Refactor material shaders generator to use modular features as extensions

Source/Engine/Graphics/Materials/MaterialShaderFeatures.h

@@ -0,0 +1,70 @@
+// Copyright (c) 2012-2021 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#include "MaterialShader.h"
+#include "Engine/Core/Math/Rectangle.h"
+
+// Material shader features are plugin-based functionalities that are reusable between different material domains.
+struct MaterialShaderFeature
+{
+#if USE_EDITOR
+    struct GeneratorData
+    {
+        const Char* Template;
+        int32 ConstantsSize;
+        int32 ResourcesCount;
+    };
+#endif;
+};
+
+// Material shader feature that add support for Forward shading inside the material shader.
+struct ForwardShadingFeature : MaterialShaderFeature
+{
+    enum { MaxLocalLights = 4 };
+
+    enum { SRVs = 3 };
+
+    PACK_STRUCT(struct Data
+        {
+        LightData DirectionalLight;
+        LightShadowData DirectionalLightShadow;
+        LightData SkyLight;
+        ProbeData EnvironmentProbe;
+        ExponentialHeightFogData ExponentialHeightFog;
+        Vector3 Dummy2;
+        uint32 LocalLightsCount;
+        LightData LocalLights[MaxLocalLights];
+        });
+
+    static void Bind(MaterialShader::BindParameters& params, byte*& cb, int32& srv);
+};
+
+// Material shader feature that adds geometry hardware tessellation (using Hull and Domain shaders).
+struct TessellationFeature : MaterialShaderFeature
+{
+    enum { SRVs = 0 };
+
+    static void Bind(MaterialShader::BindParameters& params, byte*& cb, int32& srv)
+    {
+    }
+#if USE_EDITOR
+    static void Generate(GeneratorData& data);
+#endif
+};
+
+// Material shader feature that adds lightmap sampling feature.
+struct LightmapFeature : MaterialShaderFeature
+{
+    enum { SRVs = 3 };
+
+    PACK_STRUCT(struct Data
+        {
+        Rectangle LightmapArea;
+        });
+
+    static bool Bind(MaterialShader::BindParameters& params, byte*& cb, int32& srv);
+#if USE_EDITOR
+    static void Generate(GeneratorData& data);
+#endif
+};