Fix nullptr deref when flooding deco

Broken in ff4500620e, where the code that constructs DecorationTools got moved from GameModel::BuildMenus to GameModel::InitTools. BuildMenus used to run fairly late, while InitTools is run fairly early, before GameModel's view member is initialized. This wasn't a problem before f52e047037, since which DecorationTools access Renderer through GameView, rather than directly.

src/gui/game/GameController.cpp

@@ -83,12 +83,11 @@ GameController::GameController():
 	HasDone(false)
 {
 	gameView = new GameView();
-	gameModel = new GameModel();
+	gameModel = new GameModel(gameView); // mvc is a joke
 	gameModel->BuildQuickOptionMenu(this);
 
 	gameView->AttachController(this);
 	gameModel->AddObserver(gameView);
-	gameModel->view = gameView; // mvc is a joke
 
 	gameView->SetDebugHUD(GlobalPrefs::Ref().Get("Renderer.DebugMode", false));
 

src/gui/game/GameModel.cpp

@@ -50,7 +50,7 @@ HistoryEntry::~HistoryEntry()
 	//   so the default dtor for ~HistoryEntry cannot be generated.
 }
 
-GameModel::GameModel():
+GameModel::GameModel(GameView *newView):
 	activeMenu(SC_POWDERS),
 	currentBrush(0),
 	currentUser(0, ""),
@@ -61,7 +61,8 @@ GameModel::GameModel():
 	colour(255, 0, 0, 255),
 	edgeMode(EDGE_VOID),
 	ambientAirTemp(R_TEMP + 273.15f),
-	decoSpace(DECOSPACE_SRGB)
+	decoSpace(DECOSPACE_SRGB),
+	view(newView)
 {
 	sim = new Simulation();
 	sim->useLuaCallbacks = true;

src/gui/game/GameModel.h

@@ -133,8 +133,10 @@ private:
 	std::optional<int> queuedVote;
 	bool threadedRendering = false;
 
+	GameView *view;
+
 public:
-	GameModel();
+	GameModel(GameView *newView);
 	~GameModel();
 
 	void Tick();
@@ -302,5 +304,8 @@ public:
 	void BeforeSim();
 	void AfterSim();
 
-	GameView *view = nullptr;
+	GameView *GetView() const
+	{
+		return view;
+	}
 };

src/gui/game/tool/SampleTool.cpp

@@ -23,7 +23,7 @@ void SampleTool::Draw(Simulation * sim, Brush const &brush, ui::Point position)
 {
 	if(gameModel.GetColourSelectorVisibility())
 	{
-		pixel colour = gameModel.view->GetPixelUnderMouse();
+		pixel colour = gameModel.GetView()->GetPixelUnderMouse();
 		gameModel.SetColourSelectorColour(RGB<uint8_t>::Unpack(colour).WithAlpha(0xFF));
 	}
 	else

src/lua/LuaSimulation.cpp

@@ -831,7 +831,7 @@ static int floodDeco(lua_State *L)
 
 	auto *lsi = GetLSI();
 	// hilariously broken, intersects with console and all Lua graphics
-	auto &rendererFrame = lsi->gameModel->view->GetRendererFrame();
+	auto &rendererFrame = lsi->gameModel->GetView()->GetRendererFrame();
 	auto loc = RGB<uint8_t>::Unpack(rendererFrame[{ x, y }]);
 	lsi->sim->ApplyDecorationFill(rendererFrame, x, y, r, g, b, a, loc.Red, loc.Green, loc.Blue);
 	return 0;