Method AllocateSortBuffer

Source/Engine/Particles/ParticlesData.cpp:162–208

}

bool ParticleBuffer::AllocateSortBuffer()
{
    ASSERT(Emitter && GPU.SortedIndices == nullptr && GPU.SortingKeys == nullptr);
    if (Emitter->Graph.SortModules.IsEmpty())
        return false;
    const int32 sortedIndicesCount = Capacity * Emitter->Graph.SortModules.Count();
    uint32 indexSize = sizeof(uint32);
    PixelFormat indexFormat = PixelFormat::R32_UInt;
    auto r16Support = GPUDevice::Instance->GetFormatFeatures(PixelFormat::R16_UInt).Support;
    auto indexFormatRequirements = FormatSupport::Buffer | FormatSupport::UnorderedAccessReadOnly;
    if (Mode == ParticlesSimulationMode::GPU)
        indexFormatRequirements |= FormatSupport::UnorderedAccess;
    if (Capacity <= MAX_uint16 &&  EnumHasAllFlags(r16Support, indexFormatRequirements))
    {
        // 16-bit indices
        indexSize = sizeof(uint16);
        indexFormat = PixelFormat::R16_UInt;
    }

    switch (Mode)
    {
    case ParticlesSimulationMode::CPU:
    {
        GPU.SortedIndices = GPUDevice::Instance->CreateBuffer(TEXT("ParticleSortedIndices"));
        if (GPU.SortedIndices->Init(GPUBufferDescription::Buffer(sortedIndicesCount * indexSize, GPUBufferFlags::ShaderResource, indexFormat, nullptr, indexSize, GPUResourceUsage::Dynamic)))
            return true;
        break;
    }
#if COMPILE_WITH_GPU_PARTICLES
    case ParticlesSimulationMode::GPU:
    {
        GPU.SortingKeys = GPUDevice::Instance->CreateBuffer(TEXT("ParticleSortingKeys"));
        if (GPU.SortingKeys->Init(GPUBufferDescription::Buffer(sortedIndicesCount * sizeof(float), GPUBufferFlags::ShaderResource | GPUBufferFlags::UnorderedAccess, PixelFormat::R32_Float, nullptr, sizeof(float))))
            return true;
        GPU.SortedIndices = GPUDevice::Instance->CreateBuffer(TEXT("ParticleSortedIndices"));
        if (GPU.SortedIndices->Init(GPUBufferDescription::Buffer(sortedIndicesCount * indexSize, GPUBufferFlags::ShaderResource | GPUBufferFlags::UnorderedAccess, indexFormat, nullptr, indexSize)))
            return true;
        break;
    }
#endif
    default:
        CRASH;
        return true;
    }

    return false;
}

void ParticleBuffer::Clear()
{