Graphics: Rework shadowing (add cascaded shadow mapping)

- Add support for per-viewer shadows
- Add cascaded shadow mapping for directional lights (wip)
- Rework the way lights are sent to the shaders (they are now selected once per viewer)
- Fixes PointLight shadow mapping (using a dedicated pass)
- Lights out of frustum for every viewers are no longer processed (wip)

include/Nazara/Graphics/DirectionalLightShadowData.hpp

@@ -0,0 +1,94 @@
+// Copyright (C) 2023 Jérôme "Lynix" Leclercq (lynix680@gmail.com)
+// This file is part of the "Nazara Engine - Graphics module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#pragma once
+
+#ifndef NAZARA_GRAPHICS_DIRECTIONALLIGHTSHADOWDATA_HPP
+#define NAZARA_GRAPHICS_DIRECTIONALLIGHTSHADOWDATA_HPP
+
+#include <NazaraUtils/Prerequisites.hpp>
+#include <Nazara/Graphics/Config.hpp>
+#include <Nazara/Graphics/DepthPipelinePass.hpp>
+#include <Nazara/Graphics/Light.hpp>
+#include <Nazara/Graphics/LightShadowData.hpp>
+#include <Nazara/Graphics/ShadowViewer.hpp>
+#include <NazaraUtils/FixedVector.hpp>
+#include <NazaraUtils/SparsePtr.hpp>
+#include <unordered_map>
+
+namespace Nz
+{
+	class FramePipeline;
+	class DirectionalLight;
+
+	class NAZARA_GRAPHICS_API DirectionalLightShadowData : public LightShadowData
+	{
+		public:
+			DirectionalLightShadowData(FramePipeline& pipeline, ElementRendererRegistry& elementRegistry, const DirectionalLight& light, std::size_t cascadeCount);
+			DirectionalLightShadowData(const DirectionalLightShadowData&) = delete;
+			DirectionalLightShadowData(DirectionalLightShadowData&&) = delete;
+			~DirectionalLightShadowData() = default;
+
+			inline void EnableShadowStabilization(bool enable);
+
+			inline std::size_t GetCascadeCount() const;
+			inline void GetCascadeData(const AbstractViewer* viewer, SparsePtr<float> distance, SparsePtr<Matrix4f> viewProjMatrix) const;
+
+			inline bool IsShadowStabilization() const;
+
+			void PrepareRendering(RenderFrame& renderFrame, const AbstractViewer* viewer) override;
+
+			void RegisterMaterialInstance(const MaterialInstance& matInstance) override;
+			void RegisterPassInputs(FramePass& pass, const AbstractViewer* viewer) override;
+			void RegisterToFrameGraph(FrameGraph& frameGraph, const AbstractViewer* viewer) override;
+			void RegisterViewer(const AbstractViewer* viewer) override;
+
+			const Texture* RetrieveLightShadowmap(const BakedFrameGraph& bakedGraph, const AbstractViewer* viewer) const override;
+
+			void UnregisterMaterialInstance(const MaterialInstance& matInstance) override;
+			void UnregisterViewer(const AbstractViewer* viewer) override;
+
+			DirectionalLightShadowData& operator=(const DirectionalLightShadowData&) = delete;
+			DirectionalLightShadowData& operator=(DirectionalLightShadowData&&) = delete;
+
+		private:
+			struct CascadeData;
+
+			template<typename F> void ForEachCascade(F&& callback);
+
+			void ComputeLightView(CascadeData& cascade, const Frustumf& cascadeFrustum, float cascadeDist);
+			void StabilizeShadows(CascadeData& cascade);
+
+			NazaraSlot(Light, OnLightShadowMapSettingChange, m_onLightShadowMapSettingChange);
+			NazaraSlot(Light, OnLightTransformInvalided, m_onLightTransformInvalidated);
+
+			struct CascadeData
+			{
+				std::optional<DepthPipelinePass> depthPass;
+				std::size_t attachmentIndex;
+				Matrix4f viewProjMatrix;
+				ShadowViewer viewer;
+				float distance;
+			};
+
+			struct PerViewerData
+			{
+				FixedVector<CascadeData, 8> cascades;
+				std::size_t textureArrayAttachmentIndex;
+			};
+
+			std::size_t m_cascadeCount;
+			std::unordered_map<const AbstractViewer*, std::unique_ptr<PerViewerData>> m_viewerData;
+			ElementRendererRegistry& m_elementRegistry;
+			FramePipeline& m_pipeline;
+			const DirectionalLight& m_light;
+			bool m_isShadowStabilizationEnabled;
+			float m_invTexelScale;
+			float m_texelScale;
+	};
+}
+
+#include <Nazara/Graphics/DirectionalLightShadowData.inl>
+
+#endif // NAZARA_GRAPHICS_DIRECTIONALLIGHTSHADOWDATA_HPP