make Stella remember the last window position (now Center option makes a difference!)

src/common/FrameBufferSDL2.cxx

@@ -31,7 +31,8 @@
 FrameBufferSDL2::FrameBufferSDL2(OSystem& osystem)
   : FrameBuffer(osystem),
     myWindow(nullptr),
-    myRenderer(nullptr)
+    myRenderer(nullptr),
+    myCenter(false)
 {
   ASSERT_MAIN_THREAD;
 
@@ -88,11 +89,11 @@ void FrameBufferSDL2::queryHardware(vector<Common::Size>& fullscreenRes,
   ASSERT_MAIN_THREAD;
 
   // Get number of displays (for most systems, this will be '1')
-  int maxDisplays = SDL_GetNumVideoDisplays();
+  myNumDisplays = SDL_GetNumVideoDisplays();
 
   // First get the maximum fullscreen desktop resolution
   SDL_DisplayMode display;
-  for(int i = 0; i < maxDisplays; ++i)
+  for(int i = 0; i < myNumDisplays; ++i)
   {
     SDL_GetDesktopDisplayMode(i, &display);
     fullscreenRes.emplace_back(display.w, display.h);
@@ -102,14 +103,14 @@ void FrameBufferSDL2::queryHardware(vector<Common::Size>& fullscreenRes,
   // Try to take into account taskbars, etc, if available
 #if SDL_VERSION_ATLEAST(2,0,5)
   SDL_Rect r;
-  for(int i = 0; i < maxDisplays; ++i)
+  for(int i = 0; i < myNumDisplays; ++i)
   {
     // Display bounds minus dock
     SDL_GetDisplayUsableBounds(i, &r);  // Requires SDL-2.0.5 or higher
     windowedRes.emplace_back(r.w, r.h);
   }
 #else
-  for(int i = 0; i < maxDisplays; ++i)
+  for(int i = 0; i < myNumDisplays; ++i)
   {
     SDL_GetDesktopDisplayMode(i, &display);
     windowedRes.emplace_back(display.w, display.h);
@@ -162,6 +163,27 @@ Int32 FrameBufferSDL2::getCurrentDisplayIndex()
   return SDL_GetWindowDisplayIndex(myWindow);
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+void FrameBufferSDL2::getCurrentWindowPos(int& x, int&y)
+{
+  ASSERT_MAIN_THREAD;
+
+  if (myCenter ||
+    !myWindow || (SDL_GetWindowFlags(myWindow) & SDL_WINDOW_FULLSCREEN_DESKTOP))
+  {
+    // restore to last saved window position
+    x = myOSystem.settings().getInt("pos.x");
+    y = myOSystem.settings().getInt("pos.y");
+  }
+  else
+  {
+    // save current window position
+    SDL_GetWindowPosition(myWindow, &x, &y);
+    myOSystem.settings().setValue("pos.x", x);
+    myOSystem.settings().setValue("pos.y", y);
+  }
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 bool FrameBufferSDL2::setVideoMode(const string& title, const VideoMode& mode)
 {
@@ -171,15 +193,8 @@ bool FrameBufferSDL2::setVideoMode(const string& title, const VideoMode& mode)
   if(SDL_WasInit(SDL_INIT_VIDEO) == 0)
     return false;
 
-  // Always recreate renderer (some systems need this)
-  if(myRenderer)
-  {
-    SDL_DestroyRenderer(myRenderer);
-    myRenderer = nullptr;
-  }
-
   Int32 displayIndex = mode.fsIndex;
-  if(displayIndex == -1)
+  if (displayIndex == -1)
   {
     // windowed mode
     if (myWindow)
@@ -187,16 +202,27 @@ bool FrameBufferSDL2::setVideoMode(const string& title, const VideoMode& mode)
       // Show it on same screen as the previous window
       displayIndex = SDL_GetWindowDisplayIndex(myWindow);
     }
-    if(displayIndex < 0)
+    if (displayIndex < 0)
     {
-      // fallback to the first screen
+      // fallback to the last used screen if still existing
-      displayIndex = 0;
+      displayIndex = std::min(myNumDisplays, myOSystem.settings().getInt("display"));
     }
   }
 
-  uInt32 pos = myOSystem.settings().getBool("center")
+  // get current windows position
-                 ? SDL_WINDOWPOS_CENTERED_DISPLAY(displayIndex)
+  int posX, posY;
-                 : SDL_WINDOWPOS_UNDEFINED_DISPLAY(displayIndex);
+  getCurrentWindowPos(posX, posY);
+
+  // Always recreate renderer (some systems need this)
+  if(myRenderer)
+  {
+    SDL_DestroyRenderer(myRenderer);
+    myRenderer = nullptr;
+  }
+
+  myCenter = myOSystem.settings().getBool("center");
+  if (myCenter)
+    posX = posY = SDL_WINDOWPOS_CENTERED_DISPLAY(displayIndex);
   uInt32 flags = mode.fsIndex != -1 ? SDL_WINDOW_FULLSCREEN_DESKTOP : 0;
 
   // macOS seems to have issues with destroying the window, and wants to
@@ -221,6 +247,7 @@ bool FrameBufferSDL2::setVideoMode(const string& title, const VideoMode& mode)
   {
     // Even though window size stayed the same, the title may have changed
     SDL_SetWindowTitle(myWindow, title.c_str());
+    SDL_SetWindowPosition(myWindow, posX, posY);
   }
 #else
   // macOS wants to *never* re-create the window
@@ -236,7 +263,7 @@ bool FrameBufferSDL2::setVideoMode(const string& title, const VideoMode& mode)
 #endif
   else
   {
-    myWindow = SDL_CreateWindow(title.c_str(), pos, pos,
+    myWindow = SDL_CreateWindow(title.c_str(), posX, posY,
                                 mode.screen.w, mode.screen.h, flags);
     if(myWindow == nullptr)
     {
@@ -311,6 +338,7 @@ void FrameBufferSDL2::invalidate()
 {
   ASSERT_MAIN_THREAD;
 
+
   SDL_RenderClear(myRenderer);
 }
 

src/common/FrameBufferSDL2.hxx

@@ -97,6 +97,23 @@ class FrameBufferSDL2 : public FrameBuffer
     */
     void readPixels(uInt8* buffer, uInt32 pitch, const Common::Rect& rect) const override;
 
+    /**
+      This method is called to query the video hardware for the index
+      of the display the current window is displayed on
+
+      @return  the current display index or a negative value if no
+               window is displayed
+    */
+    Int32 getCurrentDisplayIndex() override;
+
+    /**
+      This method is called to query the current window position.
+
+      @param x  The x-position retrieved
+      @param y  The y-position retrieved
+    */
+    void getCurrentWindowPos(int& x, int& y) override;
+
     /**
       Clear the frame buffer
     */
@@ -119,15 +136,6 @@ class FrameBufferSDL2 : public FrameBuffer
                        vector<Common::Size>& windowedRes,
                        VariantList& renderers) override;
 
-    /**
-      This method is called to query the video hardware for the index
-      of the display the current window is displayed on
-
-      @return  the current display index or a negative value if no
-               window is displayed
-    */
-    Int32 getCurrentDisplayIndex() override;
-
     /**
       This method is called to change to the given video mode.
 
@@ -184,6 +192,9 @@ class FrameBufferSDL2 : public FrameBuffer
     // Used by mapRGB (when palettes are created)
     SDL_PixelFormat* myPixelFormat;
 
+    // center setting of curent window
+    bool myCenter;
+
   private:
     // Following constructors and assignment operators not supported
     FrameBufferSDL2() = delete;

src/emucore/FrameBuffer.cxx

@@ -55,7 +55,8 @@ FrameBuffer::FrameBuffer(OSystem& osystem)
     myGrabMouse(false),
     myHiDPIAllowed(false),
     myHiDPIEnabled(false),
-    myCurrentModeList(nullptr)
+    myCurrentModeList(nullptr),
+    myNumDisplays(1)
 {
 }
 

src/emucore/FrameBuffer.hxx

@@ -335,6 +335,23 @@ class FrameBuffer
     */
     virtual void readPixels(uInt8* buffer, uInt32 pitch, const Common::Rect& rect) const = 0;
 
+    /**
+      This method is called to query the video hardware for the index
+      of the display the current window is displayed on
+
+      @return  the current display index or a negative value if no
+               window is displayed
+    */
+    virtual Int32 getCurrentDisplayIndex() = 0;
+
+    /**
+      This method is called to query the current window position.
+
+      @param x  The x-position retrieved
+      @param y  The y-position retrieved
+    */
+    virtual void getCurrentWindowPos(int& x, int& y) = 0;
+
     /**
       Clear the framebuffer.
     */
@@ -354,8 +371,6 @@ class FrameBuffer
                                vector<Common::Size>& windowedRes,
                                VariantList& renderers) = 0;
 
-    virtual Int32 getCurrentDisplayIndex() = 0;
-
     /**
       This method is called to change to the given video mode.
 
@@ -497,6 +512,14 @@ class FrameBuffer
     // Title of the main window/screen
     string myScreenTitle;
 
+    // Number of displays
+    int myNumDisplays;
+
+    // The resolution of the attached displays in fullscreen mode
+    // The primary display is typically the first in the array
+    // Windowed modes use myDesktopSize directly
+    vector<Common::Size> myFullscreenDisplays;
+
   private:
     // Draws the frame stats overlay
     void drawFrameStats(float framesPerSecond);
@@ -522,11 +545,6 @@ class FrameBuffer
     // Maximum absolute dimensions of the desktop area
     Common::Size myAbsDesktopSize;
 
-    // The resolution of the attached displays in fullscreen mode
-    // The primary display is typically the first in the array
-    // Windowed modes use myDesktopSize directly
-    vector<Common::Size> myFullscreenDisplays;
-
     // Supported renderers
     VariantList myRenderers;
 

src/emucore/OSystem.cxx

@@ -233,6 +233,11 @@ void OSystem::loadConfig(const Settings::Options& options)
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void OSystem::saveConfig()
 {
+  // Save the current window position and display on system shutdown
+  int x, y;
+  myFrameBuffer->getCurrentWindowPos(x, y);
+  settings().setValue("display", myFrameBuffer->getCurrentDisplayIndex());
+
   // Ask all subsystems to save their settings
   if(myFrameBuffer)
   {

src/emucore/Settings.cxx

@@ -37,7 +37,10 @@ Settings::Settings()
   setPermanent("video", "");
   setPermanent("speed", "1.0");
   setPermanent("vsync", "true");
-  setPermanent("center", "false");
+  setPermanent("center", "true");
+  setPermanent("pos.x", 50);
+  setPermanent("pos.y", 50);
+  setPermanent("display", 0);
   setPermanent("palette", "standard");
   setPermanent("uimessages", "true");