added emulation speed hotkeys

docs/index.html

@@ -1767,7 +1767,17 @@
       <td>Backspace</td>
     </tr>
     <tr>
-      <td>Toggle 'Turbo' mode</td>
+      <td><i>Decrease</i> emulation speed (disables 'Turbo' mode)</td>
+      <td>Shift-Control + s</td>
+      <td>Shift-Control + s</td>
+    </tr>
+    <tr>
+      <td><i>Increase</i> emulation speed (disables 'Turbo' mode)</td>
+      <td>Control + s</td>
+      <td>Control + s</td>
+    </tr>
+    <tr>
+      <td>Toggle 'Turbo' mode (maximum emulation speed)</td>
       <td>Control + t</td>
       <td>Control + t</td>
     </tr>

src/common/PKeyboardHandler.cxx

@@ -525,6 +525,8 @@ PhysicalKeyboardHandler::EventMappingArray PhysicalKeyboardHandler::DefaultCommo
   {Event::SettingIncrease,          KBDK_KP_9, KBDM_CTRL},
 
   {Event::ToggleInter,              KBDK_I, KBDM_CTRL},
+  {Event::DecreaseSpeed,            KBDK_S, KBDM_SHIFT | KBDM_CTRL},
+  {Event::IncreaseSpeed,            KBDK_S, KBDM_CTRL },
   {Event::ToggleTurbo,              KBDK_T, KBDM_CTRL},
   {Event::ToggleJitter,             KBDK_J, MOD3},
   {Event::ToggleFrameStats,         KBDK_L, MOD3},

src/emucore/Console.cxx

@@ -73,6 +73,45 @@
 
 #include "Console.hxx"
 
+namespace {
+  // Emulation speed is a positive float that multiplies the framerate. However, the UI controls
+  // adjust speed in terms of a speedup factor (1/10, 1/9 .. 1/2, 1, 2, 3, .., 10). The following
+  // mapping and formatting functions implement this conversion. The speedup factor is represented
+  // by an integer value between -900 and 900 (0 means no speedup).
+
+  constexpr int MAX_SPEED = 900;
+  constexpr int MIN_SPEED = -900;
+  constexpr int SPEED_STEP = 10;
+
+  int mapSpeed(float speed)
+  {
+    speed = std::abs(speed);
+
+    return BSPF::clamp(
+      static_cast<int>(round(100 * (speed >= 1 ? speed - 1 : -1 / speed + 1))),
+      MIN_SPEED, MAX_SPEED
+    );
+  }
+
+  float unmapSpeed(int speed)
+  {
+    float f_speed = static_cast<float>(speed) / 100;
+
+    return speed < 0 ? -1 / (f_speed - 1) : 1 + f_speed;
+  }
+
+  string formatSpeed(int speed) {
+    stringstream ss;
+
+    ss
+      << std::setw(3) << std::fixed << std::setprecision(0)
+      << (unmapSpeed(speed) * 100);
+
+    return ss.str();
+  }
+}
+
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 Console::Console(OSystem& osystem, unique_ptr<Cartridge>& cart,
                  const Properties& props, AudioSettings& audioSettings)
@@ -503,6 +542,31 @@ void Console::toggleTurbo()
   myOSystem.frameBuffer().showMessage(ss.str());
 }
 
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+void Console::changeSpeed(int direction)
+{
+  int speed = mapSpeed(myOSystem.settings().getFloat("speed"));
+  bool turbo = myOSystem.settings().getBool("turbo");
+
+  speed = BSPF::clamp(speed + direction * SPEED_STEP, MIN_SPEED, MAX_SPEED);
+  myOSystem.settings().setValue("speed", unmapSpeed(speed));
+
+  // update rate
+  initializeAudio();
+
+  if(turbo)
+  {
+    myOSystem.settings().setValue("turbo", false);
+    // update VSync
+    initializeVideo();
+  }
+
+  ostringstream val;
+
+  val << formatSpeed(speed) << "%";
+  myOSystem.frameBuffer().showMessage("Emulation speed", val.str(), speed, MIN_SPEED, MAX_SPEED);
+}
+
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void Console::togglePhosphor()
 {
@@ -890,9 +954,8 @@ void Console::changeAutoFireRate(int direction)
   if(rate)
     val << rate << " Hz";
   else
-  {
     val << "Off";
-  }
+
   myOSystem.frameBuffer().showMessage("Autofire rate", val.str(), rate, 0, isNTSC ? 30 : 25);
 }
 

src/emucore/Console.hxx

@@ -213,6 +213,12 @@ class Console : public Serializable, public ConsoleIO
     */
     void toggleTurbo();
 
+    /**
+      Change emulation speed
+
+      @param direction  +1 indicates increase, -1 indicates decrease.
+    */
+    void changeSpeed(int direction = +1);
 
     /**
       Toggles phosphor effect.

src/emucore/Event.hxx

@@ -127,6 +127,7 @@ class Event
       PreviousSettingGroup, NextSettingGroup,
       TogglePlayBackMode,
       DecreaseAutoFire, IncreaseAutoFire,
+      DecreaseSpeed, IncreaseSpeed,
 
       LastType
     };

src/emucore/EventHandler.cxx

@@ -1220,6 +1220,14 @@ void EventHandler::handleEvent(Event::Type event, Int32 value, bool repeated)
     ///////////////////////////////////////////////////////////////////////////
     // Misc events
 
+    case Event::DecreaseSpeed:
+      if(pressed) myOSystem.console().changeSpeed(-1);
+      return;
+
+    case Event::IncreaseSpeed:
+      if(pressed) myOSystem.console().changeSpeed(+1);
+      return;
+
     case Event::ToggleTurbo:
       if (pressed && !repeated) myOSystem.console().toggleTurbo();
       return;
@@ -2403,7 +2411,9 @@ EventHandler::EmulActionList EventHandler::ourEmulActionList = { {
   { Event::TogglePauseMode,         "Toggle Pause mode",                     "" },
   { Event::StartPauseMode,          "Start Pause mode",                      "" },
   { Event::Fry,                     "Fry cartridge",                         "" },
-  { Event::ToggleTurbo,             "Toggle Turbo mode",                     "" },
+  { Event::DecreaseSpeed,           "Decrease emulation speed",              "" },
+  { Event::IncreaseSpeed,           "Increase emulation speed",              "" },
+  { Event::ToggleTurbo,             "Toggle 'Turbo' mode",                   "" },
   { Event::DebuggerMode,            "Toggle Debugger mode",                  "" },
 
   { Event::ConsoleSelect,           "Select",                                "" },
@@ -2634,7 +2644,7 @@ EventHandler::MenuActionList EventHandler::ourMenuActionList = { {
 const Event::EventSet EventHandler::MiscEvents = {
   Event::Quit, Event::ReloadConsole, Event::Fry, Event::StartPauseMode,
   Event::TogglePauseMode, Event::OptionsMenuMode, Event::CmdMenuMode, Event::ExitMode,
-  Event::ToggleTurbo,
+  Event::ToggleTurbo, Event::DecreaseSpeed, Event::IncreaseSpeed,
   Event::TakeSnapshot, Event::ToggleContSnapshots, Event::ToggleContSnapshotsFrame,
   // Event::MouseAxisXMove, Event::MouseAxisYMove,
   // Event::MouseButtonLeftValue, Event::MouseButtonRightValue,

src/emucore/EventHandler.hxx

@@ -558,7 +558,7 @@ class EventHandler
     #else
       REFRESH_SIZE         = 0,
     #endif
-      EMUL_ACTIONLIST_SIZE = 162 + PNG_SIZE + COMBO_SIZE + REFRESH_SIZE,
+      EMUL_ACTIONLIST_SIZE = 164 + PNG_SIZE + COMBO_SIZE + REFRESH_SIZE,
       MENU_ACTIONLIST_SIZE = 18
     ;