handle rounded refresh rates like 59.94 Hz

disable refresh adjust option for macOS

src/common/FrameBufferSDL2.cxx

@@ -234,8 +234,6 @@ bool FrameBufferSDL2::setVideoMode(const string& title, const VideoMode& mode)
     return false;
 
   const bool fullScreen = mode.fsIndex != -1;
-  const bool shouldAdapt = fullScreen && myOSystem.settings().getBool("tia.fs_refresh")
-    && gameRefreshRate() && refreshRate() % gameRefreshRate() != 0;
   bool forceCreateRenderer = false;
 
   // Get windowed window's last display
@@ -272,8 +270,17 @@ bool FrameBufferSDL2::setVideoMode(const string& title, const VideoMode& mode)
     posY = BSPF::clamp(posY, y0 + 50, y1 - 50);
   }
 
+#ifndef BSPF_MACOS
+  // macOS does not allow to change the display refresh rate
   SDL_DisplayMode adaptedSdlMode;
+  const bool shouldAdapt = fullScreen && myOSystem.settings().getBool("tia.fs_refresh")
+    && gameRefreshRate()
+    // take care of 59.94 Hz
+    && refreshRate() % gameRefreshRate() != 0 && refreshRate() % (gameRefreshRate() - 1) != 0;
   const bool adaptRefresh = shouldAdapt && adaptRefreshRate(displayIndex, adaptedSdlMode);
+#else
+  const bool adaptRefresh = false;
+#endif
   const uInt32 flags = SDL_WINDOW_ALLOW_HIGHDPI
     | (fullScreen ? adaptRefresh ? SDL_WINDOW_FULLSCREEN : SDL_WINDOW_FULLSCREEN_DESKTOP : 0);
 
@@ -331,6 +338,7 @@ bool FrameBufferSDL2::setVideoMode(const string& title, const VideoMode& mode)
 
     setWindowIcon();
   }
+#ifndef BSPF_MACOS
   if(adaptRefresh)
   {
     // Switch to mode for adapted refresh rate
@@ -346,10 +354,11 @@ bool FrameBufferSDL2::setVideoMode(const string& title, const VideoMode& mode)
       Logger::info(msg.str());
     }
   }
-
+#endif
   return createRenderer(forceCreateRenderer);
 }
 
+#ifndef BSPF_MACOS
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 bool FrameBufferSDL2::adaptRefreshRate(Int32 displayIndex, SDL_DisplayMode& adaptedSdlMode)
 {
@@ -363,7 +372,10 @@ bool FrameBufferSDL2::adaptRefreshRate(Int32 displayIndex, SDL_DisplayMode& adap
 
   const int currentRefreshRate = sdlMode.refresh_rate;
   const int wantedRefreshRate = gameRefreshRate();
-  float factor = float(currentRefreshRate) / wantedRefreshRate;
+  // Take care of rounded refresh rates (e.g. 59.94 Hz)
+  float factor = std::min(float(currentRefreshRate) / wantedRefreshRate,
+                          float(currentRefreshRate) / (wantedRefreshRate - 1));
+  // Calculate difference taking care of integer factors (e.g. 100/120)
   float bestDiff = std::abs(factor - std::round(factor)) / factor;
   bool adapt = false;
 
@@ -382,6 +394,8 @@ bool FrameBufferSDL2::adaptRefreshRate(Int32 displayIndex, SDL_DisplayMode& adap
       return adapt;
     }
     factor = float(closestSdlMode.refresh_rate) / sdlMode.refresh_rate;
+    factor = std::min(float(sdlMode.refresh_rate) / sdlMode.refresh_rate,
+                      float(sdlMode.refresh_rate) / (sdlMode.refresh_rate - 1));
     const float diff = std::abs(factor - std::round(factor)) / factor;
     if(diff < bestDiff)
     {
@@ -399,7 +413,74 @@ bool FrameBufferSDL2::adaptRefreshRate(Int32 displayIndex, SDL_DisplayMode& adap
 
   // Only change if the display supports a better refresh rate
   return adapt;
+
+#if 0
+  // Adapting resfresh rate and display size
+  const bool hiDpi = myOSystem.settings().getBool("hidpi");
+  const float mult = float(font().getFontHeight()) / getFontDesc("medium").height * hiDpi ? 2 : 1;
+  const Int32 minWidth  = FBMinimum::Width * mult;
+  const Int32 minHeight = FBMinimum::Height * mult;
+  SDL_DisplayMode sdlMode;
+
+  if(SDL_GetCurrentDisplayMode(displayIndex, &sdlMode) != 0)
+  {
+    Logger::error("ERROR: Display mode could not be retrieved");
+    return false;
+  }
+
+  const int numModes = SDL_GetNumDisplayModes(displayIndex);
+  if(numModes < 0)
+  {
+    Logger::error("ERROR: Number of display modes could not be retrieved");
+    return false;
+  }
+
+  const int currentRefreshRate = sdlMode.refresh_rate;
+  const int wantedRefreshRate = gameRefreshRate();
+  // Take care of rounded refresh rates (e.g. 59.94)
+  float factor = std::min(float(currentRefreshRate) / wantedRefreshRate,
+                          float(currentRefreshRate) / (wantedRefreshRate - 1));
+  // Calculate difference taking care of integer factors (e.g. 100/120)
+  float bestDiff = std::abs(factor - std::round(factor)) / factor;
+  bool adapt = false;
+
+  for(int mode = 0; mode < numModes; ++mode)
+  {
+    // Note: Display modes returned are sorted by width, height,... refresh_rate
+    if(SDL_GetDisplayMode(displayIndex, mode, &sdlMode) != 0)
+    {
+      Logger::error("ERROR: Display modes could not be retrieved");
+      return false;
+    }
+    // skip too small modes
+    if(sdlMode.w < minWidth || sdlMode.h < minHeight)
+      continue;
+
+    cerr << sdlMode.w << "x" << sdlMode.h << " " << sdlMode.refresh_rate << " Hz" << endl;
+
+    factor = std::min(float(sdlMode.refresh_rate) / wantedRefreshRate,
+                      float(sdlMode.refresh_rate) / (wantedRefreshRate - 1));
+    const float diff = std::abs(factor - std::round(factor)) / factor;
+    if(diff < bestDiff)
+    {
+      bestDiff = diff;
+      adaptedSdlMode = sdlMode;
+      adapt = true;
+    }
+  }
+
+  cerr << "refresh rate adapt ";
+  if(adapt)
+    cerr << "required (" << currentRefreshRate << " Hz -> " << adaptedSdlMode.refresh_rate << " Hz)";
+  else
+    cerr << "not required/possible";
+  cerr << endl;
+
+  // Only change if the display supports a better refresh rate
+  return adapt;
+#endif
 }
+#endif
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 bool FrameBufferSDL2::createRenderer(bool force)
@@ -540,7 +621,7 @@ int FrameBufferSDL2::gameRefreshRate() const
     const string format = myOSystem.console().getFormatString();
     const bool isNtsc = format == "NTSC" || format == "PAL60" || format == "SECAM60";
 
-    return isNtsc ? 60 : 50;
+    return isNtsc ? 60 : 50; // The code will take care of 59/49 Hz
   }
   return 0;
 }

src/common/FrameBufferSDL2.hxx

@@ -181,6 +181,7 @@ class FrameBufferSDL2 : public FrameBuffer
     */
     bool setVideoMode(const string& title, const VideoMode& mode) override;
 
+  #ifndef BSPF_MACOS
     /**
       Checks if the display refresh rate should be adapted to game refresh rate in (real) fullscreen mode
 
@@ -190,6 +191,7 @@ class FrameBufferSDL2 : public FrameBuffer
       @return  True if the refresh rate should be changed
     */
     bool adaptRefreshRate(Int32 displayIndex, SDL_DisplayMode& adaptedSdlMode);
+  #endif
 
     /**
       Create a new renderer if required

src/gui/VideoAudioDialog.cxx

@@ -153,10 +153,12 @@ void VideoAudioDialog::addDisplayTab()
   myUseStretch = new CheckboxWidget(myTab, _font, xpos + INDENT, ypos + 1, "Stretch");
   wid.push_back(myUseStretch);
 
+#ifndef BSPF_MACOS
   // Adapt refresh rate
   ypos += lineHeight + VGAP;
   myRefreshAdapt = new CheckboxWidget(myTab, _font, xpos + INDENT, ypos + 1, "Adapt display refresh rate");
   wid.push_back(myRefreshAdapt);
+#endif
 
   // FS overscan
   ypos += lineHeight + VGAP;
@@ -484,8 +486,10 @@ void VideoAudioDialog::loadConfig()
   myFullScreenMode->setSelected(mode);*/
   // Fullscreen stretch setting
   myUseStretch->setState(instance().settings().getBool("tia.fs_stretch"));
+#ifndef BSPF_MACOS
   // Adapt refresh rate
   myRefreshAdapt->setState(instance().settings().getBool("tia.fs_refresh"));
+#endif
   // Fullscreen overscan setting
   myTVOverscan->setValue(instance().settings().getInt("tia.fs_overscan"));
   handleFullScreenChange();
@@ -597,8 +601,10 @@ void VideoAudioDialog::saveConfig()
   instance().settings().setValue("fullscreen", myFullscreen->getState());
   // Fullscreen stretch setting
   instance().settings().setValue("tia.fs_stretch", myUseStretch->getState());
+#ifndef BSPF_MACOS
   // Adapt refresh rate
   instance().settings().setValue("tia.fs_refresh", myRefreshAdapt->getState());
+#endif
   // Fullscreen overscan
   instance().settings().setValue("tia.fs_overscan", myTVOverscan->getValueLabel());
 
@@ -712,7 +718,9 @@ void VideoAudioDialog::setDefaults()
       myFullscreen->setState(false);
       //myFullScreenMode->setSelectedIndex(0);
       myUseStretch->setState(false);
+    #ifndef BSPF_MACOS
       myRefreshAdapt->setState(false);
+    #endif
       myTVOverscan->setValue(0);
       myTIAZoom->setValue(300);
       myVSizeAdjust->setValue(0);
@@ -838,7 +846,9 @@ void VideoAudioDialog::handleFullScreenChange()
 {
   bool enable = myFullscreen->getState();
   myUseStretch->setEnabled(enable);
+#ifndef BSPF_MACOS
   myRefreshAdapt->setEnabled(enable);
+#endif
   myTVOverscan->setEnabled(enable);
 }
 

src/gui/VideoAudioDialog.hxx

@@ -73,7 +73,9 @@ class VideoAudioDialog : public Dialog
     CheckboxWidget*   myFullscreen{nullptr};
     CheckboxWidget*   myUseStretch{nullptr};
     SliderWidget*     myTVOverscan{nullptr};
+  #ifndef BSPF_MACOS
     CheckboxWidget*   myRefreshAdapt{nullptr};
+  #endif
     SliderWidget*     myTIAZoom{nullptr};
     SliderWidget*     myVSizeAdjust{nullptr};