Add a delay before automatically switching discs

Some games don't behave as expected if we eject the disc as soon as
we receive the DVDLowStopMotor command. For instance, Baten Kaitos
never shows the prompt to switch discs or the "Reading disc..." text
(but works correctly other than that).

1 files changed, 19 insertions, 7 deletions

diff --git a/Source/Core/Core/HW/DVD/DVDInterface.cpp b/Source/Core/Core/HW/DVD/DVDInterface.cpp
index f83aa54bbc..599620a9c7 100644
--- a/Source/Core/Core/HW/DVD/DVDInterface.cpp
+++ b/Source/Core/Core/HW/DVD/DVDInterface.cpp
@@ -240,9 +240,11 @@ static size_t s_auto_disc_change_index;
 
 // Events
 static CoreTiming::EventType* s_finish_executing_command;
+static CoreTiming::EventType* s_auto_change_disc;
 static CoreTiming::EventType* s_eject_disc;
 static CoreTiming::EventType* s_insert_disc;
 
+static void AutoChangeDiscCallback(u64 userdata, s64 cyclesLate);
 static void EjectDiscCallback(u64 userdata, s64 cyclesLate);
 static void InsertDiscCallback(u64 userdata, s64 cyclesLate);
 static void FinishExecutingCommandCallback(u64 userdata, s64 cycles_late);
@@ -398,6 +400,7 @@ void Init()
   Reset();
   s_DICVR.Hex = 1;  // Disc Channel relies on cover being open when no disc is inserted
 
+  s_auto_change_disc = CoreTiming::RegisterEvent("AutoChangeDisc", AutoChangeDiscCallback);
   s_eject_disc = CoreTiming::RegisterEvent("EjectDisc", EjectDiscCallback);
   s_insert_disc = CoreTiming::RegisterEvent("InsertDisc", InsertDiscCallback);
 
@@ -471,6 +474,11 @@ bool IsDiscInside()
   return DVDThread::HasDisc();
 }
 
+static void AutoChangeDiscCallback(u64 userdata, s64 cyclesLate)
+{
+  AutoChangeDisc();
+}
+
 static void EjectDiscCallback(u64 userdata, s64 cyclesLate)
 {
   SetDisc(nullptr, {});
@@ -1039,15 +1047,19 @@ void ExecuteCommand(u32 command_0, u32 command_1, u32 command_2, u32 output_addr
     INFO_LOG(DVDINTERFACE, "DVDLowStopMotor %s %s", command_1 ? "eject" : "",
              command_2 ? "kill!" : "");
 
-    bool auto_disc_change = Config::Get(Config::MAIN_AUTO_DISC_CHANGE) &&
-                            !Movie::IsPlayingInput() && DVDThread::IsInsertedDiscRunning();
-    if (auto_disc_change)
-      auto_disc_change = AutoChangeDisc();
-    if (auto_disc_change)
-      OSD::AddMessage("Changing discs automatically...", OSD::Duration::NORMAL);
+    const bool force_eject = command_1 && !command_2;
 
-    if (!auto_disc_change && command_1 && !command_2)
+    if (Config::Get(Config::MAIN_AUTO_DISC_CHANGE) && !Movie::IsPlayingInput() &&
+        DVDThread::IsInsertedDiscRunning() && !s_auto_disc_change_paths.empty())
+    {
+      CoreTiming::ScheduleEvent(force_eject ? 0 : SystemTimers::GetTicksPerSecond() / 2,
+                                s_auto_change_disc);
+      OSD::AddMessage("Changing discs automatically...", OSD::Duration::NORMAL);
+    }
+    else if (force_eject)
+    {
       EjectDiscCallback(0, 0);
+    }
     break;
   }