libcruft-util/point.ipp

154 lines
4.4 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 2014-2015 Danny Robson <danny@nerdcruft.net>
*/
#include "maths.hpp"
#include <algorithm>
namespace util {
//-------------------------------------------------------------------------
template <size_t S, typename T>
template <typename U>
typename std::common_type<T,U>::type
util::point<S,T>::distance (const point<S,U> &rhs) const {
return std::sqrt (distance2 (rhs));
}
//-------------------------------------------------------------------------
template <size_t S, typename T>
template <typename U>
typename std::common_type<T,U>::type
util::point<S,T>::distance2 (const point<S,U> &rhs) const {
typedef typename std::common_type<T,U>::type result_t;
result_t sum { 0 };
for (size_t i = 0; i < S; ++i)
sum += pow2 (this->data[i] - rhs.data[i]);
return sum;
}
//-------------------------------------------------------------------------
template <size_t S, typename T>
template <typename U>
typename std::common_type<T,U>::type
util::point<S,T>::manhattan (const point<S,U> &rhs) const {
typedef typename std::common_type<T,U>::type result_t;
result_t sum { 0 };
for (size_t i = 0; i < S; ++i)
sum += std::abs (this->data[i] - rhs.data[i]);
return sum;
}
//-------------------------------------------------------------------------
template<size_t S, typename T>
template<size_t D>
point<D,T> point<S,T>::redim (void) const {
point<D,T> out;
std::copy_n (std::begin (this->data),
min (S, D),
std::begin (out.data));
return out;
}
//-------------------------------------------------------------------------
template<size_t S, typename T>
template<size_t D>
point<D,T> point<S,T>::redim (const point<D,T> &fill) const {
point<D,T> out;
static constexpr auto L1 = min (S, D);
static constexpr auto L2 = D - L1;
std::copy_n (std::begin (this->data),
L1,
std::begin (out.data));
std::copy_n (fill.data + L1,
L2,
out.data + L1);
return out;
}
//-------------------------------------------------------------------------
template <size_t S, typename T>
template <size_t D>
point<D,T> point<S,T>::redim (T fill) const
{
point<D,T> out;
auto cursor = std::copy_n (std::begin (this->data),
min (S, D),
std::begin (out.data));
std::fill (cursor, std::end (out.data), fill);
return out;
}
///------------------------------------------------------------------------
/// expand point to use homogenous coordinates of a higher dimension.
/// ie, fill with (0,..,0,1)
template <size_t S, typename T>
template <size_t D>
point<D,T>
point<S,T>::homog (void) const
{
static_assert (D > S, "homog will not overwrite data");
point<D,T> out;
// Copy the existing data
auto c = std::copy (this->begin (),
this->end (),
out.begin ());
// Fill until the second last element with zeros
auto f = std::fill_n (c, D - S - 1, T{0});
// Last element should be one
*f = T{1};
return out;
}
//-------------------------------------------------------------------------
template <size_t S, typename T>
template <typename U>
point<S,U>
point<S,T>::cast (void) const
{
point<S,U> out;
std::copy (std::begin (this->data),
std::end (this->data),
std::begin (out.data));
return out;
}
}