Files
2024-02-26 19:00:48 +01:00

60 lines
2.3 KiB
C++

// Copyright (c) 2012-2024 Wojciech Figat. All rights reserved.
#pragma once
#include "../RendererPass.h"
#include "Engine/Graphics/GPUPipelineStatePermutations.h"
/// <summary>
/// Bitonic Sort implementation using GPU compute shaders.
/// It has a complexity of O(n*(log n)^2), which is inferior to most traditional sorting algorithms, but because GPUs have so many threads,
/// and because each thread can be utilized, the algorithm can fully load the GPU, taking advantage of its high ALU and bandwidth capabilities.
/// </summary>
class BitonicSort : public RendererPass<BitonicSort>
{
private:
AssetReference<Shader> _shader;
GPUBuffer* _dispatchArgsBuffer = nullptr;
GPUConstantBuffer* _cb;
GPUShaderProgramCS* _indirectArgsCS;
GPUShaderProgramCS* _preSortCS;
GPUShaderProgramCS* _innerSortCS;
GPUShaderProgramCS* _outerSortCS;
GPUShaderProgramCS* _copyIndicesCS;
public:
/// <summary>
/// Sorts the specified buffer of index-key pairs.
/// </summary>
/// <param name="context">The GPU context.</param>
/// <param name="sortingKeysBuffer">The sorting keys buffer. Used as a structured buffer of type Item (see above).</param>
/// <param name="countBuffer">The buffer that contains a items counter value.</param>
/// <param name="counterOffset">The offset into counter buffer to find count for this list. Must be a multiple of 4 bytes.</param>
/// <param name="sortAscending">True to sort in ascending order (smallest to largest), otherwise false to sort in descending order.</param>
/// <param name="sortedIndicesBuffer">The output buffer for sorted values extracted from the sorted sortingKeysBuffer after algorithm run. Valid for uint value types - used as RWBuffer.</param>
void Sort(GPUContext* context, GPUBuffer* sortingKeysBuffer, GPUBuffer* countBuffer, uint32 counterOffset, bool sortAscending, GPUBuffer* sortedIndicesBuffer);
public:
// [RendererPass]
String ToString() const override;
bool Init() override;
void Dispose() override;
#if COMPILE_WITH_DEV_ENV
void OnShaderReloading(Asset* obj)
{
_preSortCS = nullptr;
_innerSortCS = nullptr;
_outerSortCS = nullptr;
invalidateResources();
}
#endif
protected:
// [RendererPass]
bool setupResources() override;
};