Prevent setting double scale on smaller screens. Fixes #166

src/PowderToySDL.cpp

@@ -50,6 +50,8 @@ using namespace std;
 extern "C" IMAGE_DOS_HEADER __ImageBase;
 #endif
 
+int desktopWidth = 1280, desktopHeight = 1024;
+
 SDL_Surface * sdl_scrn;
 int scale = 1;
 bool fullscreen = false;
@@ -173,6 +175,9 @@ int SDLOpen()
 		fprintf(stderr, "Initializing SDL: %s\n", SDL_GetError());
 		return 1;
 	}
+	const SDL_VideoInfo * vidInfo = SDL_GetVideoInfo();
+	desktopWidth = vidInfo->current_w;
+	desktopHeight = vidInfo->current_h;
 	SDL_EnableUNICODE(1);
 #if defined(WIN) && defined(WINCONSOLE)
 	//On Windows, SDL redirects stdout to stdout.txt, which can be annoying when debugging, here we redirect back to the console
@@ -492,6 +497,7 @@ int main(int argc, char * argv[])
 	ui::Engine::Ref().Fullscreen = fullscreen;
 
 	engine = &ui::Engine::Ref();
+	engine->SetMaxSize(desktopWidth, desktopHeight);
 	engine->Begin(XRES+BARSIZE, YRES+MENUSIZE);
 
 	GameController * gameController = new GameController();

src/dialogues/ErrorMessage.cpp

@@ -12,7 +12,7 @@
 #include "PowderToy.h"
 
 ErrorMessage::ErrorMessage(std::string title, std::string message,  ErrorMessageCallback * callback_):
-	ui::Window(ui::Point(-1, -1), ui::Point(200, 75)),
+	ui::Window(ui::Point(-1, -1), ui::Point(200, 35)),
 	callback(callback_)
 {
 	ui::Label * titleLabel = new ui::Label(ui::Point(4, 5), ui::Point(Size.X-8, 16), title);
@@ -21,11 +21,15 @@ ErrorMessage::ErrorMessage(std::string title, std::string message,  ErrorMessage
 	titleLabel->Appearance.VerticalAlign = ui::Appearance::AlignMiddle;
 	AddComponent(titleLabel);
 
-	ui::Label * messageLabel = new ui::Label(ui::Point(4, 24), ui::Point(Size.X-8, 60), message);
+	ui::Label * messageLabel = new ui::Label(ui::Point(4, 24), ui::Point(Size.X-8, -1), message);
+	messageLabel->SetMultiline(true);
 	messageLabel->Appearance.HorizontalAlign = ui::Appearance::AlignLeft;
 	messageLabel->Appearance.VerticalAlign = ui::Appearance::AlignTop;
 	AddComponent(messageLabel);
 
+	Size.Y += messageLabel->Size.Y+12;
+	Position.Y = (ui::Engine::Ref().GetHeight()-Size.Y)/2;
+
 	class DismissAction: public ui::ButtonAction
 	{
 		ErrorMessage * message;

src/interface/DropDown.cpp

@@ -88,7 +88,7 @@ DropDown::DropDown(Point position, Point size):
 void DropDown::OnMouseClick(int x, int y, unsigned int button)
 {
 	DropDownWindow * newWindow = new DropDownWindow(this);
-	ui::Engine().Ref().ShowWindow(newWindow);
+	ui::Engine::Ref().ShowWindow(newWindow);
 }
 
 void DropDown::Draw(const Point& screenPos)

src/interface/Engine.cpp

@@ -14,6 +14,8 @@ using namespace std;
 
 Engine::Engine():
 	state_(NULL),
+	maxWidth(0),
+	maxHeight(0),
 	mousex_(0),
 	mousey_(0),
 	mousexp_(0),
@@ -148,6 +150,12 @@ void Engine::SetSize(int width, int height)
 	height_ = height;
 }
 
+void Engine::SetMaxSize(int width, int height)
+{
+	maxWidth = width;
+	maxHeight = height;
+}
+
 void Engine::Tick()
 {
 	if(state_ != NULL)

src/interface/Engine.h

@@ -57,6 +57,10 @@ namespace ui
 		inline int GetMouseY() { return mousey_; }
 		inline int GetWidth() { return width_; }
 		inline int GetHeight() { return height_; }
+		inline int GetMaxWidth() { return maxWidth; }
+		inline int GetMaxHeight() { return maxHeight; }
+
+		inline void SetMaxSize(int width, int height);
 
 		inline void SetSize(int width, int height);
 		
@@ -90,6 +94,9 @@ namespace ui
 		int mouseyp_;
 		int width_;
 		int height_;
+
+		int maxWidth;
+		int maxHeight;
 	};
 
 }

src/options/OptionsController.cpp

@@ -6,6 +6,7 @@
  */
 
 #include "OptionsController.h"
+#include "dialogues/ErrorMessage.h"
 
 OptionsController::OptionsController(Simulation * sim, ControllerCallback * callback_):
 	callback(callback_),
@@ -61,7 +62,19 @@ void OptionsController::SetFullscreen(bool fullscreen)
 
 void OptionsController::SetScale(bool scale)
 {
+	if(scale)
+	{
+		if(ui::Engine::Ref().GetMaxWidth() >= ui::Engine::Ref().GetWidth() * 2 && ui::Engine::Ref().GetMaxHeight() >= ui::Engine::Ref().GetHeight() * 2)
 			model->SetScale(scale);
+		else
+		{
+			new ErrorMessage("Screen resolution error", "Your screen size is too small to use this scale mode.");
+			model->SetScale(false);
+		}
+	}
+	else
+		model->SetScale(scale);
+
 }
 
 OptionsView * OptionsController::GetView()