Add measured FPS to OSD, squash a bunch of minor bugs.

src/common/module.mk

@@ -17,7 +17,8 @@ MODULE_OBJS := \
 	src/common/StateManager.o \
 	src/common/ZipHandler.o \
 	src/common/AudioQueue.o \
-	src/common/AudioSettings.o
+	src/common/AudioSettings.o \
+	src/common/FpsMeter.o
 
 MODULE_DIRS += \
 	src/common

src/debugger/Debugger.cxx

@@ -157,6 +157,8 @@ void Debugger::quit(bool exitrom)
     myOSystem.eventHandler().handleEvent(Event::LauncherMode, 1);
   else
     myOSystem.eventHandler().leaveDebugMode();
+
+  myOSystem.console().tia().clearPendingFrame();
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

src/emucore/Console.cxx

@@ -148,7 +148,6 @@ Console::Console(OSystem& osystem, unique_ptr<Cartridge>& cart,
   // Note that this can be overridden if a format is forced
   //   For example, if a PAL ROM is forced to be NTSC, it will use NTSC-like
   //   properties (60Hz, 262 scanlines, etc), but likely result in flicker
-  setTIAProperties();
   if(myDisplayFormat == "NTSC")
   {
     myCurrentFormat = 1;
@@ -180,6 +179,8 @@ Console::Console(OSystem& osystem, unique_ptr<Cartridge>& cart,
     myConsoleTiming = ConsoleTiming::secam;
   }
 
+  setTIAProperties();
+
   bool joyallow4 = myOSystem.settings().getBool("joyallow4");
   myOSystem.eventHandler().allowAllDirections(joyallow4);
 
@@ -387,6 +388,7 @@ void Console::setFormat(uInt32 format)
     myTIA->frameReset();
     initializeVideo();  // takes care of refreshing the screen
     initializeAudio(); // ensure that audio synthesis is set up to match emulation speed
+    myOSystem.resetFps(); // Reset FPS measurement
   }
 
   myOSystem.frameBuffer().showMessage(message);
@@ -975,7 +977,8 @@ void Console::generateColorLossPalette()
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 float Console::getFramerate() const
 {
-  return myTIA->frameBufferFrameRate();
+  return
+    static_cast<float>(myEmulationTiming.linesPerSecond()) / myTIA->frameBufferScanlinesLastFrame();
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

src/emucore/EmulationTiming.cxx

@@ -134,6 +134,12 @@ uInt32 EmulationTiming::cyclesPerSecond() const
   return myCyclesPerSecond;
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+uInt32 EmulationTiming::linesPerSecond() const
+{
+  return myLinesPerSecond;
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 uInt32 EmulationTiming::audioFragmentSize() const
 {
@@ -181,7 +187,7 @@ void EmulationTiming::recalculate()
 
     case ConsoleTiming::pal:
     case ConsoleTiming::secam:
-      myCyclesPerSecond = uInt32(round(mySpeedFactor * 312 * 76 * 50) / 38);
+      myAudioSampleRate = uInt32(round(mySpeedFactor * 312 * 76 * 50) / 38);
       break;
 
     default:
@@ -204,4 +210,6 @@ void EmulationTiming::recalculate()
     myPrebufferFragmentCount,
     discreteDivCeil(myMaxCyclesPerTimeslice * myAudioSampleRate, myAudioFragmentSize * myCyclesPerSecond)
   ) + myAudioQueueExtraFragments;
+
+  myLinesPerSecond = myCyclesPerSecond / 76;
 }

src/emucore/EmulationTiming.hxx

@@ -49,6 +49,8 @@ class EmulationTiming {
 
     uInt32 cyclesPerFrame() const;
 
+    uInt32 linesPerSecond() const;
+
     uInt32 cyclesPerSecond() const;
 
     uInt32 audioFragmentSize() const;
@@ -82,6 +84,7 @@ class EmulationTiming {
     uInt32 myAudioSampleRate;
     uInt32 myAudioQueueCapacity;
     uInt32 myPrebufferFragmentCount;
+    uInt32 myLinesPerSecond;
 
     float mySpeedFactor;
 

src/emucore/FrameBuffer.cxx

@@ -229,8 +229,8 @@ FBInitStatus FrameBuffer::createDisplay(const string& title,
 
   // Create surfaces for TIA statistics and general messages
   myStatsMsg.color = kColorInfo;
-  myStatsMsg.w = font().getMaxCharWidth() * 30 + 3;
+  myStatsMsg.w = font().getMaxCharWidth() * 40 + 3;
-  myStatsMsg.h = (font().getFontHeight() + 2) * 2;
+  myStatsMsg.h = (font().getFontHeight() + 2) * 3;
 
   if(!myStatsMsg.surface)
   {
@@ -361,7 +361,7 @@ void FrameBuffer::update(bool force)
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void FrameBuffer::updateInEmulationMode()
+void FrameBuffer::updateInEmulationMode(float framesPerSecond)
 {
   // Update method that is specifically tailored to emulation mode
   // Typically called from a thread, so it needs to be separate from
@@ -374,7 +374,7 @@ void FrameBuffer::updateInEmulationMode()
 
   // Show frame statistics
   if(myStatsMsg.enabled)
-    drawFrameStats();
+    drawFrameStats(framesPerSecond);
 
   myLastScanlines = myOSystem.console().tia().frameBufferScanlinesLastFrame();
   myPausedCount = 0;
@@ -410,39 +410,50 @@ void FrameBuffer::showMessage(const string& message, MessagePosition position,
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void FrameBuffer::drawFrameStats()
+void FrameBuffer::drawFrameStats(float framesPerSecond)
 {
   const ConsoleInfo& info = myOSystem.console().about();
-  char msg[30];
   uInt32 color;
-  const int XPOS = 2, YPOS = 0;
+  int xPos = 2, yPos = 0;
-  int xPos = XPOS;
+  const int dy = font().getFontHeight() + 2;
+
+  ostringstream ss;
 
   myStatsMsg.surface->invalidate();
 
   // draw scanlines
   color = myOSystem.console().tia().frameBufferScanlinesLastFrame() != myLastScanlines ?
       uInt32(kDbgColorRed) : myStatsMsg.color;
-  std::snprintf(msg, 30, "%3u", myOSystem.console().tia().frameBufferScanlinesLastFrame());
+
-  myStatsMsg.surface->drawString(font(), msg, xPos, YPOS,
+  ss
+    << myOSystem.console().tia().frameBufferScanlinesLastFrame()
+    << " / "
+    << std::fixed << std::setprecision(1) << myOSystem.console().getFramerate()
+    << "Hz => "
+    << info.DisplayFormat;
+
+  myStatsMsg.surface->drawString(font(), ss.str(), xPos, yPos,
                                  myStatsMsg.w, color, TextAlign::Left, 0, true, kBGColor);
-  xPos += font().getStringWidth(msg);
 
-  // draw frequency
+  yPos += dy;
-  std::snprintf(msg, 30, " => %s", info.DisplayFormat.c_str());
+  ss.str("");
-  myStatsMsg.surface->drawString(font(), msg, xPos, YPOS,
-                                 myStatsMsg.w, myStatsMsg.color, TextAlign::Left, 0, true, kBGColor);
-  xPos += font().getStringWidth(msg);
 
-  std::snprintf(msg, 30, " @ %5.2ffps", myOSystem.console().getFramerate());
+  ss
+    << std::fixed << std::setprecision(1) << framesPerSecond
+    << "fps @ "
+    << std::fixed << std::setprecision(2) << 100 * myOSystem.settings().getFloat("speed")
+    << "% speed";
 
-  myStatsMsg.surface->drawString(font(), msg, xPos, YPOS,
+  myStatsMsg.surface->drawString(font(), ss.str(), xPos, yPos,
                                  myStatsMsg.w, myStatsMsg.color, TextAlign::Left, 0, true, kBGColor);
 
-  // draw bankswitching type
+  yPos += dy;
-  string bsinfo = info.BankSwitch +
+  ss.str("");
-    (myOSystem.settings().getBool("dev.settings") ? "| Developer" : "");
+
-  myStatsMsg.surface->drawString(font(), bsinfo, XPOS, YPOS + font().getFontHeight(),
+  ss << info.BankSwitch;
+  if (myOSystem.settings().getBool("dev.settings")) ss << "| Developer";
+
+  myStatsMsg.surface->drawString(font(), ss.str(), xPos, yPos,
                                  myStatsMsg.w, myStatsMsg.color, TextAlign::Left, 0, true, kBGColor);
 
   myStatsMsg.surface->setDstPos(myImageRect.x() + 10, myImageRect.y() + 8);

src/emucore/FrameBuffer.hxx

@@ -120,7 +120,7 @@ class FrameBuffer
     /**
       There is a dedicated update method for emulation mode.
      */
-    void updateInEmulationMode();
+    void updateInEmulationMode(float framesPerSecond);
 
     /**
       Shows a message onscreen.
@@ -471,7 +471,7 @@ class FrameBuffer
 
   private:
     // Draws the frame stats overlay
-    void drawFrameStats();
+    void drawFrameStats(float framesPerSecond);
 
     // Indicates the number of times the framebuffer was initialized
     uInt32 myInitializedCount;

src/emucore/OSystem.cxx

@@ -30,14 +30,13 @@
   #include "CheatManager.hxx"
 #endif
 
-#include <chrono>
-
 #include "FSNode.hxx"
 #include "MD5.hxx"
 #include "Cart.hxx"
 #include "CartDetector.hxx"
 #include "FrameBuffer.hxx"
 #include "TIASurface.hxx"
+#include "TIAConstants.hxx"
 #include "Settings.hxx"
 #include "PropsSet.hxx"
 #include "EventHandler.hxx"
@@ -60,10 +59,15 @@
 
 using namespace std::chrono;
 
+namespace {
+  constexpr uInt32 FPS_METER_QUEUE_SIZE = 100;
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 OSystem::OSystem()
   : myLauncherUsed(false),
-    myQuitLoop(false)
+    myQuitLoop(false),
+    myFpsMeter(FPS_METER_QUEUE_SIZE)
 {
   // Get built-in features
   #ifdef SOUND_SUPPORT
@@ -481,6 +485,12 @@ void OSystem::logMessage(const string& message, uInt8 level)
   }
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+void OSystem::resetFps()
+{
+  myFpsMeter.reset();
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 unique_ptr<Console> OSystem::openConsole(const FilesystemNode& romfile, string& md5)
 {
@@ -651,7 +661,10 @@ double OSystem::dispatchEmulation(EmulationWorker& emulationWorker)
   bool framePending = tia.newFramePending();
   // ... and copy it to the frame buffer. It is important to do this before
   // the worker is started to avoid racing.
-  if (framePending) tia.renderToFrameBuffer();
+  if (framePending) {
+    myFpsMeter.render(tia.framesSinceLastRender());
+    tia.renderToFrameBuffer();
+  }
 
   // Start emulation on a dedicated thread. It will do its own scheduling to sync 6507 and real time
   // and will run until we stop the worker.
@@ -665,7 +678,7 @@ double OSystem::dispatchEmulation(EmulationWorker& emulationWorker)
 
   // Render the frame. This may block, but emulation will continue to run on the worker, so the
   // audio pipeline is kept fed :)
-  if (framePending) myFrameBuffer->updateInEmulationMode();
+  if (framePending) myFrameBuffer->updateInEmulationMode(myFpsMeter.fps());
 
   // Stop the worker and wait until it has finished
   uInt64 totalCycles = emulationWorker.stop();
@@ -691,11 +704,20 @@ void OSystem::mainLoop()
   // The emulation worker
   EmulationWorker emulationWorker;
 
+  myFpsMeter.reset(TIAConstants::initialGarbageFrames);
+
   for(;;)
   {
+    bool wasEmulation = myEventHandler->state() == EventHandlerState::EMULATION;
+
     myEventHandler->poll(getTicks());
     if(myQuitLoop) break;  // Exit if the user wants to quit
 
+    if (!wasEmulation && myEventHandler->state() == EventHandlerState::EMULATION) {
+      myFpsMeter.reset();
+      virtualTime = high_resolution_clock::now();
+    }
+
     double timesliceSeconds;
 
     if (myEventHandler->state() == EventHandlerState::EMULATION)

src/emucore/OSystem.hxx

@@ -40,9 +40,12 @@ class StateManager;
 class VideoDialog;
 class EmulationWorker;
 
+#include <chrono>
+
 #include "FSNode.hxx"
 #include "FrameBufferConstants.hxx"
 #include "EventHandlerConstants.hxx"
+#include "FpsMeter.hxx"
 #include "bspf.hxx"
 #include "AudioSettings.hxx"
 
@@ -367,6 +370,11 @@ class OSystem
     */
     const string& logMessages() const { return myLogMessages; }
 
+    /**
+      Reset FPS measurement.
+     */
+    void resetFps();
+
   public:
     //////////////////////////////////////////////////////////////////////
     // The following methods are system-specific and can be overrided in
@@ -510,6 +518,8 @@ class OSystem
     string myFeatures;
     string myBuildInfo;
 
+    FpsMeter myFpsMeter;
+
   private:
     /**
       Creates the various framebuffers/renderers available in this system.

src/emucore/tia/TIA.cxx

@@ -181,10 +181,9 @@ void TIA::reset()
     frameReset();  // Recalculate the size of the display
   }
 
-  myFrontBufferFrameRate = myFrameBufferFrameRate = 0;
   myFrontBufferScanlines = myFrameBufferScanlines = 0;
 
-  myNewFramePending = false;
+  myFramesSinceLastRender = 0;
 
   // Must be done last, after all other items have reset
   enableFixedColors(mySettings.getBool(mySettings.getBool("dev.settings") ? "dev.debugcolors" : "plr.debugcolors"));
@@ -293,8 +292,6 @@ bool TIA::save(Serializer& out) const
 
     out.putInt(myFrameBufferScanlines);
     out.putInt(myFrontBufferScanlines);
-    out.putDouble(myFrameBufferFrameRate);
-    out.putDouble(myFrontBufferFrameRate);
   }
   catch(...)
   {
@@ -366,8 +363,6 @@ bool TIA::load(Serializer& in)
 
     myFrameBufferScanlines = in.getInt();
     myFrontBufferScanlines = in.getInt();
-    myFrameBufferFrameRate = in.getDouble();
-    myFrontBufferFrameRate = in.getDouble();
   }
   catch(...)
   {
@@ -799,7 +794,7 @@ bool TIA::saveDisplay(Serializer& out) const
     out.putByteArray(myFramebuffer, 160* TIAConstants::frameBufferHeight);
     out.putByteArray(myBackBuffer, 160 * TIAConstants::frameBufferHeight);
     out.putByteArray(myFrontBuffer, 160 * TIAConstants::frameBufferHeight);
-    out.putBool(myNewFramePending);
+    out.putInt(myFramesSinceLastRender);
   }
   catch(...)
   {
@@ -819,7 +814,7 @@ bool TIA::loadDisplay(Serializer& in)
     in.getByteArray(myFramebuffer, 160 * TIAConstants::frameBufferHeight);
     in.getByteArray(myBackBuffer, 160 * TIAConstants::frameBufferHeight);
     in.getByteArray(myFrontBuffer, 160 * TIAConstants::frameBufferHeight);
-    myNewFramePending = in.getBool();
+    myFramesSinceLastRender = in.getInt();
   }
   catch(...)
   {
@@ -841,11 +836,12 @@ void TIA::update(DispatchResult& result, uInt64 maxCycles)
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void TIA::renderToFrameBuffer()
 {
-  if (!myNewFramePending) return;
+  if (myFramesSinceLastRender == 0) return;
+
+  myFramesSinceLastRender = 0;
 
   memcpy(myFramebuffer, myFrontBuffer, 160 * TIAConstants::frameBufferHeight);
 
-  myFrameBufferFrameRate = myFrontBufferFrameRate;
   myFrameBufferScanlines = myFrontBufferScanlines;
 }
 
@@ -1198,10 +1194,9 @@ void TIA::onFrameComplete()
 
   memcpy(myFrontBuffer, myBackBuffer, 160 * TIAConstants::frameBufferHeight);
 
-  myFrontBufferFrameRate = frameRate();
   myFrontBufferScanlines = scanlinesLastFrame();
 
-  myNewFramePending = true;
+  myFramesSinceLastRender++;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

src/emucore/tia/TIA.hxx

@@ -207,7 +207,17 @@ class TIA : public Device
     /**
       Did we generate a new frame?
      */
-    bool newFramePending() { return myNewFramePending; }
+    bool newFramePending() { return myFramesSinceLastRender  > 0; }
+
+    /**
+     * Clear any pending frames.
+     */
+    void clearPendingFrame() { myFramesSinceLastRender = 0; }
+
+    /**
+      The number of frames since we did last render to the front buffer.
+     */
+    uInt32 framesSinceLastRender() { return myFramesSinceLastRender; }
 
     /**
       Render the pending frame to the framebuffer and clear the flag.
@@ -248,13 +258,6 @@ class TIA : public Device
     */
     ConsoleTiming consoleTiming() const { return myConsole.timing(); }
 
-    float frameRate() const { return myFrameManager ? myFrameManager->frameRate() : 0; }
-
-    /**
-      The same, but for the frame in the frame buffer.
-     */
-    float frameBufferFrameRate() const { return myFrameBufferFrameRate; }
-
     /**
       Enables/disables color-loss for PAL modes only.
 
@@ -694,10 +697,9 @@ class TIA : public Device
     // We snapshot frame statistics when the back buffer is copied to the front buffer
     // and when the front buffer is copied to the frame buffer
     uInt32 myFrontBufferScanlines, myFrameBufferScanlines;
-    float myFrontBufferFrameRate, myFrameBufferFrameRate;
 
-    // Did we emit a frame?
+    // Frames since the last time a frame was rendered to the render buffer
-    bool myNewFramePending;
+    uInt32 myFramesSinceLastRender;
 
     /**
      * Setting this to true injects random values into undefined reads.

src/emucore/tia/frame-manager/AbstractFrameManager.cxx

@@ -37,8 +37,6 @@ void AbstractFrameManager::reset()
   myCurrentFrameFinalLines = 0;
   myPreviousFrameFinalLines = 0;
   myTotalFrames = 0;
-  myFrameRate = 0;
-  myFrameRate = 60.0;
 
   onReset();
 }
@@ -101,9 +99,6 @@ void AbstractFrameManager::notifyFrameComplete()
   myTotalFrames++;
 
   if (myOnFrameComplete) myOnFrameComplete();
-
-  myFrameRate = (layout() == FrameLayout::pal ? 15600.0 : 15720.0) /
-    myCurrentFrameFinalLines;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -130,7 +125,6 @@ bool AbstractFrameManager::save(Serializer& out) const
     out.putInt(myPreviousFrameFinalLines);
     out.putInt(myTotalFrames);
     out.putInt(uInt32(myLayout));
-    out.putDouble(myFrameRate);
 
     return onSave(out);
   }
@@ -155,7 +149,6 @@ bool AbstractFrameManager::load(Serializer& in)
     myPreviousFrameFinalLines = in.getInt();
     myTotalFrames = in.getInt();
     myLayout = FrameLayout(in.getInt());
-    myFrameRate = float(in.getDouble());
 
     return onLoad(in);
   }

src/emucore/tia/frame-manager/AbstractFrameManager.hxx

@@ -107,13 +107,6 @@ class AbstractFrameManager : public Serializable
      */
     FrameLayout layout() const { return myLayout; }
 
-    /**
-     * The current frame rate. This is calculated dynamically from the number of
-     * scanlines in the last frames and used to control sleep time in the
-     * dispatch loop.
-     */
-    float frameRate() const { return myFrameRate; }
-
     /**
      * Save state.
      */
@@ -289,11 +282,6 @@ class AbstractFrameManager : public Serializable
      */
     uInt32 myTotalFrames;
 
-    /**
-     * Frame rate (see above.)
-     */
-    float myFrameRate;
-
   private:
 
     /**