Changed 'romviewer' option to be treated as a multiplier for the zoom level of snapshots.

Old settings will still work (0 means off, 1 or 2 mean 1x and 2x zoom).  Floats are now supported too,
so we get fractional scaling.

Still TODO is update the UI to modify this setting.

Changes.txt

@@ -120,7 +120,8 @@
   * Added option to change pitch of Pitfall II music.
 
   * ROM Info Launcher can now display multiple lines per property and
-    bank switching type.
+    bank switching type.  Related to this, added fractional (25% increments)
+    snapshot zooms.
 
   * In file listings, you can now select directories by holding 'Shift' on
     the first character entered.  Entering characters in lowercase still

src/emucore/Settings.cxx

@@ -351,7 +351,6 @@ void Settings::validate()
 
   i = getInt("romviewer");
   if(i < 0) setValue("romviewer", "0");
-  else if(i > 2)  setValue("romviewer", "2");
 
   i = getInt("loglevel");
   if(i < int(Logger::Level::MIN) || i > int(Logger::Level::MAX))

src/gui/LauncherDialog.cxx

@@ -37,6 +37,7 @@
 #include "Props.hxx"
 #include "PropsSet.hxx"
 #include "RomInfoWidget.hxx"
+#include "TIAConstants.hxx"
 #include "Settings.hxx"
 #include "Widget.hxx"
 #include "Font.hxx"
@@ -123,15 +124,11 @@ LauncherDialog::LauncherDialog(OSystem& osystem, DialogContainer& parent,
 
   // Add list with game titles
   // Before we add the list, we need to know the size of the RomInfoWidget
-  xpos = HBORDER;  ypos += lineHeight + 4;
+  float imgZoom = getRomInfoZoom();
-  int romWidth = 0;
+  int romWidth = imgZoom * TIAConstants::viewableWidth;
-  int romSize = instance().settings().getInt("romviewer");
+  if(romWidth > 0) romWidth += 10;
-  if(romSize > 1 && w >= 1000 && h >= 720)
-    romWidth = 660;
-  else if(romSize > 0 && w >= 640 && h >= 480)
-    romWidth = 365;
-
   int listWidth = _w - (romWidth > 0 ? romWidth+8 : 0) - 20;
+  xpos = HBORDER;  ypos += lineHeight + 4;
   myList = new FileListWidget(this, font, xpos, ypos,
                               listWidth, _h - 43 - bheight - fontHeight - lineHeight);
   myList->setEditable(false);
@@ -142,10 +139,17 @@ LauncherDialog::LauncherDialog(OSystem& osystem, DialogContainer& parent,
   if(romWidth > 0)
   {
     xpos += myList->getWidth() + 8;
-    myRomInfoWidget = new RomInfoWidget(this,
+
-        romWidth < 660 ? instance().frameBuffer().smallFont() :
+    // Initial surface size is the same as the viewable area
-                         instance().frameBuffer().infoFont(),
+    Common::Size imgSize(TIAConstants::viewableWidth*imgZoom,
-        xpos, ypos, romWidth, myList->getHeight());
+                         TIAConstants::viewableHeight*imgZoom);
+
+    // Calculate font area, and in the process the font that can be used
+    Common::Size fontArea(romWidth, myList->getHeight() - imgSize.h);
+    const GUI::Font& rominfoFont = getRomInfoFont(fontArea);
+
+    myRomInfoWidget = new RomInfoWidget(this, rominfoFont,
+        xpos, ypos, romWidth, myList->getHeight(), imgSize);
   }
 
   // Add textfield to show current directory
@@ -207,8 +211,7 @@ LauncherDialog::LauncherDialog(OSystem& osystem, DialogContainer& parent,
   // Create (empty) context menu for ROM list options
   myMenu = make_unique<ContextMenu>(this, osystem.frameBuffer().font(), EmptyVarList);
 
-
+  // Create global props dialog, which is used to temporarily override
-  // Create global props dialog, which is used to temporarily overrride
   // ROM properties
   myGlobalProps = make_unique<GlobalPropsDialog>(this,
     myUseMinimalUI ? osystem.frameBuffer().launcherFont() : osystem.frameBuffer().font());
@@ -325,6 +328,36 @@ void LauncherDialog::applyFiltering()
   );
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+float LauncherDialog::getRomInfoZoom()
+{
+  // The ROM info area is some multiple of the minimum TIA image size
+  // However, it can't exceed 70% of the total dialog width, nor less than
+  // the base size of the TIA image
+  float zoom = instance().settings().getFloat("romviewer");
+  if(zoom < 1.F)
+    return 0.F;
+  else if(zoom * TIAConstants::viewableWidth > _w * 0.7F)
+    return (_w * 0.7F) / TIAConstants::viewableWidth;
+  else
+    return zoom;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+const GUI::Font& LauncherDialog::getRomInfoFont(const Common::Size& area)
+{
+  // TODO: Perhaps offer a setting to override the font used?
+
+  // Try to pick a font that works best, based on the available area
+  if(area.h / instance().frameBuffer().launcherFont().getLineHeight() >= 8)
+    return instance().frameBuffer().launcherFont();
+  else if(area.h / instance().frameBuffer().infoFont().getLineHeight() >= 8 &&
+          area.w / instance().frameBuffer().infoFont().getMaxCharWidth() >= 80)
+    return instance().frameBuffer().infoFont();
+  else
+    return instance().frameBuffer().smallFont();
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void LauncherDialog::loadRomInfo()
 {

src/gui/LauncherDialog.hxx

@@ -98,6 +98,9 @@ class LauncherDialog : public Dialog
     void updateUI();
     void applyFiltering();
 
+    float getRomInfoZoom();
+    const GUI::Font& getRomInfoFont(const Common::Size& area);
+
     void loadRom();
     void loadRomInfo();
     void handleContextMenu();

src/gui/RomInfoWidget.cxx

@@ -29,16 +29,14 @@
 #include "PNGLibrary.hxx"
 #include "Rect.hxx"
 #include "Widget.hxx"
-#include "TIAConstants.hxx"
 #include "RomInfoWidget.hxx"
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 RomInfoWidget::RomInfoWidget(GuiObject* boss, const GUI::Font& font,
-                             int x, int y, int w, int h)
+                             int x, int y, int w, int h,
+                             const Common::Size& imgSize)
   : Widget(boss, font, x, y, w, h),
-    myAvail(w > 400 ?
+    myAvail(imgSize)
-      Common::Size(TIAConstants::viewableWidth*2, TIAConstants::viewableHeight*2) :
-      Common::Size(TIAConstants::viewableWidth, TIAConstants::viewableHeight))
 {
   _flags = Widget::FLAG_ENABLED;
   _bgcolor = kDlgColor;
@@ -87,7 +85,7 @@ void RomInfoWidget::parseProperties(const FilesystemNode& node)
   if(mySurface == nullptr)
   {
     mySurface = instance().frameBuffer().allocateSurface(
-        TIAConstants::viewableWidth*2, TIAConstants::viewableHeight*2, FrameBuffer::ScalingInterpolation::blur);
+        myAvail.w, myAvail.h, FrameBuffer::ScalingInterpolation::blur);
     mySurface->applyAttributes();
 
     dialog().addSurface(mySurface);
@@ -205,11 +203,12 @@ void RomInfoWidget::drawWidget(bool hilite)
     s.drawString(font, mySurfaceErrorMsg, x, y, _w - 10, onTop ? _textcolor : _shadowcolor);
   }
 
-  int xpos = _x + 8, ypos = _y + yoff + 10;
+  int xpos = _x + 8, ypos = _y + yoff + 5;
   for(const auto& info: myRomInfo)
   {
     int lines = s.drawString(_font, info, xpos, ypos, _w - 16, _font.getFontHeight() * 3,
                              onTop ? _textcolor : _shadowcolor);
+    if(ypos >= _h)  break;
     ypos += _font.getLineHeight() + (lines - 1) * _font.getFontHeight();
   }
 }

src/gui/RomInfoWidget.hxx

@@ -31,7 +31,8 @@ class RomInfoWidget : public Widget
 {
   public:
     RomInfoWidget(GuiObject *boss, const GUI::Font& font,
-                  int x, int y, int w, int h);
+                  int x, int y, int w, int h,
+                  const Common::Size& imgSize);
     virtual ~RomInfoWidget() = default;
 
     void setProperties(const Properties& props, const FilesystemNode& node);