Graphics: Add support for multi-viewer rendering (a bit hacky)

examples/DeferredShading/main.cpp

@@ -789,7 +789,7 @@ int main()
 		bloomBlendPass.AddInput(bloomTextureB);
 		bloomBlendPass.AddOutput(backbuffer);
 
-		graph.SetBackbufferOutput(backbuffer);
+		graph.AddBackbufferOutput(backbuffer);
 
 		return graph.Bake();
 	}();

examples/PhysicsDemo/main.cpp

@@ -158,9 +158,12 @@ int main()
 
 	entt::entity text2D = registry.create();
 	{
+		std::shared_ptr<Nz::TextSprite> sprite2D = std::make_shared<Nz::TextSprite>(spriteMaterial);
+		sprite2D->Update(Nz::SimpleTextDrawer::Draw("Voix ambiguë d'un cœur qui, au zéphyr, préfère les jattes de kiwis", 72));
+
 		registry.emplace<Nz::NodeComponent>(text2D).SetPosition(Nz::Vector3f(0.f, 200.f, 0.f));
 		auto& gfxComponent = registry.emplace<Nz::GraphicsComponent>(text2D);
-		gfxComponent.AttachRenderable(sprite, 2);
+		gfxComponent.AttachRenderable(sprite2D, 2);
 	}
 
 	entt::entity viewer = registry.create();
@@ -254,7 +257,7 @@ int main()
 	Nz::Clock secondClock;
 	unsigned int fps = 0;
 
-	//Nz::Mouse::SetRelativeMouseMode(true);
+	Nz::Mouse::SetRelativeMouseMode(true);
 
 	float elapsedTime = 0.f;
 	Nz::UInt64 time = Nz::GetElapsedMicroseconds();

include/Nazara/Graphics/ForwardFramePipeline.hpp

@@ -26,6 +26,7 @@
 namespace Nz
 {
 	class RenderFrame;
+	class RenderTarget;
 
 	class NAZARA_GRAPHICS_API ForwardFramePipeline : public FramePipeline
 	{
@@ -99,6 +100,7 @@ namespace Nz
 			std::unordered_map<AbstractViewer*, ViewerData> m_viewers;
 			std::unordered_map<MaterialPass*, MaterialData> m_materials;
 			std::unordered_map<WorldInstancePtr, std::unordered_map<const InstancedRenderable*, RenderableData>> m_renderables;
+			std::unordered_map<const RenderTarget*, std::vector<const ViewerData*>> m_viewerPerTarget;
 			std::unordered_set<AbstractViewer*> m_invalidatedViewerInstances;
 			std::unordered_set<MaterialPass*> m_invalidatedMaterials;
 			std::unordered_set<WorldInstance*> m_invalidatedWorldInstances;

include/Nazara/Graphics/FrameGraph.hpp

@@ -31,12 +31,11 @@ namespace Nz
 			~FrameGraph() = default;
 
 			inline std::size_t AddAttachment(FramePassAttachment attachment);
+			inline void AddBackbufferOutput(std::size_t backbufferOutput);
 			inline FramePass& AddPass(std::string name);
 
 			BakedFrameGraph Bake();
 
-			inline void SetBackbufferOutput(std::size_t backbufferOutput);
-
 			FrameGraph& operator=(const FrameGraph&) = delete;
 			FrameGraph& operator=(FrameGraph&&) noexcept = default;
 
@@ -86,7 +85,6 @@ namespace Nz
 
 			struct WorkData
 			{
-				std::size_t backbufferResourceIndex;
 				std::vector<std::shared_ptr<RenderPass>> renderPasses;
 				std::vector<PhysicalPassData> physicalPasses;
 				std::vector<TextureData> textures;
@@ -109,7 +107,7 @@ namespace Nz
 			void ReorderPasses();
 			void TraverseGraph(std::size_t passIndex);
 
-			std::optional<std::size_t> m_backbufferOutput;
+			std::vector<std::size_t> m_backbufferOutputs;
 			std::vector<FramePass> m_framePasses;
 			std::vector<FramePassAttachment> m_attachments;
 			WorkData m_pending;

include/Nazara/Graphics/FrameGraph.inl

@@ -16,16 +16,16 @@ namespace Nz
 		return id;
 	}
 
+	inline void FrameGraph::AddBackbufferOutput(std::size_t backbufferOutput)
+	{
+		m_backbufferOutputs.push_back(backbufferOutput);
+	}
+
 	inline FramePass& FrameGraph::AddPass(std::string name)
 	{
 		std::size_t id = m_framePasses.size();
 		return m_framePasses.emplace_back(*this, id, std::move(name));
 	}
-
-	inline void FrameGraph::SetBackbufferOutput(std::size_t backbufferOutput)
-	{
-		m_backbufferOutput = backbufferOutput;
-	}
 }
 
 #include <Nazara/Graphics/DebugOff.hpp>

src/Nazara/Graphics/ForwardFramePipeline.cpp

@@ -136,8 +136,6 @@ namespace Nz
 		// Update UBOs and materials
 		UploadPool& uploadPool = renderFrame.GetUploadPool();
 
-		bool prepare = false;
-
 		renderFrame.Execute([&](CommandBufferBuilder& builder)
 		{
 			builder.BeginDebugRegion("UBO Update", Color::Yellow);
@@ -336,6 +334,7 @@ namespace Nz
 		m_bakedFrameGraph.Execute(renderFrame);
 		m_rebuildFrameGraph = false;
 
+		m_viewerPerTarget.clear();
 		const Vector2ui& frameSize = renderFrame.GetSize();
 		for (auto&& [viewer, viewerData] : m_viewers)
 		{
@@ -344,13 +343,25 @@ namespace Nz
 			viewerData.prepare = false;
 
 			const RenderTarget& renderTarget = viewer->GetRenderTarget();
+
+			m_viewerPerTarget[&renderTarget].push_back(&viewerData);
+		}
+
+		for (auto&& [renderTargetPtr, viewerDataVec] : m_viewerPerTarget)
+		{
 			Recti renderRegion(0, 0, frameSize.x, frameSize.y);
-			const ShaderBindingPtr& blitShaderBinding = viewerData.blitShaderBinding;
+
-			const std::shared_ptr<Texture>& sourceTexture = m_bakedFrameGraph.GetAttachmentTexture(viewerData.colorAttachment);
+			const RenderTarget& renderTarget = *renderTargetPtr;
+			const auto& viewers = viewerDataVec;
 
 			renderFrame.Execute([&](CommandBufferBuilder& builder)
 			{
-				builder.TextureBarrier(PipelineStage::ColorOutput, PipelineStage::FragmentShader, MemoryAccess::ColorWrite, MemoryAccess::ShaderRead, TextureLayout::ColorOutput, TextureLayout::ColorInput, *sourceTexture);
+				for (const ViewerData* viewerData : viewers)
+				{
+					const std::shared_ptr<Texture>& sourceTexture = m_bakedFrameGraph.GetAttachmentTexture(viewerData->colorAttachment);
+
+					builder.TextureBarrier(PipelineStage::ColorOutput, PipelineStage::FragmentShader, MemoryAccess::ColorWrite, MemoryAccess::ShaderRead, TextureLayout::ColorOutput, TextureLayout::ColorInput, *sourceTexture);
+				}
 
 				std::array<CommandBufferBuilder::ClearValues, 2> clearValues;
 				clearValues[0].color = Color::Black;
@@ -363,12 +374,16 @@ namespace Nz
 					{
 						builder.SetScissor(renderRegion);
 						builder.SetViewport(renderRegion);
-
 						builder.BindPipeline(*graphics->GetBlitPipeline());
 						builder.BindVertexBuffer(0, *graphics->GetFullscreenVertexBuffer());
-						builder.BindShaderBinding(0, *blitShaderBinding);
 
-						builder.Draw(3);
+						for (const ViewerData* viewerData : viewers)
+						{
+							const ShaderBindingPtr& blitShaderBinding = viewerData->blitShaderBinding;
+
+							builder.BindShaderBinding(0, *blitShaderBinding);
+							builder.Draw(3);
+						}
 					}
 					builder.EndDebugRegion();
 				}
@@ -503,9 +518,8 @@ namespace Nz
 			});
 		}
 
-		//FIXME: This doesn't handle multiple window viewers
 		for (auto&& [viewer, viewerData] : m_viewers)
-			frameGraph.SetBackbufferOutput(viewerData.colorAttachment);
+			frameGraph.AddBackbufferOutput(viewerData.colorAttachment);
 
 		return frameGraph.Bake();
 	}

src/Nazara/Graphics/FrameGraph.cpp

@@ -33,7 +33,7 @@ namespace Nz
 
 	BakedFrameGraph FrameGraph::Bake()
 	{
-		if (!m_backbufferOutput.has_value())
+		if (m_backbufferOutputs.empty())
 			throw std::runtime_error("no backbuffer output has been set");
 
 		m_pending.attachmentReadList.clear();
@@ -46,17 +46,18 @@ namespace Nz
 		m_pending.renderPasses.clear();
 		m_pending.textures.clear();
 
-		m_pending.backbufferResourceIndex = m_backbufferOutput.value();
-
 		BuildReadWriteList();
 
-		auto it = m_pending.attachmentWriteList.find(m_pending.backbufferResourceIndex);
+		for (std::size_t output : m_backbufferOutputs)
-		if (it == m_pending.attachmentWriteList.end())
+		{
-			throw std::runtime_error("no pass writes to backbuffer");
+			auto it = m_pending.attachmentWriteList.find(output);
+			if (it == m_pending.attachmentWriteList.end())
+				throw std::runtime_error("no pass writes to backbuffer");
 
-		const std::vector<std::size_t>& backbufferPasses = it->second;
+			const std::vector<std::size_t>& backbufferPasses = it->second;
-		for (std::size_t passIndex : backbufferPasses)
+			for (std::size_t passIndex : backbufferPasses)
-			TraverseGraph(passIndex);
+				TraverseGraph(passIndex);
+		}
 
 		std::reverse(m_pending.passList.begin(), m_pending.passList.end());
 
@@ -88,8 +89,22 @@ namespace Nz
 				bakedSubpass.commandCallback = framePass.GetCommandCallback();
 
 				for (const auto& output : framePass.GetOutputs())
+				{
 					bakedPass.outputTextureIndices.push_back(Retrieve(m_pending.attachmentToTextures, output.attachmentId));
 
+					auto& clearValues = bakedPass.outputClearValues.emplace_back();
+					if (output.clearColor)
+						clearValues.color = *output.clearColor;
+				}
+
+				// Add depth-stencil clear values
+				auto& dsClearValues = bakedPass.outputClearValues.emplace_back();
+				if (const auto& depthStencilClear = framePass.GetDepthStencilClear())
+				{
+					dsClearValues.depth = depthStencilClear->depth;
+					dsClearValues.stencil = depthStencilClear->stencil;
+				}
+
 				std::size_t attachmentId;
 				if (attachmentId = framePass.GetDepthStencilOutput(); attachmentId != FramePass::InvalidAttachmentId)
 					bakedPass.outputTextureIndices.push_back(Retrieve(m_pending.attachmentToTextures, attachmentId));
@@ -228,12 +243,14 @@ namespace Nz
 		}
 
 		// Add TextureUsage::Sampled to backbuffer output
+		for (std::size_t output : m_backbufferOutputs)
+		{
+			auto it = m_pending.attachmentToTextures.find(output);
+			assert(it != m_pending.attachmentToTextures.end());
 
-		auto it = m_pending.attachmentToTextures.find(m_pending.backbufferResourceIndex);
+			auto& backbufferTexture = m_pending.textures[it->second];
-		assert(it != m_pending.attachmentToTextures.end());
+			backbufferTexture.usage |= TextureUsage::ShaderSampling;
-
+		}
-		auto& backbufferTexture = m_pending.textures[it->second];
-		backbufferTexture.usage |= TextureUsage::ShaderSampling;
 	}
 
 	void FrameGraph::BuildBarriers()

src/Nazara/Graphics/Graphics.cpp

@@ -163,6 +163,16 @@ namespace Nz
 			throw std::runtime_error("failed to instantiate blit shader");
 
 		RenderPipelineInfo pipelineInfo;
+
+		// Alpha blending
+		pipelineInfo.blending = true;
+		pipelineInfo.blend.modeColor = BlendEquation::Add;
+		pipelineInfo.blend.modeAlpha = BlendEquation::Add;
+		pipelineInfo.blend.srcColor = BlendFunc::One;
+		pipelineInfo.blend.dstColor = BlendFunc::One;
+		pipelineInfo.blend.srcAlpha = BlendFunc::One;
+		pipelineInfo.blend.dstAlpha = BlendFunc::One;
+
 		pipelineInfo.pipelineLayout = m_blitPipelineLayout;
 		pipelineInfo.shaderModules.push_back(std::move(blitShader));
 		pipelineInfo.vertexBuffers.assign({