HW/GBACore: Expose the ability to run for a single frame.

2 files changed, 35 insertions, 15 deletions

diff --git a/Source/Core/Core/HW/GBACore.cpp b/Source/Core/Core/HW/GBACore.cpp
index 5eaf204b21..5f2c3ff5b6 100644
--- a/Source/Core/Core/HW/GBACore.cpp
+++ b/Source/Core/Core/HW/GBACore.cpp
@@ -470,12 +470,20 @@ void Core::SetupEvent()
   m_event.priority = 0x80;
 }
 
+void Core::RunFrame(u16 keys)
+{
+  PushEvent({
+      .event_type = SyncEventType::RunFrame,
+      .keys = keys,
+  });
+}
+
 void Core::SyncJoybus(u64 gc_ticks, u16 keys)
 {
   PushEvent({
-      .run_until_ticks = gc_ticks,
+      .event_type = SyncEventType::TimeSync,
       .keys = keys,
-      .event_type = JoybusEventType::TimeSync,
+      .run_until_ticks = gc_ticks,
   });
 }
 
@@ -491,9 +499,9 @@ void Core::SendJoybusCommand(u64 gc_ticks, int transfer_time, u8* buffer, u16 ke
   m_command_pending.store(true, std::memory_order_relaxed);
 
   PushEvent({
-      .run_until_ticks = gc_ticks,
+      .event_type = SyncEventType::RunCommand,
       .keys = keys,
-      .event_type = JoybusEventType::RunCommand,
+      .run_until_ticks = gc_ticks,
   });
 }
 
@@ -510,7 +518,7 @@ void Core::Flush()
   m_event_thread.WaitForCompletion();
 }
 
-void Core::PushEvent(JoybusEvent event)
+void Core::PushEvent(SyncEvent event)
 {
   if (m_event_thread.IsRunning())
     m_event_thread.Push(event);
@@ -518,12 +526,22 @@ void Core::PushEvent(JoybusEvent event)
     HandleEvent(event);
 }
 
-void Core::HandleEvent(JoybusEvent event)
+void Core::HandleEvent(SyncEvent event)
 {
   m_keys = event.keys;
+
+  if (event.event_type == SyncEventType::RunFrame)
+  {
+    m_last_gc_ticks = m_system.GetCoreTiming().GetTicks();
+    m_gc_ticks_remainder = 0;
+
+    m_core->runFrame(m_core);
+    return;
+  }
+
   RunUntil(event.run_until_ticks);
 
-  if (event.event_type != JoybusEventType::RunCommand)
+  if (event.event_type != SyncEventType::RunCommand)
     return;
 
   if (m_link_enabled && !m_force_disconnect)
diff --git a/Source/Core/Core/HW/GBACore.h b/Source/Core/Core/HW/GBACore.h
index 64f61a0eb7..110b79a16a 100644
--- a/Source/Core/Core/HW/GBACore.h
+++ b/Source/Core/Core/HW/GBACore.h
@@ -72,6 +72,7 @@ public:
   void SetForceDisconnect(bool force_disconnect);
   void EReaderQueueCard(std::string_view card_path);
 
+  void RunFrame(u16 keys);
   void SyncJoybus(u64 gc_ticks, u16 keys);
   void SendJoybusCommand(u64 gc_ticks, int transfer_time, u8* buffer, u16 keys);
   int GetJoybusResponse(u8* data_out);
@@ -90,19 +91,20 @@ private:
   void RunFor(u64 gc_ticks);
   void Flush();
 
-  enum class JoybusEventType : u8
+  enum class SyncEventType : u8
   {
     TimeSync,
     RunCommand,
+    RunFrame,
   };
-  struct JoybusEvent
+  struct SyncEvent
   {
-    u64 run_until_ticks{};
+    SyncEventType event_type{};
     u16 keys{};
-    JoybusEventType event_type{};
+    u64 run_until_ticks{};  // Not used by SyncEventType::RunFrame.
   };
-  void PushEvent(JoybusEvent event);
-  void HandleEvent(JoybusEvent event);
+  void PushEvent(SyncEvent event);
+  void HandleEvent(SyncEvent event);
 
   bool LoadBIOS(const char* bios_path);
   bool LoadSave(const char* save_path);
@@ -137,7 +139,7 @@ private:
 
   std::weak_ptr<GBAHostInterface> m_host;
 
-  // Set by the GC thread before issuing a JoybusEventType::RunCommand.
+  // Set by the GC thread before issuing a SyncEventType::RunCommand.
   int m_joybus_command_transfer_time{};
   GBASIOJOYCommand m_joybus_command{};
 
@@ -149,7 +151,7 @@ private:
   std::atomic_bool m_command_pending{};
 
   // The entire threaded GBA runs within events pushed to this queue.
-  Common::WorkQueueThreadSP<JoybusEvent> m_event_thread;
+  Common::WorkQueueThreadSP<SyncEvent> m_event_thread;
 
   ::Core::System& m_system;
 };