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point: prefer explicit over blocked namespacing

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Danny Robson 2016-12-12 15:45:43 +11:00
parent 9711272989
commit 17b5514df4
1 changed files with 93 additions and 95 deletions
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188
point.ipp
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@ -18,104 +18,102 @@
#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");
///------------------------------------------------------------------------
/// 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>
util::point<D,T>
util::point<S,T>::homog (void) const
{
static_assert (D > S, "homog will not overwrite data");
point<D,T> out;
point<D,T> out;
// Copy the existing data
auto c = std::copy (this->begin (),
this->end (),
out.begin ());
// 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});
// 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};
// 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)
{
using type_t = typename std::common_type<T,U>::type;
static_assert (std::is_floating_point<type_t>::value,
"sqrt likely requires fractional types");
return std::sqrt (distance2 (a, b));
}
//-------------------------------------------------------------------------
template <size_t S, typename T, typename U>
constexpr 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 <typename T, typename U>
typename std::common_type<T,U>::type
octile (point2<T> a, point2<U> b)
{
using type_t = typename std::common_type<T,U>::type;
static_assert (!std::is_integral<type_t>::value,
"octile requires more than integer precision");
const type_t D1 = 1;
const type_t D2 = std::sqrt (type_t {2});
auto diff = util::abs (a - b);
// distance for axis-aligned walks
auto axis = D1 * (diff.x + diff.y);
// the savings from diagonal walks
auto diag = (D2 - 2 * D1) * util::min (diff);
return axis + diag;
}
//-------------------------------------------------------------------------
template <size_t S, typename T, typename U>
constexpr 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 += util::abs (a.data[i] - b.data[i]);
return sum;
}
//-------------------------------------------------------------------------
template <size_t S, typename T, typename U>
constexpr typename std::common_type<T,U>::type
chebyshev(point<S,T> a, point<S,U> b)
{
return util::max (abs (a - b));
}
return out;
}
//-------------------------------------------------------------------------
template <size_t S, typename T, typename U>
typename std::common_type<T,U>::type
util::distance (point<S,T> a, point<S,U> b)
{
using type_t = typename std::common_type<T,U>::type;
static_assert (std::is_floating_point<type_t>::value,
"sqrt likely requires fractional types");
return std::sqrt (distance2 (a, b));
}
//-------------------------------------------------------------------------
template <size_t S, typename T, typename U>
constexpr typename std::common_type<T,U>::type
util::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 <typename T, typename U>
typename std::common_type<T,U>::type
util::octile (point2<T> a, point2<U> b)
{
using type_t = typename std::common_type<T,U>::type;
static_assert (!std::is_integral<type_t>::value,
"octile requires more than integer precision");
const type_t D1 = 1;
const type_t D2 = std::sqrt (type_t {2});
auto diff = util::abs (a - b);
// distance for axis-aligned walks
auto axis = D1 * (diff.x + diff.y);
// the savings from diagonal walks
auto diag = (D2 - 2 * D1) * util::min (diff);
return axis + diag;
}
//-------------------------------------------------------------------------
template <size_t S, typename T, typename U>
constexpr typename std::common_type<T,U>::type
util::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 += util::abs (a.data[i] - b.data[i]);
return sum;
}
//-------------------------------------------------------------------------
template <size_t S, typename T, typename U>
constexpr typename std::common_type<T,U>::type
util::chebyshev(point<S,T> a, point<S,U> b)
{
return util::max (abs (a - b));
}