System: Pull screenshot format from path extension

src/core/settings.cpp

@@ -2131,6 +2131,21 @@ const char* Settings::GetDisplayScreenshotFormatExtension(DisplayScreenshotForma
   return s_display_screenshot_format_extensions[static_cast<size_t>(format)];
 }
 
+std::optional<DisplayScreenshotFormat> Settings::GetDisplayScreenshotFormatFromFileName(const std::string_view filename)
+{
+  const std::string_view extension = Path::GetExtension(filename);
+  int index = 0;
+  for (const char* name : s_display_screenshot_format_extensions)
+  {
+    if (StringUtil::EqualNoCase(extension, name))
+      return static_cast<DisplayScreenshotFormat>(index);
+
+    index++;
+  }
+
+  return std::nullopt;
+}
+
 static constexpr const std::array s_memory_card_type_names = {
   "None", "Shared", "PerGame", "PerGameTitle", "PerGameFileTitle", "NonPersistent",
 };

src/core/settings.h

@@ -547,6 +547,7 @@ struct Settings : public GPUSettings
   static const char* GetDisplayScreenshotFormatName(DisplayScreenshotFormat mode);
   static const char* GetDisplayScreenshotFormatDisplayName(DisplayScreenshotFormat mode);
   static const char* GetDisplayScreenshotFormatExtension(DisplayScreenshotFormat mode);
+  static std::optional<DisplayScreenshotFormat> GetDisplayScreenshotFormatFromFileName(const std::string_view filename);
 
   static std::optional<MemoryCardType> ParseMemoryCardTypeName(const char* str);
   static const char* GetMemoryCardTypeName(MemoryCardType type);

src/core/system.cpp

@@ -5277,8 +5277,16 @@ void System::SaveScreenshot(const char* path, DisplayScreenshotMode mode, Displa
     return;
 
   std::string auto_path;
-  if (!path)
+  if (!path || path[0] == '\0')
+  {
     path = (auto_path = GetScreenshotPath(Settings::GetDisplayScreenshotFormatExtension(format))).c_str();
+  }
+  else
+  {
+    // If the user chose a specific format, use that.
+    format =
+      Settings::GetDisplayScreenshotFormatFromFileName(FileSystem::GetDisplayNameFromPath(path)).value_or(format);
+  }
 
   GPUBackend::RenderScreenshotToFile(path, mode, quality, true);
 }