Reimplement custom PNG banners in game list

Fixes https://bugs.dolphin-emu.org/issues/10938
and makes PNG banners available in DolphinQt2 for the first time.

Source/Core/UICommon/GameFile.cpp

@@ -13,6 +13,7 @@
 #include <memory>
 #include <sstream>
 #include <string>
+#include <tuple>
 #include <utility>
 #include <vector>
 
@@ -21,9 +22,11 @@
 #include "Common/CommonTypes.h"
 #include "Common/FileUtil.h"
 #include "Common/Hash.h"
+#include "Common/Image.h"
 #include "Common/IniFile.h"
 #include "Common/NandPaths.h"
 #include "Common/StringUtil.h"
+#include "Common/Swap.h"
 
 #include "Core/Boot/Boot.h"
 #include "Core/ConfigManager.h"
@@ -39,6 +42,16 @@ namespace UICommon
 {
 static const std::string EMPTY_STRING;
 
+bool operator==(const GameBanner& lhs, const GameBanner& rhs)
+{
+  return std::tie(lhs.buffer, lhs.width, lhs.height) == std::tie(rhs.buffer, rhs.width, rhs.height);
+}
+
+bool operator!=(const GameBanner& lhs, const GameBanner& rhs)
+{
+  return !operator==(lhs, rhs);
+}
+
 const std::string& GameFile::Lookup(DiscIO::Language language,
                                     const std::map<DiscIO::Language, std::string>& strings)
 {
@@ -177,6 +190,7 @@ void GameFile::DoState(PointerWrap& p)
   p.Do(m_apploader_date);
 
   m_volume_banner.DoState(p);
+  m_custom_banner.DoState(p);
   p.Do(m_custom_name);
 }
 
@@ -190,7 +204,7 @@ bool GameFile::IsElfOrDol() const
   return name_end == ".elf" || name_end == ".dol";
 }
 
-bool GameFile::BannerChanged()
+bool GameFile::WiiBannerChanged()
 {
   // Wii banners can only be read if there is a save file.
   // In case the cache was created without a save file existing,
@@ -210,11 +224,62 @@ bool GameFile::BannerChanged()
   return !m_pending.volume_banner.buffer.empty();
 }
 
-void GameFile::BannerCommit()
+void GameFile::WiiBannerCommit()
 {
   m_volume_banner = std::move(m_pending.volume_banner);
 }
 
+bool GameFile::ReadPNGBanner(const std::string& path)
+{
+  File::IOFile file(path, "rb");
+  if (!file)
+    return false;
+
+  std::vector<u8> png_data(file.GetSize());
+  if (!file.ReadBytes(png_data.data(), png_data.size()))
+    return false;
+
+  GameBanner& banner = m_pending.custom_banner;
+  std::vector<u8> data_out;
+  if (!Common::LoadPNG(png_data, &data_out, &banner.width, &banner.height))
+    return false;
+
+  // Make an ARGB copy of the RGBA data
+  banner.buffer.resize(data_out.size() / sizeof(u32));
+  for (size_t i = 0; i < banner.buffer.size(); i++)
+  {
+    const size_t j = i * sizeof(u32);
+    banner.buffer[i] = (Common::swap32(data_out.data() + j) >> 8) + (data_out[j] << 24);
+  }
+
+  return true;
+}
+
+bool GameFile::CustomBannerChanged()
+{
+  std::string path, name;
+  SplitPath(m_file_path, &path, &name, nullptr);
+
+  // This icon naming format is intended as an alternative to Homebrew Channel icons
+  // for those who don't want to have a Homebrew Channel style folder structure.
+  if (!ReadPNGBanner(path + name + ".png"))
+  {
+    // Homebrew Channel icon naming. Typical for DOLs and ELFs, but we also support it for volumes.
+    if (!ReadPNGBanner(path + "icon.png"))
+    {
+      // If no custom icon is found, go back to the non-custom one.
+      m_pending.custom_banner = {};
+    }
+  }
+
+  return m_pending.custom_banner != m_custom_banner;
+}
+
+void GameFile::CustomBannerCommit()
+{
+  m_custom_banner = std::move(m_pending.custom_banner);
+}
+
 const std::string& GameFile::GetName(bool long_name) const
 {
   if (!m_custom_name.empty())
@@ -287,4 +352,9 @@ std::string GameFile::GetWiiFSPath() const
   return Common::GetTitleDataPath(m_title_id, Common::FROM_CONFIGURED_ROOT);
 }
 
+const GameBanner& GameFile::GetBannerImage() const
+{
+  return m_custom_banner.empty() ? m_volume_banner : m_custom_banner;
+}
+
 }  // namespace UICommon