1 files changed, 82 insertions, 0 deletions
diff --git a/Source/Core/VideoCommon/Assets/CustomAssetLibrary.cpp b/Source/Core/VideoCommon/Assets/CustomAssetLibrary.cpp
new file mode 100644
index 0000000000..062f5801e1
--- /dev/null
+++ b/Source/Core/VideoCommon/Assets/CustomAssetLibrary.cpp
@@ -0,0 +1,82 @@
+// Copyright 2023 Dolphin Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "VideoCommon/Assets/CustomAssetLibrary.h"
+
+#include <algorithm>
+
+#include "Common/Logging/Log.h"
+#include "VideoCommon/GraphicsModSystem/Runtime/CustomTextureData.h"
+
+namespace VideoCommon
+{
+namespace
+{
+std::size_t GetAssetSize(const CustomTextureData& data)
+{
+  std::size_t total = 0;
+  for (const auto& level : data.m_levels)
+  {
+    total += level.data.size();
+  }
+  return total;
+}
+}  // namespace
+CustomAssetLibrary::LoadInfo CustomAssetLibrary::LoadGameTexture(const AssetID& asset_id,
+                                                                 CustomTextureData* data)
+{
+  const auto load_info = LoadTexture(asset_id, data);
+  if (load_info.m_bytes_loaded == 0)
+    return {};
+
+  // Note: 'LoadTexture()' ensures we have a level loaded
+  const auto& first_mip = data->m_levels[0];
+
+  // Verify that each mip level is the correct size (divide by 2 each time).
+  u32 current_mip_width = first_mip.width;
+  u32 current_mip_height = first_mip.height;
+  for (u32 mip_level = 1; mip_level < static_cast<u32>(data->m_levels.size()); mip_level++)
+  {
+    if (current_mip_width != 1 || current_mip_height != 1)
+    {
+      current_mip_width = std::max(current_mip_width / 2, 1u);
+      current_mip_height = std::max(current_mip_height / 2, 1u);
+
+      const VideoCommon::CustomTextureData::Level& level = data->m_levels[mip_level];
+      if (current_mip_width == level.width && current_mip_height == level.height)
+        continue;
+
+      ERROR_LOG_FMT(VIDEO,
+                    "Invalid custom game texture size {}x{} for texture asset {}. Mipmap level {} "
+                    "must be {}x{}.",
+                    level.width, level.height, asset_id, mip_level, current_mip_width,
+                    current_mip_height);
+    }
+    else
+    {
+      // It is invalid to have more than a single 1x1 mipmap.
+      ERROR_LOG_FMT(VIDEO,
+                    "Custom game texture {} has too many 1x1 mipmaps. Skipping extra levels.",
+                    asset_id);
+    }
+
+    // Drop this mip level and any others after it.
+    while (data->m_levels.size() > mip_level)
+      data->m_levels.pop_back();
+  }
+
+  // All levels have to have the same format.
+  if (std::any_of(data->m_levels.begin(), data->m_levels.end(),
+                  [&first_mip](const VideoCommon::CustomTextureData::Level& l) {
+                    return l.format != first_mip.format;
+                  }))
+  {
+    ERROR_LOG_FMT(VIDEO, "Custom game texture {} has inconsistent formats across mip levels.",
+                  asset_id);
+
+    return {};
+  }
+
+  return load_info;
+}
+}  // namespace VideoCommon