alexpete
85 lines
2.3 KiB
C++
85 lines
2.3 KiB
C++
/*
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* All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
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* its licensors.
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*
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* For complete copyright and license terms please see the LICENSE at the root of this
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* distribution (the "License"). All use of this software is governed by the License,
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* or, if provided, by the license below or the license accompanying this file. Do not
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* remove or modify any license notices. This file 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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*
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*/
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#pragma once
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// include required headers
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#include "StandardHeaders.h"
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#include "Vector.h"
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#include <AzCore/std/string/string.h>
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namespace MCore
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{
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/**
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* The hash function.
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* The hash function must return an non-negative (so positive) integer, based on a key value.
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* Use partial template specialization to implement hashing functions for different data types.
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*/
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template <typename Key>
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MCORE_INLINE uint32 Hash(const Key& key)
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{
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MCORE_ASSERT(false); // you should implement this function
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MCORE_UNUSED(key);
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//#pragma message (MCORE_ERROR "You should implement the Hash function for some specific Key type that you used")
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return 0;
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}
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template<>
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MCORE_INLINE uint32 Hash<AZStd::string>(const AZStd::string& key)
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{
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uint32 result = 0;
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const size_t length = key.size();
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for (size_t i = 0; i < length; ++i)
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{
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result = (result << 4) + key[i];
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const uint32 g = result & 0xf0000000L;
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if (g != 0)
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{
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result ^= g >> 24;
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}
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result &= ~g;
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}
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return result;
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}
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template<>
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MCORE_INLINE uint32 Hash<int32>(const int32& key)
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{
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return (uint32)Math::Abs(static_cast<float>(key));
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}
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template<>
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MCORE_INLINE uint32 Hash<uint32>(const uint32& key)
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{
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return key;
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}
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template<>
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MCORE_INLINE uint32 Hash<float>(const float& key)
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{
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return (uint32)Math::Abs(key * 12345.0f);
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}
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template<>
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MCORE_INLINE uint32 Hash<AZ::Vector3>(const AZ::Vector3& key)
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{
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return (uint32)Math::Abs(key.GetX() * 101.0f + key.GetY() * 1002.0f + key.GetZ() * 10003.0f);
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}
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} // namespace MCore
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