61 lines
2.4 KiB
C++
61 lines
2.4 KiB
C++
// Copyright Epic Games, Inc. All Rights Reserved.
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/*=============================================================================
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HaltonUtilities.h: Class definition for optimized evaluation of Halton
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sequences.
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=============================================================================*/
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#pragma once
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// Copyright (c) 2012 Leonhard Gruenschloss (leonhard@gruenschloss.org)
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights to
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// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
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// of the Software, and to permit persons to whom the Software is furnished to do
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// so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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// SOFTWARE.
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// This file has been adapted to UE
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#include "Containers/Array.h"
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/**
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* Builds Faure permutation sets to support up to 64 dimensions. The permutation sets
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* are linearized for quick upload to the GPU is desired.
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*
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* Consider adding extended dimensionality support if necessary.
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*/
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class FHaltonSequence
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{
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public:
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FHaltonSequence();
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static uint32 GetNumberOfDimensions() { return 64; }
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float Sample(int Dimension, unsigned int Index) const;
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const TArray<int>& GetFaurePermutations() const { return FaurePermutations; }
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const TArray<int>& GetFaurePermutationOffsets() const { return FaurePermutationOffsets; }
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private:
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int Invert(int Base, int Digits, int Index, const TArray<int>& Permutation);
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void InitTables(const TArray<TArray<int>>& Permutations);
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void BuildPermutation(int Size, int Base, int Digits, const TArray<TArray<int>>& Permutations);
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void FlattenPermutation(const TArray<int>& PermutationLocal);
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TArray<int> FaurePermutations;
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TArray<int> FaurePermutationOffsets;
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};
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