Fix TIA images saved in '1x' mode to not use TV effects (fixes #643).

Changes.txt

@@ -35,6 +35,9 @@
 
   * Make NTSC custom phase shift not affect Yellow anymore.
 
+  * Fixed '1x' snapshot mode; TV effects are now disabled.  This mode
+    now generates a clean, pixel-exact image.
+
   * A ROM properties file may now be placed next to the ROM (with the same
     name as the ROM, except ending in .pro), and Stella will automatically
     apply the properties to the ROM. [NOTE: this was present in 6.2, but

src/debugger/gui/TiaOutputWidget.cxx

@@ -179,7 +179,7 @@ void TiaOutputWidget::drawWidget(bool hilite)
   bool visible = instance().console().tia().electronBeamPos(scanx, scany);
   scanoffset = width * scany + scanx;
   uInt8* tiaOutputBuffer = instance().console().tia().outputBuffer();
-  TIASurface& tiaSurface(instance().frameBuffer().tiaSurface());
+  const TIASurface& tiaSurface = instance().frameBuffer().tiaSurface();
 
   for(uInt32 y = 0, i = yStart * width; y < height; ++y)
   {

src/emucore/TIASurface.cxx

@@ -148,32 +148,19 @@ const FBSurface& TIASurface::baseSurface(Common::Rect& rect) const
   uInt32 tiaw = myTIA->width(), width = tiaw * 2, height = myTIA->height();
   rect.setBounds(0, 0, width, height);
 
-  // Get Blargg buffer and width
-  uInt32 *blarggBuf, blarggPitch;
-  myTiaSurface->basePtr(blarggBuf, blarggPitch);
-  double blarggXFactor = double(blarggPitch) / width;
-  bool useBlargg = ntscEnabled();
-
   // Fill the surface with pixels from the TIA, scaled 2x horizontally
   uInt32 *buf_ptr, pitch;
   myBaseTiaSurface->basePtr(buf_ptr, pitch);
 
   for(uInt32 y = 0; y < height; ++y)
-  {
     for(uInt32 x = 0; x < width; ++x)
-    {
-      if (useBlargg)
-        *buf_ptr++ = blarggBuf[y * blarggPitch + uInt32(nearbyint(x * blarggXFactor))];
-      else
         *buf_ptr++ = myPalette[*(myTIA->frameBuffer() + y * tiaw + x / 2)];
-    }
-  }
 
   return *myBaseTiaSurface;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-uInt32 TIASurface::mapIndexedPixel(uInt8 indexedColor, uInt8 shift)
+uInt32 TIASurface::mapIndexedPixel(uInt8 indexedColor, uInt8 shift) const
 {
   return myPalette[indexedColor | shift];
 }

src/emucore/TIASurface.hxx

@@ -70,14 +70,18 @@ class TIASurface
     void setPalette(const PaletteArray& tia_palette, const PaletteArray& rgb_palette);
 
     /**
-      Get the TIA base surface for use in saving to a PNG image.
+      Get a TIA surface that has no post-processing whatsoever.  This is
+      currently used to save PNG image in the so-called '1x mode'.
+
+      @param rect   Specifies the area in which the surface data is valid
     */
     const FBSurface& baseSurface(Common::Rect& rect) const;
 
     /**
-      Use the palette to map a single indexed pixel color. This is used by the TIA output widget.
+      Use the palette to map a single indexed pixel color. This is used by the
+      TIA output widget.
      */
-    uInt32 mapIndexedPixel(uInt8 indexedColor, uInt8 shift = 0);
+    uInt32 mapIndexedPixel(uInt8 indexedColor, uInt8 shift = 0) const;
 
     /**
       Get the NTSCFilter object associated with the framebuffer
@@ -220,7 +224,7 @@ class TIASurface
     bool mySaveSnapFlag{false};
 
     // The palette handler
-    unique_ptr<PaletteHandler>myPaletteHandler;
+    unique_ptr<PaletteHandler> myPaletteHandler;
 
   private:
     // Following constructors and assignment operators not supported