Implement triple buffering in TIA.

src/debugger/gui/TiaOutputWidget.cxx

@@ -168,6 +168,8 @@ void TiaOutputWidget::drawWidget(bool hilite)
   uInt32 scanx, scany, scanoffset;
   bool visible = instance().console().tia().electronBeamPos(scanx, scany);
   scanoffset = width * scany + scanx;
+  uInt8* tiaOutputBuffer = instance().console().tia().outputBuffer();
+  TIASurface& tiaSurface(instance().frameBuffer().tiaSurface());
 
   for(uInt32 y = 0, i = 0; y < height; ++y)
   {
@@ -175,7 +177,7 @@ void TiaOutputWidget::drawWidget(bool hilite)
     for(uInt32 x = 0; x < width; ++x, ++i)
     {
       uInt8 shift = i >= scanoffset ? 1 : 0;
-      uInt32 pixel = instance().frameBuffer().tiaSurface().pixel(i, shift);
+      uInt32 pixel = tiaSurface.mapIndexedPixel(tiaOutputBuffer[i], shift);
       *line_ptr++ = pixel;
       *line_ptr++ = pixel;
     }

src/emucore/DispatchResult.hxx

@@ -43,7 +43,7 @@ class DispatchResult
 
     void setOk(uInt32 cycles);
 
-    void setDebugger(uInt32 cycles, const string& message = "", int address = -1, bool wasReadTrap = -1);
+    void setDebugger(uInt32 cycles, const string& message = "", int address = -1, bool wasReadTrap = false);
 
     void setFatal(uInt32 cycles);
 

src/emucore/OSystem.cxx

@@ -678,8 +678,8 @@ void OSystem::mainLoop()
       timesliceSeconds = dispatchEmulation(myConsole ? myConsole->emulationTiming().cyclesPerSecond() : 1);
 
       if (myConsole && myConsole->tia().newFramePending()) {
+        myConsole->tia().renderToFrameBuffer();
         myFrameBuffer->updateInEmulationMode();
-        myConsole->tia().clearNewFramePending();
       }
     } else {
       timesliceSeconds = 1. / 30.;

src/emucore/TIASurface.cxx

@@ -138,11 +138,12 @@ const FBSurface& TIASurface::baseSurface(GUI::Rect& rect) const
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-uInt32 TIASurface::pixel(uInt32 idx, uInt8 shift)
+uInt32 TIASurface::mapIndexedPixel(uInt8 indexedColor, uInt8 shift)
 {
-  return myPalette[*(myTIA->frameBuffer() + idx) | shift];
+  return myPalette[indexedColor | shift];
 }
 
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void TIASurface::setNTSC(NTSCFilter::Preset preset, bool show)
 {

src/emucore/TIASurface.hxx

@@ -73,10 +73,9 @@ class TIASurface
     const FBSurface& baseSurface(GUI::Rect& rect) const;
 
     /**
-      Get the TIA pixel associated with the given TIA buffer index,
+      Use the palette to map a single indexed pixel color. This is used by the TIA output widget.
-      shifting by the given offset (for greyscale values).
      */
-    uInt32 pixel(uInt32 idx, uInt8 shift = 0);
+    uInt32 mapIndexedPixel(uInt8 indexedColor, uInt8 shift = 0);
 
     /**
       Get the NTSCFilter object associated with the framebuffer

src/emucore/tia/TIA.cxx

@@ -196,6 +196,7 @@ void TIA::reset()
 void TIA::frameReset()
 {
   memset(myBackBuffer, 0, 160 * TIAConstants::frameBufferHeight);
+  memset(myFrontBuffer, 0, 160 * TIAConstants::frameBufferHeight);
   memset(myFramebuffer, 0, 160 * TIAConstants::frameBufferHeight);
   enableColorLoss(mySettings.getBool("dev.settings") ? "dev.colorloss" : "plr.colorloss");
 }
@@ -784,6 +785,7 @@ bool TIA::saveDisplay(Serializer& out) const
   {
     out.putByteArray(myFramebuffer, 160* TIAConstants::frameBufferHeight);
     out.putByteArray(myBackBuffer, 160 * TIAConstants::frameBufferHeight);
+    out.putByteArray(myFrontBuffer, 160 * TIAConstants::frameBufferHeight);
     out.putBool(myNewFramePending);
   }
   catch(...)
@@ -803,6 +805,7 @@ bool TIA::loadDisplay(Serializer& in)
     // Reset frame buffer pointer and data
     in.getByteArray(myFramebuffer, 160*TIAConstants::frameBufferHeight);
     in.getByteArray(myBackBuffer, 160 * TIAConstants::frameBufferHeight);
+    in.getByteArray(myFrontBuffer, 160 * TIAConstants::frameBufferHeight);
     myNewFramePending = in.getBool();
   }
   catch(...)
@@ -817,13 +820,19 @@ bool TIA::loadDisplay(Serializer& in)
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void TIA::update(DispatchResult& result, uInt32 maxCycles)
 {
-  uInt64 timestampOld = myTimestamp;
-
   mySystem->m6502().execute(maxCycles, result);
 
   updateEmulation();
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+void TIA::renderToFrameBuffer()
+{
+  if (!myNewFramePending) return;
+
+  memcpy(myFramebuffer, myFrontBuffer, 160 * TIAConstants::frameBufferHeight);
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void TIA::update(uInt32 maxCycles)
 {
@@ -1171,7 +1180,7 @@ void TIA::onFrameComplete()
   if (missingScanlines > 0)
     memset(myBackBuffer + 160 * myFrameManager->getY(), 0, missingScanlines * 160);
 
-  memcpy(&myFramebuffer, &myBackBuffer, 160 * TIAConstants::frameBufferHeight);
+  memcpy(myFrontBuffer, myBackBuffer, 160 * TIAConstants::frameBufferHeight);
   myNewFramePending = true;
 }
 

src/emucore/tia/TIA.hxx

@@ -210,9 +210,15 @@ class TIA : public Device
     bool newFramePending() { return myNewFramePending; }
 
     /**
-      Clear the flag
+      Render the pending frame to the framebuffer and clear the flag.
      */
-    void clearNewFramePending() { myNewFramePending = false; }
+    void renderToFrameBuffer();
+
+    /**
+      Return the buffer that holds the currently drawing TIA frame
+      (the TIA output widget needs this).
+     */
+    uInt8* outputBuffer() { return myBackBuffer; }
 
     /**
       Returns a pointer to the internal frame buffer.
@@ -673,6 +679,7 @@ class TIA : public Device
     // The frame is rendered to the backbuffer and only copied to the framebuffer
     // upon completion
     uInt8 myBackBuffer[160 * TIAConstants::frameBufferHeight];
+    uInt8 myFrontBuffer[160 * TIAConstants::frameBufferHeight];
 
     // Did we emit a frame?
     bool myNewFramePending;