VideoCommon: add material asset. A material is similar to other graphics engines where it provides data to be used in conjunction with a shader asset to generate a runtime AbstractShader

Source/Core/VideoCommon/Assets/MaterialAsset.h

@@ -0,0 +1,61 @@
+// Copyright 2023 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <optional>
+#include <string>
+#include <variant>
+#include <vector>
+
+#include <picojson.h>
+
+#include "Common/CommonTypes.h"
+#include "Common/EnumFormatter.h"
+#include "VideoCommon/Assets/CustomAsset.h"
+
+namespace VideoCommon
+{
+struct MaterialProperty
+{
+  using Value = std::variant<std::string>;
+  enum class Type
+  {
+    Type_Undefined,
+    Type_TextureAsset,
+    Type_Max = Type_TextureAsset
+  };
+  std::string m_code_name;
+  Type m_type = Type::Type_Undefined;
+  std::optional<Value> m_value;
+};
+
+struct MaterialData
+{
+  static bool FromJson(const CustomAssetLibrary::AssetID& asset_id, const picojson::object& json,
+                       MaterialData* data);
+  std::string shader_asset;
+  std::vector<MaterialProperty> properties;
+};
+
+// Much like Unity and Unreal materials, a Dolphin material does very little on its own
+// Its sole purpose is to provide data (through properties) that are used in conjunction
+// with a shader asset that is provided by name.  It is up to user of this asset to
+// use the two together to create the relevant runtime data
+class MaterialAsset final : public CustomLoadableAsset<MaterialData>
+{
+public:
+  using CustomLoadableAsset::CustomLoadableAsset;
+
+private:
+  CustomAssetLibrary::LoadInfo LoadImpl(const CustomAssetLibrary::AssetID& asset_id) override;
+};
+
+}  // namespace VideoCommon
+
+template <>
+struct fmt::formatter<VideoCommon::MaterialProperty::Type>
+    : EnumFormatter<VideoCommon::MaterialProperty::Type::Type_Max>
+{
+  constexpr formatter() : EnumFormatter({"Undefined", "Texture"}) {}
+};