Renderer: Refactor transient resources (allow access at any time)

include/Nazara/Renderer/TransientResources.inl

@@ -0,0 +1,100 @@
+// Copyright (C) 2023 Jérôme "Lynix" Leclercq (lynix680@gmail.com)
+// This file is part of the "Nazara Engine - Renderer module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <NazaraUtils/Algorithm.hpp>
+#include <NazaraUtils/MemoryHelper.hpp>
+#include <Nazara/Renderer/Debug.hpp>
+
+namespace Nz
+{
+	inline void TransientResources::FlushReleaseQueue()
+	{
+		for (Releasable* releasable : m_releaseQueue)
+		{
+			releasable->Release();
+			PlacementDestroy(releasable);
+		}
+		m_releaseQueue.clear();
+
+		for (auto& memoryblock : m_releaseMemoryPool)
+			memoryblock.clear();
+	}
+
+	template<typename T>
+	void TransientResources::PushForRelease(T&& value)
+	{
+		static_assert(std::is_rvalue_reference_v<decltype(value)>);
+
+		return PushReleaseCallback([v = std::move(value)] {});
+	}
+
+	template<typename F>
+	void TransientResources::PushReleaseCallback(F&& callback)
+	{
+		using Functor = ReleasableLambda<std::remove_cv_t<std::remove_reference_t<F>>>;
+
+		constexpr std::size_t functorSize = sizeof(Functor);
+		constexpr std::size_t functorAlignment = alignof(Functor);
+
+		// Try to minimize lost space
+		struct
+		{
+			Block* block = nullptr;
+			UInt64 alignedOffset = 0;
+			UInt64 lostSpace = 0;
+		} bestBlock;
+
+		for (Block& block : m_releaseMemoryPool)
+		{
+			std::size_t freeOffset = block.size();
+
+			UInt64 alignedOffset = Align(freeOffset, functorAlignment);
+			if (alignedOffset + functorSize > block.capacity())
+				continue; //< Not enough space
+
+			UInt64 lostSpace = alignedOffset - 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;
+			newBlock.reserve(BlockSize);
+
+			bestBlock.block = &m_releaseMemoryPool.emplace_back(std::move(newBlock));
+			bestBlock.alignedOffset = 0;
+			bestBlock.lostSpace = 0;
+		}
+
+		Block& targetBlock = *bestBlock.block;
+		targetBlock.resize(bestBlock.alignedOffset + functorSize);
+
+		Functor* releasable = reinterpret_cast<Functor*>(&targetBlock[bestBlock.alignedOffset]);
+		PlacementNew(releasable, std::forward<F>(callback));
+
+		m_releaseQueue.push_back(releasable);
+	}
+
+	template<typename T>
+	template<typename U>
+	TransientResources::ReleasableLambda<T>::ReleasableLambda(U&& lambda) :
+	m_lambda(std::forward<U>(lambda))
+	{
+	}
+
+	template<typename T>
+	void TransientResources::ReleasableLambda<T>::Release()
+	{
+		m_lambda();
+	}
+}
+
+#include <Nazara/Renderer/DebugOff.hpp>