And the process starts again.

Added shortcut key to toggle TV scanline jittering, and have it default
to off.  I'd really like to enable it again eventually, or perhaps use some
of the code in the case where scanline jumps are *really* large (since it
seems to emulate the output for every TV I've ever seen).

Bumped version #.


git-svn-id: svn://svn.code.sf.net/p/stella/code/trunk@3221 8b62c5a3-ac7e-4cc8-8f21-d9a121418aba

Changes.txt

@@ -12,6 +12,15 @@
                                Release History
 ===========================================================================
 
+4.6.5 to 4.6.6: (October xx, 2015)
+
+  * Added 'Alt/Cmd + j' shortcut key and 'tv.jitter' commandline argument
+    to toggle the TV scanline jittering emulation added in the last
+    release.  Also, this jittering now defaults to off.
+
+-Have fun!
+
+
 4.6.1 to 4.6.5: (September 26, 2015)
 
   * Added mappable events for toggling TV color/BW, left difficulty A/B
@@ -50,8 +59,6 @@
 
   * Updated included PNG library to latest stable version.
 
--Have fun!
-
 
 4.6 to 4.6.1: (April 22, 2015)
 

docs/index.html

@@ -1447,6 +1447,12 @@
       <td>Shift-Alt + .</td>
       <td>Shift-Cmd + .</td>
     </tr>
+
+    <tr>
+      <td>Toggle TV scanline 'jitter'</td>
+      <td>Shift-Alt + j</td>
+      <td>Shift-Cmd + j</td>
+    </tr>
   </table>
 
   <p><b>Other Keys (cannot be remapped, except those marked with '*')</b></p>

src/common/Version.hxx

@@ -22,7 +22,7 @@
 
 #include <cstdlib>
 
-#define STELLA_VERSION "4.6.5"
+#define STELLA_VERSION "4.6.6_svn"
 #define STELLA_BUILD atoi("$Rev$" + 6)
 
 #endif

src/emucore/Console.cxx

@@ -891,6 +891,14 @@ void Console::toggleFixedColors() const
     myOSystem.frameBuffer().showMessage("Fixed debug colors disabled");
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+void Console::toggleJitter() const
+{
+  bool enabled = myTIA->toggleJitter();
+  string message = string("TV scanline jitter") + (enabled ? " enabled" : " disabled");
+  myOSystem.frameBuffer().showMessage(message);
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void Console::attachDebugger(Debugger& dbg)
 {

src/emucore/Console.hxx

@@ -280,6 +280,11 @@ class Console : public Serializable
     */
     void toggleFixedColors() const;
 
+    /**
+      Toggles the TIA 'scanline jitter' mode.
+    */
+    void toggleJitter() const;
+
   private:
     /**
       Sets various properties of the TIA (YStart, Height, etc) based on

src/emucore/EventHandler.cxx

@@ -424,6 +424,10 @@ void EventHandler::handleKeyEvent(StellaKey key, StellaMod mod, bool state)
           myOSystem.console().togglePhosphor();
           break;
 
+        case KBDK_J:  // Alt-j toggles scanline jitter
+          myOSystem.console().toggleJitter();
+          break;
+
         case KBDK_L:
           myOSystem.frameBuffer().toggleFrameStats();
           break;

src/emucore/Settings.cxx

@@ -58,6 +58,7 @@ Settings::Settings(OSystem& osystem)
   setInternal("tv.filter", "0");
   setInternal("tv.scanlines", "25");
   setInternal("tv.scaninter", "true");
+  setInternal("tv.jitter", "false");
   // TV options when using 'custom' mode
   setInternal("tv.contrast", "0.0");
   setInternal("tv.brightness", "0.0");

src/emucore/TIA.cxx

@@ -58,6 +58,7 @@ TIA::TIA(Console& console, Sound& sound, Settings& settings)
     myPALFrameCounter(0),
     myBitsEnabled(true),
     myCollisionsEnabled(true),
+    myJitterEnabled(false),
     myNextFrameJitter(0),
     myCurrentFrameJitter(0)
 
@@ -80,6 +81,9 @@ TIA::TIA(Console& console, Sound& sound, Settings& settings)
 
   // Should undriven pins be randomly pulled high or low?
   myTIAPinsDriven = mySettings.getBool("tiadriven");
+
+  // Enable scanline jittering
+  myJitterEnabled = mySettings.getBool("tv.jitter");
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -657,7 +661,7 @@ inline void TIA::endFrame()
   }
 
   // Account for frame jitter, skipping the first few frames
-  if(myFrameCounter > 3)
+  if(myJitterEnabled && myFrameCounter > 3)
   {
     // Set the jitter amount for the current frame
     myCurrentFrameJitter = myNextFrameJitter * 160;
@@ -901,6 +905,19 @@ bool TIA::driveUnusedPinsRandom(uInt8 mode)
   return myTIAPinsDriven;
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+bool TIA::toggleJitter(uInt8 mode)
+{
+  // If mode is 0 or 1, use it as a boolean (off or on)
+  // Otherwise, flip the state
+  bool on = (mode == 0 || mode == 1) ? bool(mode) :
+            myJitterEnabled = !myJitterEnabled;
+  myJitterEnabled = on;
+  mySettings.setValue("tv.jitter", myJitterEnabled);
+
+  return myJitterEnabled;
+}
+
 #ifdef DEBUGGER_SUPPORT
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void TIA::updateScanline()
@@ -909,8 +926,7 @@ void TIA::updateScanline()
   if(!myPartialFrameFlag)
     startFrame();
 
-  // true either way:
-  myPartialFrameFlag = true;
+  myPartialFrameFlag = true;  // true either way
 
   int totalClocks = (mySystem->cycles() * 3) - myClockWhenFrameStarted;
   int endClock = ((totalClocks + 228) / 228) * 228;

src/emucore/TIA.hxx

@@ -317,6 +317,16 @@ class TIA : public Device
     */
     bool driveUnusedPinsRandom(uInt8 mode = 2);
 
+    /**
+      Enables/disable/toggle 'scanline jittering' mode.
+
+      @param mode  1/0 indicates on/off, otherwise flip from
+                   its current state
+
+      @return  Whether the mode was enabled or disabled
+    */
+    bool toggleJitter(uInt8 mode = 2);
+
 #ifdef DEBUGGER_SUPPORT
     /**
       This method should be called to update the TIA with a new scanline.
@@ -616,6 +626,9 @@ class TIA : public Device
     // Whether TIA bits/collisions are currently enabled/disabled
     bool myBitsEnabled, myCollisionsEnabled;
   
+    // Whether to enable jitter emulation
+    bool myJitterEnabled;
+
     // Derived from the difference between the scanline counts of the
     // current and prior frames.  If non-zero the next frame should jitter.
     Int32 myNextFrameJitter;