Implement UploadPool to efficiently update UBOs

src/Nazara/VulkanRenderer/VulkanUploadPool.cpp

@@ -0,0 +1,96 @@
+// Copyright (C) 2020 Jérôme Leclercq
+// This file is part of the "Nazara Engine - Vulkan Renderer"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/VulkanRenderer/VulkanUploadPool.hpp>
+#include <cassert>
+#include <Nazara/VulkanRenderer/Debug.hpp>
+
+namespace Nz
+{
+	auto VulkanUploadPool::Allocate(UInt64 size) -> std::optional<AllocationData>
+	{
+		const auto& deviceProperties = m_device.GetPhysicalDeviceInfo().properties;
+		UInt64 preferredAlignement = deviceProperties.limits.optimalBufferCopyOffsetAlignment;
+
+		return Allocate(size, preferredAlignement);
+	}
+
+	auto VulkanUploadPool::Allocate(UInt64 size, UInt64 alignment) -> std::optional<AllocationData>
+	{
+		assert(size <= m_blockSize);
+
+		// Try to minimize lost space
+		struct
+		{
+			Block* block = nullptr;
+			UInt64 alignedOffset = 0;
+			UInt64 lostSpace = 0;
+		} bestBlock;
+
+		for (Block& block : m_blocks)
+		{
+			UInt64 alignedOffset = AlignPow2(block.freeOffset, alignment);
+			if (alignedOffset + size > m_blockSize)
+				continue; //< Not enough space
+
+			UInt64 lostSpace = alignedOffset - block.freeOffset;
+
+			if (!bestBlock.block || lostSpace < bestBlock.lostSpace)
+			{
+				bestBlock.block = &block;
+				bestBlock.alignedOffset = alignedOffset;
+				bestBlock.lostSpace = lostSpace;
+			}
+		}
+
+		// No block found, allocate a new one
+		if (!bestBlock.block)
+		{
+			Block newBlock;
+			if (!newBlock.buffer.Create(m_device, 0U, m_blockSize, VK_BUFFER_USAGE_TRANSFER_SRC_BIT))
+			{
+				NazaraError("Failed to create block buffer: " + TranslateVulkanError(newBlock.buffer.GetLastErrorCode()));
+				return {};
+			}
+
+			VkMemoryRequirements requirement = newBlock.buffer.GetMemoryRequirements();
+
+			if (!newBlock.blockMemory.Create(m_device, requirement.size, requirement.memoryTypeBits, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT))
+			{
+				NazaraError("Failed to allocate block memory: " + TranslateVulkanError(newBlock.blockMemory.GetLastErrorCode()));
+				return {};
+			}
+
+			if (!newBlock.buffer.BindBufferMemory(newBlock.blockMemory))
+			{
+				NazaraError("Failed to bind buffer memory: " + TranslateVulkanError(newBlock.buffer.GetLastErrorCode()));
+				return {};
+			}
+
+			if (!newBlock.blockMemory.Map())
+			{
+				NazaraError("Failed to map buffer memory: " + TranslateVulkanError(newBlock.buffer.GetLastErrorCode()));
+				return {};
+			}
+
+			bestBlock.block = &m_blocks.emplace_back(std::move(newBlock));
+			bestBlock.alignedOffset = 0;
+			bestBlock.lostSpace = 0;
+		}
+
+		AllocationData allocationData;
+		allocationData.buffer = bestBlock.block->buffer;
+		allocationData.mappedPtr = static_cast<UInt8*>(bestBlock.block->blockMemory.GetMappedPointer()) + bestBlock.alignedOffset;
+		allocationData.offset = bestBlock.alignedOffset;
+		allocationData.size = size;
+
+		return allocationData;
+	}
+
+	void VulkanUploadPool::Reset()
+	{
+		for (Block& block : m_blocks)
+			block.freeOffset = 0;
+	}
+}