Capture the actual current frame number when opening the rewind selector

src/core/imgui_overlays.cpp

@@ -1644,8 +1644,9 @@ void ImGuiManager::RenderRewindSelector()
 
     // Display state info for current selection
     const auto& current_state = states[current_index];
-    const u32 frame_diff = (states.empty() || current_index == 0) ?
-                           0 : (states[0].frame_number - current_state.frame_number);
+    const u32 current_frame = System::Internal::GetRewindSelectorCurrentFrame();
+    const u32 frame_diff = (states.empty() || current_state.frame_number >= current_frame) ?
+                           0 : (current_frame - current_state.frame_number);
     const float seconds_ago = frame_diff / System::GetVideoFrameRate();
 
     ImGui::Text("Frame: %u", current_state.frame_number);

src/core/system.cpp

@@ -307,6 +307,7 @@ struct ALIGN_TO_CACHE_LINE StateVars
   bool rewind_selector_open = false;
   bool was_paused_before_rewind_selector = false;
   size_t rewind_selector_index = 0;
+  u32 rewind_selector_current_frame = 0;
   std::vector<System::RewindStateInfo> rewind_selector_states;
 
   const BIOS::ImageInfo* bios_image_info = nullptr;
@@ -3773,8 +3774,9 @@ void System::SetRewindState(bool enabled)
     {
       if (!IsRewindStateSelectorOpen())
       {
-        GPUThread::RunOnThread([]() {
-          System::OpenRewindStateSelector();
+        const u32 current_frame = System::GetFrameNumber();
+        GPUThread::RunOnThread([current_frame]() {
+          System::OpenRewindStateSelector(current_frame);
         });
       }
       else
@@ -5292,12 +5294,13 @@ void System::CleanupRewindStates()
     INFO_LOG("Cleaned up {} rewind state director{}", cleaned_dirs, (cleaned_dirs == 1) ? "y" : "ies");
 }
 
-void System::OpenRewindStateSelector()
+void System::OpenRewindStateSelector(u32 current_frame_number)
 {
   if (!IsValid() || !g_settings.rewind_enable || !g_settings.rewind_use_save_states)
     return;
 
   s_state.rewind_selector_open = true;
+  s_state.rewind_selector_current_frame = current_frame_number;
   s_state.rewind_selector_states = GetAvailableRewindStates();
   s_state.rewind_selector_index = 0;
 
@@ -5352,6 +5355,11 @@ size_t& GetRewindSelectorIndex()
   return s_state.rewind_selector_index;
 }
 
+u32 GetRewindSelectorCurrentFrame()
+{
+  return s_state.rewind_selector_current_frame;
+}
+
 } // namespace System::Internal
 
 bool System::IsRunaheadActive()

src/core/system.h

@@ -382,7 +382,7 @@ void DeleteRewindStatesAfter(u32 frame_number);
 void CleanupRewindStates();
 
 /// Opens the rewind state selector UI.
-void OpenRewindStateSelector();
+void OpenRewindStateSelector(u32 current_frame_number);
 
 /// Closes the rewind state selector UI.
 void CloseRewindStateSelector();
@@ -495,6 +495,9 @@ const std::vector<RewindStateInfo>& GetRewindSelectorStates();
 /// Returns a reference to the rewind selector index (for UI rendering).
 size_t& GetRewindSelectorIndex();
 
+/// Returns the current frame number when the rewind selector was opened.
+u32 GetRewindSelectorCurrentFrame();
+
 } // namespace Internal
 
 } // namespace System