Ups, add missing file.

src/common/FpsMeter.cxx

@@ -0,0 +1,70 @@
+//============================================================================
+//
+//   SSSS    tt          lll  lll
+//  SS  SS   tt           ll   ll
+//  SS     tttttt  eeee   ll   ll   aaaa
+//   SSSS    tt   ee  ee  ll   ll      aa
+//      SS   tt   eeeeee  ll   ll   aaaaa  --  "An Atari 2600 VCS Emulator"
+//  SS  SS   tt   ee      ll   ll  aa  aa
+//   SSSS     ttt  eeeee llll llll  aaaaa
+//
+// Copyright (c) 1995-2018 by Bradford W. Mott, Stephen Anthony
+// and the Stella Team
+//
+// See the file "License.txt" for information on usage and redistribution of
+// this file, and for a DISCLAIMER OF ALL WARRANTIES.
+//============================================================================
+
+#include "FpsMeter.hxx"
+
+using namespace std::chrono;
+
+FpsMeter::FpsMeter(uInt32 queueSize)
+  : myQueue(queueSize)
+{
+  reset();
+}
+
+void FpsMeter::reset(uInt32 garbageFrameLimit)
+{
+  myQueue.clear();
+  myQueueOffset = 0;
+  myFrameCount = 0;
+  myFps = 0;
+  myGarbageFrameCounter = 0;
+  myGarbageFrameLimit = garbageFrameLimit;
+}
+
+void FpsMeter::render(uInt32 frameCount)
+{
+  if (myGarbageFrameCounter < myGarbageFrameLimit) {
+    myGarbageFrameCounter += frameCount;
+    return;
+  }
+
+  uInt32 queueSize = myQueue.capacity();
+  entry first, last = (entry){.frames = frameCount, .timestamp = high_resolution_clock::now()};
+
+  if (myQueue.size() < queueSize) {
+    myQueue.push_back(last);
+    myFrameCount += frameCount;
+
+    first = myQueue.at(myQueueOffset);
+  } else {
+    myFrameCount = myFrameCount - myQueue.at(myQueueOffset).frames + frameCount;
+    myQueue.at(myQueueOffset) = last;
+
+    myQueueOffset = (myQueueOffset + 1) % queueSize;
+    first = myQueue.at(myQueueOffset);
+  }
+
+  float myTimeInterval =
+    duration_cast<duration<float>>(last.timestamp - first.timestamp).count();
+
+  if (myTimeInterval > 0) myFps = (myFrameCount - first.frames) / myTimeInterval;
+}
+
+float FpsMeter::fps() const
+{
+  return myFps;
+}

src/common/FpsMeter.hxx

@@ -0,0 +1,66 @@
+//============================================================================
+//
+//   SSSS    tt          lll  lll
+//  SS  SS   tt           ll   ll
+//  SS     tttttt  eeee   ll   ll   aaaa
+//   SSSS    tt   ee  ee  ll   ll      aa
+//      SS   tt   eeeeee  ll   ll   aaaaa  --  "An Atari 2600 VCS Emulator"
+//  SS  SS   tt   ee      ll   ll  aa  aa
+//   SSSS     ttt  eeeee llll llll  aaaaa
+//
+// Copyright (c) 1995-2018 by Bradford W. Mott, Stephen Anthony
+// and the Stella Team
+//
+// See the file "License.txt" for information on usage and redistribution of
+// this file, and for a DISCLAIMER OF ALL WARRANTIES.
+//============================================================================
+
+#ifndef FPS_METER_HXX
+#define FPS_METER_HXX
+
+#include <chrono>
+
+#include "bspf.hxx"
+
+class FpsMeter
+{
+  public:
+
+    FpsMeter(uInt32 queueSize);
+
+    void reset(uInt32 garbageFrameLimit = 0);
+
+    void render(uInt32 frameCount);
+
+    float fps() const;
+
+  private:
+
+    struct entry {
+      uInt32 frames;
+      std::chrono::time_point<std::chrono::high_resolution_clock> timestamp;
+    };
+
+  private:
+
+    vector<entry> myQueue;
+
+    uInt32 myQueueOffset;
+
+    uInt32 myFrameCount;
+
+    uInt32 myGarbageFrameCounter;
+    uInt32 myGarbageFrameLimit;
+
+    float myFps;
+
+  private:
+
+    FpsMeter(const FpsMeter&) = delete;
+    FpsMeter(FpsMeter&&) = delete;
+    FpsMeter& operator=(const FpsMeter&) = delete;
+    FpsMeter& operator=(FpsMeter&&) = delete;
+
+};
+
+#endif // FPS_METER_HXX