46 lines
1.3 KiB
C++
46 lines
1.3 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 Danny Robson <danny@nerdcruft.net>
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*/
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#ifndef __UTIL_NOISE_LUT_HPP
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#define __UTIL_NOISE_LUT_HPP
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#include <cstdlib>
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#include <type_traits>
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#include "types.hpp"
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namespace util {
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namespace noise {
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extern const size_t PERM[256];
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extern const double LUT [256];
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template <typename T>
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typename std::enable_if<std::is_integral<T>::value, size_t>::type
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permute (T idx) {
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return PERM[(size_t)idx % elems (PERM)];
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}
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template <typename T1, typename T2, typename ...R>
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size_t permute (T1 t1, T2 t2, R ...r) {
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auto p = permute (t1);
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p += permute (t2, r...);
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return p % elems (PERM);
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}
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}
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}
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#endif
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