VideoCommon: move custom texture data to assets

Source/Core/VideoCommon/Assets/CustomTextureData.h

@@ -0,0 +1,32 @@
+// Copyright 2023 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "Common/CommonTypes.h"
+#include "VideoCommon/TextureConfig.h"
+
+namespace VideoCommon
+{
+class CustomTextureData
+{
+public:
+  struct Level
+  {
+    std::vector<u8> data;
+    AbstractTextureFormat format = AbstractTextureFormat::RGBA8;
+    u32 width = 0;
+    u32 height = 0;
+    u32 row_length = 0;
+  };
+  std::vector<Level> m_levels;
+};
+
+bool LoadDDSTexture(CustomTextureData* texture, const std::string& filename);
+bool LoadDDSTexture(CustomTextureData::Level* level, const std::string& filename, u32 mip_level);
+bool LoadPNGTexture(CustomTextureData* texture, const std::string& filename);
+bool LoadPNGTexture(CustomTextureData::Level* level, const std::string& filename);
+}  // namespace VideoCommon