Method AcquireBuffer

src/Tests.cpp:851–931

}

bool StagingBufferCollection::AcquireBuffer(VkDeviceSize size, VkBuffer& outBuffer, void*& outMappedPtr)
{
    assert(size <= MAX_TOTAL_SIZE);

    // Try to find existing unused buffer with best size.
    size_t bestIndex = SIZE_MAX;
    for(size_t i = 0, count = m_Bufs.size(); i < count; ++i)
    {
        BufInfo& currBufInfo = m_Bufs[i];
        if(!currBufInfo.Used && currBufInfo.Size >= size &&
            (bestIndex == SIZE_MAX || currBufInfo.Size < m_Bufs[bestIndex].Size))
        {
            bestIndex = i;
        }
    }

    if(bestIndex != SIZE_MAX)
    {
        m_Bufs[bestIndex].Used = true;
        outBuffer = m_Bufs[bestIndex].Buffer;
        outMappedPtr = m_Bufs[bestIndex].MappedPtr;
        return true;
    }

    // Allocate new buffer with requested size.
    if(m_TotalSize + size <= MAX_TOTAL_SIZE)
    {
        BufInfo bufInfo;
        bufInfo.Size = size;
        bufInfo.Used = true;

        VkBufferCreateInfo bufCreateInfo = { VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO };
        bufCreateInfo.size = size;
        bufCreateInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;

        VmaAllocationCreateInfo allocCreateInfo = {};
        allocCreateInfo.usage = VMA_MEMORY_USAGE_AUTO;
        allocCreateInfo.flags = VMA_ALLOCATION_CREATE_HOST_ACCESS_RANDOM_BIT | VMA_ALLOCATION_CREATE_MAPPED_BIT;

        VmaAllocationInfo allocInfo;
        VkResult res = vmaCreateBuffer(g_hAllocator, &bufCreateInfo, &allocCreateInfo, &bufInfo.Buffer, &bufInfo.Allocation, &allocInfo);
        bufInfo.MappedPtr = allocInfo.pMappedData;
        TEST(res == VK_SUCCESS && bufInfo.MappedPtr);

        outBuffer = bufInfo.Buffer;
        outMappedPtr = bufInfo.MappedPtr;

        m_Bufs.push_back(std::move(bufInfo));

        m_TotalSize += size;

        return true;
    }

    // There are some unused but smaller buffers: Free them and try again.
    bool hasUnused = false;
    for(size_t i = 0, count = m_Bufs.size(); i < count; ++i)
    {