Bug fixing, harcode min ystart to 0.

.vscode/settings.json

@@ -64,6 +64,9 @@
         "__hash_table": "cpp",
         "array": "cpp",
         "queue": "cpp",
-        "unordered_map": "cpp"
+        "unordered_map": "cpp",
+        "istream": "cpp",
+        "thread": "cpp",
+        "utility": "cpp"
     }
 }

src/emucore/Console.cxx

@@ -680,10 +680,9 @@ void Console::changeYStart(int direction)
   }
   else if(direction == -1)  // decrease YStart
   {
-    if(ystart == TIAConstants::minYStart-1 && myAutodetectedYstart > 0)
+    if(ystart == 0)
     {
-      myOSystem.frameBuffer().showMessage("YStart at minimum");
+      throw runtime_error("cannot happen");
-      return;
     }
 
     --ystart;
@@ -694,7 +693,7 @@ void Console::changeYStart(int direction)
 
   ostringstream val;
   val << ystart;
-  if(ystart == TIAConstants::minYStart-1) {
+  if(ystart == 0) {
     redetectYStart();
     ystart = myAutodetectedYstart;
 
@@ -707,12 +706,12 @@ void Console::changeYStart(int direction)
       // We've reached the auto-detect value, so reset
       myOSystem.frameBuffer().showMessage("YStart " + val.str() + " (Auto)");
       val.str("");
-      val << TIAConstants::minYStart-1;
+      val << static_cast<int>(0);
     }
     else
       myOSystem.frameBuffer().showMessage("YStart " + val.str());
 
-    myAutodetectedYstart = false;
+    myYStartAutodetected = false;
   }
 
   myProperties.set(Display_YStart, val.str());
@@ -723,14 +722,23 @@ void Console::changeYStart(int direction)
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void Console::updateYStart(uInt32 ystart)
 {
-  if (ystart == TIAConstants::minYStart-1 && !myYStartAutodetected) {
+  if (ystart > TIAConstants::maxYStart) return;
-    redetectYStart();
-    ystart = myAutodetectedYstart;
-  } else if (ystart <= TIAConstants::maxYStart) myYStartAutodetected = false;
 
-  if (ystart <= TIAConstants::maxYStart) {
+  ostringstream ss;
+  ss << ystart;
+
+  if (ss.str() == myProperties.get(Display_YStart)) return;
+
+  myProperties.set(Display_YStart, ss.str());
+
+  if (ystart == 0) {
+    redetectYStart();
+    myTIA->setYStart(myAutodetectedYstart);
+    myTIA->frameReset();
+  } else {
     myTIA->setYStart(ystart);
     myTIA->frameReset();
+    myYStartAutodetected = false;
   }
 }
 
@@ -772,7 +780,7 @@ void Console::setTIAProperties()
 {
   uInt32 ystart = atoi(myProperties.get(Display_YStart).c_str());
   if(ystart != 0)
-    ystart = BSPF::clamp(ystart, TIAConstants::minYStart, TIAConstants::maxYStart);
+    ystart = BSPF::clamp(ystart, 0u, TIAConstants::maxYStart);
   uInt32 height = atoi(myProperties.get(Display_Height).c_str());
   if(height != 0)
     height = BSPF::clamp(height, TIAConstants::minViewableHeight, TIAConstants::maxViewableHeight);

src/emucore/tia/TIAConstants.hxx

@@ -23,7 +23,7 @@
 namespace TIAConstants {
 
   constexpr uInt32 frameBufferHeight = 320;
-  constexpr uInt32 minYStart = 1, maxYStart = 64;
+  constexpr uInt32 maxYStart = 64;
   constexpr uInt32 minViewableHeight = 210, maxViewableHeight = 256;
   constexpr uInt32 initialGarbageFrames = 10;
 }

src/gui/GameInfoDialog.cxx

@@ -307,10 +307,10 @@ GameInfoDialog::GameInfoDialog(
   t = new StaticTextWidget(myTab, font, HBORDER, ypos+2, "Y-start ");
   myYStart = new SliderWidget(myTab, font, t->getRight(), ypos, swidth, lineHeight,
                               "   ", 0, kYStartChanged, 5 * fontWidth, "px");
-  myYStart->setMinValue(TIAConstants::minYStart-1);
+  myYStart->setMinValue(0);
   myYStart->setMaxValue(TIAConstants::maxYStart);
   // one tickmark every ~10 pixel
-  myYStart->setTickmarkInterval((TIAConstants::maxYStart - (TIAConstants::minYStart-1) + 5) / 10);
+  myYStart->setTickmarkInterval((TIAConstants::maxYStart + 5) / 10);
   wid.push_back(myYStart);
 
   int iWidth = ifont.getCharWidth('2');
@@ -532,8 +532,6 @@ void GameInfoDialog::saveConfig()
 
   // Display properties
   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");
@@ -571,6 +569,11 @@ void GameInfoDialog::saveConfig()
     instance().frameBuffer().tiaSurface().enablePhosphor(myPhosphor->getState(), myPPBlend->getValue());
     if (reset)
       instance().console().tia().frameReset();
+  } else {
+    myGameProperties.set(
+      Display_YStart,
+      myYStart->getValueLabel() == "Auto" ? "0" : myYStart->getValueLabel()
+    );
   }
 }
 
@@ -703,7 +706,7 @@ void GameInfoDialog::handleCommand(CommandSender* sender, int cmd,
     }
 
     case kYStartChanged:
-      if(myYStart->getValue() == TIAConstants::minYStart-1)
+      if(myYStart->getValue() == 0)
       {
         myYStart->setValueLabel("Auto");
         myYStart->setValueUnit("");