97 lines
2.9 KiB
C++
97 lines
2.9 KiB
C++
/*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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* Copyright 2012-2015 Danny Robson <danny@nerdcruft.net>
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*/
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#ifdef __UTIL_NOISE_BASIS_WORLEY_IPP
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#error
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#endif
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#define __UTIL_NOISE_BASIS_WORLEY_IPP
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#include "../../debug.hpp"
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namespace util { namespace noise { namespace basis {
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///////////////////////////////////////////////////////////////////////////
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template <size_t S, typename T, size_t F>
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worley<S,T,F>::worley (seed_t _seed):
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m_seed (_seed)
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{ ; }
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//-------------------------------------------------------------------------
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template <size_t S, typename T, size_t F>
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util::range<T>
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worley<S,T,F>::bounds (void) const
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{
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return { 0.0, 1.5 };
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}
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//-------------------------------------------------------------------------
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template <size_t S, typename T, size_t F>
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seed_t
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worley<S,T,F>::seed (void) const
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{
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return m_seed;
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}
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//-------------------------------------------------------------------------
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template <size_t S, typename T, size_t F>
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seed_t
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worley<S,T,F>::seed (seed_t _seed)
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{
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return m_seed = _seed;
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}
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//-------------------------------------------------------------------------
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template <size_t S, typename T, size_t F>
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T
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worley<S,T,F>::operator() (point<S,T> p) const noexcept
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{
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// extract integer and fractional parts. be careful to always round down
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auto p_int = floor (p).template cast<intmax_t> ();
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auto p_rem = (p - p_int).template as<point> ();
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// setup an array of distances
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constexpr size_t COUNT = type::distance<S,1>::OFFSET_SIZE;
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T distances[COUNT];
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std::transform (std::begin (this->OFFSETS), std::end (this->OFFSETS),
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distances,
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[p_int,p_rem,this] (auto i) {
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auto q = this->generate (p_int + i);
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return distance2 (q + i, p_rem);
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});
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// find the f'th lowest value
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static_assert (F < COUNT, "worley order must be less than search radius");
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std::partial_sort (distances, distances + F, distances + COUNT);
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CHECK_GE (distances[F], 0);
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return distances[F];
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}
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//////////////////////////////////////////////////////////////////////////
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template <size_t S, typename T, size_t F>
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point<S,T>
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worley<S,T,F>::generate (point<S,intmax_t> p) const
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{
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return rand::coord<util::point,T> (m_seed, p);
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}
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} } }
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