unwind logic started, TODO: adapt RewindManager

src/common/RewindManager.cxx

@@ -15,6 +15,8 @@
 // this file, and for a DISCLAIMER OF ALL WARRANTIES.
 //============================================================================
 
+#include <cmath>
+
 #include "OSystem.hxx"
 #include "Serializer.hxx"
 #include "StateManager.hxx"
@@ -25,15 +27,19 @@
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 RewindManager::RewindManager(OSystem& system, StateManager& statemgr)
   : myOSystem(system),
-    myStateManager(statemgr)
+    myStateManager(statemgr),
+    myIsNTSC(true) // TODO
 {
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 bool RewindManager::addState(const string& message)
 {
+  // TODO: remove following (preceding???) (all invalid) states
+  // myStateList.removeToFront(); from current() + 1 (or - 1???)
+
   if(myStateList.full())
-    myStateList.removeLast();  // remove the oldest state file
+    compressStates();
 
   RewindState& state = myStateList.addFirst();
   Serializer& s = state.data;
@@ -41,7 +47,8 @@ bool RewindManager::addState(const string& message)
   s.reset();  // rewind Serializer internal buffers
   if(myStateManager.saveState(s) && myOSystem.console().tia().saveDisplay(s))
   {
-    state.message = "Rewind " + message;
+    state.message = message;
+    state.cycle = myOSystem.console().tia().cycles();
     return true;
   }
   return false;
@@ -52,15 +59,19 @@ bool RewindManager::rewindState()
 {
   if(!myStateList.empty())
   {
+    // TODO: get state previous to the current state instead of first()
     RewindState& state = myStateList.first();
     Serializer& s = state.data;
+    string message = getMessage(state);
 
     s.reset();  // rewind Serializer internal buffers
     myStateManager.loadState(s);
     myOSystem.console().tia().loadDisplay(s);
 
     // Show message indicating the rewind state
-    myOSystem.frameBuffer().showMessage(state.message);
+    myOSystem.frameBuffer().showMessage(message);
+
+    // TODO: Do NOT remove state (TODO later somewhere else: stop emulation)
     myStateList.removeFirst();
 
     return true;
@@ -68,3 +79,80 @@ bool RewindManager::rewindState()
   else
     return false;
 }
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+bool RewindManager::unwindState()
+{
+  if(!atFirst()) // or last???
+  {
+    // TODO: get state next to the current state
+    /*RewindState& state = myStateList.???()
+    Serializer& s = state.data;
+    string message = getMessage(state);
+
+    s.reset();  // rewind Serializer internal buffers
+    myStateManager.loadState(s);
+    myOSystem.console().tia().loadDisplay(s);
+
+    // Show message indicating the rewind state
+    myOSystem.frameBuffer().showMessage(message);*/
+    return true;
+  }    
+  return false;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+void RewindManager::compressStates()
+{
+  myStateList.removeLast();  // remove the oldest state file
+  // TODO: add smart state removal
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+string RewindManager::getMessage(RewindState& state)
+{
+  const Int64 NTSC_FREQ = 1193182;
+  const Int64 PAL_FREQ  = 1182298;
+  Int64 diff = myOSystem.console().tia().cycles() - state.cycle,
+    freq = myIsNTSC ? NTSC_FREQ : PAL_FREQ,
+    diffUnit;
+  stringstream message;
+  string unit;
+
+  message << (diff >= 0 ? "Rewind" : "Unwind");
+  diff = abs(diff);
+
+  if(diff < 76 * 2)
+  {
+    unit = "cycle";
+    diffUnit = diff;
+  }
+  else if(diff < 76 * 262 * 2)
+  {
+    unit = "scanline";
+    diffUnit = diff / 76;
+  }
+  else if(diff < NTSC_FREQ * 2)
+  {
+    unit = "frame";
+    diffUnit = diff / (76 * 262);
+  }
+  else if(diff < NTSC_FREQ * 60 * 2)
+  {
+    unit = "second";
+    diffUnit = diff / NTSC_FREQ;
+  }
+  else
+  {
+    unit = "minute";
+    diffUnit = diff / (NTSC_FREQ * 60);
+  }
+  message << " " << diffUnit << " " << unit;
+  if(diffUnit != 1)
+    message << "s";
+
+  // add optional message (TODO: when smart removal works, we have to do something smart with this part too)
+  if(!state.message.empty())
+    message << " (" << state.message << ")";
+  return message.str();
+}

src/common/RewindManager.hxx

@@ -49,7 +49,14 @@ class RewindManager
     */
     bool rewindState();
 
-    bool empty() const { return myStateList.empty(); }
+    /** 
+      Unwind one level of the state list, and display the message associated
+      with that state.
+    */
+    bool unwindState();
+
+    bool atLast() const { return myStateList.empty(); }
+    bool atFirst() const { return false; } // TODO
     void clear() { myStateList.clear(); }
 
   private:
@@ -62,6 +69,7 @@ class RewindManager
     struct RewindState {
       Serializer data;
       string message;
+      uInt64 cycle;
 
       // We do nothing on object instantiation or copy
       RewindState() { }
@@ -70,6 +78,13 @@ class RewindManager
 
     Common::LinkedObjectPool<RewindState, MAX_SIZE> myStateList;
 
+    bool myIsNTSC;
+
+    void compressStates();
+
+    string getMessage(RewindState& state);
+
+
   private:
     // Following constructors and assignment operators not supported
     RewindManager() = delete;

src/debugger/Debugger.cxx

@@ -451,22 +451,34 @@ void Debugger::nextFrame(int frames)
   lockBankswitchState();
 }
 
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-bool Debugger::rewindState()
+bool Debugger::windState(bool unwind)
 {
   RewindManager& r = myOSystem.state().rewindManager();
 
   mySystem.clearDirtyPages();
 
   unlockBankswitchState();
-  bool result = r.rewindState();
+  bool result = unwind ? r.unwindState() : r.rewindState();
   lockBankswitchState();
 
-  myDialog->rewindButton().setEnabled(!r.empty());
+  myDialog->rewindButton().setEnabled(!r.atLast());
+  myDialog->unwindButton().setEnabled(!r.atFirst());
 
   return result;
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+bool Debugger::rewindState()
+{
+  return windState(false);
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+bool Debugger::unwindState()
+{
+  return windState(true);
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void Debugger::clearAllBreakPoints()
 {
@@ -505,7 +517,8 @@ void Debugger::saveOldState(string rewindMsg)
   {
     RewindManager& r = myOSystem.state().rewindManager();
     r.addState(rewindMsg);
-    myDialog->rewindButton().setEnabled(!r.empty());
+    myDialog->rewindButton().setEnabled(!r.atLast());
+    myDialog->unwindButton().setEnabled(!r.atFirst());
   }
 }
 
@@ -519,7 +532,8 @@ void Debugger::setStartState()
   RewindManager& r = myOSystem.state().rewindManager();
   if(myOSystem.state().mode() == StateManager::Mode::Off)
     r.clear();
-  myDialog->rewindButton().setEnabled(!r.empty());
+  myDialog->rewindButton().setEnabled(!r.atLast());
+  myDialog->unwindButton().setEnabled(!r.atFirst());
 
   // Save initial state, but don't add it to the rewind list
   saveOldState();

src/debugger/Debugger.hxx

@@ -270,6 +270,7 @@ class Debugger : public DialogContainer
     void nextScanline(int lines);
     void nextFrame(int frames);
     bool rewindState();
+    bool unwindState();
 
     void toggleBreakPoint(uInt16 bp);
 
@@ -326,6 +327,8 @@ class Debugger : public DialogContainer
     static PseudoRegister ourPseudoRegisters[NUM_PSEUDO_REGS];
 
   private:
+    bool windState(bool unwind);
+
     // Following constructors and assignment operators not supported
     Debugger() = delete;
     Debugger(const Debugger&) = delete;

src/debugger/DebuggerParser.cxx

@@ -1837,6 +1837,19 @@ void DebuggerParser::executeUndef()
     commandResult << red("no such label");
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+// "unwind"
+void DebuggerParser::executeUnwind()
+{
+  if(debugger.unwindState())
+  {
+    debugger.rom().invalidate();
+    commandResult << "unwind by one level";
+  }
+  else
+    commandResult << "no states left to rewind";
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 // "v"
 void DebuggerParser::executeV()
@@ -2611,6 +2624,16 @@ DebuggerParser::Command DebuggerParser::commands[kNumCommands] = {
     std::mem_fn(&DebuggerParser::executeUndef)
   },
 
+  {
+    "unwind",
+    "Unwind state to last step/trace/scanline/frame",
+    "Unwind currently only works in the debugger",
+    false,
+    true,
+    { kARG_END_ARGS },
+    std::mem_fn(&DebuggerParser::executeUnwind)
+  },
+
   {
     "v",
     "Overflow Flag: set (0 or 1), or toggle (no arg)",

src/debugger/DebuggerParser.hxx

@@ -68,7 +68,7 @@ class DebuggerParser
     string saveScriptFile(string file);
 
   private:
-    enum { kNumCommands = 76 };
+    enum { kNumCommands = 77 };
 
     // Constants for argument processing
     enum {
@@ -209,6 +209,7 @@ class DebuggerParser
     void executeType();
     void executeUHex();
     void executeUndef();
+    void executeUnwind();
     void executeV();
     void executeWatch();
     void executeX();

src/debugger/gui/DebuggerDialog.cxx

@@ -92,7 +92,10 @@ void DebuggerDialog::handleKeyDown(StellaKey key, StellaMod mod)
     switch(key)
     {
       case KBDK_R:
-        doRewind();
+        if(!instance().eventHandler().kbdShift(mod))
+          doRewind();
+        else
+          doUnwind();
         break;
       case KBDK_S:
         doStep();
@@ -141,6 +144,10 @@ void DebuggerDialog::handleCommand(CommandSender* sender, int cmd,
       doRewind();
       break;
 
+    case kDDUnwindCmd:
+      doUnwind();
+      break;
+
     case kDDExitCmd:
       doExitDebugger();
       break;
@@ -189,6 +196,12 @@ void DebuggerDialog::doRewind()
   instance().debugger().parser().run("rewind");
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+void DebuggerDialog::doUnwind()
+{
+  instance().debugger().parser().run("unwind");
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void DebuggerDialog::doExitDebugger()
 {
@@ -375,7 +388,7 @@ void DebuggerDialog::addRomArea()
                    bwidth, bheight, "Exit", kDDExitCmd);
 
   bwidth = myLFont->getStringWidth("< ") + 4;
-  bheight = bheight * 5 + 4*4;
+  bheight = bheight * 3 + 4 * 2;
   buttonX -= (bwidth + 5);
   buttonY = r.top + 5;
   myRewindButton =
@@ -383,6 +396,14 @@ void DebuggerDialog::addRomArea()
                      bwidth, bheight, "<", kDDRewindCmd);
   myRewindButton->clearFlags(WIDGET_ENABLED);
 
+  buttonY += bheight + 4;
+  bheight = (myLFont->getLineHeight() + 2) * 2 + 4 * 1;
+  myUnwindButton =
+    new ButtonWidget(this, *myLFont, buttonX, buttonY,
+                     bwidth, bheight, ">", kDDUnwindCmd);
+  myUnwindButton->clearFlags(WIDGET_ENABLED);
+
+
   int xpos = buttonX - 8*myLFont->getMaxCharWidth() - 20, ypos = 20;
   DataGridOpsWidget* ops = new DataGridOpsWidget(this, *myLFont, xpos, ypos);
 

src/debugger/gui/DebuggerDialog.hxx

@@ -62,6 +62,7 @@ class DebuggerDialog : public Dialog
     CartRamWidget& cartRam() const     { return *myCartRam;      }
     EditTextWidget& message() const    { return *myMessageBox;   }
     ButtonWidget& rewindButton() const { return *myRewindButton; }
+    ButtonWidget& unwindButton() const { return *myUnwindButton; }
 
     void showFatalMessage(const string& msg);
 
@@ -75,6 +76,7 @@ class DebuggerDialog : public Dialog
     void doScanlineAdvance();
     void doAdvance();
     void doRewind();
+    void doUnwind();
     void doExitDebugger();
     void doExitRom();
 
@@ -96,6 +98,7 @@ class DebuggerDialog : public Dialog
       kDDAdvCmd       = 'DDav',
       kDDSAdvCmd      = 'DDsv',
       kDDRewindCmd    = 'DDrw',
+      kDDUnwindCmd    = 'DDuw',
       kDDExitCmd      = 'DDex',
       kDDExitFatalCmd = 'DDer'
     };
@@ -113,6 +116,7 @@ class DebuggerDialog : public Dialog
     CartRamWidget*   myCartRam;
     EditTextWidget*  myMessageBox;
     ButtonWidget*    myRewindButton;
+    ButtonWidget*    myUnwindButton;
     unique_ptr<GUI::MessageBox> myFatalError;
 
     unique_ptr<GUI::Font> myLFont;  // used for labels