Graphics/RenderSystem: Add support for external swapchains

include/Nazara/Graphics/Systems/RenderSystem.hpp

@@ -41,8 +41,13 @@ namespace Nz
 			RenderSystem(RenderSystem&&) = delete;
 			~RenderSystem();
 
+			inline void AttachExternalSwapchain(WindowSwapchain& swapchain);
+
 			WindowSwapchain& CreateSwapchain(Window& window, const SwapchainParameters& parameters = SwapchainParameters{});
 
+			void DestroySwapchain(WindowSwapchain& swapchain);
+			inline void DetachExternalSwapchain(WindowSwapchain& swapchain);
+
 			inline FramePipeline& GetFramePipeline();
 			inline const FramePipeline& GetFramePipeline() const;
 
@@ -136,6 +141,7 @@ namespace Nz
 			std::unordered_map<entt::entity, GraphicsEntity*> m_graphicsEntities;
 			std::unordered_map<entt::entity, LightEntity*> m_lightEntities;
 			std::unordered_map<Skeleton*, SharedSkeleton> m_sharedSkeletonInstances;
+			std::vector<std::reference_wrapper<WindowSwapchain>> m_externalSwapchains;
 			std::vector<std::unique_ptr<WindowSwapchain>> m_windowSwapchains;
 			ElementRendererRegistry m_elementRegistry;
 			MemoryPool<CameraEntity> m_cameraEntityPool;

include/Nazara/Graphics/Systems/RenderSystem.inl

@@ -2,11 +2,23 @@
 // This file is part of the "Nazara Engine - Graphics module"
 // For conditions of distribution and use, see copyright notice in Config.hpp
 
-#include <type_traits>
+#include <Nazara/Core/Error.hpp>
 #include <Nazara/Graphics/Debug.hpp>
 
 namespace Nz
 {
+	inline void RenderSystem::AttachExternalSwapchain(WindowSwapchain& swapchain)
+	{
+		m_windowSwapchains.emplace_back(&swapchain);
+	}
+
+	inline void RenderSystem::DetachExternalSwapchain(WindowSwapchain& swapchain)
+	{
+		auto it = std::find_if(m_externalSwapchains.begin(), m_externalSwapchains.end(), [&](WindowSwapchain& externalSwapchain) { return &externalSwapchain == &swapchain; });
+		NazaraAssert(it != m_externalSwapchains.end(), "external swapchain is not part of this render system");
+		m_externalSwapchains.erase(it);
+	}
+
 	inline FramePipeline& RenderSystem::GetFramePipeline()
 	{
 		return *m_pipeline;
@@ -19,3 +31,4 @@ namespace Nz
 }
 
 #include <Nazara/Graphics/DebugOff.hpp>
+

src/Nazara/Graphics/Systems/RenderSystem.cpp

@@ -55,22 +55,36 @@ namespace Nz
 		return *m_windowSwapchains.emplace_back(std::make_unique<WindowSwapchain>(Graphics::Instance()->GetRenderDevice(), window, parameters));
 	}
 
+	void RenderSystem::DestroySwapchain(WindowSwapchain& swapchain)
+	{
+		auto it = std::find_if(m_windowSwapchains.begin(), m_windowSwapchains.end(), [&](const auto& ptr) { return ptr.get() == &swapchain; });
+		NazaraAssert(it != m_windowSwapchains.end(), "invalid swapchain");
+
+		m_windowSwapchains.erase(it);
+	}
+
 	void RenderSystem::Update(Time /*elapsedTime*/)
 	{
 		UpdateObservers();
 		UpdateInstances();
 
-		for (auto& swapchainPtr : m_windowSwapchains)
+		auto HandleSwapchain = [&](WindowSwapchain& swapchain)
 		{
-			RenderFrame frame = swapchainPtr->AcquireFrame();
+			RenderFrame frame = swapchain.AcquireFrame();
 			if (!frame)
-				continue;
+				return;
 
 			if (!m_cameraEntities.empty())
 				m_pipeline->Render(frame);
 
 			frame.Present();
-		}
+		};
+
+		for (auto& swapchainPtr : m_windowSwapchains)
+			HandleSwapchain(*swapchainPtr);
+
+		for (WindowSwapchain& swapchain : m_externalSwapchains)
+			HandleSwapchain(swapchain);
 	}
 
 	void RenderSystem::OnCameraDestroy([[maybe_unused]] entt::registry& registry, entt::entity entity)