allow redo with Ctrl-Y

src/gui/game/GameController.cpp

@@ -232,34 +232,60 @@ GameController::~GameController()
 void GameController::HistoryRestore()
 {
 	std::deque<Snapshot*> history = gameModel->GetHistory();
-	if(history.size())
+	unsigned int historyPosition = gameModel->GetHistoryPosition();
+	if(historyPosition > 0 && historyPosition <= history.size())
 	{
-		Snapshot * snap = history.back();
-		gameModel->GetSimulation()->Restore(*snap);
-		if(history.size()>1)
+		if (historyPosition == history.size())
 		{
-			history.pop_back();
-			delete snap;
-			gameModel->SetHistory(history);
+			Snapshot * newSnap = gameModel->GetSimulation()->CreateSnapshot();
+			history.push_back(newSnap);
 		}
+		Snapshot * snap = history[historyPosition - 1];
+		gameModel->GetSimulation()->Restore(*snap);
+		gameModel->SetHistory(history);
+		gameModel->SetHistoryPosition(historyPosition - 1);
 	}
 }
 
 void GameController::HistorySnapshot()
 {
 	std::deque<Snapshot*> history = gameModel->GetHistory();
+	unsigned int historyPosition = gameModel->GetHistoryPosition();
 	Snapshot * newSnap = gameModel->GetSimulation()->CreateSnapshot();
 	if(newSnap)
 	{
+		while (historyPosition < history.size())
+		{
+			Snapshot * snap = history.back();
+			history.pop_back();
+			delete snap;
+		}
 		if(history.size() >= 1) //History limit is current 1
 		{
 			Snapshot * snap = history.front();
 			history.pop_front();
 			//snap->Particles.clear();
 			delete snap;
+			if (historyPosition > history.size())
+			{
+				historyPosition--;
+			}
 		}
 		history.push_back(newSnap);
 		gameModel->SetHistory(history);
+		gameModel->SetHistoryPosition(historyPosition + 1);
+	}
+}
+
+void GameController::HistoryForward()
+{
+	std::deque<Snapshot*> history = gameModel->GetHistory();
+	unsigned int historyPosition = gameModel->GetHistoryPosition();
+	if(historyPosition < history.size() - 1)
+	{
+		Snapshot * snap = history[historyPosition + 1];
+		gameModel->GetSimulation()->Restore(*snap);
+		gameModel->SetHistoryPosition(historyPosition + 1);
 	}
 }
 

src/gui/game/GameController.h

@@ -73,6 +73,7 @@ public:
 
 	void HistoryRestore();
 	void HistorySnapshot();
+	void HistoryForward();
 
 	void AdjustGridSize(int direction);
 	void InvertAirSim();

src/gui/game/GameModel.cpp

@@ -28,6 +28,7 @@ GameModel::GameModel():
 	currentFile(NULL),
 	currentUser(0, ""),
 	toolStrength(1.0f),
+	historyPosition(0),
 	activeColourPreset(0),
 	colourSelector(false),
 	colour(255, 0, 0, 255),
@@ -423,11 +424,22 @@ std::deque<Snapshot*> GameModel::GetHistory()
 {
 	return history;
 }
+
+unsigned int GameModel::GetHistoryPosition()
+{
+	return historyPosition;
+}
+
 void GameModel::SetHistory(std::deque<Snapshot*> newHistory)
 {
 	history = newHistory;
 }
 
+void GameModel::SetHistoryPosition(unsigned int newHistoryPosition)
+{
+	historyPosition = newHistoryPosition;
+}
+
 void GameModel::SetVote(int direction)
 {
 	if(currentSave)

src/gui/game/GameModel.h

@@ -65,6 +65,7 @@ private:
 	User currentUser;
 	float toolStrength;
 	std::deque<Snapshot*> history;
+	unsigned int historyPosition;
 
 	size_t activeColourPreset;
 	std::vector<ui::Colour> colourPresets;
@@ -129,7 +130,9 @@ public:
 	void BuildQuickOptionMenu(GameController * controller);
 
 	std::deque<Snapshot*> GetHistory();
+	unsigned int GetHistoryPosition();
 	void SetHistory(std::deque<Snapshot*> newHistory);
+	void SetHistoryPosition(unsigned int newHistoryPosition);
 
 	void UpdateQuickOptions();
 

src/gui/game/GameView.cpp

@@ -1545,7 +1545,14 @@ void GameView::OnKeyPress(int key, Uint16 character, bool shift, bool ctrl, bool
 			}
 		break;
 	case 'y':
-		c->SwitchAir();
+		if (ctrl)
+		{
+			c->HistoryForward();
+		}
+		else
+		{
+			c->SwitchAir();
+		}
 		break;
 	case SDLK_ESCAPE:
 	case 'q':