libcruft-util/point.ipp

94 lines
2.7 KiB
C++

/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Copyright 2014-2015 Danny Robson <danny@nerdcruft.net>
*/
#include "maths.hpp"
#include <algorithm>
namespace util {
///------------------------------------------------------------------------
/// 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, typename U>
typename std::common_type<T,U>::type
distance (point<S,T> a, point<S,U> b)
{
return std::sqrt (distance2 (a, b));
}
//-------------------------------------------------------------------------
template <size_t S, typename T, typename U>
typename std::common_type<T,U>::type
distance2 (point<S,T> a, point<S,U> b)
{
typename std::common_type<T,U>::type sum {0};
for (size_t i = 0; i < S; ++i)
sum += pow2 (a.data[i] - b.data[i]);
return sum;
}
//-------------------------------------------------------------------------
template <size_t S, typename T, typename U>
typename std::common_type<T,U>::type
manhattan (point<S,T> a, point<S,U> b)
{
typename std::common_type<T,U>::type sum {0};
for (size_t i = 0; i < S; ++i)
sum += std::abs (a.data[i] - b.data[i]);
return sum;
}
//-------------------------------------------------------------------------
template <size_t S, typename T, typename U>
typename std::common_type<T,U>::type
chebyshev(point<S,T> a, point<S,U> b)
{
return util::max (abs (a - b));
}
}