Dialogs drawn outside the underlying basedialog area no longer leave parts around.

There is still some work TODO for TIA mode; that is coming next.

src/common/FrameBufferSDL2.cxx

@@ -306,11 +306,7 @@ bool FrameBufferSDL2::setVideoMode(const string& title, const VideoMode& mode)
     Logger::log(msg, 0);
     return false;
   }
-
-  // Always clear the (double-buffered) renderer surface
-  SDL_RenderClear(myRenderer);
-  SDL_RenderPresent(myRenderer);
-  SDL_RenderClear(myRenderer);
+  clear();
 
   SDL_RendererInfo renderinfo;
   if(SDL_GetRendererInfo(myRenderer, &renderinfo) >= 0)
@@ -352,15 +348,6 @@ string FrameBufferSDL2::about() const
   return out.str();
 }
 
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void FrameBufferSDL2::invalidate()
-{
-  ASSERT_MAIN_THREAD;
-
-
-  SDL_RenderClear(myRenderer);
-}
-
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void FrameBufferSDL2::showCursor(bool show)
 {
@@ -436,6 +423,7 @@ void FrameBufferSDL2::readPixels(uInt8* pixels, uInt32 pitch,
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void FrameBufferSDL2::clear()
 {
-  invalidate();
-  renderToScreen();
+  ASSERT_MAIN_THREAD;
+
+  SDL_RenderClear(myRenderer);
 }

src/common/FrameBufferSDL2.hxx

@@ -112,7 +112,7 @@ class FrameBufferSDL2 : public FrameBuffer
     void updateWindowedPos() override;
 
     /**
-      Clear the frame buffer
+      Clear the frame buffer.
     */
     void clear() override;
 
@@ -143,13 +143,6 @@ class FrameBufferSDL2 : public FrameBuffer
     */
     bool setVideoMode(const string& title, const VideoMode& mode) override;
 
-    /**
-      This method is called to invalidate the contents of the entire
-      framebuffer (ie, mark the current content as invalid, and erase it on
-      the next drawing pass).
-    */
-    void invalidate() override;
-
     /**
       This method is called to create a surface with the given attributes.
 
@@ -189,7 +182,7 @@ class FrameBufferSDL2 : public FrameBuffer
     // Used by mapRGB (when palettes are created)
     SDL_PixelFormat* myPixelFormat;
 
-    // center setting of curent window
+    // Center setting of current window
     bool myCenter;
 
     // last position of windowed window

src/emucore/FrameBuffer.cxx

@@ -944,7 +944,8 @@ void FrameBuffer::setAvailableVidModes(uInt32 baseWidth, uInt32 baseHeight)
   {
     // Windowed and fullscreen mode differ only in screen size
     myWindowedModeList.add(
-        VideoMode(baseWidth, baseHeight, baseWidth, baseHeight, VideoMode::Stretch::None)
+        VideoMode(baseWidth, baseHeight, baseWidth, baseHeight,
+        VideoMode::Stretch::None)
     );
     for(uInt32 i = 0; i < myFullscreenDisplays.size(); ++i)
     {
@@ -1069,10 +1070,11 @@ FrameBuffer::VideoMode::VideoMode(uInt32 iw, uInt32 ih, uInt32 sw, uInt32 sh,
     {
       case Stretch::Preserve:
       case Stretch::Fill:
-      case Stretch::None:
         screen.w = iw;
         screen.h = ih;
         break;
+      case Stretch::None:
+        break;  // Do not change image or screen rects whatsoever
     }
   }
 

src/emucore/FrameBuffer.hxx

@@ -73,7 +73,8 @@ class FrameBuffer
       friend ostream& operator<<(ostream& os, const VideoMode& vm)
       {
         os << "image=" << vm.image << "  screen=" << vm.screen
-           << "  stretch= " << (vm.stretch == Stretch::Preserve ? "preserve" : "fill")
+           << "  stretch=" << (vm.stretch == Stretch::Preserve ? "preserve" :
+                               vm.stretch == Stretch::Fill ? "fill" : "none")
            << "  desc=" << vm.description << "  zoom=" << vm.zoom
            << "  fsIndex= " << vm.fsIndex;
         return os;
@@ -391,13 +392,6 @@ class FrameBuffer
     virtual bool setVideoMode(const string& title,
                               const FrameBuffer::VideoMode& mode) = 0;
 
-    /**
-      This method is called to invalidate the contents of the entire
-      framebuffer (ie, mark the current content as invalid, and erase it on
-      the next drawing pass).
-    */
-    virtual void invalidate() = 0;
-
     /**
       This method is called to create a surface with the given attributes.
 

src/gui/DialogContainer.cxx

@@ -94,6 +94,8 @@ bool DialogContainer::draw(bool full)
 
   // If the top dialog is dirty, then all below it must be redrawn too
   bool dirty = needsRedraw();
+  if(dirty)
+    myOSystem.frameBuffer().clear();
 
   myDialogStack.applyAll([&](Dialog*& d){
     if(dirty)