PerfMon/ImGui: Add average VPS value to OSD

pcsx2/ImGui/ImGuiOverlays.cpp

@@ -363,7 +363,7 @@ __ri void ImGuiManager::DrawPerformanceOverlay(float& position_y, float scale, f
 			}
 
 			if (GSConfig.OsdShowVPS)
-				s_speed_line.append_format("{}VPS: {:.2f}", s_speed_line.empty() ? "" : " | ", PerformanceMetrics::GetFPS());
+				s_speed_line.append_format("{}VPS: {:.2f} (Avg. {:.2f})", s_speed_line.empty() ? "" : " | ", PerformanceMetrics::GetFPS(), PerformanceMetrics::GetAvgVPS());
 
 			if (GSConfig.OsdShowSpeed)
 			{

pcsx2/PerformanceMetrics.cpp

@@ -19,6 +19,7 @@
 static const float UPDATE_INTERVAL = 0.5f;
 
 static float s_fps = 0.0f;
+static PerformanceMetrics::AverageFPS s_avg_vps;
 static float s_internal_fps = 0.0f;
 static float s_minimum_frame_time = 0.0f;
 static float s_minimum_frame_time_accumulator = 0.0f;
@@ -85,6 +86,7 @@ void PerformanceMetrics::Clear()
 	Reset();
 
 	s_fps = 0.0f;
+	s_avg_vps.ClearStats();
 	s_internal_fps = 0.0f;
 	s_minimum_frame_time = 0.0f;
 	s_average_frame_time = 0.0f;
@@ -183,6 +185,7 @@ void PerformanceMetrics::Update(bool gs_register_write, bool fb_blit, bool is_sk
 	s_average_frame_time = std::exchange(s_average_frame_time_accumulator, 0.0f) / static_cast<float>(s_unskipped_frames_since_last_update);
 	s_maximum_frame_time = std::exchange(s_maximum_frame_time_accumulator, 0.0f);
 	s_fps = static_cast<float>(s_frames_since_last_update) / time;
+	s_avg_vps.UpdateAvgFPS(s_fps);
 	s_average_gpu_time = s_accumulated_gpu_time / static_cast<float>(s_unskipped_frames_since_last_update);
 	s_average_gpu_vs_invocations = static_cast<double>(s_accumulated_gpu_vs_invocations) / static_cast<double>(s_unskipped_frames_since_last_update);
 	s_average_gpu_ps_invocations = static_cast<double>(s_accumulated_gpu_ps_invocations) / static_cast<double>(s_unskipped_frames_since_last_update);
@@ -329,6 +332,11 @@ float PerformanceMetrics::GetFPS()
 	return s_fps;
 }
 
+float PerformanceMetrics::GetAvgVPS()
+{
+	return s_avg_vps.GetAvgFPS();
+}
+
 float PerformanceMetrics::GetInternalFPS()
 {
 	return s_internal_fps;

pcsx2/PerformanceMetrics.h

@@ -4,6 +4,7 @@
 #pragma once
 
 #include <array>
+#include <cstring>
 #include "common/Threading.h"
 
 namespace PerformanceMetrics
@@ -15,6 +16,61 @@ namespace PerformanceMetrics
 		DISPFBBlit
 	};
 
+	class AverageFPS
+	{
+	private:
+		#define FPS_BUFFER_SIZE 8
+		float fps_buff[FPS_BUFFER_SIZE];
+		int count;
+		int pos;
+
+	public:
+		void ClearStats()
+		{
+			count = 0;
+			pos = 0;
+			std::memset(&fps_buff[0], 0, sizeof(float) * FPS_BUFFER_SIZE);
+		}
+
+		AverageFPS()
+		{
+			ClearStats();
+		}
+
+		void UpdateAvgFPS(float new_fps_val)
+		{
+			// If the change is quite dramatic, the user has either turned off the frame limiter or the game is dying.
+			// Clear it to catch it up quickly.
+			if (count > 0)
+			{
+				const float last_fps_val = fps_buff[(pos - 1) & (FPS_BUFFER_SIZE - 1)];
+				if (std::abs(last_fps_val - new_fps_val) > last_fps_val * 0.20f)
+					ClearStats();
+			}
+
+			fps_buff[pos] = new_fps_val;
+			pos = (pos + 1) & (FPS_BUFFER_SIZE - 1); // if you use values which don't become all 1's, make it %.
+			count = std::min(count + 1, FPS_BUFFER_SIZE);
+		}
+
+		float GetAvgFPS()
+		{
+			if (count == 0)
+				return 0.0f;
+
+			float avg_fps = 0.0f;
+
+			for (int i = 0; i < count; i++)
+			{
+				avg_fps += fps_buff[i];
+			}
+
+			avg_fps /= static_cast<float>(count);
+
+			return avg_fps;
+		}
+	};
+
 	static constexpr u32 NUM_FRAME_TIME_SAMPLES = 150;
 	using FrameTimeHistory = std::array<float, NUM_FRAME_TIME_SAMPLES>;
 
@@ -36,6 +92,7 @@ namespace PerformanceMetrics
 	bool IsInternalFPSValid();
 
 	float GetFPS();
+	float GetAvgVPS();
 	float GetInternalFPS();
 	float GetSpeed();
 	float GetAverageFrameTime();