GameSettings: Add disallow force NTSC timings trait

src/frontend-common/game_settings.cpp

@@ -25,6 +25,7 @@ std::array<std::pair<const char*, const char*>, static_cast<u32>(Trait::Count)>
   {"DisableTrueColor", TRANSLATABLE("GameSettingsTrait", "Disable True Color")},
   {"DisableUpscaling", TRANSLATABLE("GameSettingsTrait", "Disable Upscaling")},
   {"DisableScaledDithering", TRANSLATABLE("GameSettingsTrait", "Disable Scaled Dithering")},
+  {"DisableForceNTSCTimings", TRANSLATABLE("GameSettingsTrait", "Disallow Forcing NTSC Timings")},
   {"DisableWidescreen", TRANSLATABLE("GameSettingsTrait", "Disable Widescreen")},
   {"DisablePGXP", TRANSLATABLE("GameSettingsTrait", "Disable PGXP")},
   {"DisablePGXPCulling", TRANSLATABLE("GameSettingsTrait", "Disable PGXP Culling")},
@@ -517,6 +518,18 @@ void Entry::ApplySettings(bool display_osd_messages) const
     g_settings.gpu_widescreen_hack = false;
   }
 
+  if (HasTrait(Trait::DisableForceNTSCTimings))
+  {
+    if (display_osd_messages && g_settings.gpu_force_ntsc_timings)
+    {
+      g_host_interface->AddOSDMessage(
+        g_host_interface->TranslateStdString("OSDMessage", "Forcing NTSC Timings disallowed by game settings."),
+        osd_duration);
+    }
+
+    g_settings.gpu_force_ntsc_timings = false;
+  }
+
   if (HasTrait(Trait::DisablePGXP))
   {
     if (display_osd_messages && g_settings.gpu_pgxp_enable)

src/frontend-common/game_settings.h

@@ -16,6 +16,7 @@ enum class Trait : u32
   DisableTrueColor,
   DisableUpscaling,
   DisableScaledDithering,
+  DisableForceNTSCTimings,
   DisableWidescreen,
   DisablePGXP,
   DisablePGXPCulling,