added optional refresh rate adaption in fullscreen mode

src/common/FrameBufferSDL2.cxx

@@ -340,9 +340,74 @@ bool FrameBufferSDL2::setVideoMode(const string& title, const VideoMode& mode)
   if(SDL_GetRendererInfo(myRenderer, &renderinfo) >= 0)
     myOSystem.settings().setValue("video", renderinfo.name);
 
+  adaptRefreshRate();
+
   return true;
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+bool FrameBufferSDL2::adaptRefreshRate()
+{
+  const bool adapt = myOSystem.settings().getBool("tia.refresh");
+
+  // adapt only in emulation (and debugger?) and fullscreen mode
+  // TODO: adapt while creating new window
+  if(adapt && fullScreen()
+     && (myBufferType == BufferType::Emulator/* || myBufferType == BufferType::Debugger*/))
+  {
+    SDL_DisplayMode sdlMode;
+
+    if(SDL_GetWindowDisplayMode(myWindow, &sdlMode) != 0)
+    {
+      Logger::error("Display mode could not be retrieved");
+      return false;
+    }
+
+    const int currentRefreshRate = sdlMode.refresh_rate;
+    const string format = myOSystem.console().getFormatString();
+    const bool isNtsc = format == "NTSC" || format == "PAL60" || format == "SECAM60";
+
+    sdlMode.refresh_rate = isNtsc ? 60 : 50; // TODO: check for multiples e.g. 120/100 too
+
+    if(currentRefreshRate != sdlMode.refresh_rate)
+    {
+      const int display = SDL_GetWindowDisplayIndex(myWindow);
+      SDL_DisplayMode closestSdlMode;
+
+      if(SDL_GetClosestDisplayMode(display, &sdlMode, &closestSdlMode) == NULL)
+      {
+        Logger::error("Closest display mode could not be retrieved");
+        return false;
+      }
+      // Note: Modes are scanned with size being first priority,
+      //       therefore the size will never change.
+      // Only change if the display supports a better refresh rate
+      if(currentRefreshRate != closestSdlMode.refresh_rate)
+      {
+        // Switch to new mode
+        if(SDL_SetWindowDisplayMode(myWindow, &closestSdlMode) != 0)
+        {
+          Logger::error("Display refresh rate change failed");
+          return false;
+        }
+        // Any change only works in real fullscreen mode!
+        if(SDL_SetWindowFullscreen(myWindow, SDL_WINDOW_FULLSCREEN) != 0)
+        {
+          Logger::error("Display fullscreen change failed");
+          return false;
+        }
+        ostringstream msg;
+
+        msg << "Display refresh rate changed from " << currentRefreshRate << "Hz to "
+          << closestSdlMode.refresh_rate << "Hz";
+        Logger::info(msg.str());
+        return true;
+      }
+    }
+  }
+  return false;
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void FrameBufferSDL2::setTitle(const string& title)
 {

src/common/FrameBufferSDL2.hxx

@@ -181,6 +181,14 @@ class FrameBufferSDL2 : public FrameBuffer
     */
     bool setVideoMode(const string& title, const VideoMode& mode) override;
 
+
+    /**
+      Adapt display refresh rate to game refresh rate in (real) fullscreen mode
+
+      @return  True if the refresh rate was changed
+    */
+    bool adaptRefreshRate();
+
     /**
       This method is called to create a surface with the given attributes.
 

src/emucore/FrameBuffer.hxx

@@ -81,6 +81,13 @@ class FrameBuffer
       }
     };
 
+    struct DisplayMode
+    {
+      uInt32 display;
+      Common::Size size;
+      uInt32 refresh_rate;
+    };
+
     enum class BufferType {
       None,
       Launcher,
@@ -439,6 +446,7 @@ class FrameBuffer
     virtual int scaleY(int y) const { return y; }
 
   protected:
+
     /**
       This method is called to query and initialize the video hardware
       for desktop and fullscreen resolution information.  Since several

src/emucore/Settings.cxx

@@ -54,6 +54,7 @@ Settings::Settings()
   setPermanent("tia.fs_stretch", "false");
   setPermanent("tia.fs_overscan", "0");
   setPermanent("tia.vsizeadjust", 0);
+  setPermanent("tia.refresh", "false");
   setPermanent("tia.dbgcolors", "roygpb");
   // Palette options
   setPermanent("palette", PaletteHandler::SETTING_STANDARD);

src/gui/VideoAudioDialog.cxx

@@ -166,9 +166,14 @@ void VideoAudioDialog::addDisplayTab()
   myTVOverscan->setMinValue(0); myTVOverscan->setMaxValue(10);
   myTVOverscan->setTickmarkIntervals(2);
   wid.push_back(myTVOverscan);
+
+  // Adapt refresh rate
   ypos += lineHeight + VGAP;
+  myRefreshAdjust = new CheckboxWidget(myTab, _font, xpos + INDENT, ypos + 1, "Adapt refresh rate");
+  wid.push_back(myRefreshAdjust);
 
   // Vertical size
+  ypos += lineHeight + VGAP;
   myVSizeAdjust =
     new SliderWidget(myTab, _font, xpos, ypos-1, swidth, lineHeight,
                      "V-Size adjust", lwidth, kVSizeChanged, fontWidth * 7, "%", 0, true);
@@ -176,6 +181,7 @@ void VideoAudioDialog::addDisplayTab()
   myVSizeAdjust->setTickmarkIntervals(2);
   wid.push_back(myVSizeAdjust);
 
+
   // Add items for tab 0
   addToFocusList(wid, myTab, tabID);
 }
@@ -486,6 +492,8 @@ void VideoAudioDialog::loadConfig()
   myUseStretch->setState(instance().settings().getBool("tia.fs_stretch"));
   // Fullscreen overscan setting
   myTVOverscan->setValue(instance().settings().getInt("tia.fs_overscan"));
+  // Adapt refresh rate
+  myRefreshAdjust->setState(instance().settings().getBool("tia.refresh"));
   handleFullScreenChange();
 
   // Aspect ratio setting (NTSC and PAL)
@@ -597,6 +605,8 @@ void VideoAudioDialog::saveConfig()
   instance().settings().setValue("tia.fs_stretch", myUseStretch->getState());
   // Fullscreen overscan
   instance().settings().setValue("tia.fs_overscan", myTVOverscan->getValueLabel());
+  // Adapt refresh rate
+  instance().settings().setValue("tia.refresh", myRefreshAdjust->getState());
 
   // TIA zoom levels
   instance().settings().setValue("tia.zoom", myTIAZoom->getValue() / 100.0);
@@ -709,6 +719,7 @@ void VideoAudioDialog::setDefaults()
       //myFullScreenMode->setSelectedIndex(0);
       myUseStretch->setState(false);
       myTVOverscan->setValue(0);
+      myRefreshAdjust->setState(false);
       myTIAZoom->setValue(300);
       myVSizeAdjust->setValue(0);
 
@@ -834,6 +845,7 @@ void VideoAudioDialog::handleFullScreenChange()
   bool enable = myFullscreen->getState();
   myUseStretch->setEnabled(enable);
   myTVOverscan->setEnabled(enable);
+  myRefreshAdjust->setEnabled(enable);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

src/gui/VideoAudioDialog.hxx

@@ -74,6 +74,7 @@ class VideoAudioDialog : public Dialog
     //PopUpWidget*      myFullScreenMode;
     CheckboxWidget*   myUseStretch{nullptr};
     SliderWidget*     myTVOverscan{nullptr};
+    CheckboxWidget*   myRefreshAdjust{nullptr};
     SliderWidget*     myTIAZoom{nullptr};
     SliderWidget*     myVSizeAdjust{nullptr};