libcruft-util/range.cpp

/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * Copyright 2011-2012 Danny Robson <danny@nerdcruft.net>
 */


#include "range.hpp"

#include "debug/assert.hpp"
#include "maths.hpp"
#include "random.hpp"

#include <cmath>
#include <cstdint>


///////////////////////////////////////////////////////////////////////////////
template <typename T>
cruft::range<T>::range (T _lo, T _hi):
        lo (_lo),
        hi (_hi)
{
    sanity ();
}


///////////////////////////////////////////////////////////////////////////////
template <typename T>
T
cruft::range<T>::magnitude (void) const
{
    return hi - lo;
}


///////////////////////////////////////////////////////////////////////////////
template <typename T>
bool
cruft::range<T>::contains (T val) const
{
    return val >= lo && val <= hi;
}


//-----------------------------------------------------------------------------
template <typename T>
bool
cruft::range<T>::contains (const range <T> &r) const
{
    return r.lo >= lo && r.hi <= hi;
}


//-----------------------------------------------------------------------------
template <typename T>
T
cruft::range<T>::at (float t) const
{
    return static_cast<T> (lo + (hi - lo) * t);
}


//-----------------------------------------------------------------------------
template <typename T>
T
cruft::range<T>::clamp (T val) const
{
    return std::max (lo, std::min (val, hi));
}


//-----------------------------------------------------------------------------
template <typename T>
void
cruft::range<T>::expand (T val)
{
    // The arguments to min and max are such that expansion from initial NaN
    // values should change both min and max to be that value.
    lo = std::min (val, lo);
    hi = std::max (val, hi);
}


///////////////////////////////////////////////////////////////////////////////
template <typename T>
cruft::range<T>&
cruft::range<T>::operator*= (T val)
{
    lo *= val;
    hi *= val;

    return *this;
}


//-----------------------------------------------------------------------------
template <typename T>
cruft::range<T>
cruft::range<T>::operator* (T val) const
{
    return cruft::range<T> (lo * val, hi * val);
}


//-----------------------------------------------------------------------------
template <typename T>
cruft::range<T>
cruft::range<T>::operator- (T val) const
{
    return cruft::range<T> (lo - val, hi - val);
}


//-----------------------------------------------------------------------------
template <typename T>
cruft::range<T>
cruft::range<T>::operator+ (T val) const
{
    return cruft::range<T> (
        lo + val,
        hi + val
    );
}


///////////////////////////////////////////////////////////////////////////////
template <typename T>
T
cruft::range<T>::random (void) const
{
    if constexpr (std::is_floating_point_v<T>) {
        return std::uniform_real_distribution<T> (lo, hi) (cruft::random::generator ());
    } else {
        return std::uniform_int_distribution<T> (lo, hi) (cruft::random::generator ());
    }
}


///////////////////////////////////////////////////////////////////////////////
namespace cruft {
    template <>
    bool
    range<float>::operator ==(const range<float> &rhs) const
    {
        return almost_equal (lo, rhs.lo) &&
               almost_equal (hi, rhs.hi);
    }


    template <>
    bool
    range<double>::operator ==(const range<double> &rhs) const
    {
        return almost_equal (lo, rhs.lo) &&
               almost_equal (hi, rhs.hi);
    }
}


//-----------------------------------------------------------------------------
template <typename T>
bool
cruft::range<T>::operator ==(const cruft::range<T> &rhs) const
{
    return lo == rhs.lo && hi == rhs.hi;
}


///////////////////////////////////////////////////////////////////////////////
template <typename T>
void
cruft::range<T>::sanity (void) const
{
    CHECK (lo <= hi);
}


//-----------------------------------------------------------------------------
namespace cruft {
    template <>
    void
    range<double>::sanity (void) const
    {
        if (std::isnan (lo) || std::isnan (hi))
            return;
        CHECK (lo <= hi);
    }
}


//-----------------------------------------------------------------------------
template struct cruft::range<double>;
template struct cruft::range<float>;
template struct cruft::range<int8_t>;
template struct cruft::range<int16_t>;
template struct cruft::range<int32_t>;
template struct cruft::range<int64_t>;
template struct cruft::range<uint8_t>;
template struct cruft::range<uint16_t>;
template struct cruft::range<uint32_t>;
template struct cruft::range<uint64_t>;