE(16,16)
INSTANTIATE(26, 6)
INSTANTIATE(32,32)