Implement a simple benchmarking mode which logs FPS to a file

Very useful to compare performance between two builds, check the impact of
a configuration option, etc. FPS log is stored in User/Logs/fps.txt and is
reset each time you launch a game. Only enabled if you check the "Log FPS
to file" option in your graphics settings.

Could be improved a bit: currently logs only every 1s (so you can't really
see small variations), maybe output more infos to the fps.txt like
average/stddev (but Excel/Libreoffice/Google Docs can compute that easily
too).

Source/Core/VideoCommon/CMakeLists.txt

@@ -6,6 +6,7 @@ set(SRCS	Src/BPFunctions.cpp
 			Src/DLCache.cpp
 			Src/Debugger.cpp
 			Src/Fifo.cpp
+			Src/FPSCounter.cpp
 			Src/FramebufferManagerBase.cpp
 			Src/HiresTextures.cpp
 			Src/ImageWrite.cpp

Source/Core/VideoCommon/Src/FPSCounter.cpp

@@ -0,0 +1,64 @@
+// Copyright (C) 2003 Dolphin Project.
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, version 2.0.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License 2.0 for more details.
+
+// A copy of the GPL 2.0 should have been included with the program.
+// If not, see http://www.gnu.org/licenses/
+
+// Official SVN repository and contact information can be found at
+// http://code.google.com/p/dolphin-emu/
+
+#include "FPSCounter.h"
+#include "FileUtil.h"
+#include "Timer.h"
+#include "VideoConfig.h"
+
+#define FPS_REFRESH_INTERVAL 1000
+
+static unsigned int s_counter = 0;
+static unsigned int s_fps = 0;
+static unsigned int s_fps_last_counter = 0;
+static unsigned long s_last_update_time = 0;
+static File::IOFile s_bench_file;
+
+void InitFPSCounter()
+{
+	s_counter = s_fps_last_counter = 0;
+	s_fps = 0;
+	s_last_update_time = Common::Timer::GetTimeMs();
+
+	if (s_bench_file.IsOpen())
+		s_bench_file.Close();
+}
+
+static void LogFPSToFile(unsigned long val)
+{
+	if (!s_bench_file.IsOpen())
+		s_bench_file.Open(File::GetUserPath(D_LOGS_IDX) + "fps.txt", "w");
+
+	char buffer[256];
+	snprintf(buffer, 256, "%ld\n", val);
+	s_bench_file.WriteArray(buffer, strlen(buffer));
+}
+
+int UpdateFPSCounter()
+{
+	if (Common::Timer::GetTimeMs() - s_last_update_time >= FPS_REFRESH_INTERVAL)
+	{
+		s_last_update_time = Common::Timer::GetTimeMs();
+		s_fps = s_counter - s_fps_last_counter;
+		s_fps_last_counter = s_counter;
+		if (g_ActiveConfig.bLogFPSToFile)
+			LogFPSToFile(s_fps);
+	}
+
+	s_counter++;
+	return s_fps;
+}

Source/Core/VideoCommon/Src/FPSCounter.h

@@ -0,0 +1,28 @@
+// Copyright (C) 2003 Dolphin Project.
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, version 2.0.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License 2.0 for more details.
+
+// A copy of the GPL 2.0 should have been included with the program.
+// If not, see http://www.gnu.org/licenses/
+
+// Official SVN repository and contact information can be found at
+// http://code.google.com/p/dolphin-emu/
+
+#ifndef _FPS_COUNTER_H_
+#define _FPS_COUNTER_H_
+
+// Initializes the FPS counter.
+void InitFPSCounter();
+
+// Called when a frame is rendered. Returns the value to be displayed on
+// screen as the FPS counter (updated every second).
+int UpdateFPSCounter();
+
+#endif // _FPS_COUNTER_H_

Source/Core/VideoCommon/Src/VideoConfig.cpp

@@ -59,6 +59,7 @@ void VideoConfig::Load(const char *ini_file)
 	iniFile.Get("Settings", "UseRealXFB", &bUseRealXFB, 0);
 	iniFile.Get("Settings", "SafeTextureCacheColorSamples", &iSafeTextureCache_ColorSamples,128);
 	iniFile.Get("Settings", "ShowFPS", &bShowFPS, false); // Settings
+	iniFile.Get("Settings", "LogFPSToFile", &bLogFPSToFile, false);
 	iniFile.Get("Settings", "ShowInputDisplay", &bShowInputDisplay, false);
 	iniFile.Get("Settings", "OverlayStats", &bOverlayStats, false);
 	iniFile.Get("Settings", "OverlayProjStats", &bOverlayProjStats, false);
@@ -186,6 +187,7 @@ void VideoConfig::Save(const char *ini_file)
 	iniFile.Set("Settings", "UseRealXFB", bUseRealXFB);
 	iniFile.Set("Settings", "SafeTextureCacheColorSamples", iSafeTextureCache_ColorSamples);
 	iniFile.Set("Settings", "ShowFPS", bShowFPS);
+	iniFile.Set("Settings", "LogFPSToFile", bLogFPSToFile);
 	iniFile.Set("Settings", "ShowInputDisplay", bShowInputDisplay);
 	iniFile.Set("Settings", "OverlayStats", bOverlayStats);
 	iniFile.Set("Settings", "OverlayProjStats", bOverlayProjStats);

Source/Core/VideoCommon/Src/VideoConfig.h

@@ -97,6 +97,7 @@ struct VideoConfig
 	bool bTexFmtOverlayEnable;
 	bool bTexFmtOverlayCenter;
 	bool bShowEFBCopyRegions;
+	bool bLogFPSToFile;
 	
 	// Render
 	bool bWireFrame;

Source/Core/VideoCommon/VideoCommon.vcxproj

@@ -183,6 +183,7 @@
     <ClCompile Include="Src\DLCache.cpp" />
     <ClCompile Include="Src\EmuWindow.cpp" />
     <ClCompile Include="Src\Fifo.cpp" />
+    <ClCompile Include="Src\FPSCounter.cpp" />
     <ClCompile Include="Src\FramebufferManagerBase.cpp" />
     <ClCompile Include="Src\HiresTextures.cpp" />
     <ClCompile Include="Src\ImageWrite.cpp" />
@@ -228,6 +229,7 @@
     <ClInclude Include="Src\DLCache.h" />
     <ClInclude Include="Src\EmuWindow.h" />
     <ClInclude Include="Src\Fifo.h" />
+    <ClInclude Include="Src\FPSCounter.h" />
     <ClInclude Include="Src\FramebufferManagerBase.h" />
     <ClInclude Include="Src\HiresTextures.h" />
     <ClInclude Include="Src\ImageWrite.h" />

Source/Core/VideoCommon/VideoCommon.vcxproj.filters

@@ -119,6 +119,9 @@
     <ClCompile Include="Src\LightingShaderGen.cpp">
       <Filter>Shader Generators</Filter>
     </ClCompile>
+    <ClCompile Include="Src\FPSCounter.cpp">
+      <Filter>Util</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="Src\CommandProcessor.h" />
@@ -246,6 +249,9 @@
     <ClInclude Include="Src\LightingShaderGen.h">
       <Filter>Shader Generators</Filter>
     </ClInclude>
+    <ClInclude Include="Src\FPSCounter.h">
+      <Filter>Util</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <None Include="CMakeLists.txt" />