Another pass at resolving ystart issues. Reverts 02b0c13a and b9bbbe1 .

src/emucore/Console.cxx

@@ -87,6 +87,7 @@ Console::Console(OSystem& osystem, unique_ptr<Cartridge>& cart,
     myCurrentFormat(0),   // Unknown format @ start,
     myAutodetectedYstart(0),
     myYStartAutodetected(false),
+    myFormatAutodetected(false),
     myUserPaletteDefined(false),
     myConsoleTiming(ConsoleTiming::ntsc),
     myAudioSettings(audioSettings)
@@ -143,6 +144,7 @@ Console::Console(OSystem& osystem, unique_ptr<Cartridge>& cart,
     {
       autodetected = "*";
       myCurrentFormat = 0;
+      myFormatAutodetected = true;
     }
   }
 
@@ -284,8 +286,6 @@ void Console::autodetectYStart(bool reset)
 
   // Don't forget to reset the SC progress bars again
   myOSystem.settings().setValue("fastscbios", fastscbios);
-
-  myYStartAutodetected = true;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -370,17 +370,17 @@ void Console::setFormat(uInt32 format)
 
   string saveformat, message;
   string autodetected = "";
-  bool reset = true;
 
   myCurrentFormat = format;
   switch(myCurrentFormat)
   {
     case 0:  // auto-detect
     {
+      if (myFormatAutodetected) return;
+
       string oldDisplayFormat = myDisplayFormat;
       redetectFrameLayout();
-      myTIA->update();
+      myFormatAutodetected = true;
-      reset = oldDisplayFormat != myDisplayFormat;
       saveformat = "AUTO";
       autodetected = "*";
       myConsoleTiming = myDisplayFormat == "PAL" ? ConsoleTiming::pal : ConsoleTiming::ntsc;
@@ -391,45 +391,48 @@ void Console::setFormat(uInt32 format)
       saveformat = myDisplayFormat = "NTSC";
       myConsoleTiming = ConsoleTiming::ntsc;
       message = "NTSC mode";
+      myFormatAutodetected = false;
       break;
     case 2:
       saveformat = myDisplayFormat = "PAL";
       myConsoleTiming = ConsoleTiming::pal;
       message = "PAL mode";
+      myFormatAutodetected = false;
       break;
     case 3:
       saveformat = myDisplayFormat = "SECAM";
       myConsoleTiming = ConsoleTiming::secam;
       message = "SECAM mode";
+      myFormatAutodetected = false;
       break;
     case 4:
       saveformat = myDisplayFormat = "NTSC50";
       myConsoleTiming = ConsoleTiming::ntsc;
       message = "NTSC50 mode";
+      myFormatAutodetected = false;
       break;
     case 5:
       saveformat = myDisplayFormat = "PAL60";
       myConsoleTiming = ConsoleTiming::pal;
       message = "PAL60 mode";
+      myFormatAutodetected = false;
       break;
     case 6:
       saveformat = myDisplayFormat = "SECAM60";
       myConsoleTiming = ConsoleTiming::secam;
       message = "SECAM60 mode";
+      myFormatAutodetected = false;
       break;
   }
   myProperties.set(Display_Format, saveformat);
 
   myConsoleInfo.DisplayFormat = myDisplayFormat + autodetected;
 
-  if(reset)
+  setPalette(myOSystem.settings().getString("palette"));
-  {
+  setTIAProperties();
-    setPalette(myOSystem.settings().getString("palette"));
+  initializeVideo();  // takes care of refreshing the screen
-    setTIAProperties();
+  initializeAudio(); // ensure that audio synthesis is set up to match emulation speed
-    initializeVideo(); // takes care of refreshing the screen
+  myOSystem.resetFps(); // Reset FPS measurement
-    initializeAudio(); // ensure that audio synthesis is set up to match emulation speed
-    myOSystem.resetFps(); // Reset FPS measurement
-  }
 
   myOSystem.frameBuffer().showMessage(message);
 
@@ -696,31 +699,28 @@ void Console::changeYStart(int direction)
   else
     return;
 
-  ostringstream val;
-  val << ystart;
   if(ystart == 0) {
     redetectYStart();
     ystart = myAutodetectedYstart;
+    myYStartAutodetected = true;
 
-    myOSystem.frameBuffer().showMessage("YStart autodetected");
+    myProperties.set(Display_YStart, "0");
   }
-  else
+  else {
-  {
+    ostringstream ss;
-    if(myAutodetectedYstart > 0 && myAutodetectedYstart == ystart)
+    ss << ystart;
-    {
-      // We've reached the auto-detect value, so reset
-      myOSystem.frameBuffer().showMessage("YStart " + val.str() + " (Auto)");
-      val.str("");
-      val << static_cast<int>(0);
-    }
-    else
-      myOSystem.frameBuffer().showMessage("YStart " + val.str());
 
-    myYStartAutodetected = false;
+    myProperties.set(Display_YStart, ss.str());
   }
 
-  myProperties.set(Display_YStart, val.str());
+  if (ystart != myTIA->ystart()) myTIA->setYStart(ystart);
-  myTIA->setYStart(ystart);
+
+  ostringstream ss;
+
+  if(myAutodetectedYstart == ystart) ss << "YStart " << ystart << " (Auto)";
+  else ss << "YStart " << ystart;
+
+  myOSystem.frameBuffer().showMessage(ss.str());
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -728,20 +728,15 @@ void Console::updateYStart(uInt32 ystart)
 {
   if (ystart > TIAConstants::maxYStart) return;
 
-  ostringstream ss;
-  ss << ystart;
-
-  if (ss.str() == myProperties.get(Display_YStart)) return;
-
-  myProperties.set(Display_YStart, ss.str());
-
   if (ystart == 0) {
+    if (myYStartAutodetected) return;
+
     redetectYStart();
-    myTIA->setYStart(myAutodetectedYstart);
+    myYStartAutodetected = true;
-  } else {
+    ystart = myAutodetectedYstart;
-    myTIA->setYStart(ystart);
-    myYStartAutodetected = false;
   }
+
+  if (ystart != myTIA->ystart()) myTIA->setYStart(ystart);
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -782,6 +777,11 @@ void Console::setTIAProperties()
   uInt32 ystart = atoi(myProperties.get(Display_YStart).c_str());
   if(ystart != 0)
     ystart = BSPF::clamp(ystart, 0u, TIAConstants::maxYStart);
+  else {
+    ystart = myAutodetectedYstart;
+    myYStartAutodetected = true;
+  }
+
   uInt32 height = atoi(myProperties.get(Display_Height).c_str());
   if(height != 0)
     height = BSPF::clamp(height, TIAConstants::minViewableHeight, TIAConstants::maxViewableHeight);
@@ -801,7 +801,7 @@ void Console::setTIAProperties()
     myTIA->setLayout(FrameLayout::pal);
   }
 
-  myTIA->setYStart(myAutodetectedYstart ? myAutodetectedYstart : ystart);
+  myTIA->setYStart(ystart);
   myTIA->setHeight(height);
 
   myEmulationTiming.updateFrameLayout(myTIA->frameLayout());

src/emucore/Console.hxx

@@ -420,6 +420,9 @@ class Console : public Serializable
     // Is ystart currently autodetected?
     bool myYStartAutodetected;
 
+    // Is the TV format autodetected?
+    bool myFormatAutodetected;
+
     // Indicates whether an external palette was found and
     // successfully loaded
     bool myUserPaletteDefined;

src/emucore/tia/TIA.cxx

@@ -178,7 +178,7 @@ void TIA::reset()
   if (myFrameManager)
   {
     myFrameManager->reset();
-    enableColorLoss(mySettings.getBool(mySettings.getBool("dev.settings") ? "dev.colorloss" : "plr.colorloss"));
+    frameReset();  // Recalculate the size of the display
   }
 
   myFrontBufferScanlines = myFrameBufferScanlines = 0;
@@ -189,16 +189,20 @@ void TIA::reset()
   enableFixedColors(mySettings.getBool(mySettings.getBool("dev.settings") ? "dev.debugcolors" : "plr.debugcolors"));
   setFixedColorPalette(mySettings.getString("tia.dbgcolors"));
 
-  // Blank the various framebuffers; they may contain graphical garbage
-  memset(myBackBuffer, 0, 160 * TIAConstants::frameBufferHeight);
-  memset(myFrontBuffer, 0, 160 * TIAConstants::frameBufferHeight);
-  memset(myFramebuffer, 0, 160 * TIAConstants::frameBufferHeight);
-
 #ifdef DEBUGGER_SUPPORT
   createAccessBase();
 #endif // DEBUGGER_SUPPORT
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+void TIA::frameReset()
+{
+  memset(myBackBuffer, 0, 160 * TIAConstants::frameBufferHeight);
+  memset(myFrontBuffer, 0, 160 * TIAConstants::frameBufferHeight);
+  memset(myFramebuffer, 0, 160 * TIAConstants::frameBufferHeight);
+  enableColorLoss(mySettings.getBool(mySettings.getBool("dev.settings") ? "dev.colorloss" : "plr.colorloss"));
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void TIA::install(System& system)
 {

src/emucore/tia/TIA.hxx

@@ -136,6 +136,11 @@ class TIA : public Device
     */
     void reset() override;
 
+    /**
+      Reset frame to current YStart/Height properties.
+    */
+    void frameReset();
+
     /**
       Install TIA in the specified system.  Invoked by the system
       when the TIA is attached to it.
@@ -249,7 +254,7 @@ class TIA : public Device
     /**
       Changes the current Height/YStart properties.
       Note that calls to these method(s) must be eventually followed by
-      ::reset() for the changes to take effect.
+      ::frameReset() for the changes to take effect.
     */
     void setHeight(uInt32 height) { myFrameManager->setFixedHeight(height); }
     void setYStart(uInt32 ystart) { myFrameManager->setYstart(ystart); }

src/gui/GameInfoDialog.cxx

@@ -531,22 +531,18 @@ void GameInfoDialog::saveConfig()
   myGameProperties.set(Controller_MouseAxis, mcontrol);
 
   // Display properties
-  const string& ystart = myGameProperties.get(Display_YStart);
+  myGameProperties.set(Display_YStart, myYStart->getValue() == 0 ? "0" : myYStart->getValueLabel());
-  uInt32 oldYStart = atoi(ystart.c_str());
-  const string& height = myGameProperties.get(Display_Height);
-  uInt32 oldHeight = atoi(height.c_str());
-
   myGameProperties.set(Display_Format, myFormat->getSelectedTag().toString());
-  myGameProperties.set(Display_YStart, myYStart->getValueLabel() == "Auto" ? "0" :
-                       myYStart->getValueLabel());
   myGameProperties.set(Display_Height, myHeight->getValueLabel() == "Auto" ? "0" :
                        myHeight->getValueLabel());
   myGameProperties.set(Display_Phosphor, myPhosphor->getState() ? "YES" : "NO");
+
   myGameProperties.set(Display_PPBlend, myPPBlend->getValueLabel() == "Default" ? "0" :
                        myPPBlend->getValueLabel());
 
   // Always insert; if the properties are already present, nothing will happen
   instance().propSet().insert(myGameProperties);
+  instance().saveConfig();
 
   // In any event, inform the Console
   if(instance().hasConsole())
@@ -563,28 +559,14 @@ void GameInfoDialog::saveConfig()
 
     // update 'Display' tab settings immediately
     instance().console().setFormat(myFormat->getSelected());
+    instance().console().updateYStart(myYStart->getValue());
 
-    // only call tia().reset() when values have changed
+    if(uInt32(myHeight->getValue()) != TIAConstants::minViewableHeight - 1 &&
-    bool reset = false;
-    if(uInt32((myYStart->getValue()) != 0 || oldYStart != 0) &&
-      uInt32(myYStart->getValue()) != instance().console().tia().ystart())
-    {
-      instance().console().updateYStart(myYStart->getValue());
-      reset = true;
-    }
-    if(uInt32((myHeight->getValue()) != TIAConstants::minViewableHeight - 1 || oldHeight != 0) &&
        uInt32(myHeight->getValue()) != instance().console().tia().height())
     {
       instance().console().tia().setHeight(myHeight->getValue());
-      reset = true;
     }
     instance().frameBuffer().tiaSurface().enablePhosphor(myPhosphor->getState(), myPPBlend->getValue());
-    if (reset)
-      instance().console().tia().reset();
-
-    // Certain calls above may blank the TIA image (notably, setFormat)
-    // So we make sure we have a valid image when the dialog exits
-    instance().console().tia().renderToFrameBuffer();
   }
 }