Nice graphics for Showing windows

src/PowderToy.cpp

@@ -67,7 +67,7 @@ int main(int argc, char * argv[])
 	ui::Engine::Ref().g->AttachSDLSurface(SDLOpen());
 
 	ui::Engine * engine = &ui::Engine::Ref();
-	engine->Begin(XRES, YRES);
+	engine->Begin(XRES+BARSIZE, YRES+MENUSIZE);
 
 	GameController * gameController = new GameController();
 	engine->ShowWindow(gameController->GetView());

src/interface/Engine.cpp

@@ -19,7 +19,9 @@ Engine::Engine():
 	mousexp_(0),
 	mouseyp_(0),
 	FpsLimit(60.0f),
-	windows(stack<Window*>())
+	windows(stack<Window*>()),
+	lastBuffer(NULL),
+	prevBuffers(stack<pixel*>())
 {
 }
 
@@ -61,15 +63,34 @@ void Engine::ShowWindow(Window * window)
 	}
 	if(state_)
 	{
+		if(lastBuffer)
+		{
+			prevBuffers.push(lastBuffer);
+		}
+		lastBuffer = (pixel*)malloc((width_ * height_) * PIXELSIZE);
+		g->fillrect(0, 0, width_, height_, 0, 0, 0, 100);
+		memcpy(lastBuffer, g->vid, (width_ * height_) * PIXELSIZE);
+
 		windows.push(state_);
 	}
 	state_ = window;
+
 }
 
 void Engine::CloseWindow()
 {
 	if(!windows.empty())
 	{
+		if(!prevBuffers.empty())
+		{
+			lastBuffer = prevBuffers.top();
+			prevBuffers.pop();
+		}
+		else
+		{
+			free(lastBuffer);
+			lastBuffer = NULL;
+		}
 		state_ = windows.top();
 		windows.pop();
 	}
@@ -120,10 +141,17 @@ void Engine::Tick(float dt)
 
 void Engine::Draw()
 {
+	if(lastBuffer && !(state_->Position.X == 0 && state_->Position.Y == 0 && state_->Size.X == width_ && state_->Size.Y == height_))
+	{
+		memcpy(g->vid, lastBuffer, (width_ * height_) * PIXELSIZE);
+	}
+	else
+	{
+		g->Clear();
+	}
 	if(state_)
 		state_->DoDraw();
 	g->Blit();
-	g->Clear();
 }
 
 void Engine::onKeyPress(int key, bool shift, bool ctrl, bool alt)

src/interface/Engine.h

@@ -54,6 +54,8 @@ namespace ui
 		float FpsLimit;
 		Graphics * g;
 	private:
+		pixel * lastBuffer;
+		std::stack<pixel*> prevBuffers;
 		std::stack<Window*> windows;
 		//Window* statequeued_;
 		Window* state_;

src/preview/PreviewView.cpp

@@ -19,6 +19,7 @@ PreviewView::PreviewView():
 void PreviewView::OnDraw()
 {
 	Graphics * g = ui::Engine::Ref().g;
+	g->clearrect(Position.X-2, Position.Y-2, Size.X+4, Size.Y+4);
 	g->drawrect(Position.X, Position.Y, Size.X, Size.Y, 255, 255, 255, 255);
 }